Gamma glutamyltranspeptidase activity and viral hepatitis in dialysis population

The influence of hemodialysis on FibroTest parameters

Chronic hepatitis C viral infection is an important cause of morbidity and mortality in patients with end-stage renal disease treated with hemodialysis. Liver fibrosis represents a main determinant of liver disease prognosis and clinical management, and its assessment by liver biopsy can decide treatment allocation. Although liver biopsy is the gold standard for staging liver fibrosis, it is an invasive procedure associated with complications that are more prevalent in patients with end-stage renal disease. FibroTest represents a surrogate marker of fibrosis which evaluates the levels of apolipoprotein A1, total bilirubin, haptoglobin, gamma-glutamyltransferase and α2-macroglobulin, generating a score that indicates the level of fibrosis. Discrepancies were observed in clinical practice between FibroTest score and histopathological findings. The aim of this study was to evaluate how hemodialysis influences the level of each FibroTest parameter and the final score. The systematic literature review conducted by us suggests that hemodialysis induces a reduction in apolipoprotein A1, haptoglobin and bilirubin levels, with an increase in gamma-glutamyltransferase and alpha-2-macroglobulin levels. In conclusion, hemodialysis modifies the levels of FibroTest parameters, suggesting that it may also have an impact on the accuracy of liver fibrosis assessment in hemodialysis patients.

Hepatitis B Virus Infection in the Dialysis Population: Current Perspectives

One of the major advances in the management of patients on regular dialysis has been the control of the spread of hepatitis B virus (HBV) infection in dialysis units. The rate of HBsAg positive patients on regular dialysis in the developed world is currently low, but outbreaks of HBV continue to occur. The diffusion of HBV in dialysis units in developing countries is higher, although available information is not abundant. There are limited data on the natural history of HBV in the dialysis population; they support a detrimental effect of HBV on survival in dialysis patients. The HBV viral load in HbsAg-positive dialysis patients appears low and stable over time and numerous mechanisms have been posited to explain it. Several assays for detecting HBV DNA in serum are available but they should not be used for purposes of routine screening within dialysis units. The epidemiology and clinical significance of occult HBV infection in the dialysis population needs to be addressed adequately - this remains an area of active research. Recent recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No controlled trials for the treatment of hepatitis B with either interferon or lamivudine in dialysis patients are currently available.

The Management of Viral Hepatitis in CKD Patients: An Unresolved Problem

Chronic kidney disease (CKD) patients in dialysis (HD) show peculiar, atypical features of clinical presentation and diseases (cardiovascular, metabolic, hematologic). This is also true for viral hepatitis infections, for which CKD patients represent an important risk group. In the past, hepatitis B virus (HBV) was the major cause of viral hepatitis in end-stage renal disease (ESRD). However, the introduction of a rigorous infection-control strategy, routine screening of patients and staff for hepatitis B serologic markers, vaccination of susceptible patients and staff, use of separate rooms and dedicated machines for HD of HbsAg-positive patients have all led to a decline in the spread of HBV infection in dialysis. Despite the prevalence of the antibody-hepatitis C virus (HCV), there has been a marked decrease in HD patients; after the introduction of routine screening for HCV and the use of erythropoietin, its occurrence ranges from 5% to 25% in the United States, with a prevalence of 6.8% in Europe. In CKD and in HD patients, the presence of HBV and HCV is an independent and significant risk factor for death and this risk may be at least partially attributed to chronic liver disease with its attendant complications. Liver disease can progress with modest hepatic inflammation and prominent fibrosis; the natural history of viral hepatitis in these patients is dependent on the immune dysfunction typical of kidney disease. Despite recent advances in antiviral therapy, there are still many uncertainties in regards to the efficacy and long-term outcomes of treatment with antiviral agents.

Differential Effect of Viral Hepatitis Infection on Mortality among Korean Maintenance Dialysis Patients: A Prospective Multicenter Cohort Study

The role of infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) in terms of survival among dialysis patients remains incompletely understood. In the present multicenter prospective cohort study, we investigated the prevalences of HBV and HCV infection among 3,321 patients receiving maintenance dialysis in Korea, and assessed the impacts of these infections on survival. All included patients underwent hepatitis B antigen (HBsAg) and HCV antibody (Ab) testing, which revealed that 236 patients (7.1%) were HBsAg-positive, and 123 patients (3.7%) were HCV Ab-positive. HBsAg-positive and HCV Ab-positive patients were matched to hepatitis virus-negative patients using a propensity score at a ratio of 1:2. The prevalences of HBV and HCV infection did not significantly differ according to dialysis modality. Linear-by-linear association analysis revealed that hepatitis B prevalence significantly increased with increasing dialysis vintage (p = 0.001), and hepatitis C prevalence tended to be higher with increasing dialysis vintage (p = 0.074). We compared the survival of HBsAg-positive and HCV Ab-positive patients to that of hepatitis virus-negative patients. After propensity score matching, cumulative survival did not differ between HBsAg-positive and HBsAg-negative patients (p = 0.37), while HCV Ab-positive patients showed significantly lower survival than HCV Ab-negative patients (p = 0.03). The main conclusions of the present study are that HBV infection prevalence increased with longer dialysis vintage, and that both HBV and HCV infections were most prevalent among patients with the longest dialysis vintage. Additionally, HCV infection among maintenance dialysis patients is associated with an increased risk of mortality.

Liver enzymes serum levels in patients with chronic kidney disease on hemodialysis: a comprehensive review

We reviewed the literature regarding the serum levels of the enzymes aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase in patients with chronic kidney disease on hemodialysis with and without viral hepatitis. Original articles published up to January 2013 on adult patients with chronic kidney disease on hemodialysis were selected. These articles contained the words "transaminases" "aspartate aminotransferase" "alanine aminotransferase" "gamma glutamyl transferase," "liver enzymes", AND "dialysis" OR "hemodialysis". A total of 823 articles were retrieved. After applying the inclusion and exclusion criteria, 49 articles were selected. The patients with chronic kidney disease on hemodialysis had reduced serum levels of aminotransferases due to hemodilution, lower pyridoxine levels, or elevated homocysteine levels. The chronic kidney disease patients on hemodialysis infected with the hepatitis C virus also had lower aminotransferase levels compared with the infected patients without chronic kidney disease. This reduction is in part due to decreased viremia caused by the dialysis method, the production of a hepatocyte growth factor and endogenous interferon-α, and lymphocyte activation, which decreases viral action on hepatocytes. Few studies were retrieved on gamma-glutamyl transferase serum levels; those found reported that there were no differences between the patients with or without chronic kidney disease. The serum aminotransferase levels were lower in the patients with chronic kidney disease on hemodialysis (with or without viral hepatitis) than in the patients with normal renal function; this reduction has a multifactorial origin.

Hepatitis B and C virus infection among hemodialysis patients in Yogyakarta, Indonesia: Prevalence and molecular evidence for nosocomial transmission

Hemodialysis patients are at an increased risk of acquiring hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. However, the prevalence of hepatitis viral infection and its genotype distribution among hemodialysis patients in Indonesia are unclear. In order to investigate these issues and the possibility of nosocomial transmission, 161 hemodialysis patients and 35 staff members at one of the hemodialysis unit in Yogyakarta, Indonesia, were tested for serological and virological markers of both viruses. HBV surface antigen (HBsAg) was detected in 18 patients (11.2%) and in two staff members (5.7%). Anti-HCV was detected in 130 patients (80.7%) but not in any staff members. Occult HBV and HCV infection were detected in 21 (14.7%) and 4 (12.9%) patients, respectively. The overall prevalence rates of HBV and HCV infection among patients were 24.2% and 83.2%, respectively. HCV infection was independently associated with hemodialysis duration and the number of blood transfusions. Phylogenetic analysis revealed that 23 of 39 tested HBV strains (59%) were genotype B, 11 (28.2%) were genotype C, and 5 (12.8%) were genotype A. HCV genotype 1a was dominant (95%) among 100 tested HCV strains. Nosocomial transmission was suspected because the genotype distribution differed from that of the general population in Indonesia, and because the viral genomes of several strains were identical. These findings suggest that HBV and HCV infection is common among hemodialysis patients in Yogyakarta, and probably occurs through nosocomial infection. Implementation of strict infection-control programs is necessary in hemodialysis units in Indonesia.

Hepatitis C virus infection and dialysis: 2012 update

Hepatitis C virus infection is still common among dialysis patients, but the natural history of HCV in this group is not completely understood. Recent evidence has been accumulated showing that anti-HCV positive serologic status is significantly associated with lower survival in dialysis population; an increased risk of liver and cardiovascular disease-related mortality compared with anti-HCV negative subjects has been found. According to a novel meta-analysis (fourteen studies including 145,608 unique patients), the adjusted RR for liver disease-related death and cardiovascular mortality was 3.82 (95% CI, 1.92; 7.61) and 1.26 (95% CI, 1.10; 1.45), respectively. It has been suggested that the decision to treat HCV in patients with chronic kidney disease be based on the potential benefits and risks of therapy, including life expectancy, candidacy for kidney transplant, and co-morbidities. According to recent guidelines, the antiviral treatment of choice in HCV-infected patients on dialysis is mono-therapy but fresh data suggest the use of modern antiviral approaches (i.e., pegylated interferon plus ribavirin). The summary estimate for sustained viral response and drop-out rate was 56% (95% CI, 28-84) and 25% (95% CI, 10-40) in a pooled analysis including 151 dialysis patients on combination antiviral therapy (conventional or pegylated interferon plus ribavirin).

Liver enzymes in patients with chronic kidney disease undergoing peritoneal dialysis and hemodialysis

OBJECTIVE

The present study was designed to analyze the serum levels of aspartate and alanine aminotransferases, gamma-glutamyl transferase, and the hematocrit in patients with chronic kidney disease who were undergoing peritoneal dialysis or hemodialysis.

PATIENTS AND METHODS

Twenty patients on peritoneal dialysis and 40 on hemodialysis were assessed, and the patients were matched according to the length of time that they had been on dialysis. Blood samples were collected (both before and after the session for those on hemodialysis) to measure the enzymes and the hematocrit.

RESULTS

In the samples from the patients who were undergoing peritoneal dialysis, the aspartate and alanine aminotransferase levels were slightly higher compared with the samples collected from the patients before the hemodialysis session and slightly lower compared with the samples collected after the hemodialysis session. The levels of gamma-glutamyl transferase in the hemodialysis patients were slightly higher than the levels in the patients who were undergoing peritoneal dialysis. In addition, the levels of aminotransferases and gamma-glutamyl transferase that were collected before the hemodialysis session were significantly lower than the values collected after the session. The hematocrit levels were significantly lower in the patients who were on peritoneal dialysis compared with the patients on hemodialysis (both before and after the hemodialysis session), and the levels were also significantly lower before hemodialysis compared with after hemodialysis.

CONCLUSION

The aminotransferase levels in the patients who were undergoing peritoneal dialysis were slightly higher compared with the samples collected before the hemodialysis session, whereas the aminotransferase levels were slightly lower compared with the samples collected after the session. The hematocrits and the aminotransferase and gamma-glutamyl transferase levels of the samples collected after the hemodialysis session were significantly higher than the samples collected before the session. Taken together, the present data suggest that hemodilution could alter the serum levels of liver enzymes.

Hepatic disorders in chronic kidney disease

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are the most common and serious causes of liver damage in patients with chronic kidney disease (CKD). The natural histories of HBV and HCV infections in patients with CKD are not fully understood; however, recent evidence has emphasized the adverse effect of HBV and/or HCV infection on survival in this population. Chronic liver disease is the fourth most important cause of death after renal transplantation. The negative effect of HCV infection on survival among renal transplant recipients has been linked to liver dysfunction and extrahepatic complications, such as chronic glomerulonephritis, post-transplantation diabetes mellitus, chronic allograft nephropathy, and sepsis. The transmission of HCV by solid organ transplantation has been unequivocally demonstrated. Renal transplant recipients who receive kidneys from HCV-positive donors are at increased risk of death. Although several studies have shown that in patients with HCV infection and chronic renal failure renal transplantation is associated with better survival than is dialysis, recent clinical guidelines recommend that kidneys from HCV-infected donors should not be used in HCV-seropositive recipients without detectable HCV viremia. Monotherapy with conventional interferon has been suggested to be a useful treatment for hepatitis C infection in patients on dialysis. Although no evidence suggests that patients with CKD are more prone to suffer from hepatic toxic effects than individuals with normal kidney function, patients with CKD usually receive multiple medications; and drug interactions may, therefore, have a role in the pathogenesis of drug-induced liver disease in this population.

Health care-associated transmission of hepatitis B and C viruses in hemodialysis units

Liver disease is a significant cause of morbidity and mortality in patients receiving long-term dialysis. This article summarizes the most recent information on epidemiology, clinical significance, and management of infection by hepatitis B and C viruses in this population.

Efficacy of an Intravenous Calcium Gluconate Infusion in Controlling Serum Calcium after Parathyroidectomy for Secondary Hyperparathyroidism

Introduction: Intravenous calcium gluconate has been used to prevent postoperative hypo-calcaemia (POH) following parathyroidectomy for secondary hyperparathyroidism in chronic kidney disease (CKD). Materials and Methods: Retrospective data were obtained for 36 patients with CKD stage 4 and 5 after parathyroid surgery, correlating albumin-corrected serum calcium with the infusion rate of calcium gluconate. Calcium flux was characterised along with excursions out of the target calcium range of 2 to 3 mmol/L. With this data, an improved titration regimen was constructed. Results: Mean peak efflux rate (PER) from the extracellular calcium pool was 2.97 mmol/h occurring 26.6 hours postoperatively. Peak calcium efflux tended to occur later in cases of severe POH. Eighty-one per cent of patients had excursions outside of the target cal-cium range of 2 to 3 mmol/L. Mean time of onset for hypocalcaemia was 2 days postoperatively. Hypocalcaemia was transient in 25% and persistent in 11% of patients. Conclusion: A simple titration regimen was constructed in which a 10% calcium gluconate infusion was started at 4.5 mL/h when serum calcium was <2 mmol/L, then increased to 6.5 mL/h and finally to 9.0 mL/h if calcium continued falling. Preoperative oral calcium and calcitriol doses were maintained. Blood testing was done 6-hourly, but when a higher infusion rate was needed, 4-hourly blood testing was preferred. Monitoring was discontinued if no hypocalcaemia developed in the first 4 days after surgery. If hypocalcaemia persisted 6 days after surgery, then the infusion was stopped with further monitoring for 24 hours. Key words: Chronic kidney failure, Hypocalcaemia, Practice guidelines, Renal dialysis

Gammaglutamyltransferase in ESRD as a predictor of all-cause and cardiovascular mortality: another facet of oxidative stress burden

The enzyme gamma-glutamyltransferase (GGT) is an established marker of liver function and alcohol consumption and represents the major factor responsible for the extra-cellular catabolism of the main antioxidant in mammalian cells, Glutathione. ESRD is a condition characterized by a high risk of death and cardiovascular (CV) complications and with a high prevalence of liver disease but the link between GGT and clinical outcomes has never been studied in this population. We tested the predictive power of GGT for overall and cardiovascular mortality in a cohort study in 584 ESRD patients. Over a 4 years follow up 194 patients died. GGT was higher in non-survivors (median 25 UI/l, interquartile range 16-45 UI/l) than in survivors (22, 15-33 UI/l) (P=0.006). On univariate Cox regression analysis plasma GGT predicted both all-cause [HR (10 UI/l increase): 1.04, 95% CI: 1.01-1.06, P=0.006] and cardiovascular mortality [HR: 1.03, 95% CI: 1.00-1.05, P=0.04]. These relationships held true in multivariate Cox regression analyses [HR: 1.06, 95% CI: 1.03-1.10 (P<0.001) and 1.05, 95% CI: 1.01-1.10, P=0.01] adjusting for liver disease as well as Framingham risk factors and non traditional risk factors including C reactive Protein (CRP). High GGT in ESRD patients is a strong, independent risk marker for all cause and cardiovascular death. The predictive power of GGT for these outcomes likely reflects the involvement of this enzyme in oxidative stress mechanisms.

Hepatitis B virus infection and the dialysis patient

Prevention of nosocomial transmission of hepatitis B virus (HBV) has been a signal achievement in the management of chronic kidney disease. The rate of serum hepatitis B surface antigen (HBsAg) seropositivity in patients on maintenance hemodialysis in the developed world is currently low (0-10%) but outbreaks of acute HBV infection continue to occur in this setting. The prevalence of HBV infection within dialysis units in developing countries appears higher (2-20%) based on relatively few reports. Although data are limited, HBV infection in dialysis population diminishes survival; HBV viral load in HBsAg-positive dialysis patients is reportedly low and stable over time. Updated recommendations for the management of HBsAg chronic carriers on maintenance dialysis have been issued. No rigorously controlled treatment trials for treatment of hepatitis B with either interferon or lamivudine therapy in dialysis patients are currently available.