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Kuhn C, Mohebbi N, Ritter A. Metabolic acidosis in chronic kidney disease: mere consequence or also culprit? Pflugers Arch 2024; 476:579-592. [PMID: 38279993 PMCID: PMC11006741 DOI: 10.1007/s00424-024-02912-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/29/2024]
Abstract
Metabolic acidosis is a frequent complication in non-transplant chronic kidney disease (CKD) and after kidney transplantation. It occurs when net endogenous acid production exceeds net acid excretion. While nephron loss with reduced ammoniagenesis is the main cause of acid retention in non-transplant CKD patients, additional pathophysiological mechanisms are likely inflicted in kidney transplant recipients. Functional tubular damage by calcineurin inhibitors seems to play a key role causing renal tubular acidosis. Notably, experimental and clinical studies over the past decades have provided evidence that metabolic acidosis may not only be a consequence of CKD but also a driver of disease. In metabolic acidosis, activation of hormonal systems and the complement system resulting in fibrosis have been described. Further studies of changes in renal metabolism will likely contribute to a deeper understanding of the pathophysiology of metabolic acidosis in CKD. While alkali supplementation in case of reduced serum bicarbonate < 22 mmol/l has been endorsed by CKD guidelines for many years to slow renal functional decline, among other considerations, beneficial effects and thresholds for treatment have lately been under intense debate. This review article discusses this topic in light of the most recent results of trials assessing the efficacy of dietary and pharmacological interventions in CKD and kidney transplant patients.
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Affiliation(s)
- Christian Kuhn
- Clinic for Nephrology and Transplantation Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
| | | | - Alexander Ritter
- Clinic for Nephrology and Transplantation Medicine, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
- Clinic for Nephrology, University Hospital Zurich, Zurich, Switzerland.
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Tariq H, Dobre M. Metabolic acidosis post kidney transplantation. Front Physiol 2022; 13:989816. [PMID: 36082221 PMCID: PMC9445136 DOI: 10.3389/fphys.2022.989816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/01/2022] [Indexed: 11/23/2022] Open
Abstract
Metabolic acidosis, a common complication in patients with chronic kidney disease (CKD), results in a multitude of deleterious effects. Though the restoration of kidney function following transplantation is generally accompanied by a correction of metabolic acidosis, a subset of transplant recipients remains afflicted by this ailment and its subsequent morbidities. The vulnerability of kidney allografts to metabolic acidosis can be attributed to reasons similar to pathogenesis of acidosis in non-transplant CKD, and to transplant specific causes, including donor related, recipient related, immune mediated factors, and immunosuppressive medications. Correction of metabolic acidosis in kidney transplantation either with alkali therapy or through dietary manipulations may have potential benefits and the results of such clinical trials are eagerly awaited. This review summarizes the published evidence on the pathogenesis and clinical consequences of chronic metabolic acidosis in kidney transplant recipients.
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Affiliation(s)
- Hafsa Tariq
- Division of Nephrology, University of Rochester Medical Center, Rochester, NY, United States
| | - Mirela Dobre
- Division of Nephrology and Hypertension, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH, United States
- *Correspondence: Mirela Dobre,
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Katopodis P, Pappas EM, Katopodis KP. Acid-base abnormalities and liver dysfunction. Ann Hepatol 2022; 27:100675. [PMID: 35074477 DOI: 10.1016/j.aohep.2022.100675] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 02/04/2023]
Abstract
In addition to the kidneys and lungs, the liver also plays an important role in the regulation of the Acid-Base Equilibrium (ABE). The involvement of the liver in the regulation of ABE is crucial because of its role in lactic acid metabolism, urea production and in protein homeostasis. The main acid-base imbalance that occurs in patients with liver cirrhosis is Respiratory Alkalosis (RAlk). Due to the fact that in these patients additional pathophysiological mechanisms that affect the ABE are present, other disorders may appear which compensate or enhance the primary disorder. Conventional ABE reading models fail to identify and assess the underlying disorders in patients with liver cirrhosis. This weakness of the classical models led to the creation of new physicochemical mathematical models that take into account all the known parameters that develop and affect the ABE. In addition to the RAlk, in patients with liver cirrhosis, metabolic alkalosis (due to hypoalbuminemia), hyponatremic metabolic acidosis, hyperchloremic metabolic acidosis, lactic acidosis and metabolic alkalosis due to urea metabolism are some of the pathophysiological mechanisms that affect the ABE.
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Affiliation(s)
- Periklis Katopodis
- Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UK.
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Association of serum bicarbonate with graft survival and mortality in kidney transplant recipients. J Nephrol 2021; 35:619-627. [PMID: 34843097 DOI: 10.1007/s40620-021-01197-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
BACKGROUND Metabolic acidosis is an independent risk factor for kidney disease progression with a high prevalence after kidney transplantation (KTx). Remarkably, it is still unclear if there is an impact of metabolic acidosis on graft function and death after KTx. Thus, we wanted to investigate if serum bicarbonate is associated with long-term graft outcome and mortality after KTx. METHODS We performed a single-center retrospective study including adult de novo KTx patients between 1999 and 2015. Cox proportional hazard model was used to analyze a possible association between time-dependent serum bicarbonate measurements and graft failure or death. RESULTS Four hundred thirty KTRs were included in the analysis with a mean age of 50.9 ± 13.4 years. Mean observation time was 4.7 ± 2.8 years. Two hundred eighty-four (66%) patients were male and 318 (74%) had received a deceased donor kidney transplant. Mean bicarbonate and eGFR levels 1 year post-transplant amounted to 22.9 ± 3.1 mEq/L and 61 ± 26 ml/min/1.73 m2, respectively. Prevalence of metabolic acidosis was 31% 1 year after transplantation. Fourteen (3%) patients died and 31 (7%) suffered from graft failure. Higher bicarbonate levels were associated with significantly lower hazards for graft failure (Hazard Ratio (HR) = 0.88; 95% Confidence Interval (CI): 0.79-0.98) and mortality (HR = 0.79; 95% CI 0.66-0.93) after adjusting for potential confounders such as age, donor type and time-varying eGFR. CONCLUSIONS Our analysis showed that higher serum bicarbonate levels are positively associated with long-term graft and patient survival in kidney transplant recipients. Thus, serum bicarbonate may serve as a predictor and independent risk factor for graft and patient outcome after KTx as has been previously shown for patients with CKD.
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Tinti F, Umbro I, D’Alessandro M, Lai S, Merli M, Noce A, Di Daniele N, Mazzaferro S, Mitterhofer AP. Cholemic Nephropathy as Cause of Acute and Chronic Kidney Disease. Update on an Under-Diagnosed Disease. Life (Basel) 2021; 11:1200. [PMID: 34833076 PMCID: PMC8620937 DOI: 10.3390/life11111200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 12/14/2022] Open
Abstract
Cholemic nephropathy (CN) is a recognized cause of acute kidney injury (AKI) in patients with severe hyperbilirubinemia (sHyb) and jaundice. Pathophysiological mechanisms of CN are not completely understood, but it seems caused both by direct toxicity of cholephiles and bile casts formation in nephrons enhanced by prolonged exposure to sHyb, particularly in the presence of promoting factors, as highlighted by a literature reviewed and by personal experience. The aim of our update is to retrace CN in its pathophysiology, risk factors, diagnosis and treatment, underlining the role of sHyb, promoting factors, and CN-AKI diagnostic criteria in the different clinical settings associated with this often-concealed disease. Our purpose is to focus on clinical manifestation of CN, exploring the possible transition to CKD. Cholemic nephropathy is an overlooked clinical entity that enters differential diagnosis with other causes of AKI. Early diagnosis and treatment are essential because renal injury could be fully reversible as rapidly as bilirubin levels are reduced. In conclusion, our proposal is to introduce an alert for considering CN in diagnostic and prognostic scores that include bilirubin and/or creatinine with acute renal involvement, with the aim of early diagnosis and treatment of sHyb to reduce the burden on renal outcome.
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Affiliation(s)
- Francesca Tinti
- Nephrology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, 00185 Rome, Italy; (I.U.); (S.L.); (S.M.)
| | - Ilaria Umbro
- Nephrology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, 00185 Rome, Italy; (I.U.); (S.L.); (S.M.)
| | - Mariadomenica D’Alessandro
- Clinical Pathology Unit, Department of General Surgery “P.Stefanini”, Sapienza University of Rome, 00161 Rome, Italy;
| | - Silvia Lai
- Nephrology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, 00185 Rome, Italy; (I.U.); (S.L.); (S.M.)
| | - Manuela Merli
- Gastroenterology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, 00185 Rome, Italy;
| | - Annalisa Noce
- UOC of Internal Medicine—Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (A.N.); (N.D.D.)
| | - Nicola Di Daniele
- UOC of Internal Medicine—Center of Hypertension and Nephrology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy; (A.N.); (N.D.D.)
| | - Sandro Mazzaferro
- Nephrology Unit, Department of Translational and Precision Medicine, Sapienza University of Rome, 00185 Rome, Italy; (I.U.); (S.L.); (S.M.)
| | - Anna Paola Mitterhofer
- Nephrology and Dialysis Unit, Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
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George K, Upadhyay AD, Subbiah AK, Yadav RK, Mahajan S, Bhowmik D, Agarwal SK, Bagchi S. Metabolic acidosis in the initial 6 months after renal transplantation: A prospective study. Nephrology (Carlton) 2021; 27:90-96. [PMID: 34302717 DOI: 10.1111/nep.13954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND There is limited information about the incidence of metabolic acidosis (MA) after renal transplantation. This single centre prospective study aimed to delineate the incidence and risk factors of MA in the first 6 months after renal transplantation (RTX). DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS Patients who underwent RTX between November 2018 and July 2020 were monitored with weekly measurement of serum bicarbonate level for 6 months and those who were diagnosed with MA were evaluated further to characterize the type of MA. RESULTS One hundred and twenty-five patients were included in the study, 89 (71.2%) of whom developed MA. Seventy-two patients developed MA in the first month, 11 during the 2-3 months and 6 between 4 and 6 months after transplantation. Of the 89 patients, 55(61.8%) had type 1 renal tubular acidosis (T1RTA), 27 (30.3%) had type 2 RTA (T2RTA) and 7 (7.9%) type 4 RTA (T4RTA). Two patient who had T1RTA, subsequently developed high anion gap MA following severe graft rejection. On stepwise multivariate regression analysis, serum creatinine at time of diagnosis of MA [OR (95% CI): 12.02 (1.79 to 80.59), p = .01] and high tacrolimus C0 levels [OR (95% CI): 2.43 (1.0 to 5.90), p = .049], were independent risk factors for MA. CONCLUSION There is a high incidence of MA in the initial 6 months post-transplant with serum creatinine and high tacrolimus C0 levels being independent risk factors.
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Affiliation(s)
- Kristin George
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Ashish Datt Upadhyay
- Department of Biostatistics, All India Institute of Medical Sciences, New Delhi, India
| | - Arun Kumar Subbiah
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Raj Kanwar Yadav
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Sandeep Mahajan
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Dipankar Bhowmik
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Sanjay Kumar Agarwal
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Soumita Bagchi
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
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Eren N, Gungor O, Sarisik FN, Sokmen F, Tutuncu D, Cetin GY, Yazici A, Gökçay Bek S, Altun E, Altunoren O, Cefle A. Renal Tubular Acidosis in Patients with Systemic Lupus Erythematosus. Kidney Blood Press Res 2021; 45:883-889. [PMID: 33108786 DOI: 10.1159/000509841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 07/01/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Renal tubular acidosis (RTA) is a clinical manifestation that occurs with insufficiency in restoring bicarbonate or disruption in hydrogen ion elimination as a result of a disruption in tubulus functions, causing normal anion gap-opening metabolic acidosis. In the present study, we aimed to investigate the prevalence of RTA in the largest systemic lupus erythematosus (SLE) patient population to date. MATERIALS AND METHODS SLE patients, who were followed up in 2 different healthcare centers, were included. Patients with metabolic acidosis (pH <7.35 and HCO3 <22 mEq/L) in venous blood gas analysis were determined. The serum and urine anion GAP of these patients were estimated, and the urine pH was assessed. RTA presence was evaluated as metabolic acidosis with a normal serum anion gap and a positive urine anion GAP. RESULTS A total of 108 patients were included in the present study. The mean age of the patients was 41.5 ± 1.2 and 87% were female. The SLE diagnosis duration was 75 ± 5 months. The mean creatinine value was 0.6 ± 0.1 mg/dL and the mean eGFR was 111 ± 2 mL/min. According to the blood gas analysis, 18 patients (16.7% of the total) had RTA. Sixteen of these patients had type 1 RTA and 2 had type 2 RTA; type 4 RTA was not determined in any of the patients. CONCLUSION RTA should be considered in SLE patients even if they have normal eGFR values. This is the largest study to examine the prevalence of RTA in SLE patients in the literature.
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Affiliation(s)
- Necmi Eren
- Department of Nephrology, Medical Faculty, Kocaeli University, Kocaeli, Turkey,
| | - Ozkan Gungor
- Department of Nephrology, Medical Faculty, Kahramanmaraş Sutcu Imam University, Kahramanmaras, Turkey
| | - Feyza Nur Sarisik
- Department of Nephrology, Medical Faculty, Kahramanmaraş Sutcu Imam University, Kahramanmaras, Turkey
| | - Fatih Sokmen
- Department of Nephrology, Medical Faculty, Kahramanmaraş Sutcu Imam University, Kahramanmaras, Turkey
| | - Didem Tutuncu
- Department of Nephrology, Medical Faculty, Kahramanmaraş Sutcu Imam University, Kahramanmaras, Turkey
| | - Gozde Yildirim Cetin
- Department of Nephrology, Medical Faculty, Kahramanmaraş Sutcu Imam University, Kahramanmaras, Turkey
| | - Ayten Yazici
- Department of Rheumatology, Medical Faculty, Kocaeli University, Kocaeli, Turkey
| | - Sibel Gökçay Bek
- Department of Nephrology, Medical Faculty, Kocaeli University, Kocaeli, Turkey
| | - Eda Altun
- Department of Nephrology, Gölcük State Hospital, Kocaeli, Turkey
| | - Orcun Altunoren
- Department of Nephrology, Medical Faculty, Kahramanmaraş Sutcu Imam University, Kahramanmaras, Turkey
| | - Ayse Cefle
- Department of Rheumatology, Medical Faculty, Kocaeli University, Kocaeli, Turkey
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Ritter A, Mohebbi N. Causes and Consequences of Metabolic Acidosis in Patients after Kidney Transplantation. Kidney Blood Press Res 2020; 45:792-801. [PMID: 33040055 DOI: 10.1159/000510158] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/01/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Metabolic acidosis (MA) is a common complication in kidney transplantation (KTx). It is more prevalent in KTx than in CKD, and it occurs at higher glomerular filtration rates. The pathophysiologic understanding of MA in KTx and its clinical impact has been highlighted by few recent studies. However, no guidelines exist yet for the treatment of MA after KTx. SUMMARY MA in KTx seems to share pathophysiologic mechanisms with CKD, such as impaired ammoniagenesis. Additional kidney transplant-specific factors seem to alter not only the prevalence but also the phenotype of MA, which typically shows features of renal tubular acidosis. There is evidence that calcineurin inhibitors, immunological factors, process of donation, donor characteristics, and diet may contribute to MA occurrence. According to several mainly observational studies, MA seems to play a role in disturbed bone metabolism, cardiovascular morbidity, declining graft function, and mortality. A better understanding of the pathophysiology and evidence from randomized controlled trials, in particular, are needed to clarify the role of MA and the potential benefit of alkali treatment in KTx. Alkali therapy might not only be beneficial but also cost effective and safe. Key Messages: MA seems to be associated with several negative outcomes in KTx. A deeper understanding of the pathophysiology and clinical consequences of MA in KTx is crucial. Clinical trials will have to determine the potential benefits of alkali therapy.
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Affiliation(s)
- Alexander Ritter
- Division of Nephrology, University Hospital of Zurich, Zurich, Switzerland
| | - Nilufar Mohebbi
- Division of Nephrology, University Hospital of Zurich, Zurich, Switzerland, .,Praxis und Dialysezentrum Zürich-City, Zurich, Switzerland,
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Wiegand A, Graf N, Bonani M, Frey D, Wüthrich RP, Mohebbi N. Relationship of Serum Bicarbonate Levels with 1-Year Graft Function in Kidney Transplant Recipients in Switzerland. Kidney Blood Press Res 2019; 44:1179-1188. [PMID: 31536994 DOI: 10.1159/000502527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/06/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Metabolic acidosis (MA) is common in kidney transplant recipients (KTRs). Several studies have shown that MA is involved in the progression of chronic kidney disease. However, it is unclear if there is also a relationship between serum bicarbonate and graft function after kidney transplantation (KTx). We hypothesized that low serum bicarbonate is associated with a lower estimated glomerular filtration rate (eGFR) 1 year after KTx. METHODS We performed a post hoc analysis of a single-center, open-label randomized trial in 90 KTRs and investigated the relationship of serum bicarbonate and graft function in the first year after KTx. RESULTS Prevalence of MA was high after KTx (63%) and decreased to 28% after 1 year. Bicarbonate (20.6 ± 3.0 to 22.7 ± 2.7 mmol/L) increased in the first year after transplantation whereas eGFR (53.4 ± 15.8 to 56.9 ± 18.5 mL/min/1.73 m2) did not change significantly. Higher serum bicarbonate (p = 0.029) was associated with higher eGFR in the first year after KTx. CONCLUSION Prevalence of MA is high in KTRs. In the first year after KTx, serum bicarbonate was positively correlated with eGFR, suggesting a potential role of MA in kidney graft function.
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Affiliation(s)
- Anna Wiegand
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | | | - Marco Bonani
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Diana Frey
- Division of Rheumatology, University Hospital Zurich, Zurich, Switzerland
| | - Rudolf P Wüthrich
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Nilufar Mohebbi
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland,
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Effect of Sodium Bicarbonate in Kidney Transplant Recipients With Chronic Metabolic Acidosis. Transplant Direct 2019; 5:e464. [PMID: 31334338 PMCID: PMC6616137 DOI: 10.1097/txd.0000000000000910] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 05/22/2019] [Accepted: 05/24/2019] [Indexed: 11/25/2022] Open
Abstract
Background Metabolic acidosis (MA) is a common complication after kidney transplantation and regarded to increase mortality, graft failure, and bone fractures. Here, we conducted a retrospective cohort study to analyze the effect of sodium bicarbonate on those events. Methods All kidney transplant recipients of the German health insurance Allgemeine Ortskrankenkasse (AOK) were selected, who received their transplantation between 2007 and 2015. Three groups were formed: (1) control group (no acidosis, n = 3602), (2) acidosis group (encoded acidosis, n = 370), and (3) treatment group (encoded therapy, n = 769). The study endpoints were mortality, death-censored graft failure, and bone fractures. Results The prevalence of MA in the first year after transplantation was 46.2%. The 5-year patient and graft survival were 89.8% and 89.3% in the control group, 90% and 90.8% in the acidosis group, and 87.5% and 81.6% in the treatment group, respectively. The rate of bone fractures did not differ between the groups. Neither log-rank tests nor multivariable Cox regression analyses could detect a negative impact of MA on mortality (hazard ratio [HR] 0.94; confidence interval [CI] 0.67-1.30), graft failure (HR1.18; CI 0.82-1.72), or the incidence of bone fractures (HR1.19; CI 0.92-1.55). Treatment with sodium bicarbonate was associated with an increased risk of graft failure (HR1.52; CI 1.03-2.25), whereas mortality (HR0.86; CI 0.59-1.26) and the incidence of bone fractures (HR1.16; CI 0.86-1.56) were not altered. Conclusions MA is common after kidney transplantation but not associated with an increased frequency of death, graft failure, or bone fractures. Conversely, sodium bicarbonate therapy increased the incidence of graft failure.
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11
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Fernando ME, Jayanivash J, Srinivasaprasad ND, Suren S, Thirumalvalavan K. Post-Renal Transplant Metabolic Acidosis: A Neglected Entity. Indian J Nephrol 2019; 29:116-121. [PMID: 30983752 PMCID: PMC6440336 DOI: 10.4103/ijn.ijn_93_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Metabolic acidosis is a prevalent yet overlooked entity among renal transplant recipients (RTRs) and incurs adverse effects on graft function. Although graft dysfunction and calcineurin inhibitor usage have been linked with renal tubular acidosis (RTA), there is no Indian data on prevalence or risk factors of post-transplant acidosis. A cross-sectional study was conducted on 106 adult RTRs, with a transplant duration of >6 months and an estimated glomerular filtration rate (GFR) >40 ml/min/1.73 m2. Acidosis was diagnosed on basis of plasma bicarbonate and arterial pH. Serum and urine electrolytes with anion gap were determined to diagnose and type RTA. Acidosis was diagnosed in 44 of 106 patients (41.5%) with 23 (52.27%) having severe acidosis. Type I RTA was the most common subtype (52.5%) followed by type IV (30.9%) and type II RTA (7.5%). The correlation between estimated glomerular filtration rate and acidosis was minimally linear (r = 0.1088), with multivariate analysis revealing previous acute rejection episodes, current serum tacrolimus levels, cotrimoxazole usage and intake of animal proteins to be independent risk factors. The serum albumin levels were low in the acidosis group and showed linear correlation with bicarbonate levels (r = 0.298). There is a high prevalence of metabolic acidosis in RTRs with type I RTA being most common subtype. Screening of RTRs on a regular basis is a feasible approach for early diagnosis and intervention. However, prospective studies are needed to demonstrate the effect of acidosis on graft survival and benefit of bicarbonate therapy in RTRs.
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Affiliation(s)
- M E Fernando
- Department of Nephrology, Government Stanley Hospital, The Tamilnadu DR MGR Medical University, Chennai, Tamil Nadu, India
| | - J Jayanivash
- Department of Nephrology, Government Stanley Hospital, The Tamilnadu DR MGR Medical University, Chennai, Tamil Nadu, India
| | - N D Srinivasaprasad
- Department of Nephrology, Government Stanley Hospital, The Tamilnadu DR MGR Medical University, Chennai, Tamil Nadu, India
| | - S Suren
- Department of Nephrology, Government Stanley Hospital, The Tamilnadu DR MGR Medical University, Chennai, Tamil Nadu, India
| | - K Thirumalvalavan
- Department of Nephrology, Government Stanley Hospital, The Tamilnadu DR MGR Medical University, Chennai, Tamil Nadu, India
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Avila-Poletti D, De Azevedo L, Iommi C, Heldal K, Musso CG. Hyperchloremic metabolic acidosis in the kidney transplant patient. Postgrad Med 2019; 131:171-175. [PMID: 30924703 DOI: 10.1080/00325481.2019.1592360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Hyperchloremic metabolic acidosis of renal origin results from a defect in renal tubular acidification mechanism, and this tubular dysfunction can consist of an altered tubular proton secretion or bicarbonate reabsorption capability. Studies have documented that all forms of renal tubular acidosis (RTA), type I to IV, are documented in kidney transplant patients. Among RTA pathophysiologic mechanisms have been described the renal mass reduction, hyperkalemia, hyperparathyroidism, graft rejection, immunologic diseases, and some drugs such as renin-angiotensin-aldosterone blockers, and calcineurin inhibitors. RTA can lead to serious complications as is the case of muscle protein catabolism, muscle protein synthesis inhibition, renal osteodystrophy, renal damage progression, and anemia promotion. RTA should be treated by suppressing its etiologic factor (if it is possible), avoiding hyperkalemia, and/or supplying bicarbonate or a precursor (citrate). In conclusion: Hyperchloremic metabolic acidosis of renal origin is a relatively frequent complication in kidney transplantation patients, which can be harmful, and should be adequately treated in order to avoid its renal and systemic adverse effects.
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Affiliation(s)
- Debora Avila-Poletti
- a Human Physiology Department , Instituto Universitario del Hospital Italiano de Buenos Aires , Buenos Aires , Argentina
| | - Leticia De Azevedo
- a Human Physiology Department , Instituto Universitario del Hospital Italiano de Buenos Aires , Buenos Aires , Argentina
| | - Candela Iommi
- a Human Physiology Department , Instituto Universitario del Hospital Italiano de Buenos Aires , Buenos Aires , Argentina
| | - Kristian Heldal
- b Clinic of Internal Medicine, Telemark Hospital Trust , Skien , Norway.,c Institute of Clinical Medicine, Faculty of Medicine of University of Oslo , Oslo , Norway
| | - Carlos G Musso
- a Human Physiology Department , Instituto Universitario del Hospital Italiano de Buenos Aires , Buenos Aires , Argentina
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Abstract
Objectives: Water and electrolytes disturbances often occur in renal transplant recipients. The objective is to describe the pathophysiology and the treatment of the most prevalent abnormalities. Methods: We screened PubMed for the following words in various combination: kidney transplantation and (disturbances or abnormalities) of (electrolytes or sodium or potassium or phosphate or calcium or acid-base). Results: We found abnormalities in all major electrolytes, as a consequence of tubular dysfunction caused by both rejection episodes and toxic effects of calcineurin inhibitors (CNIs; cyclosporine or tacrolimus). The renal tubular acidosis found in kidney transplant recipients is characterized by a normal anion gap and normal or high serum chloride levels. The incidence of hyperkalemia is 5-40% of patients treated with CNIs. The majority of kidney transplant recipients develop hypomagnesemia within the first weeks and months. Both cyclosporine and tacrolimus do induce hypomagnesemia by several mechanisms. Severe magnesium depletion may include clinical manifestations such as confusion, muscle weakness, tremor, dysphagia, tetany and convulsions. The immediate posttransplant period (first 3 months) is often accompanied by a decline in serum phosphate. Phosphate substitution is needed when serum levels fall below 0.5 mmol/l, or in patients with clinical symptoms and serum levels between 0.5 and 1.0 mmol/l. Hypercalcemia is also a common disorder in the chronic posttransplant phase, and is most often due to persistent hyperparathyroidism. Conclusions: Patients with kidney transplants display electrolytes abnormalities more frequently than non-transplanted patients with the same levels of renal function. A good knowledge of their physiopathology and treatment is important in the care of those patients.
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Wiegand A, Ritter A, Graf N, Arampatzis S, Sidler D, Hadaya K, Müller TF, Wagner CA, Wüthrich RP, Mohebbi N. Preservation of kidney function in kidney transplant recipients by alkali therapy (Preserve-Transplant Study): rationale and study protocol. BMC Nephrol 2018; 19:177. [PMID: 30001705 PMCID: PMC6043955 DOI: 10.1186/s12882-018-0956-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/24/2018] [Indexed: 01/01/2023] Open
Abstract
Background Graft survival after kidney transplantation has significantly improved within the last decades but there is a substantial number of patients with declining transplant function and graft loss. Over the past years several studies have shown that metabolic acidosis plays an important role in the progression of Chronic Kidney Disease (CKD) and that alkalinizing therapies significantly delayed progression of CKD. Importantly, metabolic acidosis is highly prevalent in renal transplant patients and a recent retrospective study has shown that metabolic acidosis is associated with increased risk of graft loss and patient death in kidney transplant recipients. However, no prospective trial has been initiated yet to test the role of alkali treatment on renal allograft function. Methods The Preserve-Transplant Study is an investigator-initiated, prospective, patient-blinded, multi-center, randomized, controlled phase-IV trial with two parallel-groups comparing sodium bicarbonate to placebo. The primary objective is to test if alkali treatment will preserve kidney graft function and diminish the progression of CKD in renal transplant patients by assesing the change in eGFR over 2 years from baseline. Additionally we want to investigate the underlying pathomechanisms of nephrotoxicity of metabolic acidosis. Discussion This study has the potential to provide evidence that alkali treatment may slow or reduce the progression towards graft failure and significantly decrease the rate of end stage renal disease (ESRD), thus prolonging long-term graft survival. The implementation of alkali therapy into the drug regimen of kidney transplant recipients would have a favorable risk-benefit ratio since alkali supplements are routinely used in CKD patients and represent a well-tolerated, safe and cost-effective treatment. Trial registration ClinicalTrials.gov NCT03102996. Trial registration was completed on April 6, 2017.
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Affiliation(s)
- Anna Wiegand
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Alexander Ritter
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Nicole Graf
- Graf Biostatistics, Wintherthur, Switzerland
| | - Spyridon Arampatzis
- Department of Nephrology and Hypertension, University Hospital Berne, Berne, Switzerland
| | - Daniel Sidler
- Department of Nephrology and Hypertension, University Hospital Berne, Berne, Switzerland
| | - Karine Hadaya
- Division of Nephrology, University Hospital Geneva, Geneva, Switzerland
| | - Thomas F Müller
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Rudolf P Wüthrich
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Nilufar Mohebbi
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland.
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15
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Scheiner B, Lindner G, Reiberger T, Schneeweiss B, Trauner M, Zauner C, Funk GC. Acid-base disorders in liver disease. J Hepatol 2017; 67:1062-1073. [PMID: 28684104 DOI: 10.1016/j.jhep.2017.06.023] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/21/2017] [Accepted: 06/27/2017] [Indexed: 01/15/2023]
Abstract
Alongside the kidneys and lungs, the liver has been recognised as an important regulator of acid-base homeostasis. While respiratory alkalosis is the most common acid-base disorder in chronic liver disease, various complex metabolic acid-base disorders may occur with liver dysfunction. While the standard variables of acid-base equilibrium, such as pH and overall base excess, often fail to unmask the underlying cause of acid-base disorders, the physical-chemical acid-base model provides a more in-depth pathophysiological assessment for clinical judgement of acid-base disorders, in patients with liver diseases. Patients with stable chronic liver disease have several offsetting acidifying and alkalinising metabolic acid-base disorders. Hypoalbuminaemic alkalosis is counteracted by hyperchloraemic and dilutional acidosis, resulting in a normal overall base excess. When patients with liver cirrhosis become critically ill (e.g., because of sepsis or bleeding), this fragile equilibrium often tilts towards metabolic acidosis, which is attributed to lactic acidosis and acidosis due to a rise in unmeasured anions. Interestingly, even though patients with acute liver failure show significantly elevated lactate levels, often, no overt acid-base disorder can be found because of the offsetting hypoalbuminaemic alkalosis. In conclusion, patients with liver diseases may have multiple co-existing metabolic acid-base abnormalities. Thus, knowledge of the pathophysiological and diagnostic concepts of acid-base disturbances in patients with liver disease is critical for therapeutic decision making.
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Affiliation(s)
- Bernhard Scheiner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria; Department of Respiratory and Critical Care Medicine, Otto Wagner Spital, Vienna, Austria
| | - Gregor Lindner
- Department of General Internal Medicine & Emergency Medicine, Hirslanden Klinik Im Park, Zurich, Switzerland
| | - Thomas Reiberger
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Bruno Schneeweiss
- Division of Oncology and Hematology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Christian Zauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Georg-Christian Funk
- Department of Respiratory and Critical Care Medicine, Otto Wagner Spital, Vienna, Austria.
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Schulte K, Vollmer C, Klasen V, Bräsen JH, Püchel J, Borzikowsky C, Kunzendorf U, Feldkamp T. Late conversion from tacrolimus to a belatacept-based immuno-suppression regime in kidney transplant recipients improves renal function, acid-base derangement and mineral-bone metabolism. J Nephrol 2017; 30:607-615. [PMID: 28540602 DOI: 10.1007/s40620-017-0411-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/12/2017] [Indexed: 12/19/2022]
Abstract
BACKGROUND Calcineurin inhibitor (CNI)-induced nephrotoxicity and chronic graft dysfunction with deteriorating glomerular filtration rate (GFR) are common problems of kidney transplant recipients. The aim of this study was to analyze the role of belatacept as a rescue therapy in these patients. METHODS In this retrospective, observational study we investigated 20 patients (10 females, 10 males) who were switched from a CNI (tacrolimus) to a belatacept-based immunosuppression because of CNI intolerance or marginal transplant function. Patient follow-up was 12 months. RESULTS Patients were converted to belatacept in mean 28.8 months after transplantation. Reasons for conversion were CNI intolerance (14 patients) or marginal transplant function (6 patients). Mean estimated GFR (eGFR) before conversion was 22.2 ± 9.4 ml/min at baseline and improved significantly to 28.3 ± 10.1 ml/min at 4 weeks and to 32.1 ± 12.6 ml/min at 12 months after conversion. Serum bicarbonate significantly increased from 24.4 ± 3.2 mmol/l at baseline to 28.7 ± 2.6 mmol/l after 12 months. Conversion to belatacept decreased parathyroid hormone and phosphate concentrations significantly, whereas albumin levels significantly increased. In 6 cases an acute rejection preceded clinically relevant CNI toxicity; only two patients suffered from an acute rejection after conversion. Belatacept was well tolerated and there was no increase in infectious or malignant side effects. CONCLUSION A late conversion from a tacrolimus-based immunosuppression to belatacept is safe, effective and significantly improves renal function in kidney transplant recipients. Additionally, the conversion to belatacept has a beneficial impact on acid-base balance, mineral-bone and protein metabolism, independently of eGFR.
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Affiliation(s)
- Kevin Schulte
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Christian-Albrechts University Kiel, Schittenhelmstr. 12, 24105, Kiel, Germany.
| | - Clara Vollmer
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Christian-Albrechts University Kiel, Schittenhelmstr. 12, 24105, Kiel, Germany
| | - Vera Klasen
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Christian-Albrechts University Kiel, Schittenhelmstr. 12, 24105, Kiel, Germany
| | - Jan Hinrich Bräsen
- Nephropathology, Institute for Pathology, Hannover Medical School, Hanover, Germany
| | - Jodok Püchel
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Christian-Albrechts University Kiel, Schittenhelmstr. 12, 24105, Kiel, Germany
| | - Christoph Borzikowsky
- Institute of Medical Informatics and Statistics, Christian-Albrechts University, Kiel, Germany
| | - Ulrich Kunzendorf
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Christian-Albrechts University Kiel, Schittenhelmstr. 12, 24105, Kiel, Germany
| | - Thorsten Feldkamp
- Department of Nephrology and Hypertension, University Hospital Schleswig-Holstein, Christian-Albrechts University Kiel, Schittenhelmstr. 12, 24105, Kiel, Germany
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Messa PG, Alfieri C, Vettoretti S. Metabolic acidosis in renal transplantation: neglected but of potential clinical relevance. Nephrol Dial Transplant 2015; 31:730-6. [PMID: 25934992 DOI: 10.1093/ndt/gfv098] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 03/10/2015] [Indexed: 11/12/2022] Open
Abstract
Chronic metabolic acidosis (CMA) is a common complication of the more advanced stages of chronic kidney diseases (CKD), and is associated with morbidity and mortality of CKD patients and possibly with the progression of renal disease. Nevertheless, there is limited evidence or information on the prevalence, the potential causal factors, the clinical impact and the effects of correction of CMA in kidney transplant recipients. In this review, we briefly look at the more relevant, though scanty, studies which have, over time, addressed the above-mentioned points, with the hope that in the future the interest of transplant nephrologists and surgeons will grow towards this unreasonably neglected issue.
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Affiliation(s)
- Pier Giorgio Messa
- Unit of Nephrology-Dialysis, Urology and Renal Transplantation, IRCCS Fondazione Ca' Granda-Ospedale Maggiore-Policlinico, Milano, Italy
| | - Carlo Alfieri
- Unit of Nephrology-Dialysis, Urology and Renal Transplantation, IRCCS Fondazione Ca' Granda-Ospedale Maggiore-Policlinico, Milano, Italy
| | - Simone Vettoretti
- Unit of Nephrology-Dialysis, Urology and Renal Transplantation, IRCCS Fondazione Ca' Granda-Ospedale Maggiore-Policlinico, Milano, Italy
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18
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Brunner R, Drolz A, Scherzer TM, Staufer K, Fuhrmann V, Zauner C, Holzinger U, Schneeweiß B. Renal tubular acidosis is highly prevalent in critically ill patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2015; 19:148. [PMID: 25888397 PMCID: PMC4404695 DOI: 10.1186/s13054-015-0890-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/18/2015] [Indexed: 01/28/2023]
Abstract
Introduction Hyperchloremic acidosis is frequent in critically ill patients. Renal tubular acidosis (RTA) may contribute to acidemia in the state of hyperchloremic acidosis, but the prevalence of RTA has never been studied in critically ill patients. Therefore, we aimed to investigate the prevalence, type, and possible risk factors of RTA in critically ill patients using a physical-chemical approach. Methods This prospective, observational trial was conducted in a medical ICU of a university hospital. One hundred consecutive critically ill patients at the age ≥18, expected to stay in the ICU for ≥24 h, with the clinical necessity for a urinary catheter and the absence of anuria were included. Base excess (BE) subset calculation based on a physical-chemical approach on the first 7 days after ICU admission was used to compare the effects of free water, chloride, albumin, and unmeasured anions on the standard base excess. Calculation of the urine osmolal gap (UOG) - as an approximate measure of the unmeasured urine cation NH4+ - served as determinate between renal and extrarenal bicarbonate loss in the state of hyperchloremic acidosis. Results During the first week of ICU stay 43 of the patients presented with hyperchloremic acidosis on one or more days represented as pronounced negative BEChloride. In 31 patients hyperchloremic acidosis was associated with RTA characterized by a UOG ≤150 mosmol/kg in combination with preserved renal function. However, in 26 of the 31 patients with RTA metabolic acidosis was neutralized by other acid-base disturbances leading to a normal arterial pH. Conclusions RTA is highly prevalent in critically ill patients with hyperchloremic acidosis, whereas it is often neutralized by the simultaneous occurrence of other acid-base disturbances. Trial registration Clinicaltrials.gov NCT02392091. Registered 17 March 2015
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Affiliation(s)
- Richard Brunner
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
| | - Andreas Drolz
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
| | - Thomas-Matthias Scherzer
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
| | - Katharina Staufer
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
| | - Valentin Fuhrmann
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
| | - Christian Zauner
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
| | - Ulrike Holzinger
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
| | - Bruno Schneeweiß
- Department of Medicine III - Division of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, 1090, Austria.
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