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Tavakol M, O'Brien DG, Sharpe CC, Stewart C. Twelve tips to aid interpretation of post-assessment psychometric reports. Med Teach 2024; 46:188-195. [PMID: 37542358 DOI: 10.1080/0142159x.2023.2241624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/06/2023]
Abstract
Post-assessments psychometric reports are a vital component of the assessment cycle to ensure that assessments are reliable, valid and fair to make appropriate pass-fail decisions. Students' scores can be summarised by examination of frequency distributions, central tendency measures and dispersion measures. Item discrimination indicies to assess the quality of items, and distractors that differentiate between students achieving or not achieving the learning outcomes are key. Estimating individual item reliability and item validity indices can maximise test-score reliability and validity. Test accuracy can be evaluated by assessing test reliability, consistency and validity and standard error of measurement can be used to measure the variation. Standard setting, even by experts, may be unreliable and reality checks such as the Hofstee method, P values and correlation analysis can improve validity. The Rasch model of student ability and item difficulty assists in modifying assessment questions, pinpointing areas for additional instruction. We propose 12 tips to support test developers in interpreting structured psychometric reports, including analysis and refinement of flawed items and ensuring fair assessments with accurate and defensible marks.
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Affiliation(s)
- Mohsen Tavakol
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
| | - David G O'Brien
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
| | - Claire C Sharpe
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
| | - Claire Stewart
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
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2
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Tavakol M, Stewart C, Sharpe CC, O'Brien DG. Merging relative and absolute methods: The IRT-Angoff method for pass mark identification. Med Teach 2023; 45:1309. [PMID: 37572653 DOI: 10.1080/0142159x.2023.2245549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/14/2023]
Affiliation(s)
- Mohsen Tavakol
- Medical Education Centre, The University of Nottingham, Nottingham, UK
| | - Claire Stewart
- School of Medicine, The University of Nottingham, Nottingham, UK
| | - Claire C Sharpe
- School of Medicine, The University of Nottingham, Nottingham, UK
| | - David G O'Brien
- Lincoln Medical School, The University of Nottingham, Nottingham, UK
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3
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Tavakol M, Sharpe CC, Stewart C, O'Brien DG. Ranking students in OSCEs: Issues and solutions. Med Teach 2023; 45:554. [PMID: 36635985 DOI: 10.1080/0142159x.2023.2166479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Mohsen Tavakol
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
| | - Claire C Sharpe
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
| | - Claire Stewart
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
| | - David G O'Brien
- Medical Education Centre, School of Medicine, The University of Nottingham, Nottingham, UK
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Sharpe CC, Suddle A, Stuart-Smith S. An Overview of Solid Organ Transplantation in Patients With Sickle Cell Disease. Transplantation 2023; 107:596-604. [PMID: 36210501 DOI: 10.1097/tp.0000000000004305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Sickle cell disease is a common genetic disorder affecting >300 000 people across the world. The vast majority of patients cared for in high-resource settings live well into adulthood, but many develop a high burden of disease complications. Good standard of care including disease-modifying agents and transfusion programs limits the number of patients who develop end-stage organ disease, but for those that do, the prognosis can be very poor. Solid organ transplantation is a well-established mode of treatment for patients with sickle cell disease and kidney or liver failure, but appropriate patient selection and perioperative management are important for achieving good outcomes. Hematopoietic stem cell transplantation and gene therapy may offer novel treatment options for adult patients with chronic organ damage in the future, but these are not yet widely available. For now, good, holistic care and early intervention of end-organ complications can minimize the number of patients requiring solid organ transplantation later in life.
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Affiliation(s)
- Claire C Sharpe
- Department of Inflammation Biology, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
- Department of Renal Medicine, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Abid Suddle
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Sara Stuart-Smith
- Department of Haematology, Kings College Hospital NHS Foundation Trust, London, United Kingdom
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Neffendorf JE, Mare T, Simpson ARH, Soare C, Kirthi V, Sharpe CC, Jackson TL. Effect of intravitreal anti-vascular endothelial growth factor treatment for neovascular age-related macular degeneration on renal function. Nephrol Dial Transplant 2023:7034340. [PMID: 36764668 DOI: 10.1093/ndt/gfad035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Affiliation(s)
| | - Tracey Mare
- Synnovis, King's College Hospital, London, UK
| | | | - Cristina Soare
- King's Ophthalmology Research Unit, King's College Hospital, London, UK
| | - Varo Kirthi
- King's Ophthalmology Research Unit, King's College Hospital, London, UK
| | - Claire C Sharpe
- Faculty of Life Sciences and Medicine, King's College London, UK
| | - Timothy L Jackson
- King's Ophthalmology Research Unit, King's College Hospital, London, UK.,Faculty of Life Sciences and Medicine, King's College London, UK
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Pandi SPS, Shattock MJ, Hendry BM, Sharpe CC. Stimulated phosphorylation of ERK in mouse kidney mesangial cells is dependent upon expression of Cav3.1. BMC Nephrol 2022; 23:211. [PMID: 35710406 PMCID: PMC9205043 DOI: 10.1186/s12882-022-02844-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Background T-type calcium channels (TTCC) are low voltage activated channels that are widely expressed in the heart, smooth muscle and neurons. They are known to impact on cell cycle progression in cancer and smooth muscle cells and more recently, have been implicated in rat and human mesangial cell proliferation. The aim of this study was to investigate the roles of the different isoforms of TTCC in mouse mesangial cells to establish which may be the best therapeutic target for treating mesangioproliferative kidney diseases. Methods In this study, we generated single and double knockout (SKO and DKO) clones of the TTCC isoforms CaV3.1 and CaV3.2 in mouse mesangial cells using CRISPR-cas9 gene editing. The downstream signals linked to this channel activity were studied by ERK1/2 phosphorylation assays in serum, PDGF and TGF-β1 stimulated cells. We also examined their proliferative responses in the presence of the TTCC inhibitors mibefradil and TH1177. Results We demonstrate a complete loss of ERK1/2 phosphorylation in response to multiple stimuli (serum, PDGF, TGF-β1) in CaV3.1 SKO clone, whereas the CaV3.2 SKO clone retained these phospho-ERK1/2 responses. Stimulated cell proliferation was not profoundly impacted in either SKO clone and both clones remained sensitive to non-selective TTCC blockers, suggesting a role for more than one TTCC isoform in cell cycle progression. Deletion of both the isoforms resulted in cell death. Conclusion This study confirms that TTCC are expressed in mouse mesangial cells and that they play a role in cell proliferation. Whereas the CaV3.1 isoform is required for stimulated phosphorylation of ERK1/2, the Ca V3.2 isoform is not. Our data also suggest that neither isoform is necessary for cell proliferation and that the anti-proliferative effects of mibefradil and TH1177 are not isoform-specific. These findings are consistent with data from in vivo rat mesangial proliferation Thy1 models and support the future use of genetic mouse models to test the therapeutic actions of TTCC inhibitors. Supplementary Information The online version contains supplementary material available at 10.1186/s12882-022-02844-1.
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Affiliation(s)
- Sudha Priya Soundara Pandi
- Department of Inflammation Biology, King's College London, Denmark Hill Campus, James Black Centre, London, SE5 9NU, UK.,Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Michael J Shattock
- School of Cardiovascular Medicine and Sciences, King's College London, London, UK
| | - Bruce M Hendry
- Department of Inflammation Biology, King's College London, Denmark Hill Campus, James Black Centre, London, SE5 9NU, UK
| | - Claire C Sharpe
- Department of Inflammation Biology, King's College London, Denmark Hill Campus, James Black Centre, London, SE5 9NU, UK.
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Hung RK, Binns-Roemer E, Booth JW, Hilton R, Fox J, Burns F, Harber M, Ustianowski A, Hamzah L, Burns JE, Clarke A, Price DA, Kegg S, Onyango D, Santana-Suarez B, Campbell L, Bramham K, Sharpe CC, Sabin CA, Winkler CA, Post FA. Sickle Cell Trait and Kidney Disease in People of African Ancestry With HIV. Kidney Int Rep 2022; 7:465-473. [PMID: 35257059 PMCID: PMC8897676 DOI: 10.1016/j.ekir.2021.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 11/30/2021] [Accepted: 12/06/2021] [Indexed: 11/20/2022] Open
Abstract
Introduction Sickle cell trait (SCT) has been associated with chronic kidney disease (CKD) in African Americans, although evidence for its impact in Africans and people with HIV is currently lacking. We conducted a cross-sectional study investigating the association between SCT and kidney disease in people of African ancestry with HIV in the UK. Methods The primary outcome was estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2. Secondary outcomes were eGFR <90 ml/min per 1.73 m2, end-stage kidney disease (ESKD; eGFR <15 ml/min per 1.73 m2, chronic dialysis, or having received a kidney transplant), proteinuria (protein-to-creatinine ratio >50 mg/mmol), and albuminuria (albumin-to-creatinine ratio >3 mg/mmol). Multivariable logistic regression was used to estimate the associations between SCT and kidney disease outcomes. Results A total of 2895 participants (mean age 48.1 [SD 10.3], 57.2% female) were included, of whom 335 (11.6%) had SCT and 352 (12.2%) had eGFR <60 ml/min per 1.73 m2. After adjusting for demographic, HIV, and kidney risk factors including APOL1 high-risk genotype status, individuals with SCT were more likely to have eGFR <60 ml/min per 1.73 m2 (odds ratio 1.62 [95% CI 1.14-2.32]), eGFR <90 ml/min per 1.73 m2 (1.50 [1.14-1.97]), and albuminuria (1.50 [1.09-2.05]). Stratified by APOL1 status, significant associations between SCT and GFR <60 ml/min per 1.73 m2, eGFR <90 ml/min per 1.73 m2, proteinuria, and albuminuria were observed for those with APOL1 low-risk genotypes. Conclusion Our results extend previously reported associations between SCT and kidney disease to people with HIV. In people of African ancestry with HIV, these associations were largely restricted to those with APOL1 low-risk genotypes.
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Affiliation(s)
| | - Elizabeth Binns-Roemer
- Basic Research Laboratory, Frederick National Laboratory for Cancer Research and the National Cancer Institute, Frederick, Maryland, USA
| | | | - Rachel Hilton
- Guy’s and St Thomas’ NHS Foundation Trust, London, UK
| | - Julie Fox
- King’s College London, London, UK
- Guy’s and St Thomas’ NHS Foundation Trust, London, UK
| | - Fiona Burns
- Royal Free London Hospital NHS Foundation Trust, London, UK
| | - Mark Harber
- Royal Free London Hospital NHS Foundation Trust, London, UK
| | | | - Lisa Hamzah
- St George’s Hospital NHS Foundation Trust, London, UK
| | - James E. Burns
- University College London, London, UK
- Central and North West London NHS Foundation Trust, London, UK
| | - Amanda Clarke
- Brighton and Sussex University Hospital NHS Trust, Brighton, UK
- Department of Infectious Disease, Brighton and Sussex Medical School, Brighton, UK
| | | | | | | | | | | | - Kate Bramham
- King’s College London, London, UK
- King’s College Hospital NHS Foundation Trust, London, UK
| | - Claire C. Sharpe
- King’s College London, London, UK
- King’s College Hospital NHS Foundation Trust, London, UK
| | | | - Cheryl A. Winkler
- Basic Research Laboratory, Frederick National Laboratory for Cancer Research and the National Cancer Institute, Frederick, Maryland, USA
| | - Frank A. Post
- King’s College London, London, UK
- King’s College Hospital NHS Foundation Trust, London, UK
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Jewell PD, Bramham K, Galloway J, Post F, Norton S, Teo J, Fisher R, Saha R, Hutchings S, Hopkins P, Smith P, Joslin J, Jayawardene S, Mackie S, Mudhaffer A, Holloway A, Kibble H, Akter M, Zuckerman B, Palmer K, Murphy C, Iatropoulou D, Sharpe CC, Lioudaki E. Correction to: COVID-19-related acute kidney injury; incidence, risk factors and outcomes in a large UK cohort. BMC Nephrol 2021; 22:403. [PMID: 34872500 PMCID: PMC8648146 DOI: 10.1186/s12882-021-02617-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
An amendment to this paper has been published and can be accessed via the original article.
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Affiliation(s)
- Paul D Jewell
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Kate Bramham
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK.,Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - James Galloway
- Faculty of Life Sciences and Medicine, King's College London, London, UK.,Centre for Rheumatic Disease, King's College London, London, UK
| | - Frank Post
- Faculty of Life Sciences and Medicine, King's College London, London, UK.,Department of Sexual Health and HIV, King's College Hospital NHS Foundation Trust, London, UK
| | - Sam Norton
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - James Teo
- Department of Neurosciences, King's College Hospital NHS Foundation Trust, London, UK
| | - Richard Fisher
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Rohit Saha
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Sam Hutchings
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Phil Hopkins
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK.,Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Priscilla Smith
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Jennifer Joslin
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Satish Jayawardene
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Sarah Mackie
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Ali Mudhaffer
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Amelia Holloway
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Henry Kibble
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Mosammat Akter
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Benjamin Zuckerman
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Kieran Palmer
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Ciara Murphy
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Domniki Iatropoulou
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Claire C Sharpe
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK.,Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Eirini Lioudaki
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK.
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Jewell PD, Bramham K, Galloway J, Post F, Norton S, Teo J, Fisher R, Saha R, Hutchings S, Hopkins P, Smith P, Joslin J, Jayawardene S, Mackie S, Mudhaffer A, Holloway A, Kibble H, Akter M, Zuckerman B, Palmer K, Murphy C, Iatropoulou D, Sharpe CC, Lioudaki E. COVID-19-related acute kidney injury; incidence, risk factors and outcomes in a large UK cohort. BMC Nephrol 2021; 22:359. [PMID: 34719384 PMCID: PMC8557997 DOI: 10.1186/s12882-021-02557-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 09/27/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Acute kidney injury (AKI) is common among patients hospitalised with COVID-19 and associated with worse prognosis. The aim of this study was to investigate the epidemiology, risk factors and outcomes of AKI in patients with COVID-19 in a large UK tertiary centre. METHODS We analysed data of consecutive adults admitted with a laboratory-confirmed diagnosis of COVID-19 across two sites of a hospital in London, UK, from 1st January to 13th May 2020. RESULTS Of the 1248 inpatients included, 487 (39%) experienced AKI (51% stage 1, 13% stage 2, and 36% stage 3). The weekly AKI incidence rate gradually increased to peak at week 5 (3.12 cases/100 patient-days), before reducing to its nadir (0.83 cases/100 patient-days) at the end the study period (week 10). Among AKI survivors, 84.0% had recovered renal function to pre-admission levels before discharge and none required on-going renal replacement therapy (RRT). Pre-existing renal impairment [odds ratio (OR) 3.05, 95%CI 2.24-4,18; p < 0.0001], and inpatient diuretic use (OR 1.79, 95%CI 1.27-2.53; p < 0.005) were independently associated with a higher risk for AKI. AKI was a strong predictor of 30-day mortality with an increasing risk across AKI stages [adjusted hazard ratio (HR) 1.59 (95%CI 1.19-2.13) for stage 1; p < 0.005, 2.71(95%CI 1.82-4.05); p < 0.001for stage 2 and 2.99 (95%CI 2.17-4.11); p < 0.001for stage 3]. One third of AKI3 survivors (30.7%), had newly established renal impairment at 3 to 6 months. CONCLUSIONS This large UK cohort demonstrated a high AKI incidence and was associated with increased mortality even at stage 1. Inpatient diuretic use was linked to a higher AKI risk. One third of survivors with AKI3 exhibited newly established renal impairment already at 3-6 months.
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Affiliation(s)
- Paul D Jewell
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Kate Bramham
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - James Galloway
- Faculty of Life Sciences and Medicine, King's College London, London, UK
- Centre for Rheumatic Disease, King's College London, London, UK
| | - Frank Post
- Faculty of Life Sciences and Medicine, King's College London, London, UK
- Department of Sexual Health and HIV, King's College Hospital NHS Foundation Trust, London, UK
| | - Sam Norton
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - James Teo
- Department of Neurosciences, King's College Hospital NHS Foundation Trust, London, UK
| | - Richard Fisher
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Rohit Saha
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Sam Hutchings
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Phil Hopkins
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Priscilla Smith
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Jennifer Joslin
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Satish Jayawardene
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Sarah Mackie
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Ali Mudhaffer
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Amelia Holloway
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Henry Kibble
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Mosammat Akter
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Benjamin Zuckerman
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Kieran Palmer
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Ciara Murphy
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Domniki Iatropoulou
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
| | - Claire C Sharpe
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK
- Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Eirini Lioudaki
- Renal Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK.
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Gama RM, Clery A, Griffiths K, Heraghty N, Peters AM, Palmer K, Kibble H, Vincent RP, Sharpe CC, Cairns H, Bramham K. Estimated glomerular filtration rate equations in people of self-reported black ethnicity in the United Kingdom: Inappropriate adjustment for ethnicity may lead to reduced access to care. PLoS One 2021; 16:e0255869. [PMID: 34383841 PMCID: PMC8360513 DOI: 10.1371/journal.pone.0255869] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 07/27/2021] [Indexed: 12/15/2022] Open
Abstract
Assessment in African populations suggest adjustment for ethnicity in estimated glomerular filtration rate (eGFR) equations derived from African Americans lead to overestimation of GFR and failure to determine severity in chronic kidney disease (CKD). However, studies in African Europeans are limited. We aimed to assess accuracy of eGFR equations, with and without ethnicity adjustment compared with measured GFR in people of Black ethnicity in the United Kingdom. Performance of MDRD, CKD-EPI (with and without ethnicity adjustment), Full Age Spectrum (FAS), revised Lund Malmö (LM Revised), and European Kidney Function Consortium (EKFC) eGFR equations were assessed compared to 51Cr-EDTA GFR studies extracted from hospital databases. Participants with albumin <30g/l, liver disease, <18 years, of non-Black or non-White self-reported ethnicity were excluded. Agreement was assessed by bias, precision and 30%-accuracy and was stratified for ethnicity and GFR. 1888 51Cr-EDTA studies were included (Mean age-53.7yrs; 43.6% female; 14.1% Black ethnicity). Compared to White participants, eGFR-MDRD and eGFR-CKD-EPI equations in Black participants significantly overestimated GFR (bias 20.3 and 19.7 ml/min/1.73m2 respectively, p<0.001). Disregarding the ethnicity adjustment significantly improved GFR estimates for Black participants (bias 6.7 and 2.4ml/min/1.73m2 for eGFR-MDRD and eGFR-CKD-EPI respectively, p<0.001). The LM Revised equation had the smallest bias for both White and Black participants (5.8ml and -1.1ml/min/1.73m2 respectively). 30%-accuracy was superior for GFR≥60ml/min/1.73m2 compared to <60ml/min/1.73m2 using eGFR-CKD-EPI equation for both White and Black participants (p<0.001). Multivariate regression methodology with adjustment for age, sex and log(serum creatinine) in the cohort yielded an ethnicity coefficient of 1.018 (95% CI: 1.009–1.027). Overestimation of measured GFR with eGFR equations using ethnicity adjustment factors may lead to reduced CKD diagnosis and under-recognition of severity in people of Black ethnicity. Our findings suggest that ethnicity adjustment for GFR estimation in non-African Americans may not be appropriate for use in people of Black ethnicity in the UK.
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Affiliation(s)
- Rouvick M. Gama
- King’s Kidney Care, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Amanda Clery
- School of Population Health and Environmental Sciences, King’s College London, London, United Kingdom
| | - Kathryn Griffiths
- King’s Kidney Care, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Neil Heraghty
- Department of Nuclear Medicine, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Adrien M. Peters
- Department of Nuclear Medicine, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Kieran Palmer
- King’s Kidney Care, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Henry Kibble
- King’s Kidney Care, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Royce P. Vincent
- Department of Clinical Biochemistry, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Claire C. Sharpe
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
| | - Hugh Cairns
- King’s Kidney Care, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Kate Bramham
- King’s Kidney Care, King’s College Hospital NHS Foundation Trust, London, United Kingdom
- Department of Women and Children’s Health, King’s College London, London, United Kingdom
- * E-mail:
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11
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Caplin B, Ashby D, McCafferty K, Hull R, Asgari E, Ford ML, Cole N, Antonelou M, Blakey SA, Srinivasa V, Braide-Azikwe DC, Roper T, Clark G, Cronin H, Hayes NJ, Manson B, Sarnowski A, Corbett R, Bramham K, Lioudaki E, Kumar N, Frankel A, Makanjuola D, Sharpe CC, Banerjee D, Salama AD. Risk of COVID-19 Disease, Dialysis Unit Attributes, and Infection Control Strategy among London In-Center Hemodialysis Patients. Clin J Am Soc Nephrol 2021; 16:1237-1246. [PMID: 34074636 PMCID: PMC8455047 DOI: 10.2215/cjn.03180321] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/27/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND OBJECTIVES Patients receiving in-center hemodialysis treatment face unique challenges during the coronavirus disease 2019 (COVID-19) pandemic, specifically the need to attend for treatment that prevents self-isolation. Dialysis unit attributes and isolation strategies that might reduce dialysis center COVID-19 infection rates have not been previously examined. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We explored the role of variables, including community disease burden, dialysis unit attributes (size and layout), and infection control strategies, on rates of COVID-19 among patients receiving in-center hemodialysis in London, United Kingdom, between March 2, 2020 and May 31, 2020. The two outcomes were defined as (1) a positive test for infection or admission with suspected COVID-19 and (2) admission to the hospital with suspected infection. Associations were examined using a discrete time multilevel time-to-event analysis. RESULTS Data on 5755 patients dialyzing in 51 units were analyzed; 990 (17%) tested positive and 465 (8%) were admitted with suspected COVID-19 between March 2 and May 31, 2020. Outcomes were associated with age, diabetes, local community COVID-19 rates, and dialysis unit size. A greater number of available side rooms and the introduction of mask policies for asymptomatic patients were inversely associated with outcomes. No association was seen with sex, ethnicity, or deprivation indices, nor with any of the different isolation strategies. CONCLUSIONS Rates of COVID-19 in the in-center hemodialysis population relate to individual factors, underlying community transmission, unit size, and layout.
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Affiliation(s)
- Ben Caplin
- Department of Renal Medicine, University College London, London, United Kingdom,Renal Services, Royal Free London NHS Foundation Trust, London, United Kingdom,Correspondence: Dr. Ben Caplin, Department of Renal Medicine, University College London, 2nd Floor, Royal Free Campus, Rowland Hill Street, London NW3 2PF, United Kingdom.
| | - Damien Ashby
- Kidney and Transplant Services, Imperial College Healthcare NHS Trust, London, United Kingdom
| | | | - Richard Hull
- Renal Department, St. George’s University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Elham Asgari
- Kidney Services, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Martin L. Ford
- Department of Renal Medicine, King’s College Hospital NHS Foundation Trust, London, United Kingdom,Faculty of Life Sciences & Medicine, Kings College London, London, United Kingdom
| | - Nicholas Cole
- South West Thames Renal and Transplantation Unit, Epsom and St. Helier University Hospitals NHS Trust, London, United Kingdom
| | - Marilina Antonelou
- Department of Renal Medicine, University College London, London, United Kingdom,Renal Services, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Sarah A. Blakey
- Kidney and Transplant Services, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Vinay Srinivasa
- Renal Service, Barts Health NHS Trust, London, United Kingdom
| | | | - Tayeba Roper
- Kidney Services, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Grace Clark
- Renal Services, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Helen Cronin
- Department of Renal Medicine, King’s College Hospital NHS Foundation Trust, London, United Kingdom
| | - Nathan J. Hayes
- Renal Services, North Middlesex University Hospital NHS Trust, London, United Kingdom
| | - Bethia Manson
- Renal Services, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Alexander Sarnowski
- Renal Department, St. George’s University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Richard Corbett
- Kidney and Transplant Services, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Kate Bramham
- Department of Renal Medicine, King’s College Hospital NHS Foundation Trust, London, United Kingdom,Faculty of Life Sciences & Medicine, Kings College London, London, United Kingdom
| | - Eirini Lioudaki
- Department of Renal Medicine, King’s College Hospital NHS Foundation Trust, London, United Kingdom,Faculty of Life Sciences & Medicine, Kings College London, London, United Kingdom
| | - Nicola Kumar
- Kidney Services, Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Andrew Frankel
- Kidney and Transplant Services, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - David Makanjuola
- South West Thames Renal and Transplantation Unit, Epsom and St. Helier University Hospitals NHS Trust, London, United Kingdom
| | - Claire C. Sharpe
- Department of Renal Medicine, King’s College Hospital NHS Foundation Trust, London, United Kingdom,Faculty of Life Sciences & Medicine, Kings College London, London, United Kingdom
| | - Debasish Banerjee
- Renal Department, St. George’s University Hospitals NHS Foundation Trust, London, United Kingdom
| | - Alan D. Salama
- Department of Renal Medicine, University College London, London, United Kingdom,Renal Services, Royal Free London NHS Foundation Trust, London, United Kingdom
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12
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Harzandi A, Lee S, Bidkhori G, Saha S, Hendry BM, Mardinoglu A, Shoaie S, Sharpe CC. Acute kidney injury leading to CKD is associated with a persistence of metabolic dysfunction and hypertriglyceridemia. iScience 2021; 24:102046. [PMID: 33554059 PMCID: PMC7843454 DOI: 10.1016/j.isci.2021.102046] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/12/2020] [Accepted: 01/06/2021] [Indexed: 12/14/2022] Open
Abstract
Fibrosis is the pathophysiological hallmark of progressive chronic kidney disease (CKD). The kidney is a highly metabolically active organ, and it has been suggested that disruption in its metabolism leads to renal fibrosis. We developed a longitudinal mouse model of acute kidney injury leading to CKD and an in vitro model of epithelial to mesenchymal transition to study changes in metabolism, inflammation, and fibrosis. Using transcriptomics, metabolic modeling, and serum metabolomics, we observed sustained fatty acid metabolic dysfunction in the mouse model from early to late stages of CKD. Increased fatty acid biosynthesis and downregulation of catabolic pathways for triglycerides and diacylglycerides were associated with a marked increase in these lipids in the serum. We therefore suggest that the kidney may be the source of the abnormal lipid profile seen in patients with CKD, which may provide insights into the association between CKD and cardiovascular disease. Following AKI, markers of fibrosis and inflammation go up simultaneously AKI is associated with reduced fatty acid oxidation and oxidative phosphorylation Changes in metabolism persist as chronic kidney disease develops Changes in metabolism are associated with increased serum levels of triglycerides
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Affiliation(s)
- Azadeh Harzandi
- Renal Sciences, Department of Inflammation Biology, School of Immunology & Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, SE5 9NU London, UK
| | - Sunjae Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea, 61005
- Centre for Host–Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, SE1 9RT London, UK
| | - Gholamreza Bidkhori
- Centre for Host–Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, SE1 9RT London, UK
| | - Sujit Saha
- Renal Sciences, Department of Inflammation Biology, School of Immunology & Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, SE5 9NU London, UK
| | - Bruce M. Hendry
- Renal Sciences, Department of Inflammation Biology, School of Immunology & Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, SE5 9NU London, UK
| | - Adil Mardinoglu
- Centre for Host–Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, SE1 9RT London, UK
- Science for Life Laboratory (SciLifeLab), KTH - Royal Institute of Technology, Tomtebodavägen 23, Solna, Stockholm 171 65, Sweden
- Corresponding author
| | - Saeed Shoaie
- Centre for Host–Microbiome Interactions, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London, SE1 9RT London, UK
- Science for Life Laboratory (SciLifeLab), KTH - Royal Institute of Technology, Tomtebodavägen 23, Solna, Stockholm 171 65, Sweden
- Corresponding author
| | - Claire C. Sharpe
- Renal Sciences, Department of Inflammation Biology, School of Immunology & Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, SE5 9NU London, UK
- Corresponding author
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13
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Bowes E, Joslin J, Braide-Azikiwe DCB, Tulley C, Bramham K, Saha S, Jayawardene S, Shakoane B, Wilkins CJ, Hutchings S, Hopkins P, Lioudaki E, Shaw C, Cairns H, Sharpe CC. Acute Peritoneal Dialysis With Percutaneous Catheter Insertion for COVID-19-Associated Acute Kidney Injury in Intensive Care: Experience From a UK Tertiary Center. Kidney Int Rep 2020; 6:265-271. [PMID: 33521400 PMCID: PMC7836882 DOI: 10.1016/j.ekir.2020.11.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/17/2020] [Accepted: 11/30/2020] [Indexed: 12/20/2022] Open
Abstract
Introduction During the coronavirus disease 2019 (COVID-19) pandemic in 2020, high rates of acute kidney injury (AKI) in critically unwell patients are being reported, leading to an increased demand for renal replacement therapy (RRT). Providing RRT for this large number of patients is proving challenging, and so alternatives to continuous renal replacement therapies (CRRT) in the intensive care unit (ICU) are needed. Peritoneal dialysis (PD) can be initiated immediately after percutaneous insertion of the catheter, but there are concerns about impact on ventilation and RRT efficacy. We sought to describe our recent experience with percutaneous catheter insertion and peritoneal dialysis in patients in the ICU with COVID-19 infection. Method Patients were selected according to local protocol, and catheters were inserted percutaneously by experienced operators using a Seldinger technique. Sequential Organ Failure Assessment (SOFA) score and ventilation requirements were recorded at the time of insertion and 24 hours later. Procedural complications, proportion of RRT provided by PD, renal recovery, and RRT parameters (serum potassium and maximum base excess) during PD were assessed. Results Percutaneous PD catheters were successfully inserted in 37 of 44 patients (84.1%) after a median of 13.5 days (interquartile range [IQR] = 10.0, 20.3 days) in the ICU. No adverse events were reported; SOFA scores and ventilation requirements were comparable before and after insertion; and adequate RRT parameters were achieved. The median proportion of RRT provided by PD following catheter insertion was 94.6% (IQR = 75.0, 100%). Conclusion Peritoneal dialysis provides a safe and effective alternative to CRRT in selected patients with AKI and COVID-19 infection requiring ventilation on intensive care.
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Affiliation(s)
- Elaine Bowes
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Jennifer Joslin
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK.,Faculty of Life Sciences and Medicine, King's College London, UK
| | | | - Caroline Tulley
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Kate Bramham
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK.,Faculty of Life Sciences and Medicine, King's College London, UK
| | - Sujit Saha
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Satish Jayawardene
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Babakang Shakoane
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - C Jason Wilkins
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Sam Hutchings
- Faculty of Life Sciences and Medicine, King's College London, UK.,Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Philip Hopkins
- Department of Critical Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Eirini Lioudaki
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Catriona Shaw
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Hugh Cairns
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK
| | - Claire C Sharpe
- King's Kidney Care, King's College Hospital NHS Foundation Trust, London, UK.,Faculty of Life Sciences and Medicine, King's College London, UK
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14
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Affiliation(s)
- Michael J Shattock
- School of Cardiovascular Medicine and Sciences, King's College London, London, UK
| | - Yvonne Daniel
- Public Health England, NHS Sickle Cell and Thalassaemia Screening Programme, London, UK
| | | | - Andrew Retter
- Department of Haematology, Guy's and Saint Thomas' Hospitals NHS Trust, London, UK
| | - Katherine Henderson
- Emergency Medicine, Guy's and Saint Thomas' NHS Foundation Trust Infection Service, London, UK
| | - Sarah Wilson
- Viapath Blood Sciences Laboratories, Guy's and Saint Thomas' Hospitals NHS Trust, London, UK
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15
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Roberts LN, Bramham K, Sharpe CC, Arya R. Hypercoagulability and Anticoagulation in Patients With COVID-19 Requiring Renal Replacement Therapy. Kidney Int Rep 2020; 5:1377-1380. [PMID: 32838085 PMCID: PMC7381908 DOI: 10.1016/j.ekir.2020.07.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Lara N Roberts
- King's Thrombosis Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Kate Bramham
- Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK.,Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Claire C Sharpe
- Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK.,Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Roopen Arya
- King's Thrombosis Centre, King's College Hospital NHS Foundation Trust, London, UK
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16
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Daniel Y, Hunt BJ, Retter A, Henderson K, Wilson S, Sharpe CC, Shattock MJ. Haemoglobin oxygen affinity in patients with severe COVID-19 infection. Br J Haematol 2020; 190:e126-e127. [PMID: 32453889 PMCID: PMC7283631 DOI: 10.1111/bjh.16888] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Yvonne Daniel
- Viapath Blood Sciences Laboratories, Guy's & St Thomas' Hospital, London, UK
| | - Beverley J Hunt
- Department of Haematology, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Andrew Retter
- Intensive Care, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | | | - Sarah Wilson
- Viapath Blood Sciences Laboratories, Guy's & St Thomas' Hospital, London, UK
| | - Claire C Sharpe
- Department of Renal Sciences, King's College London, London, UK
| | - Michael J Shattock
- School of Cardiovascular Medicine and Sciences, King's College London, London, UK
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17
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Cove-Smith A, Sharpe CC, Shattock MJ, Hendry BM. Ion-Channel modulator TH1177 reduces glomerular injury and serum creatinine in chronic mesangial proliferative disease in rats. BMC Nephrol 2020; 21:187. [PMID: 32429914 PMCID: PMC7236127 DOI: 10.1186/s12882-020-01842-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 05/07/2020] [Indexed: 01/17/2023] Open
Abstract
Background T-type calcium channels (TTCC) are involved in mesangial cell proliferation. In acute thy-1 nephritis in the rat TTCC inhibition reduces glomerular damage and cell proliferation. This work is extended here by a study of the non-selective TTCC inhibitor TH1177 in a chronic model of proliferative glomerulonephritis (GN) including late treatment starting after the initial inflammation has resolved. The objective was to determine the effects of TH1177 in a model of chronic mesangioproliferative renal disease. Methods Chronic GN was induced in WKY rats by unilateral nephrectomy (day − 7) followed by day 0 injection of Ox7 thy-1 mAb. Treatment with TH1177 (10–20 mg/Kg daily IP) was started on day 2 (early treatment) or on day 14 (late treatment) and compared to vehicle-treated controls until sacrifice at day 42. Glomerular disease was assessed with a damage score, fibrosis assay, cellular counts and renal function measured by serum creatinine. Results Treatment with TH11777 was associated with reduced serum creatinine, less glomerular damage, reduced fibrosis and reduced glomerular cellularity. The results for early and late TH1177 treatments were essentially the same and differed significantly from vehicle. Conclusions The ion-channel modulator TH1177 is capable of improving glomerular outcome in chronic rat GN even when treatment starts 14 days after initiation of the disease. These data are discussed in the context of the possible targets of TH1177 including TTCC, TRP family, Stim/Orai group and other cation channels. The work supports the use of genetic models to examine the roles of individual cation channels in progressive glomerulonephritis to further define the targets of TH1177.
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Affiliation(s)
- Andrea Cove-Smith
- Renal Sciences, Department of Inflammation Biology, King's College London, Renal Medicine 10 Cutcombe Road, London, SE5 9RJ, UK.,Barts Health Renal Centre, The Royal London Hospital, E1 1BB, London, UK
| | - Claire C Sharpe
- Renal Sciences, Department of Inflammation Biology, King's College London, Renal Medicine 10 Cutcombe Road, London, SE5 9RJ, UK
| | - Michael J Shattock
- Cardiovascular Sciences, The Rayne Institute, King's College London, London, SE1 7EH, UK
| | - Bruce M Hendry
- Renal Sciences, Department of Inflammation Biology, King's College London, Renal Medicine 10 Cutcombe Road, London, SE5 9RJ, UK.
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18
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Jones RA, Barratt J, Brettell EA, Cockwell P, Dalton RN, Deeks JJ, Eaglestone G, Pellatt-Higgins T, Kalra PA, Khunti K, Morris FS, Ottridge RS, Sitch AJ, Stevens PE, Sharpe CC, Sutton AJ, Taal MW, Lamb EJ. Biological variation of cardiac troponins in chronic kidney disease. Ann Clin Biochem 2020; 57:162-169. [DOI: 10.1177/0004563220906431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Background Patients with chronic kidney disease often have increased plasma cardiac troponin concentration in the absence of myocardial infarction. Incidence of myocardial infarction is high in this population, and diagnosis, particularly of non ST-segment elevation myocardial infarction (NSTEMI), is challenging. Knowledge of biological variation aids understanding of serial cardiac troponin measurements and could improve interpretation in clinical practice. The National Academy of Clinical Biochemistry (NACB) recommended the use of a 20% reference change value in patients with kidney failure. The aim of this study was to calculate the biological variation of cardiac troponin I and cardiac troponin T in patients with moderate chronic kidney disease (glomerular filtration rate [GFR] 30–59 mL/min/1.73 m2). Methods and results Plasma samples were obtained from 20 patients (median GFR 43.0 mL/min/1.73 m2) once a week for four consecutive weeks. Cardiac troponin I (Abbott ARCHITECT® i2000SR, median 4.3 ng/L, upper 99th percentile of reference population 26.2 ng/L) and cardiac troponin T (Roche Cobas® e601, median 11.8 ng/L, upper 99th percentile of reference population 14 ng/L) were measured in duplicate using high-sensitivity assays. After outlier removal and log transformation, 18 patients’ data were subject to ANOVA, and within-subject (CVI), between-subject (CVG) and analytical (CVA) variation calculated. Variation for cardiac troponin I was 15.0%, 105.6%, 8.3%, respectively, and for cardiac troponin T 7.4%, 78.4%, 3.1%, respectively. Reference change values for increasing and decreasing troponin concentrations were +60%/–38% for cardiac troponin I and +25%/–20% for cardiac troponin T. Conclusions The observed reference change value for cardiac troponin T is broadly compatible with the NACB recommendation, but for cardiac troponin I, larger changes are required to define significant change. The incorporation of separate RCVs for cardiac troponin I and cardiac troponin T, and separate RCVs for rising and falling concentrations of cardiac troponin, should be considered when developing guidance for interpretation of sequential cardiac troponin measurements.
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Affiliation(s)
- RA Jones
- Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK
| | - J Barratt
- University Hospitals of Leicester, Leicester, UK
| | - EA Brettell
- Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - P Cockwell
- Renal Medicine, Queen Elizabeth Hospital Birmingham and Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - RN Dalton
- Evelina London Children’s Hospital, London, UK
| | - JJ Deeks
- Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, UK
- Test Evaluation Research Group, University of Birmingham, Birmingham, UK
- NIHR Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - G Eaglestone
- Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK
| | - T Pellatt-Higgins
- Centre for Health Services Studies, University of Kent, Canterbury, UK
| | - PA Kalra
- Salford Royal NHS Foundation Trust, Salford, UK
| | - K Khunti
- University of Leicester, Leicester, UK
| | - FS Morris
- Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK
| | - RS Ottridge
- Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, UK
| | - AJ Sitch
- Test Evaluation Research Group, University of Birmingham, Birmingham, UK
- NIHR Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - PE Stevens
- Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK
| | - CC Sharpe
- King’s College London & King’s College Hospital NHS Foundation Trust, London, UK
| | - AJ Sutton
- Institute of Health Economics (IHE), Edmonton, Canada
| | - MW Taal
- Division of Medical Sciences and Graduate Entry Medicine, University of Nottingham, Royal Derby Hospital, Derby, UK
| | - EJ Lamb
- Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK
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19
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Lamb EJ, Sitch AJ, Barratt J, Brettell EA, Cockwell P, Dalton RN, Deeks JJ, Eaglestone G, Pellatt-Higgins T, Kalra PA, Khunti K, Loud FC, Morris FS, Ottridge RS, Stevens PE, Sharpe CC, Sutton AJ, Taal MW, Rowe C. The authors reply. Kidney Int 2020; 97:214-215. [PMID: 31901344 DOI: 10.1016/j.kint.2019.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 10/21/2019] [Indexed: 11/26/2022]
Affiliation(s)
- Edmund J Lamb
- Department of Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom.
| | - Alice J Sitch
- Test Evaluation Research Group, University of Birmingham, Birmingham, United Kingdom; NIHR Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | | | - Elizabeth A Brettell
- Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, United Kingdom
| | - Paul Cockwell
- Renal Medicine, Queen Elizabeth Hospital Birmingham, University of Birmingham, Birmingham, United Kingdom
| | - R Neil Dalton
- Evelina London Children's Hospital, London, United Kingdom
| | - Jon J Deeks
- Test Evaluation Research Group, University of Birmingham, Birmingham, United Kingdom; NIHR Birmingham Biomedical Research Centre, University of Birmingham and University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom; Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, United Kingdom
| | - Gillian Eaglestone
- Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom
| | | | - Philip A Kalra
- Salford Royal NHS Foundation Trust, Salford, United Kingdom
| | | | | | - Frances S Morris
- Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom
| | - Ryan S Ottridge
- Birmingham Clinical Trials Unit, Institute of Applied Health Research, University of Birmingham, Birmingham, United Kingdom
| | - Paul E Stevens
- Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom
| | - Claire C Sharpe
- King's College London & King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Andrew J Sutton
- Leeds Institute of Health Sciences, University of Leeds, Leeds, United Kingdom
| | | | - Ceri Rowe
- Department of Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent, United Kingdom
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20
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Newbury LJ, Wang JH, Hung G, Hendry BM, Sharpe CC. Inhibition of Kirsten-Ras reduces fibrosis and protects against renal dysfunction in a mouse model of chronic folic acid nephropathy. Sci Rep 2019; 9:14010. [PMID: 31570767 PMCID: PMC6768870 DOI: 10.1038/s41598-019-50422-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/19/2019] [Indexed: 12/30/2022] Open
Abstract
Chronic Kidney Disease is a growing problem across the world and can lead to end-stage kidney disease and cardiovascular disease. Fibrosis is the underlying mechanism that leads to organ dysfunction, but as yet we have no therapeutics that can influence this process. Ras monomeric GTPases are master regulators that direct many of the cytokines known to drive fibrosis to downstream effector cascades. We have previously shown that K-Ras is a key isoform that drives fibrosis in the kidney. Here we demonstrate that K-Ras expression and activation are increased in rodent models of CKD. By knocking down expression of K-Ras using antisense oligonucleotides in a mouse model of chronic folic acid nephropathy we can reduce fibrosis by 50% and prevent the loss of renal function over 3 months. In addition, we have demonstrated in vitro and in vivo that reduction of K-Ras expression is associated with a reduction in Jag1 expression; we hypothesise this is the mechanism by which targeting K-Ras has therapeutic benefit. In conclusion, targeting K-Ras expression with antisense oligonucleotides in a mouse model of CKD prevents fibrosis and protects against renal dysfunction.
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Affiliation(s)
- Lucy J Newbury
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK.,Department of Nephrology, Cardiff University Medical School, Cardiff, UK
| | - Jui-Hui Wang
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Gene Hung
- Ionis Pharmaceuticals, Carlsbad, California, 92010, USA
| | - Bruce M Hendry
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK
| | - Claire C Sharpe
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King's College London, London, UK.
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21
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Meeks D, Navaratnarajah A, Drasar E, Jaffer O, Wilkins CJ, Thein SL, Sharpe CC. Increased prevalence of renal cysts in patients with sickle cell disease. BMC Nephrol 2017; 18:298. [PMID: 28934953 PMCID: PMC5609069 DOI: 10.1186/s12882-017-0714-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 09/07/2017] [Indexed: 12/27/2022] Open
Abstract
Background Early detection and interventions have enabled patients with sickle cell disease (SCD) to live well into adulthood. Consequently, the chronicity of SCD allows for the insidious manifestation of multisystem complications, including renal damage. Cystic renal lesions are commonly incidentally discovered on ultrasound and computerised tomography (CT) imaging of the abdomen. Most are benign simple cysts, however, difficulties may be encountered if infection, rupture, haemorrhage or cancerous changes develop. We aimed to determine whether patients with SCD have a higher prevalence of simple renal cysts compared to non-SCD individuals. Methods Data for a group of 223 patients with SCD who had undergone an ultrasound and/or CT imaging of the abdomen were extracted for comparison with 180 control patients (haemoglobin genotype unknown), matched for age and ethnicity. Scans were evaluated for 198 SCD patients and 180 controls. Results Renal cysts were found in 58% of the SCD group and 20% of the controls (OR 5.4 (CI 2.6–11.0), RR 2.8 (CI 1.9–4.2)). Bilateral renal cysts were found in 28% of the SCD participants in comparison with 5% of the control group. In those who had one or more cysts identified, the average number of cysts was 3.76 for the SCD group and 1.94 for the controls. Men with SCD were more likely to develop cysts than women (66% vs 53%), as were men without SCD (22% vs 17%). Conclusions Simple renal cysts occur more frequently, are more abundant and develop at a younger age in patients with SCD than ethnically-matched controls. Further study of the mechanism underlying cyst formation may shed light on both sickle cell nephropathy and other cystic renal diseases.
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Affiliation(s)
- Daveena Meeks
- King's College London, Faculty of Life Sciences & Medicine, London, UK.,Royal Sussex County Hospital, Brighton, UK
| | | | - Emma Drasar
- Red Cell Centre, Whittington Hospital, London, UK
| | - Ounali Jaffer
- Department of Radiology, The Royal London Hospital, Barts Health NHS Trust, London, UK
| | - C Jason Wilkins
- Department of Radiology, King's College Hospital NHS Foundation Trust, London, UK
| | - Swee Lay Thein
- King's College London, Faculty of Life Sciences & Medicine, Molecular Haematology, London, UK.,National Heart, Lung and Blood Institute, The National Institutes of Health, Sickle Cell Branch, Bethesda, USA
| | - Claire C Sharpe
- Department of Renal Sciences, Division of Transplantation Immunology and Mucosal Biology, Faculty of Life Sciences and Medicine, King's College London, London, SE5 9RJ, UK.
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Wang JH, Joslin J, Jenkins R, Sharpe CC, Jayawardene S, Shah S. Outcomes of elderly patients with acute kidney injury on a renal high dependency unit. Int J Clin Pract 2015; 69:1209-10. [PMID: 26412709 DOI: 10.1111/ijcp.12683] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- J-H Wang
- Department of Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - J Joslin
- Department of Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - R Jenkins
- Department of Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - C C Sharpe
- Department of Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - S Jayawardene
- Department of Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK
| | - S Shah
- Department of Renal Medicine, King's College Hospital NHS Foundation Trust, London, UK.
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Shaw C, Sharpe CC. Early invasive treatment for acute coronary syndrome in patients with chronic kidney disease: do we know what we're doing? Future Cardiol 2015; 11:5-8. [PMID: 25606695 DOI: 10.2217/fca.14.71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Catriona Shaw
- UK Renal Registry, Southmead Hospital, Bristol, BS10 5NB, UK
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Somalanka S, Phanish MK, Sharpe CC, Dockrell MEC. FP021ROLE OF SMALL GTPASE NEURONAL-RAS IN THE TGFß1 MEDIATED INTRACELLULAR SIGNALLING IN THE PROXIMAL TUBULE EPITHELIAL CELLS. Nephrol Dial Transplant 2015. [DOI: 10.1093/ndt/gfv166.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Shaw C, Nitsch D, Steenkamp R, Junghans C, Shah S, O’Donoghue D, Fogarty D, Weston C, Sharpe CC. Inpatient coronary angiography and revascularisation following non-ST-elevation acute coronary syndrome in patients with renal impairment: a cohort study using the Myocardial Ischaemia National Audit Project. PLoS One 2014; 9:e99925. [PMID: 24937680 PMCID: PMC4061061 DOI: 10.1371/journal.pone.0099925] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 05/20/2014] [Indexed: 11/18/2022] Open
Abstract
Background International guidelines support an early invasive management strategy (including early coronary angiography and revascularisation) for non-ST-elevation acute coronary syndrome (NSTE-ACS) in patients with renal impairment. However, evidence from outside the UK suggests that this approach is underutilised. We aimed to describe practice within the NHS, and to determine whether the severity of renal dysfunction influenced the provision of angiography and modified the association between early revascularisation and survival. Methods We performed a cohort study, using multivariable logistic regression and propensity score analyses, of data from the Myocardial Ischaemia National Audit Project for patients presenting with NSTE-ACS to English or Welsh hospitals between 2008 and 2010. Findings Of 35 881 patients diagnosed with NSTE-ACS, eGFR of <60 ml/minute/1.73 m2 was present in 15 680 (43.7%). There was a stepwise decline in the odds of undergoing inpatient angiography with worsening renal dysfunction. Compared with an eGFR>90 ml/minute/1.73 m2, patients with an eGFR between 45–59 ml/minute/1.73 m2 were 33% less likely to undergo angiography (adjusted OR 0.67, 95% CI 0.55–0.81); those with an eGFR<30/minute/1.73 m2 had a 64% reduction in odds of undergoing angiography (adjusted OR 0.36, 95%CI 0.29–0.43). Of 16 646 patients who had inpatient coronary angiography, 58.5% underwent inpatient revascularisation. After adjusting for co-variables, inpatient revascularisation was associated with approximately a 30% reduction in death within 1 year compared with those managed medically after coronary angiography (adjusted OR 0.66, 95%CI 0.57–0.77), with no evidence of modification by renal function (p interaction = 0.744). Interpretation Early revascularisation may offer a similar survival benefit in patients with and without renal dysfunction, yet renal impairment is an important determinant of the provision of coronary angiography following NSTE-ACS. A randomised controlled trial is needed to evaluate the efficacy of an early invasive approach in patients with severe renal dysfunction to ensure that all patients who may benefit are offered this treatment option.
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Affiliation(s)
- Catriona Shaw
- UK Renal Registry, Southmead Hospital, Bristol, United Kingdom
- Department of Renal Sciences, Division of Transplantation Immunology and Mucosal Biology, Kings College London, London, United Kingdom
- * E-mail:
| | - Dorothea Nitsch
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Retha Steenkamp
- UK Renal Registry, Southmead Hospital, Bristol, United Kingdom
| | - Cornelia Junghans
- Department of Epidemiology and Public Health, University College London, London, United Kingdom
| | - Sapna Shah
- Department of Renal Medicine, Kings College Hospital, London, United Kingdom
| | - Donal O’Donoghue
- Department of Renal Medicine, Salford Royal NHS Foundation Trust, Salford, United Kingdom
| | - Damian Fogarty
- Department of Renal Medicine, Belfast Health and Social Care Trust, Belfast, Northern Ireland, United Kingdom
| | - Clive Weston
- Myocardial Ischaemia National Audit Project, College of Medicine, Swansea University, Swansea, Wales, United Kingdom
| | - Claire C. Sharpe
- Department of Renal Sciences, Division of Transplantation Immunology and Mucosal Biology, Kings College London, London, United Kingdom
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Lamb EJ, Brettell EA, Cockwell P, Dalton N, Deeks JJ, Harris K, Higgins T, Kalra PA, Khunti K, Loud F, Ottridge RS, Sharpe CC, Sitch AJ, Stevens PE, Sutton AJ, Taal MW. The eGFR-C study: accuracy of glomerular filtration rate (GFR) estimation using creatinine and cystatin C and albuminuria for monitoring disease progression in patients with stage 3 chronic kidney disease--prospective longitudinal study in a multiethnic population. BMC Nephrol 2014; 15:13. [PMID: 24423077 PMCID: PMC3898236 DOI: 10.1186/1471-2369-15-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/09/2014] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Uncertainty exists regarding the optimal method to estimate glomerular filtration rate (GFR) for disease detection and monitoring. Widely used GFR estimates have not been validated in British ethnic minority populations. METHODS/DESIGN Iohexol measured GFR will be the reference against which each estimating equation will be compared. The estimating equations will be based upon serum creatinine and/or cystatin C. The eGFR-C study has 5 components: 1) A prospective longitudinal cohort study of 1300 adults with stage 3 chronic kidney disease followed for 3 years with reference (measured) GFR and test (estimated GFR [eGFR] and urinary albumin-to-creatinine ratio) measurements at baseline and 3 years. Test measurements will also be undertaken every 6 months. The study population will include a representative sample of South-Asians and African-Caribbeans. People with diabetes and proteinuria (ACR ≥30 mg/mmol) will comprise 20-30% of the study cohort.2) A sub-study of patterns of disease progression of 375 people (125 each of Caucasian, Asian and African-Caribbean origin; in each case containing subjects at high and low risk of renal progression). Additional reference GFR measurements will be undertaken after 1 and 2 years to enable a model of disease progression and error to be built.3) A biological variability study to establish reference change values for reference and test measures.4) A modelling study of the performance of monitoring strategies on detecting progression, utilising estimates of accuracy, patterns of disease progression and estimates of measurement error from studies 1), 2) and 3).5) A comprehensive cost database for each diagnostic approach will be developed to enable cost-effectiveness modelling of the optimal strategy.The performance of the estimating equations will be evaluated by assessing bias, precision and accuracy. Data will be modelled as a linear function of time utilising all available (maximum 7) time points compared with the difference between baseline and final reference values. The percentage of participants demonstrating large error with the respective estimating equations will be compared. Predictive value of GFR estimates and albumin-to-creatinine ratio will be compared amongst subjects that do or do not show progressive kidney function decline. DISCUSSION The eGFR-C study will provide evidence to inform the optimal GFR estimate to be used in clinical practice. TRIAL REGISTRATION ISRCTN42955626.
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Affiliation(s)
- Edmund J Lamb
- Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent CT1 3NG, UK
| | - Elizabeth A Brettell
- Birmingham Clinical Trials Unit, School of Cancer Sciences, Robert Aitken Institute, University of Birmingham, Birmingham B15 2TT, UK
| | - Paul Cockwell
- University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 2TT, UK
| | | | - Jon J Deeks
- Birmingham Clinical Trials Unit, School of Cancer Sciences, Robert Aitken Institute, University of Birmingham, Birmingham B15 2TT, UK
- Test Evaluation Research Group, School of Health and Population Sciences, Public Health Building, University of Birmingham, Birmingham, B15 2TT, UK
| | - Kevin Harris
- University Hospitals of Leicester, Leicester, UK
| | - Tracy Higgins
- Centre for Health Services Studies, University of Kent, Canterbury CT2 7NF, UK
| | | | | | - Fiona Loud
- British Kidney Patient Association, Hampshire, UK
| | - Ryan S Ottridge
- Birmingham Clinical Trials Unit, School of Cancer Sciences, Robert Aitken Institute, University of Birmingham, Birmingham B15 2TT, UK
| | - Claire C Sharpe
- King’s College London & King’s College Hospital NHS Foundation Trust SE5 9RJ, London, UK
| | - Alice J Sitch
- Test Evaluation Research Group, School of Health and Population Sciences, Public Health Building, University of Birmingham, Birmingham, B15 2TT, UK
| | - Paul E Stevens
- Kent Kidney Care Centre, East Kent Hospitals University NHS Foundation Trust, Canterbury, Kent CT1 3NG, UK
| | - Andrew J Sutton
- Health Economics Unit, School of Health and Population Sciences, Occupational Health Building, University of Birmingham, Birmingham B15 2TT, UK
| | - Maarten W Taal
- Royal Derby Hospital, Uttoxeter Road, Derby DE22 3NE, UK
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Sarafidis PA, Sharpe CC, Wood E, Blacklock R, Rumjon A, Al-Yassin A, Ariyanayagam R, Simmonds S, Fletcher-Rogers J, Vinen K. Prevalence, patterns of treatment, and control of hypertension in predialysis patients with chronic kidney disease. Nephron Clin Pract 2012; 120:c147-55. [PMID: 22678150 DOI: 10.1159/000337571] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 02/20/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Data on the prevalence, treatment and control of hypertension in patients with advanced chronic kidney disease (CKD) are limited. This study aimed to examine the above factors in a cohort of predialysis patients. METHODS During a period of 4 months, we recorded information on blood pressure (BP), comorbidities, medications and related parameters of patients followed up in the Low-Clearance Clinic of our Department. Control rates of hypertension were calculated at two thresholds: <130/80 and <140/90 mm Hg. Univariate and multiple linear regression analyses were employed to assess factors associated with BP control. RESULTS In the population studied [n = 238, males 58.4%, age 66.21 ± 4.2 years (mean ± SD), estimated glomerular filtration rate 14.5 ± 4.8 ml/min/1.73 m(2)], the prevalence of hypertension was 95.0%. Treatment rate among hypertensives was at 99.1%. On average, 3.04 ± 1.32 antihypertensive drugs were used, ranging from 1 to 7 agents. BP control rates at the <130/80 and <140/90 mm Hg thresholds were 26.5% and 48.2%, respectively. The systolic goal was achieved in 31.0% and 50.4%, whereas the diastolic goal was achieved in 67.7% and 91.2% of patients, respectively. In multivariate analysis, only black race was independently and inversely related with hypertension control (β = -0.187, p = 0.030). No specific antihypertensive class showed independent associations with control. CONCLUSIONS Hypertension is highly prevalent in predialysis CKD patients. An almost universal treatment, employing a multi-agent regime, can help towards improved rates of control. Systolic BP is the main barrier to successful control and black race is associated with poorer control rates.
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Abstract
Renal physiology and pathology are complex systems that are best studied in whole living organisms. This, however, is often restricted by our desire to limit the number of animal experiments undertaken and to replace them with relevant in vitro models that can be used as surrogates for the system under test. Primary culture cells are derived directly from the relevant tissue and therefore correlate more closely with the system under examination. Although the tissue of origin is not always readily available for culture and cells may quickly change their phenotype after only a few passages, they can be used in many circumstances to validate results obtained from closely related cell lines and to confirm vital protein expression patterns. This chapter outlines methods by which proximal tubular epithelial cells and renal interstitial fibroblasts can be isolated and characterized from human renal nephrectomy tissue.
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Wang JH, Newbury LJ, Knisely AS, Monia B, Hendry BM, Sharpe CC. Antisense knockdown of Kras inhibits fibrosis in a rat model of unilateral ureteric obstruction. Am J Pathol 2011; 180:82-90. [PMID: 22074740 DOI: 10.1016/j.ajpath.2011.09.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 08/26/2011] [Accepted: 09/26/2011] [Indexed: 11/28/2022]
Abstract
Tubulointerstitial fibrosis is the hallmark of chronic kidney disease and is characterized by an increase in the number and activity of interstitial fibroblasts and by excessive matrix deposition. Ras is an intracellular signaling molecule involved in cell proliferation and differentiation. It has recently been implicated in the pathogenesis of renal fibrosis. Of the three different isoforms of Ras (Kirsten, Harvey, and Neural), we previously demonstrated that the Kirsten isoform is key in the control of renal fibroblast proliferation in vitro. In this study, we used gene therapy in the form of antisense oligonucleotides (ASOs) specifically to silence Kras (alias Ki-ras) expression in a rat model of renal fibrosis caused by unilateral ureteric obstruction. We demonstrate that renal Kras expression increases by 70% in this model compared with sham-operated animals and that treatment with ASOs can reduce total renal Kras by >90% to levels well below basal. This silencing is associated with a dramatic inhibition of interstitial fibrosis, a fivefold reduction in α-smooth muscle actin expression, and a 2.4-fold reduction in collagen I deposition. This inhibition was observed despite histologic evidence of marked interstitial inflammation. These findings demonstrate that silencing Kras expression can markedly inhibit renal fibrosis. This strategy should be considered as a new potential therapeutic avenue.
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Affiliation(s)
- Jia-Hui Wang
- Department of Renal Medicine, King's College Hospital, London, United Kingdom
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Abstract
Studies have questioned whether renal dysfunction in sickle cell disease is linked to hemolysis-associated vasculopathy. We have investigated renal function and markers of hemolysis in a cohort of 424 adult African-British patients with sickle cell disease. While significant associations were found in HbSS and HbSβ(0) (sickle cell anemia) patients with and without controlling for covariates between hemolytic markers and albuminuria, the associations were not significant in patients with HbSC. Estimated glomerular filtration rate, a marker of renal function, correlated significantly with reticulocyte count and bilirubin. Alpha thalassemia, present in 34% of the sickle cell anaemia patients, had a protective effect against albuminuria in this group. Altogether, the incidence of hyperfiltration was 71% and microalbuminuria 37%, making nephropathy a common complication of sickle cell anemia.
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Affiliation(s)
- Thomas G Day
- King’s College London School of Medicine, Molecular Haematology, London, UK
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Abstract
Despite its apparently simple molecular aetiology, sickle cell disease (SCD) has long been known to have a remarkably variable clinical course, with complications involving many organs including the kidneys. Whilst many affected individuals show no evidence of renal involvement into late adulthood, others develop renal dysfunction in childhood or early adult life with a significant proportion eventually requiring renal replacement therapy. This review explores the pathophysiology and clinical manifestations of sickle cell nephropathy (SCN) and discusses how each complication can be investigated, monitored and managed in the outpatient setting. We summarize current knowledge of genetic modulation of sickle-related renal dysfunction. We outline the evidence for various treatment options and discuss others for which little evidence currently exists.
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Denby L, Ramdas V, McBride MW, Wang J, Robinson H, McClure J, Crawford W, Lu R, Hillyard DZ, Khanin R, Agami R, Dominiczak AF, Sharpe CC, Baker AH. miR-21 and miR-214 are consistently modulated during renal injury in rodent models. Am J Pathol 2011; 179:661-72. [PMID: 21704009 PMCID: PMC3157202 DOI: 10.1016/j.ajpath.2011.04.021] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 04/01/2011] [Accepted: 04/29/2011] [Indexed: 12/19/2022]
Abstract
Transforming growth factor (TGF)-β is one of the main fibrogenic cytokines that drives the pathophysiology of progressive renal scarring. MicroRNAs (miRNAs) are endogenous non-coding RNAs that post-transcriptionally regulate gene expression. We examined the role of TGF-β-induced expression of miR-21, miRNAs in cell culture models and miRNA expression in relevant models of renal disease. In vitro, TGF-β changed expression of miR-21, miR-214, and miR-145 in rat mesangial cells (CRL-2753) and miR-214, miR-21, miR-30c, miR-200b, and miR-200c during induction of epithelial-mesenchymal transition in rat tubular epithelial cells (NRK52E). miR-214 expression was robustly modulated in both cell types, whereas in tubular epithelial cells miR-21 was increased and miR-200b and miR-200c were decreased by 58% and 48%, respectively, in response to TGF-β. TGF-β receptor-1 was found to be a target of miR-200b/c and was down-regulated after overexpression of miR-200c. To assess the differential expression of these miRNAs in vivo, we used the anti-Thy1.1 mesangial glomerulonephritis model and the unilateral ureteral obstruction model in which TGF-β plays a role and also a genetic model of hypertension, the stroke-prone spontaneously hypertensive rat with and without salt loading. The expressions of miR-214 and miR-21 were significantly increased in all in vivo models, showing a possible miRNA signature of renal damage despite differing causes.
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Affiliation(s)
- Laura Denby
- BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom
| | - Vasudev Ramdas
- BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom
| | | | - Joe Wang
- Department of Renal Medicine, The Rayne Institute, King's College London, London, United Kingdom
| | - Hollie Robinson
- BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom
| | - John McClure
- BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom
| | - Wendy Crawford
- BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom
| | - Ruifang Lu
- BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom
| | | | - Raya Khanin
- Department of Statistics, University of Glasgow, Glasgow, United Kingdom
| | - Reuven Agami
- Division of Gene Regulation, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | | - Claire C. Sharpe
- Department of Renal Medicine, The Rayne Institute, King's College London, London, United Kingdom
| | - Andrew H. Baker
- BHF Glasgow Cardiovascular Research Centre, Glasgow, United Kingdom
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Hutchison N, Hendry BM, Sharpe CC. Rho isoforms have distinct and specific functions in the process of epithelial to mesenchymal transition in renal proximal tubular cells. Cell Signal 2009; 21:1522-31. [PMID: 19477269 DOI: 10.1016/j.cellsig.2009.05.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 05/07/2009] [Accepted: 05/20/2009] [Indexed: 11/24/2022]
Abstract
Epithelial to mesenchymal transition (EMT) is involved in embryological development, cancerous metastatic spread and organ fibrosis, including the kidney. This process is largely driven by transforming growth factor-beta and recent evidence has implicated Rho as a key intracellular signalling molecule. In this study we have used RNA interference to silence the genetically distinct Rho (A, B and C) isoforms to define their individual functions in human kidney epithelial cells undergoing EMT. We demonstrate that the downregulation of the epithelial cell marker E-cadherin is dependent upon the Rho effector, Rho-kinase. However, silencing RhoA or RhoC expression also results in E-cadherin loss, though each by different mechanisms. Loss of RhoA leads to an upregulation of Snail1 and a reduction in the transcription of E-cadherin whereas loss of RhoC upregulates its breakdown via proteasomal degradation. During EMT, the upregulation of alpha-smooth muscle actin can be blocked by inhibiting the expression of RhoA, but not by that of RhoB or RhoC. This effect is independent of Rho-kinase activity. RhoC is the isoform solely responsible for stress fibre formation and inhibiting its expression reduces EMT-induced migration by 50%. RhoB appears to play a role in cell survival as inhibiting its expression leads to >300% increase in cell apoptosis and a relocalization of focal adhesion kinase. We conclude that Rho is a key signalling molecule in the process of EMT but that each isoform has a distinct and specific role.
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Affiliation(s)
- Nicol Hutchison
- King's College London, Department of Renal Medicine, London, UK
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Parker E, Newby LJ, Sharpe CC, Rossetti S, Streets AJ, Harris PC, O’Hare MJ, Ong ACM. Hyperproliferation of PKD1 cystic cells is induced by insulin-like growth factor-1 activation of the Ras/Raf signalling system. Kidney Int 2007; 72:157-65. [PMID: 17396115 PMCID: PMC2493387 DOI: 10.1038/sj.ki.5002229] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) largely results from mutations in the PKD1 gene leading to hyperproliferation of renal tubular epithelial cells and consequent cyst formation. Rodent models of PKD suggest that the multifunctional hormone insulin-like growth factor-1 (IGF-1) could play a pathogenic role in renal cyst formation. In order to test this possibility, conditionally immortalized renal epithelial cells were prepared from normal individuals and from ADPKD patients with known germline mutations in PKD1. All patient cell lines had a decreased or absence of polycystin-1 but not polycystin-2. These cells had an increased sensitivity to IGF-1 and to cyclic AMP, which required phosphatidylinositol-3 (PI3)-kinase and the mitogen-activated protein kinase, extracellular signal-regulated protein kinase (ERK) for enhanced growth. Inhibition of Ras or Raf abolished the stimulated cell proliferation. Our results suggest that haploinsufficiency of polycystin-1 lowers the activation threshold of the Ras/Raf signalling system leading to growth factor-induced hyperproliferation. Inhibition of Ras or Raf activity may be a therapeutic option for decreasing tubular cell proliferation in ADPKD.
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Affiliation(s)
- Emma Parker
- Academic Nephrology Unit, Sheffield Kidney Institute, University of Sheffield, Sheffield, UK
| | - Linda J Newby
- Academic Nephrology Unit, Sheffield Kidney Institute, University of Sheffield, Sheffield, UK
| | - Claire C Sharpe
- Department of Renal Medicine, Kings College London School of Medicine, London, UK
| | - Sandro Rossetti
- Division of Nephrology, Mayo Clinic and Foundation, Rochester, USA
| | - Andrew J Streets
- Academic Nephrology Unit, Sheffield Kidney Institute, University of Sheffield, Sheffield, UK
| | - Peter C Harris
- Division of Nephrology, Mayo Clinic and Foundation, Rochester, USA
| | - Michael J O’Hare
- LICR/UCL Breast Cancer Laboratory, University College London, London, UK
| | - Albert CM Ong
- Academic Nephrology Unit, Sheffield Kidney Institute, University of Sheffield, Sheffield, UK
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Abstract
The Rho family of guanine 5'-triphosphatases (GTPases) play a key role in regulating cell proliferation, tubulointerstitial fibrosis, and glomerular hemodynamics. The post-translational prenylation of RhoGTPases by the addition of a geranylgeranyl moiety is critical for cellular localization and signaling activity. This study investigates the effects of (i) inhibiting geranylgeranylation (GG) in human mesangial cell (HMC) proliferation and apoptosis, using GGTI 298, a specific inhibitor of GG and (ii) lovastatin, an HMG-coacetyl A-reductase inhibitor, which depletes the availability of prenylation substrates. HMC proliferation was assessed using an assay of viable cell number and measuring bromodeoxyuridine (BrdU) incorporation. Hoechst 33342 staining was used to determine apoptosis. Extracellular signal-regulated protein kinase (Erk)1/2 and Akt activation were analysed by Western blotting. Rho activation was determined using the Rhotekin pull-down assay. Immunocytochemistry was performed to study the effects on the actin cytoskeleton and RhoA localization. GGTI 298 (10-20 muM) and lovastatin (5-10 muM) potently inhibited platelet-derived growth factor and serum-stimulated HMC proliferation and induced apoptosis. These effects of lovastatin were attenuated by co-incubation with geranylgeranylpyrophosphate. C3 exoenzyme, a clostridial toxin that specifically targets Rho also inhibited BrdU incorporation and promoted apoptosis. GGTI 298 increased cytosolic expression of RhoA, prevented RhoA activation, and inhibited the activation of Erk1/2 and the survival protein Akt. GGTI 298, lovastatin, and C3 exoenzyme inhibit HMC proliferation and promote apoptosis. Inhibiting GG increases cytosolic RhoA expression, disrupts the actin cytoskeleton, and inhibits RhoA activation. These results suggest that targeting geranylgeranylated proteins with statins or GGTI 298 is a promising therapeutic strategy in human mesangioproliferative renal disease.
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Affiliation(s)
- A Khwaja
- Department of Renal Medicine, GKT School of Medicine, King's College London, Bessemer Road, London, UK
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Abstract
Ras monomeric GTPases are pivotal to many core cellular processes such as proliferation and differentiation. The post-translational prenylation of Ras with a farnesyl or a geranylgeranyl moiety is thought to be critical for its membrane binding and consequent signaling activity. Inhibitors of Ras prenylation have an anti-proliferative effect in some Ras-transformed cells. We present a study of the effects of prenylation inhibitors on endogenous, wild-type Ras in three renal cell types, namely primary adult human renal fibroblasts, primary adult human mesangial cells, and a primate renal fibroblast cell line (Vero cells). We have previously demonstrated that Ras is necessary for normal proliferation in these cells. Here we show that Ras is farnesylated and not geranylgeranylated in all three cell types. Furthermore, inhibiting Ras farnesylation has no effect on cell proliferation or Ras activation. Although inhibiting geranylgeranylation in these cells does inhibit proliferation, this is through an Ras-independent mechanism. Non-prenylated Ras is able to localize to the plasma membrane, bind Raf when cells are stimulated by epidermal growth factor or platelet-derived growth factor, and activate the Ras downstream effectors mitogen-activated protein kinase and phosphotidylinositol 3-kinase. We conclude that in wild-type cells, endogenous Ras does not need to be prenylated to be active.
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Affiliation(s)
- Arif Khwaja
- Department of Renal Medicine, King's College London, Bessemer Road, London SE5 9PJ, United Kingdom
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Abstract
BACKGROUND Many of the proliferative cytokines implicated in human mesangial cell (HMC) proliferation signal through the superfamily of Ras GTPases. The Ras antagonist, S-trans, trans- farnesylthiosalicylic acid (FTS), was used to investigate the effects of the inhibition of Ras signaling on HMC proliferation. METHODS Ras expression and membrane localization, MAPK, and Akt activation were analyzed by Western blotting. Ras activation was determined with a pull-down assay using the Ras-binding domain of Raf. HMC growth curves were assessed using the MTS assay of viable cell number, while DNA synthesis was measured with BrdU incorporation. Hoechst 33342 staining was used to determine apoptosis. RESULTS FTS reduced the membrane localization of Ras in both serum and platelet-derived growth factor (PDGF). FTS (7.5-20 micromol/L) potently inhibited PDGF-induced HMC proliferation but had no effect on serum-induced proliferation. FTS (10-20 micromol/L) inhibited both Ras and phospho-MAPK activation by serum and PDGF. Furthermore, FTS (10-20 micromol/L) increased HMC apoptosis in the presence of PDGF but not in serum. Moreover, PDGF-stimulated activation of the survival protein Akt was inhibited by FTS. In contrast, serum-stimulated activation of Akt was unaffected by FTS. CONCLUSION FTS (5-20 micromol/L) inhibits PDGF-induced but not serum-induced HMC proliferation. FTS (10-20 micromol/L) also promotes HMC apoptosis in the presence of PDGF but not serum. These effects appear to be mediated by inhibitory effects on Ras-dependent signaling that occur as a result of the dislodgment of Ras from its membrane-anchorage sites by FTS. The selectivity of FTS toward PDGF-driven HMC proliferation suggests that FTS may be a valuable therapeutic in mesangioproliferative renal disease.
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Affiliation(s)
- Arif Khwaja
- Department of Renal Medicine, GKT School of Medicine, King's College London, London, United Kingdom
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Kocher HM, Moorhead J, Sharpe CC, Dockrell MEC, Al-Nawab M, Hendry BM. Expression of Ras GTPases in normal kidney and in glomerulonephritis. Nephrol Dial Transplant 2004; 18:2284-92. [PMID: 14551355 DOI: 10.1093/ndt/gfg375] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Small monomeric Ras GTPases play critical and specific roles in the control of cellular proliferation and apoptosis but the expression of the three Ras isoforms (Ha-Ras, Ki-Ras and N-Ras) in human renal tissue is unknown. This work is an immunohistochemical study of Ras expression in normal renal tissue and in membranous glomerulonephritis (MGN), IgA nephropathy (IgAN) and IgA-negative mesangioproliferative glomerulonephritis (MPGN). METHODS Formalin-fixed, paraffin-embedded tissue was stained using pan-Ras monoclonal antibody (mAb) and Ras isoform-specific mAb. Detection employed a (DAKO Envision) modified polymer system. RESULTS The expression of Ras isoforms in normal human kidney was cell-specific. For example, N-Ras was detected in tubule epithelial cells but not in glomerular or interstitial cells. Ki-Ras was expressed in mesangial cells, interstitial cells and in proximal convoluted tubule cells (PCT) (particularly localized at brush borders) and in collecting duct cells (CD) (localized to cell membranes) but not in podocytes. Cytoplasmic Ha-Ras was detected in all the above cell types except podocytes. MGN was associated with podocyte expression of all three Ras isoforms and with reduced mesangial cell expression of Ha-Ras and Ki-Ras. IgAN was characterized by podocyte expression of Ha-Ras (but not Ki-Ras) and reduced mesangial cell expression of Ki-Ras without alterations in mesangial Ha-Ras expression. MPGN was associated with reduced mesangial cell Ha-Ras and Ki-Ras expression without significant podocyte Ras expression. CONCLUSION These disease-specific and isoform-specific alterations in Ras expression may be of significance in pathogenesis and warrant further functional investigation.
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Affiliation(s)
- Hemant M Kocher
- Department of Surgery, King's College Hospital, Guy's King's and St Thomas' School of Medicine, King's College London, London, UK
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41
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Abstract
Certain changes in cellular function are characteristic of renal disease. Foremost among these is the excessive proliferation of cells, but other phenotypic changes include dysregulated apoptosis, migration, adhesion, contraction, secretion, and receptor expression. Recent advances in cell biology have revealed an extensive role for the small monomeric GTPases of the Ras superfamily in the control of these cellular events through intracellular signalling cascades. The specific Ras genes appear to play discrete and identifiable roles in a range of complex signalling networks. These insights lead to the possibility of targeting Ras genes in a specific manner in renal therapies. For example, the process of renal cell proliferation might be sensitive to downregulation of Harvey Ras and Kirsten Ras; targeting of Rho A and related species may modulate cell migration, fibrosis, and intrarenal vasoconstriction. Possible strategies for such modulation could include the use of RNA-interacting agents such as antisense DNA and si-RNA and the use of small molecules acting on Ras directly or on related signalling molecules such as Rho kinase and Raf kinase.
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Affiliation(s)
- Bruce M Hendry
- Department of Renal Medicine, Guy's King's St. Thomas' School of Medicine, King's College, London, UK.
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43
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Abstract
Voltage-gated K(+) channels underlie repolarisation of the cardiac action potential and represent a potential therapeutic target in the treatment of cardiac dysrhythmias. However, very little is known about the relative expression of K(+) channel subunits in the human myocardium. We used a semi-quantitative RT-PCR technique to examine the relative expression of mRNAs for the voltage-gated K(+) channel subunits, Kv1.2, Kv1.4, Kv1.5, Kv2.1, Kv4.2, Kv4.3, KvLQT1, HERG and IsK in samples of human atrial appendage. Data were expressed as a percentage expression density relative to an 18S ribosomal RNA internal standard. The most abundant K(+) channel mRNAs were Kv4.3 (80.7 +/- 10.1 %), Kv1.5 (69.7 +/- 11.2 %) and HERG (55.9 +/- 21.5 %). Significant expression of KvLQT1 (33.5 +/- 5.5 %,) and Kv1.4 (26.7 +/- 9.6 %) was also detected. Levels of mRNAs for Kv1.2 and IsK were very low and neither Kv2.1 nor Kv4.2 mRNA were detected in any experiments. Whole-cell patch-clamp techniques were used to examine the outward currents of isolated human atrial myocytes at 37 degrees C. These recordings demonstrated the existence of transient (I(to1)) and sustained (I(so)) outward currents in isolated human atrial myocytes. I(to1), and not I(so), showed voltage-dependent inactivation during 100 ms pre-pulses. Both I(to1) and I(so) were inhibited by high concentrations (2 mM) of the K(+) channel blocker, 4-aminopyridine (4-AP). However, lower concentrations of 4-AP (10 microM) inhibited I(so) selectively. I(to1) recovered from inactivation relatively rapidly (tao approximately 21 ms). These data, with published information regarding the properties of expressed K(+) channels, suggest that Kv4.3 represents the predominant K(+) channel subunit underlying I(to1) with little contribution of Kv1.4. The sensitivity of Iso to very low concentrations of 4-aminopyridine and the relatively low expression of mRNA for Kv1.2 and Kv2.1 is consistent with the major contribution of Kv1.5 to this current. The physiological significance of the expression of KvLQT1 and Kv1.4 mRNA in the human atrium warrants further investigation.
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Affiliation(s)
- Federica Bertaso
- Cell Signalling Group, Department of Renal Medicine, Guy's, King's & St Thomas' School of Medicine, King's College London, Bessemer Road, London, SE5 7PJ, United Kingdom
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Sharpe CC, Dockrell MEC, Noor MI, Monia BP, Hendry BM. Role of Ras isoforms in the stimulated proliferation of human renal fibroblasts in primary culture. J Am Soc Nephrol 2000; 11:1600-1606. [PMID: 10966484 DOI: 10.1681/asn.v1191600] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The proliferation of renal fibroblasts is implicated in the pathophysiologic processes of renal fibrosis. Many of the growth factors involved in proliferation are known to activate intracellular signaling pathways that converge on Ras monomeric GTPases. Although three ras family genes exist, their functional specificity is not yet known. Using antisense oligonucleotides, a role for Kirsten (Ki)-Ras in the stimulated proliferation of a primate renal fibroblast cell line was previously demonstrated. This study examines Ras in primary cultures of adult human renal fibroblasts. Using reverse transcription-PCR, mRNA for Harvey (Ha)-ras, Ki(4B)-ras, and neural (N)-ras, but not Ki(4A)-ras, were detected. Antisense oligonucleotides targeting Ha-, Ki-, and N-ras mRNA, which were used for liposomal transfection at 100 to 200 nM, were demonstrated to be active and isoform-specific in quantitative reverse transcription-PCR assays. Cellular Ras protein levels, as estimated using isoform-specific monoclonal antibodies, indicated that Ki-Ras was the predominantly expressed isoform (>95% of total Ras protein) under both serum-containing and serum-free conditions, with N- and Ha-Ras being detected in small amounts. Consistent with this finding, the antisense oligonucleotide directed against Ki-Ras reduced total cellular Ras levels by >70%, whereas Ha-Ras, N-Ras, and control oligonucleotides had no significant effect. Proliferation of oligonucleotide-transfected cells was measured using epidermal growth factor (EGF) and serum stimulation. The Ki-Ras oligonucleotide at 100 nM reduced serum-stimulated proliferation by >50% and EGF-stimulated proliferation by 25%, compared with data obtained with the control oligonucleotide (P: < 0. 01). The N-Ras oligonucleotide was not active, compared with the control oligonucleotide. The Ha-Ras oligonucleotide was not significantly active at 100 nM but reduced serum-stimulated proliferation by 13% and EGF-stimulated growth by 40% at 200 nM (P: < 0.01). These results demonstrate that Ki-Ras(4B) is the predominantly expressed Ras isoform in human renal fibroblasts in primary culture and is important for both serum- and EGF-stimulated proliferation. Ha-Ras appears to be expressed at low levels but may also play a distinct role in stimulated proliferation.
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Affiliation(s)
- Claire C Sharpe
- Cell Signalling Group, Department of Renal Medicine, Guy's, King's College and St. Thomas' School of Medicine, King's College London, London, United Kingdom
| | - Mark E C Dockrell
- Cell Signalling Group, Department of Renal Medicine, Guy's, King's College and St. Thomas' School of Medicine, King's College London, London, United Kingdom
| | - Mazhar I Noor
- Cell Signalling Group, Department of Renal Medicine, Guy's, King's College and St. Thomas' School of Medicine, King's College London, London, United Kingdom
| | - Brett P Monia
- Department of Molecular Pharmacology, ISIS Pharmaceuticals, Carlsbad, California
| | - Bruce M Hendry
- Cell Signalling Group, Department of Renal Medicine, Guy's, King's College and St. Thomas' School of Medicine, King's College London, London, United Kingdom
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Sharpe CC, Dockrell ME, Scott R, Noor MI, Cowsert LM, Monia BP, Hendry BM. Evidence of a role for Ki-Ras in the stimulated proliferation of renal fibroblasts. J Am Soc Nephrol 1999; 10:1186-92. [PMID: 10361856 DOI: 10.1681/asn.v1061186] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Progressive renal fibrosis is driven by a range of cytokines that act via membrane receptors and intracellular signaling cascades to evoke gene transcription events and related responses. The Ras family of GTPases has been implicated in many of these signaling cascades in model systems such as 3T3 fibroblasts. However, the roleof the specific Ras isoforms Ki, Ha, and N in the stimulation of renal fibroblasts has not been defined. In this study, Ras has been inhibited in primate renal fibroblasts (vero cells) using specific phosphorothioate oligodeoxynucleotides (oligos) targeting the three isoforms. Lipofectin transfection with 200 to 400 nM Ki-Ras oligo inhibited the epidermal growth factor- and fibroblast growth factor-stimulated proliferation of vero cells by 25 to 35% with a lesser effect on serum-stimulated growth. Oligos against Ha-Ras and N-Ras were inactive with respect to control oligo. Total cellular Ras protein (estimated by Western blotting) was reduced by 60 to 90% 24 h after transfection with Ki-Ras oligo. N-Ras, Ha-Ras, and control oligos were inactive. Total Ras synthesis over 4 h measured using [35S]-cys/met pulse chase was reduced by approximately 70% by Ki-Ras oligo and not altered by other oligos. The fractional prenylation of Ras was quantified from the discrete bands on polyacrylamide gel electrophoresis and was increased by the Ki-Ras oligo alone. These data demonstrate that these renal fibroblasts predominantly express the Ki isoform of Ras and that this GTPase plays a role in the stimulated proliferation of these cells. Ras GTPases may be a target for the inhibition of processes leading to renal fibrosis.
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Affiliation(s)
- C C Sharpe
- Department of Renal Medicine, GKT School of Medicine, King's College London, United Kingdom
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