Renal dysfunction during treatment of chronic hepatitis B with tenofovir disoproxyl fumarate and associated risk factors.

OBJECTIVES: To analyze the evolution of glomerular filtration rate (GFR) and the presence of renal tubular dysfunction during the treatment of chronic hepatitis B virus (HBV) infection with tenofovir disoproxil fumarate (TDF) and to determine the risk factors involved. METHODS: Retrospective cohort observational study of adults with chronic hepatitis B. Exclusion: hepatitis C virus-HBV coinfection, diabetes, baseline GFR less than 60 ml/min. Measurements of serum and urinary creatinine and phosphate; urinary albumin, retinol-binding protein (RBP) and neutrophil gelatinase-associated lipocalin (NGAL) were performed. Univariate and multivariate analyses tracked factors associated with worsening GFR. RESULTS: A total of 120 individuals were included: 35% NAÏVE (G1); 49.2% HBV using TDF (G2); 15.8% HBV-HIV using TDF (G3); 63.3% men; 60.8% white; 30% hypertensive. Average age was 50.5 years (SD ±â€…12.9 years). Reactive HBeAg predominated in G3 ( P  < 0.001) and cirrhosis in G2 ( P  < 0.036). NGAL was elevated in 5.3% of cases (G1 = 3.2%; G2 = 8.7%; G3 = 0%; P  = 0.582), RBP in 6.7% (G1, G3 = 0%; G2 = 13.6%; P  = 0.012), urinary phosphate/creatinine ratio in 16.2% (G1 = 15.2%; G2 = 14.5%; G3 = 23.5%; P  = 0.842) and urinary albumin/creatinine ratio in 12.9% (G1 = 12.2%; G2 = 10.7%; G3 = 21.1%; P  = 0.494). Worsening of renal function occurred in 22.5% of the population (G1 = 11.9%; G2 = 28.8%; G3 = 26.3%; P  = 0.122), independently associated only with systemic arterial hypertension [adjusted odds ratio (AOR) = 4.14; P  = 0.008], but not to TDF (AOR = 2.66; P  = 0.110) or male sex (AOR = 2.39; P  = 0.135). However, the concomitance of these variables generated a high estimated risk for this outcome (51%). CONCLUSIONS: Renal tubular dysfunction was uncommon according to NGAL, RBP or urinary phosphate/creatinine ratio. TDF was not an independent factor for worsening renal function, significantly associated only with systemic arterial hypertension. However, in hypertensive men, the use of TDF should be monitored.

Role of gamma-glutamyl transferase activity in patients with chronic hepatitis C virus infection.

BACKGROUND: Increased serum gamma-glutamyl transferase (GGT) levels are frequently observed in chronic hepatitis C virus (HCV) infection. However, the significance of this finding remains unclear. The purpose of the present paper was to assess the relationship between GGT levels and clinical, biochemical and histological features in chronic HCV-infected carriers. METHODS: Patients with a liver biopsy presenting anti-HCV and HCV-RNA were evaluated. Age, gender, risk factors of transmission, serum alanine aminotransferase (ALT), GGT and alkaline phosphatase (ALP) levels and histological features were assessed in all. Data were analyzed statistically by the chi2 test and multivariate logistic regression analysis. RESULTS: Among 201 patients studied, elevated GGT levels and bile duct damage were observed in 48% and 35% of them, respectively. No association was seen between GGT level and bile duct damage or between GGT level and hepatic steatosis. Initially, age >40 years (P=0.007), elevated ALT (P=0.01), grading of inflammatory activity (P=0.004) and staging of fibrosis (P<0.001) were found to be associated with elevated GGT levels. After multivariate regression analysis, histology grading 3 and 4 inflammation activity (P=0.01) and staging 3 and 4 fibrosis (P=0.01) remained independently associated with elevated GGT level. CONCLUSIONS: A significant number of patients with chronic HCV infection had elevated serum GGT levels. Furthermore, this enzyme seemed to be useful as an indirect marker of more advanced liver disease in chronic hepatitis C.