The course of hematocrit value along the length of a dialyzer's fiber: Hemoconcentration modeling and validation methods

OBJECTIVES

Contemporary therapies for chronic kidney disease patients encompass a wide range of hemodialysis treatments, most of which rely greatly on dialyzers and hemofilters. The filtration process taking place in these devices with respect to the hemodynamic characteristics of the flow, has not yet been fully investigated. This study aims at improving the understanding of hemodynamics in a dialyzer by employing experimental methods and mathematical models.

METHODS

A semiempirical model has been formulated based on the principles of hemodynamics, considering the dominant phenomena of filtration-backfiltration and the corresponding driving forces. An in vitro hemodialysis circuit was accordingly assembled for experimental data acquisition, and subsequently for model validation. The circuit consisted of two dialyzers arranged in sequential order, in pursuance of increasing the number of sampling points. Fresh, heparinized porcine blood was used throughout the course of this study. Pressure and flow data obtained from in vitro investigations with the hemodialysis circuit were used as an input for the semiempirical model.

FINDINGS

The model predicted a substantial divergence in the course of hematocrit value along the length of the hollow fibers, which is corroborated by the experimental data. Particularly in certain operational conditions, hematocrit rose from 25% at the inlet to 65% halfway along the dialyzers' length, to end at 30% at the outlet.

CONCLUSION

Validation of the model's predictions with experimental data demonstrated a very good agreement, confirming the model's accuracy. Potential implementation of the model in clinical practice in the future might contribute greatly to an improved hemodialysis experience.

Integration of urinary neutrophil gelatinase-associated lipocalin with serum creatinine delineates acute kidney injury phenotypes in critically ill children

PURPOSE

Acute kidney injury (AKI) is prevalent in critically ill patients and associated with poor outcomes. Current AKI diagnostics- changes to serum creatinine (SCr) and urine output- are imprecise. Integration of injury biomarkers with SCr may improve diagnostic precision.

METHODS

We performed a secondary analysis of a study of critically ill children. Measurements of urine neutrophil gelatinase-associated lipocalin (uNGAL) and SCr samples from ICU admission facilitated the creation of four groups for comparison, based on elevation of SCr from baseline and reference NGAL cut-off value: uNGAL-/SCr-, uNGAL+/SCr-, uNGAL-/SCr + and uNGAL+/SCr+. The primary outcome assessed was AKI severity on Day 3.

RESULTS

178 children were studied. Compared to uNGAL-/SCr-, uNGAL+/SCr- patients had increased risk for all-stage Day 3 AKI (≥ KDIGO stage 1) (OR 3.83, [1.3-11.3], p = .025). Compared to uNGAL-/SCr+, uNGAL+/SCr + patients had increased risk for severe Day 3 AKI (≥ KDIGO stage 2) (OR 12, [1.4-102], p = .018). The only patients to suffer all-stage Day 3 AKI and mortality were uNGAL+ (3.2% uNGAL+/SCr-; 6.5% uNGAL+/SCr+).

CONCLUSIONS

Unique biomarker combinations on admission are predictive of distinct Day 3 AKI severity phenotypes. These classifications may enable a more personalized approach to the early management of AKI. Expanded study in larger populations is warranted.

Progress in multiple genetically modified minipigs for xenotransplantation in China

Pig-to-human organ transplantation provides an alternative for critical shortage of human organs worldwide. Genetically modified pigs are promising donors for xenotransplantation as they show many anatomical and physiological similarities to humans. However, immunological rejection including hyperacute rejection (HAR), acute humoral xenograft rejection (AHXR), immune cell-mediated rejection, and other barriers associated with xenotransplantation must be overcome with various strategies for the genetic modification of pigs. In this review, we summarize the outcomes of genetically modified and cloned pigs achieved by Chinese scientists to resolve the above-mentioned problems in xenotransplantation. It is now possible to knockout several porcine genes associated with the expression of sugar residues, antigens for (naturally) existing antibodies in humans, including GGTA1, CMAH, and β4GalNT2, and thereby preventing the antigen-antibody response. Moreover, insertion of human complement- and coagulation-regulatory transgenes, such as CD46, CD55, CD59, and hTBM, can further overcome effects of the humoral immune response and coagulation dysfunction, while expression of regulatory factors of immune responses can inhibit the adaptive immune rejection. Furthermore, transgenic strategies have been developed by Chinese scientists to reduce the potential risk of infections by endogenous porcine retroviruses (PERVs). Breeding of multi-gene low-immunogenicity pigs in China is also presented in this review. Lastly, we will briefly mention the preclinical studies on pig-to-non-human primate xenotransplantation conducted in several centers in China.

Periodontal and chronic kidney disease association: A systematic review and meta-analysis

AIM

Chronic kidney disease (CKD) and kidney failure is increasing globally and evidence from observational studies suggest periodontal disease may contribute to kidney functional decline.

METHODS

Electronic searches of the PubMed, EMBASE, Web of Science, Scopus and Cochrane Library databases were conducted for the purposes of conducting a systematic review. Hand searching of reference lists was also performed. Meta-analysis of observational studies involving periodontal disease and chronic kidney disease in adults was performed.

RESULTS

A total of 17 studies was selected from an initial 4055 abstracts. Pooled estimates indicated the odds of having CKD were 60% higher among patients with periodontitis: pooled OR 1.60 (95% CI 1.44-1.79, I² 35.2%, P = 0.11) compared to those without. Conversely, a similar magnitude but non-significant higher odds of having periodontal disease was found among people with CKD 1.69 (95% CI: 0.84, 3.40, I² = 89.8%, P < 0.00) versus non-CKD. Meta-regression revealed study quality based on the Newcastle-Ottawa Scale and statistical adjustment for potential confounders explained almost 35% of the heterogeneity in the studies investigating the association between CKD and periodontitis.

CONCLUSIONS

Moderate evidence for a positive association between periodontitis and CKD exists. Evidence for the opposite direction is extremely weak based on significant heterogeneity between studies.

High-intensity aerobic training lowers blood pressure and modulates the renal renin-angiotensin system in spontaneously hypertensive rats

Background: This study aimed to verify the effects of high-intensity aerobic training (HIAT) on BP control and renin-angiotensin system (RAS) components in renal tissue of SHR. Ten SHRs received HIAT or control for 8-weeks. At the end of the training, the SBP showed a reduction of ~ 30mmHg (p < .01) in HIAT and increased by ~ 15 mmHg in the  control group. HIAT resulted in a higher release of nitrite, IL-6, ACE2 and ATR2. These results indicated an association between BP, NO and renal RAS.Abbreviations: JAA: writing, carried out all experimental procedures, performed statistical analysis, original draft and revised manuscript DMS: data interpretation, formal analysis, writing, editing and revised manuscript BAP: carried all experimental procedures, revised manuscritpt CPCG: carried all experimental procedures, revised manuscritpt MEN: experimental procedures, revised manuscript and data interpretation RWP: drafted and revised manuscript RCA: writing, experimental procedures, revised manuscript JP: writing, data interpretation and revised manuscript OLF: writing, original draft and revised manuscript.

Self-Assembly of Artificial Sweetener Aspartame Yields Amyloid-like Cytotoxic Nanostructures

Recent reports have revealed the intrinsic propensity of single aromatic metabolites to undergo self-assembly and form nanostructures of amyloid nature. Hence, identifying whether aspartame, a universally consumed artificial sweetener, is inherently aggregation prone becomes an important area of investigation. Although the reports on aspartame-linked side effects describe a multitude of metabolic disorders, the mechanistic understanding of such destructive effects is largely mysterious. Since aromaticity, an aggregation-promoting factor, is intrinsic to aspartame's chemistry, it is important to know whether aspartame can undergo self-association and if such a property can predispose any cytotoxicity to biological systems. Our study finds that aspartame molecules, under mimicked physiological conditions, undergo a spontaneous self-assembly process yielding regular β-sheet-like cytotoxic nanofibrils of amyloid nature. The resultant aspartame fibrils were found to trigger amyloid cross-seeding and become a toxic aggregation trap for globular proteins, Aβ peptides, and aromatic metabolites that convert native structures to β-sheet-like fibrils. Aspartame fibrils were also found to induce hemolysis, causing DNA damage resulting in both apoptosis and necrosis-mediated cell death. Specific spatial arrangement between aspartame molecules is predicted to form a regular amyloid-like architecture with a sticky exterior that is capable of promoting viable H-bonds, electrostatic interactions, and hydrophobic contacts with biomolecules, leading to the onset of protein aggregation and cell death. Results reveal that the aspartame molecule is inherently amyloidogenic, and the self-assembly of aspartame becomes a toxic trap for proteins and cells, exposing the bitter side of such a ubiquitously used artificial sweetener.

Protein C and protein S deficiencies may be related to survival among hemodialysis patients

Background

Thrombophilia due to protein C (PC) and protein S (PS) deficiencies is highly prevalent among patients with stage 5 chronic kidney disease and is reported to arise due to extracorporeal circulation during hemodialysis (HD). This study aimed to evaluate the relationship between HD treatment and thrombophilia.

Methods

A total of 114 Japanese patients on maintenance HD (62 men, 52 women) were followed during 2008–2011. Their survival rates were compared against the duration of HD. Prior to each HD, coagulation/fibrinolysis parameters and PC and PS activities were measured using standard techniques. The patients were divided into two groups: Group 1, with PC and/or PS deficiencies (n = 32), and Group 2, without PC and PS deficiencies (n = 82). The influence of such deficiencies and duration of dialysis on survival was examined. Time-to-event analysis was applied using Kaplan-Meier estimates, and the log-rank test was proposed to test the equivalence of relative survival data. Hazard ratios and 95% confidence intervals (CI) were calculated.

Results

Of the 114 patients, 37 died (Group 1, 22; Group 2, 15). The hazard ratio (95% CI) was higher (p = 0.004) in Group 1 than Group 2. Gene analyses of PC and PS were performed in 14 patients from Group 1. No mutations in either protein were observed. We analyzed the causes of death in both groups; however, the estimated thrombophilia-related incidence of death could not be determined due to small sample size of HD patients.

Conclusions

Our results suggest that PC and PS deficiencies may be related to survival in HD patients. However, this finding warrants additional research.

Clinicians' attitudes and approaches to evaluating the potential living kidney donor-recipient relationship: An interview study

AIM

Careful assessment of the potential donor-recipient relationship is recommended by guidelines to prevent undue coercion, and to ensure realistic expectations and genuine motivations. However, relationships are complex, nuanced and value-laden, and can be challenging to evaluate in living kidney donation. We aimed to describe the attitudes and approaches of transplant clinicians towards assessing the relationship between potential living kidney donors and their recipients.

METHODS

Semi-structured interviews were conducted with 54 transplant clinicians (nephrologists, surgeons, coordinators, social workers, psychiatrists and psychologists) from 32 transplant centres across nine countries including Australia, United States, Canada and New Zealand. Transcripts were analyzed thematically.

RESULTS

Four themes were identified: protecting against vulnerability and premature decisions (ensuring genuine motivation, uncovering precarious dynamics and pre-empting conflict, shared accountability, relying on specialty psychosocial expertise, trusting intimate bonds, tempering emotional impulsivity); safeguarding against coercion (discerning power imbalance, justified inquiry, awareness of impression management); minimizing potential threat to relationships (preserving the bond, giving equitable attention to donors and recipients, ensuring realistic expectations); and ambiguities in making judgments (adjudicating appropriateness and authenticity of relationships, questioning professional intervening, uncertainties in subjective and emotional assessments).

CONCLUSIONS

Clinicians felt ethically compelled to minimize the risk of undue coercion and to protect donors and recipients when evaluating the donor-recipient relationship. However, disentangling voluntariness and altruism from potential undisclosed pressures to enact societal and family duty, making decisions within this complex, multi-stakeholder context, and avoiding the imposition of undue paternalism and donor autonomy, were challenging. Multidisciplinary expertise and practical strategies for managing uncertainties are required.

Serum Hepcidin-25 Levels Reflect the Presence of Bacteremia in Patients with Systemic Inflammatory Response Syndrome

BACKGROUND

Hepcidin-25 is a key regulatory hormone of iron homeostasis in humans, and its production is greatly upregulated by inflammation as well as iron overload. The aim of this study was to investigate the pathophysiological role of hepcidin-25 in patients with systemic inflammatory response syndrome (SIRS).

METHODS

We enrolled 113 consecutive patients (aged 63.4±21, 50 men, 63 women), with 2 or more SIRS criteria, who were admitted to our department of general medicine between August 1, 2015 and August 31, 2017. We measured complete blood cell count and serum levels of hepcidin-25, iron, iron-binding capacity, ferritin, blood urea nitrogen, creatinine, albumin, and C-reactive protein (CRP) on admission. The patients were divided into 3 group: a bacteremia group (27 patients), a culture-negative bacterial infection group (60 patients), and a non-bacterial infection group (26 patients).

RESULTS

Hepcidin-25 levels were found to be comparable in terms of SIRS criteria: 162 [2.8-579], 193 [2.24-409], and 180 [89.2-421] ng/mL in patients with 2, 3, and 4 criteria, respectively (P=0.533). However, hepcidin-25 levels were significantly higher in the bacteremia group (209 [56.7-579] ng/mL) than in either the culture-negative bacterial infection group (168 [2.24-418] ng/mL) or the non-bacterial infection group (142 [2.8-409] ng/mL). A significant positive correlation between hepcidin-25 and CRP levels was noted in the bacteremia group (r=0.528, P=0.005) and non-bacterial infection group (r=0.648, P<0.001). Moreover, iron and ferritin levels were significantly lower in the bacteremia group than in the non-bacterial infection group.

CONCLUSIONS

Our findings suggest that hepcidin-25 level may reflect the presence of bacteremia as well as the severity of inflammation in patients with SIRS.

Gender, Race and Disease Etiology Predict De Novo Malignancy Risk After Liver Transplantation: Insights for Future Individualized Cancer Screening Guidance

BACKGROUND

Malignancy after liver transplant (LT) is a leading cause of mortality, but data is limited. The aim of this study was to identify patients at higher risk for de novo malignancies after LT in a large multicenter database.

METHODS

The Scientific Registry of Transplant Recipients database comprising all 108 412 LT recipients across the United States between 1987 and March 2015 was analyzed with a median follow-up of 6.95 years. Potential risk factors for malignancies after LT were assessed using Cox regression analysis for the outcome of time to first malignancy.

RESULTS

Mean age 51.9 ± 10.8 years, 64.6% male, 74.5% white, and 15.8% with previous malignancy. Malignancies during follow-up were 4,483 (41.3%) skin, 1519 (14.0%) hematologic, and 4842 (44.7%) solid organ. The 10-year probability of de novo malignancy was 11.5% (11.3-11.8%). On multivariable analysis, age by decade (hazard ratio [HR], 1.52; P < 0.001), male sex (HR, 1.28; P < 0.001), white race (compared with other races: HR, 1.45-2.04; P < 0.001), multiorgan transplant (HR, 1.35; P < 0.001), previous malignancy (HR, 1.34; P < 0.001), and alcoholic liver disease, autoimmune, nonalcoholic steatohepatitis (HR, 1.35; P < 0.001), and primary sclerosing cholangitis pre-LT (compared with hepatitis C virus, P < 0.001) were associated with higher risk of post-LT malignancy, but type of immunosuppression was not (P = NS).

CONCLUSIONS

This large data set demonstrates the effects of ethnicity/race and etiologies of liver disease, particularly nonalcoholic steatohepatitis as additional risk factors for cancer after LT. Patients with these high-risk characteristics should be more regularly and diligently screened.

Effect of ovariectomy on the progression of chronic kidney disease-mineral bone disorder (CKD-MBD) in female Cy/+ rats

Male Cy/+ rats have shown a relatively consistent pattern of progressive kidney disease development that displays multiple key features of late stage chronic kidney disease-mineral bone disorder (CKD-MBD), specifically the development of cortical bone porosity. However, progression of disease in female Cy/+ rats, assessed in limited studies, is more heterogeneous and to date has failed to show development of the CKD-MBD phenotype, thus limiting their use as a practical model of progressive CKD-MBD. Animal and human studies suggest that estrogen may be protective against kidney disease in addition to its established protective effect on bone. Therefore, in this study, we aimed to determine the effect of ovariectomy (OVX) on the biochemical and skeletal manifestations of CKD-MBD in Cy/+ female rats. We hypothesized that OVX would accelerate development of the biochemical and skeletal features of CKD-MBD in female Cy/+ rats, similar to those seen in male Cy/+ rats. Female Cy/+ rats underwent OVX (n = 8) or Sham (n = 8) surgery at 15 weeks of age. Blood was collected every 5 weeks post-surgery until 35 weeks of age, when the rats underwent a 4-day metabolic balance, and the tibia and final blood were collected at the time of sacrifice. OVX produced the expected changes in trabecular and cortical parameters consistent with post-menopausal disease, and negative phosphorus balance compared with Sham. However, indicators of CKD-MBD were similar between OVX and Sham (similar kidney weight, plasma blood urea nitrogen, creatinine, creatinine clearance, phosphorus, calcium, parathyroid hormone, and no cortical porosity). Contrary to our hypothesis, OVX did not produce evidence of development of the CKD-MBD phenotype in female Cy/+ rats.

Knockdown of Long Noncoding RNA H19 Represses the Progress of Pulmonary Fibrosis through the Transforming Growth Factor β/Smad3 Pathway by Regulating MicroRNA 140

Long noncoding RNAs (lncRNAs) are involved in various human diseases. Recently, H19 was reported to be upregulated in fibrotic rat lung and play a stimulative role in bleomycin (BLM)-induced pulmonary fibrosis in mice. However, its expression in human fibrotic lung tissues and mechanism of action remain unclear. Here, our observations showed that H19 expression was significantly upregulated and that of microRNA 140 (miR-140) was markedly reduced in pulmonary fibrotic tissues from idiopathic pulmonary fibrosis (IPF) patients and transforming growth factor β1 (TGF-β1)-induced HBE and A549 cells. Moreover, the expression of H19 was negatively correlated with the expression of miR-140 in IPF tissues. H19 knockdown attenuated TGF-β1-induced pulmonary fibrosis in vitro Furthermore, animal experiments showed that H19 knockdown attenuated BLM-induced pulmonary fibrosis in mice. The study of molecular mechanisms showed that H19 functioned via reduction of miR-140 expression by binding to miR-140. The increase of miR-140 inhibited TGF-β1-induced pulmonary fibrosis, and H19 upregulation diminished the inhibitory effects of miR-140 on TGF-β1-induced pulmonary fibrosis, which was involved in the TGF-β/Smad3 pathway. Taken together, our findings showed that H19 knockdown attenuated pulmonary fibrosis via the regulatory network of lncRNA H19-miR-140-TGF-β/Smad3 signaling, and H19 and miR-140 might represent therapeutic targets and early diagnostic and prognostic biomarkers for patients with pulmonary fibrosis.

Chronic kidney disease and the risk of incident hearing loss

OBJECTIVES

There is a strikingly high prevalence of sensorineural hearing loss among patients with chronic kidney disease, with estimates ranging from 36% to 77%; however, longitudinal data are limited. We assessed whether lower baseline estimated glomerular filtration rate calculated using creatinine (eGFR_Cr ), as well as decline in eGFR_Cr over time, were associated with incident hearing loss.

METHODS

Serum creatinine was measured in 1,843 individuals aged 48 to 80 years without hearing loss at the start of the Epidemiology of Hearing Loss Study in 1993. Follow-up creatinine assessments were conducted at 5 (n = 1,526) and 10 (n = 1,095) years. Hearing tests were conducted at baseline and at 5-, 10-, and 15-year follow-up visits. The risk of hearing loss was assessed as a function of baseline eGFR_Cr as well as a function of a 20% decline in eGFR_Cr between baseline and 5 years and between 5 and 10 years. Cox proportional hazards regression was used to examine the risk of incident speech-frequency hearing loss, defined as pure tone average (PTA) > 25 decibels hearing loss for thresholds at 0.5, 1, 2, and 4 kHz (PTA_0.5,1,2,4 ) in either ear.

RESULTS

During 15,676 person-years of follow up, there were 802 cases of incident hearing loss. There was no statistically significant association between lower baseline eGFR_Cr and risk of incident hearing loss. Decline in eGFR_Cr was also not associated with incident hearing loss at speech frequencies.

CONCLUSION

Overall, there was no significant association between eGFR_Cr or decline in eGFR_Cr using the serum creatinine-based equation and risk of incident hearing loss.

LEVEL OF EVIDENCE

2 Laryngoscope, 130:E213-E219, 2020.

Coronary calcification as a predictor of cardiovascular mortality in advanced chronic kidney disease: a prospective long-term follow-up study

BACKGROUND

Patients with advanced chronic kidney disease (CKD) exhibit higher prevalence of coronary artery calcification (CaC) than general population. CaC has been proposed as a risk factor for mortality in end-stage CKD, but most studies in the field are based on short-term follow-up.

METHODS

We conducted a cohort, 10-year prospective longitudinal study of consecutive cases referred to the renal unit. A non-enhanced multislice coronary computed tomography was performed at baseline. CaC was assessed by Agatston method. Patients were stratified according to their CaC score: severe calcification group (CaCs< 400 HU) and mild-moderate calcification group (CaCs≥400 HU). The overall and cardiovascular (CV) mortality, CV events, and factors potentially associated with CaC development were recorded.

RESULTS

137 patients with advanced CKD were enrolled and provided consent. Overall mortality rate was 58%; 40% due to CV events. The rate of overall mortality in the severe calcification group was 75%, and 30% in the low calcification group, whereas the rate of CV mortality was 35% vs. 6%, respectively (p < 0.001). The severe calcification group was older, had higher prevalence of type 2 diabetes mellitus, former cardiologic events, and lower albumin serum levels than the mild-moderate calcification group. In a multivariate Cox model, severe CaC was a significant predictor of CV mortality (HR 5.01; 95%CI 1.28 to 19.6, p = 0.02).

CONCLUSIONS

Among advanced CKD, there was a significantly increase of CV mortality in patients with severe CaCs during a 10-year follow-up period. CaCs could be a useful prognostic tool to predict CV mortality risk in CKD patients.

Neutrophil Extracellular Traps protein composition is specific for patients with Lupus nephritis and includes methyl-oxidized αenolase (methionine sulfoxide 93)

NETs constitute a network of DNA and proteins released by neutrophils in response to infectious and immunologic triggers. NET proteins are recognized as autoantigens in ANCA vasculitis; limited knowledge is available in other autoimmune pathologies. The composition of NETs produced ex vivo by resting and Phorbol-myristate acetate (PMA) stimulated neutrophils was analyzed by high-throughput Fusion Orbitrap technology in 16 patients with Systemic Lupus Erythematosus/Lupus nephritis (9 SLE/7 LN) and in 11 controls. Seven-hundred proteins were characterized and specific fingerprints discriminated LN from SLE. We focused on methyl-oxidized αenolase (methionine sulfoxide 93) that was markedly increased in NETs from LN and was localized in NET filaments in tight connection and outlying DNA. The isotype of anti-αenolase antibodies was IgG2 in LN and IgG4 in other autoimmune glomerulonephritis (Membranous Nephropathy, MN); serum anti-αenolase IgG2 were higher in LN than in SLE and absent in MN. The same IgG2 antibodies recognized 5 epitopes of the protein one containing methionine sulphoxide 93. In conclusion, specific NET protein fingerprints characterize different subsets of SLE; methyl-oxidized αenolase is over-expressed in LN. Circulating anti-αenolase IgG2 recognize the oxidized epitope and are high in serum of LN patients. Post-translational modified NET proteins contribute to autoimmunity in patients with LN.

Clinical significance of C4d deposition in renal tissues from patients with primary Sjögren's syndrome-a preliminary study

Background

To evaluate renal expression of C4d, a complement component in the classical/mannose binding lectin (MBL) pathway, in patients with primary Sjögren’s syndrome (pSS)-associated renal impairments.

Methods

We retrospectively reviewed the clinical and pathological data from 39 patients with pSS presenting with renal impairments. C4d was examined in paraffin-embedded biopsy tissues using immunohistochemistry. Glomerular C4d positive was defined when > 75% glomeruli were globally stained. Tubulointerstitial C4d (TI-C4d) were scored semi-quantitatively as 0 (absent), 1 (spotty or weak), 2 (patchy) and 3 (diffuse). A TI-C4d score ≥ 2 was considered TI-C4d positive and included in the TI-C4d⁺ group and vice versa. Peritubular capillary (PTC) C4d was scored as 0 (absent), 1 (0~10%, minimal), 2 (10%~ 50%, focal), and 3 (> 50%, diffuse).

Results

Glomerular C4d deposition was observed in all 8 patients with pSS-related membranous nephropathy (MN) without obvious C1q deposition. Two of 5 patients with mesangial proliferative glomerulonephritis and 1 of 2 patients with IgA nephropathy had mild mesangial C4d deposition. Sixteen patients (6 glomerular dominant and 10 tubulointerstitial dominant) presented TI-C4d score ≥ 2. Patients in the TI-C4d⁺ group exhibited a higher serum creatinine level at the time of renal biopsy (TI-C4d⁺ 132.5 [89.7, 165.5] vs. TI-C4d⁻ 83.0 [70.7, 102.0] μmol/L, P = 0.008). PTC C4d was observed in 12 patients, with each of minimal, focal and diffuse staining being noted in 4 patients.

Conclusions

The MBL pathway of complement activation was potentially involved in pSS-related MN. Tubulointerstitial C4d might be a pathological marker of severe renal injury in patients with pSS-related renal impairments.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1341-y) contains supplementary material, which is available to authorized users.

Prenatal diagnosis of 17q12 microdeletion and microduplication syndrome in fetuses with congenital renal abnormalities

Background

Copy number variations (CNVs) involving the 17q12 region are associated with a broad range of clinical phenotypes. Deletion of the 17q12 chromosome results in structural or functional abnormalities in the kidney and urethra, type 5 diabetes (MODY5), and neurodevelopmental or neuropsychiatric disorders. Microduplication of 17q12 is rare and is associated with an increased risk of epilepsy and mental retardation. We studied the prenatal diagnosis of 17q12 microduplication and microdeletion syndrome in fetuses with congenital renal abnormalities.

Case presentation

We conducted a retrospective analysis of prenatal diagnoses in our hospital from January 2016 to April 2018. Abnormal renal ultrasound findings were present in 126 fetuses and the incidence of chromosomal abnormalities was 10.32%(13/126). Conventional karyotyping detected 7 of 126 fetuses as aneuploid (5.56%). In addition, chromosome microarray analysis (CMA) detected 6 fetuses(4.76%) with copy number variations (CNVs), of which 5 were shown to have 17q12 microdeletion syndrome and 1 had 17q12 microduplication syndrome. We followed up these pregnant women. The results of the testing had a significant impact on pregnancy outcome. The phenotypes of 17q12 microdeletions and microduplications vary widely, affecting patients in different ways, such as language delays, social deficiencies, and even abortion.

Conclusions

The characteristics of 17q12 microdeletions and microduplications are so vague that the condition is often misdiagnosed or missed. This study demonstrated that karyotype analysis combined with CMA can significantly improve the diagnostic rate in prenatal diagnosis of CNVs, which can provide evidence for genetic counseling in such pregnancies.

Peritoneal dialysis related infections in a tertiary care hospital in Riyadh, Saudi Arabia

OBJECTIVES

To detect the incidence of and risk factors for infections among patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD).

METHODS

A retrospective cohort study was conducted at the PD unit of King Fahad Medical City. End-stage renal disease patients above the age of 12 years who were undergoing PD management between January 2006 and March 2016 were included.

RESULTS

One hundred PD patients were enrolled in the study and examined over a total observation period of 2,553 patient-months. The leading ESRD etiology was hypertension (26.3%). The mean duration of PD was 28.05 months. A total of 45 patients developed 101 episodes of technique-related infections (TRIs). Peritonitis represented the majority of these episodes (90 episodes), with an overall rate of one episode per 28.3 patient-months. TRIs were mostly caused by coagulase-negative staphylococci. A total of 12 patients developed non-technique related infections (NTRIs). There was a statistically significant difference between patients with TRI and non-infected patients regarding the presence of diabetes and duration of dialysis. No peritonitis-related deaths were noted. In total, 21 patients continued on PD and 18 patients were shifted to hemodialysis (HD). Conclusion: In our setting, ESRD patients undergoing PD are more susceptible to TRIs than NTRIs. Diabetes increases the risk of developing TRIs. The high incidence of coagulase-negative staphylococcal TRI suggests touch contamination.

ACTH Gel in Resistant Focal Segmental Glomerulosclerosis After Kidney Transplantation

BACKGROUND

Treatment of focal segmental glomerular sclerosis (FSGS) after kidney transplantation is challenging with unpredictable outcomes. The objective was to investigate the use of adrenocorticotropic hormone (ACTH) analogue gel in kidney transplant recipients with de novo or recurrent FSGS resistant to therapeutic plasma exchange (TPE) and/or rituximab.

METHODS

We performed a retrospective review of cases of de novo or recurrent resistant FSGS at 2 large US transplant centers between April 2012 and December 2016. Proteinuria was measured by urine protein to creatinine ratio.

RESULTS

We identified 20 cases of posttransplant recurrent and de novo FSGS resistant to conventional therapy with TPE and rituximab. Mean ± SD age was 49 ± 15.5 years, 14 (70%) were male, 13 (65%) were whites, and 8 (38%) had previous kidney transplants. Median (interquartile range) of recurrent and de novo FSGS was 3 (0.75-7.5) months posttransplant. The majority of patients, 15 (75%), received TPE as a treatment at the time of diagnosis and 10 (50%) received rituximab, which was started before the use of ACTH gel. There was a significant improvement of urine protein to creatinine ratio from a mean ± SD of 8.6 ± 7.6 g/g before ACTH gel to 3.3 ± 2.3 g/g after the use of ACTH gel (P = 0.004). Ten (50%) patients achieved complete or partial remission.

CONCLUSIONS

Although, the response varied among the recipients, ACTH gel might be an effective therapy for posttransplant resistant FSGS cases that fail to respond to TPE and rituximab.

Mechanistic analyses in kidney transplant recipients prospectively randomized to two steroid free regimen-Low dose Tacrolimus with Everolimus versus standard dose Tacrolimus with Mycophenolate Mofetil

Calcineurin inhibitors (CNI), the cornerstone of immunosuppression after transplantation are implicated in nephrotoxicity and allograft dysfunction. We hypothesized that combined low doses of CNI and Everolimus (EVR) may result in better graft outcomes and greater tolerogenic milieu. Forty adult renal transplant recipients were prospectively randomized to (steroid free) low dose Tacrolimus (TAC) and EVR or standard dose TAC and Mycophenolate (MMF) after Alemtuzumab induction. Baseline characteristics were statistically similar. EVR levels were maintained at 3-8 ng/ml. TAC levels were 4.5±1.9 and 6.4±1.5 ng/ml in the TAC+EVR and TAC+MMF group respectively. Follow up was 14±4 and 17±5 months respectively and included protocol kidney biopsies at 3 and 12 months post-transplantation. Rejection-rate was lower in the TAC+EVR group. However patient and overall graft survival, eGFR and incidence of adverse events were similar. TAC+EVR induced expansion of CD4+CD25hiFoxp3+ regulatory T cells as early as 3 months and expansion of IFN-γ+CD4+CD25hiFoxp3+ regulatory T cells at 12 months post-transplant. Gene expression profile showed a trend toward decreased inflammation, angiogenesis and connective tissue growth in the TAC+EVR Group. Thus, greater tolerogenic mechanisms were found to be operating in patients with low dose TAC+EVR and this might be responsible for the lower rejection-rate than in patients on standard dose TAC+MMF. However, further studies with longer follow up and evaluating impact on T regulatory cells are warranted.

Evidence for the important role of inflammation in xenotransplantation

There is increasing evidence of a sustained state of systemic inflammation after pig-to-nonhuman primate (NHP) xenotransplantation (that has been termed systemic inflammation in xenograft recipients [SIXR]). Increases in inflammatory markers, e.g., C-reactive protein, histones, serum amyloid A, D-dimer, cytokines, chemokines, and a decrease in free triiodothyronine, have been demonstrated in the recipient NHPs. The complex interactions between inflammation, coagulation, and the immune response are well-recognized, but the role of inflammation in xenograft recipients is not fully understood. The evidence suggests that inflammation can promote the activation of coagulation and the adaptive immune response, but the exact mechanisms remain uncertain. If prolonged xenograft survival is to be achieved, anti-inflammatory strategies (e.g., the administration of anti-inflammatory agents, and/or the generation of genetically-engineered organ-source pigs that are protected from the effect of inflammation) may be necessary to prevent, control, or negate the effect of the systemic inflammation that develops in xenograft recipients. This may allow for a reduction in the intensity of exogenous immunosuppressive therapy. If immunological tolerance to a xenograft is to be obtained, then control of inflammation may be essential.

Lymphatic Migration of Immune Cells

Lymphatic vessels collect interstitial fluid that has extravasated from blood vessels and return it to the circulatory system. Another important function of the lymphatic network is to facilitate immune cell migration and antigen transport from the periphery to draining lymph nodes. This migration plays a crucial role in immune surveillance, initiation of immune responses and tolerance. Here we discuss the significance and mechanisms of lymphatic migration of innate and adaptive immune cells in homeostasis, inflammation and cancer.

Predictors of mortality in hemodialysis patients

Introduction

Mortality in patients with chronic renal failure is high compared to the general population. The objective of our study is to evaluate the predictive factors related to mortality in hemodialysis.

Methods

This is a retrospective study involving 126 hemodialysis patients in the Nephrology Department of Ibn Rochd Hospital, Casablanca. Data were collected between January 2012 and January 2016. For each of our patients, we analyzed demographic, clinical, biological and anthropometric data. The Kaplan-Meier method and the log-rank test were used to evaluate and compare survival curves. To evaluate the effect of predictors of mortality, we used the proportional Cox hazard model.

Results

The analysis of the results showed that the surviving patients were younger than the deceased patients (43.07±13.52 years versus 53.09±13.56 years, p=0.001). Also, the latter has a significantly lower albumin and prealbumin levels (p=0.01 and p=0.04 respectively). Overall survival was 80.2%. Cox regression analysis at age (HR=1.26, p<0.0002), inflammation (HR=1.15, p<0.03), AIP> 0.24 (HR=2.1, p<0.002) and cardiovascular disease (RR=2.91, p<0.001) were associated with global and cardiovascular mortality.

Conclusion

Our study showed that the mortality rate is high in our cohort. In addition, cardiovascular diseases, under nutrition and inflammation are predictive factors for mortality. Treatment and early management of these factors are essential for reducing morbidity and mortality.

Free Water Transport and Its Association with Cardiovascular Status in Children on Peritoneal Dialysis

Background:Volume overload is one of the most important factors associated with left ventricular hypertrophy (LVH) and cardiovascular disease in chronic peritoneal dialysis (PD) patients. MiniPET is a reliable tool to evaluate free water transport (FWT). In a clinical setting, the significance of FWT has not been evaluated in terms of outcome in children on PD. The objective was to define a FWT value of clinical significance in children on PD, fixing its relationship to left ventricular mass index (LVMI) as a well-known outcome parameter.Methods:MiniPET was performed with 3.86% glucose, 1-h long, to measure FWT in PD patients > 6 years old. An echocardiogram (ECG) was performed within 2 months of the MiniPET. Left ventricular hypertrophy was defined as LVMI ≥ 38.6 g/height^2.7 (95th percentile). Receiver operating characteristic curve (ROC) analysis was used to determine the cut-off value of FWT searching the highest sensitivity and specificity to differentiate patients with normal/abnormal LVMI. A p < 0.05 was considered significant.Results:Forty-six studies were performed on 32 patients, 16 males; mean age 11.59 ± 3.07 years. Mean normalized FWT (nFWT) was 144.4 ± 84.8 mL/m², corresponding to 46.7% of total ultrafiltration. Mean LVMI was 42 ± 11.3 g/m^2.7 with a negative correlation to nFWT (p < 0.01). Eighteen out of 32 patients had LVH. The ROC analysis (nFWT vs LVMI) showed an area under the curve of 0.71 (95% confidence interval [CI], 0.53 - 0.89; p = 0.04), allowing a cut-off nFWT value of 110 mL/m² to be defined, dividing the population into 2 groups of patients according to the LVMI cut-off value of 38,6 g/m^2.7.Conclusions:The nFWT showed an inverse correlation to LVMI. A nFWT value < 110 mL/m² was significantly associated with LVH. The negative relationship observed between nFWT and LVMI, and the cut-off level for nFWT according to the 95th percentile of LVMI, suggest that the regular evaluation of nFWT could become a useful tool in assessing the capacity of PD treatment to keep patients' volume status under control, avoiding cardiovascular impairment.

Composite Outcome Improves Feasibility of Clinical Trials in Peritoneal Dialysis

Background:Peritoneal dialysis (PD) is complicated by a high rate of adverse events that might be attributed to cytotoxicity of currently used PD fluids. However, clinical development of novel PD fluids is virtually non-existent, in part due to difficulties in recruiting sufficiently large populations for adequately powered trials. The aim of this study is to understand the potential impact of introducing composite outcomes on clinical trial feasibility in PD.Methods:A composite outcome "major adverse peritoneal events (MAPE)" was designed to combine clinically relevant complications of PD, such as (1) technical failure (cause-specific for peritonitis and/or insufficient dialysis), (2) peritonitis, and (3) peritoneal membrane deterioration. Incidence rates of individual endpoints were obtained from the literature and expert panel estimations, and population sizes were computed based on Chi-square test for adequately powered confirmatory randomized controlled clinical trials with 2 parallel arms.Results:Incidence rates for technical failure, peritonitis, and peritoneal membrane deterioration were estimated at 15%, 50%, and 23%, respectively, at 2 years follow-up, with adequate agreement between the literature and expert opinion. Assuming that a given intervention reduces adverse outcomes by 30%, an adequately powered clinical trial needs to recruit up to 1,720 patients when studying individual outcomes. Combining endpoints increases power in simulated trials despite considerable overlap, and the composite outcome MAPE reduces the required population to 202 patients aiming for 80% power.Conclusion:Introduction of the composite outcome MAPE, covering relevant major adverse peritoneal events, may improve the feasibility of clinical trials to adequately test novel PD fluids.

Effects of Ketoconazole, a CYP4F2 Inhibitor, and CYP4F2*3 Genetic Polymorphism on Pharmacokinetics of Vitamin K1

The objective of this study was to evaluate whether cytochrome P450 (CYP)4F2 is involved in the exposure of vitamin K₁ through a drug interaction study with ketoconazole, a CYP4F2 inhibitor, and a pharmacogenetic study with CYP4F2*3. Twenty-one participants with different CYP4F2*3 polymorphisms were enrolled (8 for *1/*1, 7 for *1/*3, and 6 for *3/*3). All participants were treated twice daily for 5 days with 200 mg of ketoconazole or placebo. Finally, a single dose of 10 mg vitamin K₁ was administered, plasma levels of vitamin K₁ were measured, and its pharmacokinetics was assessed. Ketoconazole elevated the plasma levels of vitamin K₁ and increased the average area under the concentration-time curve (AUC_inf ) and peak concentration by 41% and 40%, respectively. CYP4F2*3 polymorphism also affected plasma levels of vitamin K₁ and its pharmacokinetics in a gene dose-dependent manner. The average AUC_inf value was 659.8 ng·h/mL for CYP4F2*1/*1, 878.1 ng·h/mL for CYP4F2*1/*3, and 1125.2 ng·h/mL for CYP4F2*3/*3 (P = .010). This study revealed that ketoconazole and CYP4F2*3 polymorphism substantially increased the exposure of vitamin K₁ in humans. These findings provide a plausible explanation for variations in warfarin dose requirements resulting from interindividual variations in vitamin K₁ exposure due to CYP4F2-related drug interactions and genetic polymorphisms.

Total Extracts of Abelmoschus manihot L. Attenuates Adriamycin-Induced Renal Tubule Injury via Suppression of ROS-ERK1/2-Mediated NLRP3 Inflammasome Activation

Abelmoschus manihot (L.) Medik. (Malvaceae) is a herb used in traditional Chinese medicine to treat some kidney diseases. To date, the detailed mechanisms by which A. manihot improves some kinds of renal disease are not fully understood. In this study, we established Adriamycin-induced NRK-52E cells, the normal rat kidney epithelial cell line, injury, and Sprague-Dawley rats with Adriamycin-induced nephropathy to evaluate the role and mechanisms of total extracts of A. manihot flower (TEA) both in vitro and in vivo. We found that TEA ameliorated Adriamycin-induced cellular morphological changes, cell viability, and apoptosis through the suppression of protein oxidation and ERK1/2 signaling. However, this anti-oxidative stress role of TEA was independent of ROS inhibition. Adriamycin activated ERK1/2 signaling followed by activation of NLRP3 inflammasomes. TEA suppressed NLRP3 inflammasomes via inhibition of ERK1/2 signal transduction; decreased proteinuria and attenuated renal tubule lesions; and inhibited the expression of NLRP3 in tubules in rats with Adriamycin nephropathy. Collectively, TEA protects renal tubular cells against Adriamycin-induced tubule injury via inhibition of ROS-ERK1/2-NLRP3 inflammasomes.

[Predictive value of plasma cytokines for acute kidney injury following lung resection surgery: prospective observational study]

BACKGROUND AND OBJECTIVES

Patients undergoing lung resection surgery are at risk of developing postoperative acute kidney injury. Determination of cytokine levels allows the detection of an early inflammatory response. We investigated any temporal relationship among perioperative inflammatory status and development of acute kidney injury after lung resection surgery. Furthermore, we evaluated the impact of acute kidney injury on outcome and analyzed the feasibility of cytokines to predict acute kidney injury.

METHODS

We prospectively analyzed 174 patients scheduled for elective lung resection surgery with intra-operative periods of one-lung ventilation. Fiberoptic broncho-alveolar lavage was performed in each lung before and after one-lung ventilation periods for cytokine analysis. As well, cytokine levels were measured from arterial blood samples at five time points. Acute kidney injury was diagnosed within 48h of surgery based estabilished criteria for its diagnosis. We analyzed the association between acute kidney injury and cardiopulmonary complications, length of intensive care unit and hospital stays, intensive care unit re-admission, and short-term and long-term mortality.

RESULTS

The incidence of acute kidney injury in our study was 6.9% (12/174). Acute kidney injury patients showed higher plasma cytokine levels after surgery, but differences in alveolar cytokines were not detected. Although no patient required renal replacement therapy, acute kidney injury patients had higher incidence of cardiopulmonary complications and increased overall mortality. Plasma interleukin-6 at 6h was the most predictive cytokine of acute kidney injury (cut-off point at 4.89pg.mL^-1).

CONCLUSIONS

Increased postoperative plasma cytokine levels are associated with acute kidney injury after lung resection surgery in our study, which worsens the prognosis. Plasma interleukin-6 may be used as an early indicator for patients at risk of developing acute kidney injury after lung resection surgery.

Synergistic Protective Effects of Mitochondrial Division Inhibitor 1 and Mitochondria-Targeted Small Peptide SS31 in Alzheimer's Disease

The purpose of our study was to determine the synergistic protective effects of mitochondria-targeted antioxidant SS31 and mitochondria division inhibitor 1 (Mdivi1) in Alzheimer's disease (AD). Using biochemical methods, we assessed mitochondrial function by measuring the levels of hydrogen peroxide, lipid peroxidation, cytochrome c oxidase activity, mitochondrial ATP, and GTPase Drp1 enzymatic activity in mutant AβPP cells. Using biochemical methods, we also measured cell survival and apoptotic cell death. Amyloid-β (Aβ) levels were measured using sandwich ELISA, and using real-time quantitative RT-PCR, we assessed mtDNA (mtDNA) copy number in relation to nuclear DNA (nDNA) in all groups of cells. We found significantly reduced levels of Aβ40 and Aβ42 in mutant AβPP cells treated with SS31, Mdivi1, and SS31+Mdivi1, and the reduction of Aβ42 levels were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. The levels of mtDNA copy number and cell survival were significantly increased in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the increased levels of mtDNA copy number and cell survival were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. Mitochondrial dysfunction is significantly reduced in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the reduction is much higher in cells treated with both SS31+Mdvi1. Similarly, GTPase Drp1 activity is reduced in all treatments, but reduced much higher in SS31+Mdivi1 treated cells. These observations strongly suggest that combined treatment of SS31+Mdivi1 is effective than individual treatments of SS31 and Mdivi1. Therefore, we propose that combined treatment of SS31+Mdivi1 is a better therapeutic strategy for AD. Ours is the first study to investigate combined treatment of mitochondria-targeted antioxidant SS31 and mitochondrial division inhibitor 1 in AD neurons.

Neutral pH and low-glucose degradation product dialysis fluids induce major early alterations of the peritoneal membrane in children on peritoneal dialysis

The effect of peritoneal dialysates with low-glucose degradation products on peritoneal membrane morphology is largely unknown, with functional relevancy predominantly derived from experimental studies. To investigate this, we performed automated quantitative histomorphometry and molecular analyses on 256 standardized peritoneal and 172 omental specimens from 56 children with normal renal function, 90 children with end-stage kidney disease at time of catheter insertion, and 82 children undergoing peritoneal dialysis using dialysates with low-glucose degradation products. Follow-up biopsies were obtained from 24 children after a median peritoneal dialysis of 13 months. Prior to dialysis, mild parietal peritoneal inflammation, epithelial-mesenchymal transition and vasculopathy were present. After up to six and 12 months of peritoneal dialysis, blood microvessel density was 110 and 93% higher, endothelial surface area per peritoneal volume 137 and 95% greater, and submesothelial thickness 23 and 58% greater, respectively. Subsequent peritoneal changes were less pronounced. Mesothelial cell coverage was lower and vasculopathy advanced, whereas lymphatic vessel density was unchanged. Morphological changes were accompanied by early fibroblast activation, leukocyte and macrophage infiltration, diffuse podoplanin presence, epithelial mesenchymal transdifferentiation, and by increased proangiogenic and profibrotic cytokine abundance. These transformative changes were confirmed by intraindividual comparisons. Peritoneal microvascular density correlated with peritoneal small-molecular transport function by uni- and multivariate analysis. Thus, in children on peritoneal dialysis neutral pH dialysates containing low-glucose degradation products induce early peritoneal inflammation, fibroblast activation, epithelial-mesenchymal transition and marked angiogenesis, which determines the PD membrane transport function.

Donor Urinary C5a Levels Independently Correlate With Posttransplant Delayed Graft Function

BACKGROUND

Accumulating evidence implicates the complement cascade as pathogenically contributing to ischemia-reperfusion injury and delayed graft function (DGF) in human kidney transplant recipients. Building on observations that kidney injury can initiate in the donor before nephrectomy, we tested the hypothesis that anaphylatoxins C3a and C5a in donor urine before transplantation associate with risk of posttransplant injury.

METHODS

We evaluated the effects of C3a and C5a in donor urine on outcomes of 469 deceased donors and their corresponding 902 kidney recipients in a subset of a prospective cohort study.

RESULTS

We found a threefold increase of urinary C5a concentrations in donors with stage 2 and 3 acute kidney injury (AKI) compared donors without AKI (P < 0.001). Donor C5a was higher for the recipients with DGF (defined as dialysis in the first week posttransplant) compared with non-DGF (P = 0.002). In adjusted analyses, C5a remained independently associated with recipient DGF for donors without AKI (relative risk, 1.31; 95% confidence interval, 1.13-1.54). For donors with AKI, however, urinary C5a was not associated with DGF. We observed a trend toward better 12-month allograft function for kidneys from donors with C5a concentrations in the lowest tertile (P = 0.09). Urinary C3a was not associated with donor AKI, recipient DGF, or 12-month allograft function.

CONCLUSIONS

Urinary C5a correlates with the degree of donor AKI. In the absence of clinical donor AKI, donor urinary C5a concentrations associate with recipient DGF, providing a foundation for testing interventions aimed at preventing DGF within this high-risk patient subgroup.

Chronic kidney disease progression in kidney transplant recipients: A focus on traditional risk factors

Kidney transplant recipients are a subset of patients with chronic kidney disease (CKD) that remain at high risk for progression to dialysis and mortality. Recent advances in immunosuppression have only partially improved long-term graft and patient survival. Discovery of new immunosuppressive regimens is a slow and resource-intensive process. Hence, recognition and management of modifiable allogeneic and non-allogeneic risk factors for progression to CKD among kidney transplant recipients is of major interest for improving long-term outcomes. Graft survival is mainly determined by the quality of the allograft and by the patient's alloimmune response, which is influenced by human leukocyte antigen matching and the presence of donor-specific antibodies. Alloimmune responses manifest as acute and chronic forms of cell- and antibody-mediated rejection, which can be worsened by patient non-adherence or under-immunosuppression. However, donor and patient ages, glomerular disease recurrence, time on dialysis, pre-existing cardiovascular burden, medication side-effects and traditional risk factors, such as hypertension, proteinuria, anaemia, dyslipidaemia, diabetes and bone mineral disorder, which can ultimately lead to severe endothelial derangement, also contribute to graft loss and mortality. These traditional risk factors, common to pre-dialysis patients, often are considered of secondary importance when compared to alloimmunity and immunosuppression concerns. In this review article, we focus on the epidemiological, pathophysiological and therapeutic features of non-allogeneic traditional risk factors for CKD. We also discuss the benefit of adopting a multidisciplinary approach to pursue the same therapeutic targets recommended for pre-dialysis patients.

Drug-eluting compared to bare metal stents in patients with end-stage renal disease on dialysis: a meta-analysis

AIMS

To systematically review literature comparing bare metal stent (BMS) to drug-eluting stent (DES) in end-stage renal disease (ESRD) patients on dialysis. ESRD patients on dialysis often suffer from accelerated atherosclerosis and higher rate of stent-related complications including major adverse cardiovascular events. Because dialysis usually qualifies ineligibility for randomized clinical trials, an evidenced-based stent choice for these patients is scarce.

METHODS

PUBMED, CINHAL, COCHRANE, EMBASE and WEB OF SCIENCE were searched for studies comparing BMS vs. DES outcome in ESRD patients on dialysis.

RESULTS

Twenty studies including 64 232 patients were considered. The use of DES was significantly associated with a reduction in all-cause mortality [odds ratio (OR) 0.83, 95% confidence interval (CI) 0.76-0.89], death from a cardiovascular cause (OR 0.80, 95% CI 0.76-0.84) and target lesion revascularization/target vessel revascularization (OR 0.73, 95% CI 0.53-1.00). No significant difference was found in stent thrombosis (OR 1.08, 95% CI 0.50-2.33) and myocardial infarction incidence (OR 0.91, 95% CI 0.69-1.20).

CONCLUSIONS

Our meta-analysis shows a significant reduction in all-cause and cardiovascular mortality with the use of DES over BMS in dialyzed patients. Despite the lack of randomized studies, systematic use of DES in these high-risk patients should thus reasonably be considered as a first option in percutaneous coronary intervention candidates.

Can Metabolic Pathways Be Therapeutic Targets in Rheumatoid Arthritis?

The metabolic rewiring of tumor cells and immune cells has been viewed as a promising source of novel drug targets. Many of the molecular pathways implicated in rheumatoid arthritis (RA) directly modify synovium metabolism and transform the resident cells, such as the fibroblast-like synoviocytes (FLS), and the synovial tissue macrophages (STM), toward an overproduction of enzymes, which degrade cartilage and bone, and cytokines, which promote immune cell infiltration. Recent studies have shown metabolic changes in stromal and immune cells from RA patients. Metabolic disruption in the synovium provide the opportunity to use in vivo metabolism-based imaging techniques for patient stratification and to monitor treatment response. In addition, these metabolic changes may be therapeutically targetable. Thus, resetting metabolism of the synovial membrane offers additional opportunities for disease modulation and restoration of homeostasis in RA. In fact, rheumatologists already use the antimetabolite methotrexate, a chemotherapy agent, for the treatment of patients with inflammatory arthritis. Metabolic targets that do not compromise systemic homeostasis or corresponding metabolic functions in normal cells could increase the drug armamentarium in rheumatic diseases for combination therapy independent of systemic immunosuppression. This article summarizes what is known about metabolism in synovial tissue cells and highlights chemotherapies that target metabolism as potential future therapeutic strategies for RA.

Role of the afferent renal nerves in sodium homeostasis and blood pressure regulation in rats

New Findings

What is the central question of this study?

What are the differential roles of the mechanosensitive and chemosensitive afferent renal nerves in the reno‐renal reflex that promotes natriuresis, sympathoinhibition and normotension during acute and chronic challenges to sodium homeostasis?

What is the main finding and its importance?

The mechanosensitive afferent renal nerves contribute to an acute natriuretic sympathoinhibitory reno‐renal reflex that may be integrated within the paraventricular nucleus of the hypothalamus. Critically, the afferent renal nerves are required for the maintenance of salt resistance in Sprague–Dawley and Dahl salt‐resistant rats and attenuate the development of Dahl salt‐sensitive hypertension.

Abstract

These studies tested the hypothesis that in normotensive salt‐resistant rat phenotypes the mechanosensitive afferent renal nerve (ARN) reno‐renal reflex promotes natriuresis, sympathoinhibition and normotension during acute and chronic challenges to fluid and electrolyte homeostasis. Selective ARN ablation was conducted prior to (1) an acute isotonic volume expansion (VE) or 1 m NaCl infusion in Sprague–Dawley (SD) rats and (2) chronic high salt intake in SD, Dahl salt‐resistant (DSR), and Dahl salt‐sensitive (DSS) rats. ARN responsiveness following high salt intake was assessed ex vivo in response to noradrenaline and sodium concentration (SD, DSR and DSS) and via in vivo manipulation of renal pelvic pressure and sodium concentration (SD and DSS). ARN ablation attenuated the natriuretic and sympathoinhibitory responses to an acute VE [peak natriuresis (µeq min⁻¹) sham 52 ± 5 vs. ARN ablation 28 ± 3, P < 0.05], but not a hypertonic saline infusion in SD rats. High salt (HS) intake enhanced ARN reno‐renal reflex‐mediated natriuresis in response to direct increases in renal pelvic pressure (mechanoreceptor stimulus) in vivo and ARN responsiveness to noradrenaline ex vivo in SD, but not DSS, rats. In vivo and ex vivo ARN responsiveness to increased renal pelvic sodium concentration (chemoreceptor stimulus) was unaltered during HS intake. ARN ablation evoked sympathetically mediated salt‐sensitive hypertension in SD rats [MAP (mmHg): sham normal salt 102 ± 2 vs. sham HS 104 ± 2 vs. ARN ablation normal salt 103 ± 2 vs. ARN ablation HS 121 ± 2, P < 0.05] and DSR rats and exacerbated DSS hypertension. The mechanosensitive ARNs mediate an acute sympathoinhibitory natriuretic reflex and counter the development of salt‐sensitive hypertension.

Nutritional Strategies to Prevent Lens Cataract: Current Status and Future Strategies

Oxidative stress and the subsequent oxidative damage to lens proteins is a known causative factor in the initiation and progression of cataract formation, the leading cause of blindness in the world today. Due to the role of oxidative damage in the etiology of cataract, antioxidants have been prompted as therapeutic options to delay and/or prevent disease progression. However, many exogenous antioxidant interventions have to date produced mixed results as anti-cataract therapies. The aim of this review is to critically evaluate the efficacy of a sample of dietary and topical antioxidant interventions in the light of our current understanding of lens structure and function. Situated in the eye behind the blood-eye barrier, the lens receives it nutrients and antioxidants from the aqueous and vitreous humors. Furthermore, being a relatively large avascular tissue the lens cannot rely of passive diffusion alone to deliver nutrients and antioxidants to the distinctly different metabolic regions of the lens. We instead propose that the lens utilizes a unique internal microcirculation system to actively deliver antioxidants to these different regions, and that selecting antioxidants that can utilize this system is the key to developing novel nutritional therapies to delay the onset and progression of lens cataract.

Effects of Variability in Blood Pressure, Glucose, and Cholesterol Concentrations, and Body Mass Index on End-Stage Renal Disease in the General Population of Korea

Aim: Metabolic parameters, such as blood pressure, glucose, lipid levels, and body weight, can interact with each other, and this clustering of metabolic risk factors is related to the progression to end-stage renal disease (ESRD). The effect of variability in metabolic parameters on the risk of ESRD has not been studied previously. Methods: Using nationally representative data from the Korean National Health Insurance System, 8,199,135 participants who had undergone three or more health examinations between 2005 and 2012 were included in this analysis. Intraindividual variability in systolic blood pressure (SBP), fasting blood glucose (FBG), total cholesterol (TC), and body mass index (BMI) was assessed by examining the coefficient of variation, variability independent of the mean, and average real variability. High variability was defined as the highest quartile of variability and low variability was defined as the lower three quartiles of variability. Results: Over a median (5–95%) of 7.1 (6.5–7.5) years of follow-up after the variability assessment period, 13,600 (1.7/1000 person-years) participants developed ESRD. For each metabolic parameter, an incrementally higher risk of ESRD was observed for higher variability quartiles compared with the lowest quartile. The risk of ESRD was 46% higher in the highest quartile of SBP variability, 47% higher in the highest quartile of FBG variability, 56% higher in the highest quartile of BMI variability, and 108% higher in the highest quartile of TC variability. Compared with the group with low variability for all four parameters, the group with high variability for all four parameters had a significantly higher risk for incident ESRD (hazard ratio (HR) 4.12; 95% CI 3.72–4.57). Conclusions: Variability in each metabolic parameter was an independent predictor of the development of ESRD among the general population. There was a composite effect of the variability in additional metabolic parameters on the risk of ESRD.

Laparoscopic Approach in Management of Renal Cell Carcinoma During Pregnancy: State of the Art

Renal cell carcinoma (RCC) is extremely rare in pregnant women. However, this is one of the most reported urologic tumors during pregnancy. The aim of this review was to evaluate RCC during pregnancy in terms of epidemiology, risk factors, diagnosis, natural history of disease, and the safety of laparoscopic approach in the management of this tumor. RCC presentation is frequently made incidentally during an ultrasonography performed for other reasons, such as hydronephrosis owing to non-neoplastic causes. The optimal time for surgery during pregnancy and the consequences of surgery on the maternal and fetal well-being are major considerations. Risks for adverse pregnancy outcomes should be explained, and the patient's decision about pregnancy termination should be considered. Ultrasound is good in diagnosing renal masses, with a sensitivity comparable to that of computed tomography only for exophytic masses larger than 3 cm. Magnetic resonance imaging is reproducible and a good, though expensive, alternative to computed tomography scans for the evaluation of renal lesions in pregnant women. Radical nephrectomy or nephron-sparing surgery are essential treatments for management of RCC. Laparoscopic surgery has historically been considered dangerous during pregnancy and avoided whenever possible, because of concerns regarding surgery-related risks, such as uterine injury, miscarriage, teratogenesis, preterm birth, and hypercapnia. The laparoscopic treatment during pregnancy is becoming increasingly accepted where feasible with low morbidity. However, the combination of a multidisciplinary approach, multi-specialty communication, and skilled surgeons can give the best possible outcomes for mother and fetus.

Urinary peptidome analyses for the diagnosis of chronic kidney disease in dogs

Chronic kidney disease (CKD) is clinically important in canine medicine. Current diagnostic tools lack sensitivity for detection of subclinical CKD. The aim of the present study was to evaluate urinary peptidome analysis for diagnosis of CKD in dogs. Capillary electrophoresis coupled to mass spectrometry analysis demonstrated presence of approximately 5400 peptides in dog urine. Comparison of urinary peptide abundance of dogs with and without CKD led to the identification of 133 differentially excreted peptides (adjusted P for each peptide <0.05). Sequence information was obtained for 35 of these peptides. This 35 peptide subset and the total group of 133 peptides were used to construct two predictive models of CKD which were subsequently validated by researchers masked to results in an independent cohort of 20 dogs. Both models diagnosed CKD with an area under the receiver operating characteristic (ROC) curve of 0.88 (95% confidence intervals [CI], 0.72-1.0). Most differentially excreted peptides represented fragments of collagen I, indicating possible association with fibrotic processes in CKD (similar to the equivalent human urinary peptide CKD model, CKD273). This first study of the urinary peptidome in dogs identified peptides that were associated with presence of CKD. Future studies are needed to validate the utility of this model for diagnosis and prediction of progression of canine CKD in a clinical setting.

A repetitive acidic region contributes to the extremely rapid degradation of the cell-context essential protein TRIM52

Tripartite motif protein 52 (TRIM52) is a non-canonical TRIM family member harbouring the largest RING domain encoded in the human genome. In humans TRIM52 is conserved and has been under positive selection pressure, yet it has been lost in many non-primates. Competitive cell fitness assays demonstrated that TRIM52 ablation reduces cellular fitness in multiple different cell types. To better understand how this cell-essential factor is controlled, we investigated how expression of this non-canonical protein is regulated. Here, we show that TRIM52 mRNA is constitutively expressed from an intergenic region preceding the TRIM52 gene. Yet, TRIM52 protein is rapidly turned-over by the proteasome with a 3.5-minute half-life, one of the shortest in the human proteome. Consistent with this extremely rapid degradation rate, all three TRIM52 domains were identified to contribute to its instability. Intriguingly, a repetitive acidic loop in the RING domain was identified as one of the main destabilizing regions, which was unexpected given the prevailing notion that these sequences are poor proteasome substrates. This work indicates that the effect of such repetitive acidic regions on proteasomal degradation depends on the protein context, and it identifies TRIM52 as an attractive model protein to study what these contextual properties are.

Validation of risk prediction tools in elderly patients who initiate dialysis

PURPOSE

The number of elderly patients with end-stage renal disease on maintenance dialysis therapy is gradually increasing. The elderly population has difficulties in making decisions regarding initiation of dialysis treatment because of their high morbidity and frailty. The purpose of this study was to determine the best prognostic tool in predicting short-term mortality in elderly patients undergoing dialysis.

METHODS

This study is a multicenter retrospective study. We enrolled patients, aged ≥ 75 years, who began hemodialysis at three university hospitals in Korea from January 2010 to December 2016. We applied two comorbidity-based score tools (Thamer and Wick, each consisting of seven variables) and the Clinical Frailty Scale (CFS, seven scales), which were validated for mortality prediction in elderly incident patients. Patient's information was obtained from electronic medical records in the participating center, and mortality data (up to December 2016) were obtained from the Korean National Statistical Office. Models were compared using the area under the receiver operating characteristic curve.

RESULTS

Among the 219 patients enrolled in this study, the 3- and 6-month mortality rates were 31 (14.4%) and 48 (22.4%), respectively. Receiver operating characteristic curve analysis revealed that both score systems and the CFS showed similar performance while predicting 3- and 6-month mortality. The scores from these indices correlated with survival time.

CONCLUSION

Predicting short-term mortality and long-term survival time for elderly patients is possible using the Thamer and Wick scores and the CFS.

Gcm1 is involved in cell proliferation and fibrosis during kidney regeneration after ischemia-reperfusion injury

In acute kidney injury (AKI), the S3 segment of the proximal tubule is particularly damaged, as it is most vulnerable to ischemia. However, this region is also involved in renal tubular regeneration. To deeply understand the mechanism of the repair process after ischemic injury in AKI, we focused on glial cells missing 1 (Gcm1), which is one of the genes expressed in the S3 segment. Gcm1 is essential for the development of the placenta, and Gcm1 knockout (KO) is embryonically lethal. Thus, the function of Gcm1 in the kidney has not been analyzed yet. We analyzed the function of Gcm1 in the kidney by specifically knocking out Gcm1 in the kidney. We created an ischemia-reperfusion injury (IRI) model to observe the repair process after AKI. We found that Gcm1 expression was transiently increased during the recovery phase of IRI. In Gcm1 conditional KO mice, during the recovery phase of IRI, tubular cell proliferation reduced and transforming growth factor-β1 expression was downregulated resulting in a reduction in fibrosis. In vitro, Gcm1 overexpression promoted cell proliferation and upregulated TGF-β1 expression. These findings indicate that Gcm1 is involved in the mechanisms of fibrosis and cell proliferation after ischemic injury of the kidney.

Immunoglobulin Binding Protein 1 as a Potential Urine Biomarker in Patients with Lupus Nephritis

We evaluated the role of immunoglobulin binding protein 1 (IGBP1), a phosphoprotein associated with the B cell receptor (BCR) complex, as a urine biomarker in lupus nephritis (LN). The IGBP1 concentrations in plasma and urine of patients with LN, systemic lupus erythematosus (SLE) without nephritis and healthy controls were estimated by ELISA. IGBP1 expression in the kidneys of LN patients and transplantation donors was detected by immunohistochemistry. Microarray-based global gene expression profile of HK-2 cells with IGBP1 knock-down and fluorescence-activated cell sorting (FACS) for intracellular IGBP1 expression in human peripheral blood mononuclear cells (PBMCs) was performed. Urine IGBP1 levels were elevated significantly in LN patients, and it correlated with the clinical activity indices (complement 3 (C3) level, anti-dsDNA antibodies titer, SLE Disease Activity Index-2000 (SLEDAI-2K) and histological activity index. IGBP1 expression was increased in LN patients as compared to the donors and was detected mainly in the tubules by histopathology. In microarray analysis, several genes related to SLE pathogenesis (PPME1, ROCK2, VTCN1, IL-17R, NEU1, HLA-DM, and PTX3) responded to siRNA-mediated IGBP1 silencing. In FACS, IGBP1 was expressed mainly in the CD14⁺ cells. The overall expression of IGBP1 in PBMCs was higher in LN patients as compared with that in SLE patients without nephritis. Conclusively, urinary IGBP1 may be a novel biomarker reflecting the clinical and histological activities in LN.

Recent advances in risk prediction, therapeutics and pathogenesis of IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is the world's commonest primary glomerular disease with variable clinical presentation and progression rates that are dependent on clinical-pathologic phenotype and duration of follow-up. Overall 4-40% of patients progress to end-stage kidney disease (ESKD) by 10 years. Treatment decisions remain a challenge due to these variations. The ultimate goal of management is to prevent progression to ESKD and of vital importance is the potential reversible early detection of active glomerular inflammation prior to scarring. IgAN is globally, is the most common biopsy proven glomerulonephritis and a leading cause of ESKD. The Oxford pathological classification was devised by a collaborative pathology and nephrology network to provide an evidence-based scoring system with reproducible independent pathology features of predictive value. Clinical variables that alter prognosis include male sex, increasing age, increased body weight, smoking, Pacific Asian ethnicity, hypertension, proteinuria, and complement deficiency. Excellent conservative therapy is the cornerstone of therapy with tight blood control, renin-angiotensin system inhibition, and statin therapy. The role of immunosuppressive therapy including corticosteroids in IgAN remains open with ongoing clinical trials of low dose oral corticosteroids and enteric coated budesonide. Complement activation contributes to the pathogenic process of IgAN with evidence from genetic, serological, histological and in-vitro studies. This knowledge has translated to clinical trials of investigational agents directly targeting the alternative pathway.

Arterial Stiffness as a Risk Factor for Subclinical Coronary Artery Calcification in Predialysis Chronic Kidney Disease: From the KNOW-CKD Study

BACKGROUND/AIMS

Both arterial stiffness and coronary artery calcification (CAC) are important predictors of cardiovascular disease in the general population and in chronic kidney disease (CKD) patients. Recent studies on arterial stiffness and CAC in subjects with preserved renal function have verified the association between the two. However, the relationship is not well evaluated in CKD patients.

METHODS

This cross-sectional study analyzed 1,385 predialysis CKD patients from the KNOW-CKD cohort. Participants were divided into four groups according to brachial-ankle pulse wave velocity (baPWV) quartile. Coronary artery calcium scores (CACS) were assessed using cardiac computed tomography and CAC was defined as a CACS >100.

RESULTS

CAC prevalence was higher in the higher baPWV groups (6.4, 9.8, 23.7, and 43.8% for the 1st to 4th quartiles of baPWV, respectively, p < 0.001). In Tobit regression analyses that were fully adjusted for traditional and renal cardiovascular risk factors, the CACS ratio comparing the highest and lowest baPWV quartiles was 3.03 (95% CI, 1.59-6.87). Similarly, the OR for CAC in the highest baPWV quartile compared to the lowest quartile was 1.98 (95% CI, 1.09-3.60) in a fully adjusted multivariate logistic model. Results were consistent across analyses with different cutoffs for CAC or with different clinically relevant subgroups.

CONCLUSION

Increased arterial stiffness measured by high baPWV was associated with CAC in a predialysis CKD cohort. Longitudinal studies are needed to determine the effect of arterial stiffness on the development or progression of CAC in CKD.