[Detection of nephrotoxicity of human alpha 2b interferon with special reference to the analysis of urine enzymes in patients with chronic myeloid leukemia]

Does the antiviral therapy of patients with chronic hepatitis exert nephrotoxic effects?

INTRODUCTION

HBV and HCV chronic hepatitis can be accompanied by secondary renal disease. In addition, these patients receive antiviral drugs with potential nephrotoxicity. It is known that interferon (IFN) therapy in HCV-infected kidney transplant recipients is followed by rejection of the transplant in 50% of the cases. Ribavirin is contraindicated in hemodialyzed patients and in patients with a GFR <50 ml/min/1.73 m(2). IFN therapy requires dosage reduction and close monitoring in patients with a GFR <50 ml/min/1.73 m(2) and in patients with end stage renal disease. The aim of our study was to assess the nephrotoxicity of antiviral drugs in patients with chronic hepatitis by measuring three renal biomarkers: urinary albumin, N-acetyl-β-D-glucosaminidase (NAG) and α 1-microglobulin, as well as glomerular filtration rate (GFR-MDRD4) before and at 6 months of therapy.

METHODS

Fifty-five patients (28 male and 27 female, with a mean age of 47.85 ± 12.03 years) with chronic hepatitis (40 patients with HCV, 13 patients with HBV, 1 patient with HBV+HCV, and 1 patient with HBV+HDV) were enrolled into the study. Different antiviral drug associations were used on a case-by-case basis. The 40 patients with HCV chronic hepatitis received either Peg-IFN-α 2a+Ribavirin (37 patients) or Peg-IFN-α 2b+Ribavirin (3 patients). The 13 patients with HBV chronic hepatitis received Peg-IFN-α 2a (9 patients), Lamivudine (2 patients), Entecavir (1 patient), or Adefovir (1 patient). The patient with HBV+HCV chronic hepatitis received Peg-IFN-α 2a+Ribavirin. The patient with HBV+HDV chronic hepatitis received IFN-α 2a. Urinary albumin (ELISA), NAG (colorimetrical method), α 1-microglobulin (ELISA), and serum creatinine were measured before and at 6 months of antiviral therapy. Urinary markers were expressed as either mg/gCr (for albumin and α 1-microglobulin) or U/gCr (for NAG). Statistical analysis (Pearson's correlation coefficient, paired t-test and χ(2)-test) was performed.

RESULTS

At 6 months of therapy urinary albumin/gCr did not increase significantly: 16.58 ± 23.39 vs. 15.85 ± 24.96 mg/gCr before therapy, p = 0.87. Urinary NAG/gCr did not increase significantly: 4.21 ± 3.37 vs. 3.83 ± 3.2 U/gCr before therapy, p = 0.53. Urinary α 1-microglobulin/gCr was almost unchanged: 4.38 ± 4.47 vs. 4.38 ± 3.57 mg/gCr before therapy, p = 0.99. The GFR did not decline significantly: 92.41 ± 22.21 vs. 94.59 ± 36.1 ml/min/1.73 m(2) before therapy, p = 0.7. Ten patients (18.18%) were albuminuric before therapy, and 14 patients (25.45%) were albuminuric at 6 months of therapy, a non-significant increase (p = 0.35). We found a correlation between urinary albumin/gCr and NAG/gCr and between urinary albumin/gCr and α 1-microglobulin/gCr both at baseline and at 6 months of therapy: r = 0.54, p = 0.0005; r = 0.29, p = 0.03; r = 0.51, p = 0.0005; and r = 0.4, p = 0.002, respectively. In the patient receiving Adefovir, a known nephrotoxic drug, two of the three biomarkers (urinary albumin/gCr and NAG/gCr) increased, most notably NAG/gCr. Both HCV and HBV chronic hepatitis therapy were associated with non-significant changes in renal biomarker excretion and GFR.

CONCLUSIONS

With the exception of Adefovir, all of the drug associations used in this study were safe.

Phase II study of continuous subcutaneous interferon-alfa combined with cisplatin in advanced malignant melanoma

Interferon-alfa (IFN-alpha) and cisplatin have shown synergism in vitro against tumour cell lines and optimal effects were observed with continuous and high IFN concentration. 20 patients with advanced malignant melanoma were treated with 10 MU IFN subcutaneously continuously, daily, plus cisplatin 50 mg/m2 intravenously on days 8 and 9. Cisplatin was repeated every 4 weeks. The main toxic effects were myelosuppression, fatigue and weight loss. Toxicities always resolved completely after reduction/interruption of IFN and no life-threatening infection was observed. There were 1 complete and 6 partial responses. 6 patients had stable disease. Median time to progression was 7 months with a range of 16 to 2 months. The combined regimen of IFN-alpha and cisplatin is active in patients with multiple visceral and skeletal sites.

Transient renal impairment in rats after oral exposure to diethylene glycol

Volume, specific gravity, creatinine, lactate dehydrogenase (LDH), leucine aminopeptidase (LAP), beta-galactosidase (GAL), leucocytes, erythrocytes, nitrite, protein (albumin), glucose, ketone, urobilinogen, bilirubin and pH were estimated in urine of rats after single (by gavage) or repeated (via drinking water) oral administration of diethylene glycol (DEG). Following single or repetitive doses (daily over 90 days) of 0.2 g DEG kg-1 body weight, no change in renal function was observed (no effect level). In urine of rats treated once with 0.7 g DEG kg-1 body weight, LDH activity was significantly enhanced one day after treatment. A single dose of 2.0 g DEG kg-1 body weight resulted in an additional rise in urinary GAL activity two days after treatment, a significant rise of urinary volume and a decrease in creatinine concentration and pH on the first day. One day following a single dose of 8.0 g DEG kg-1 body weight, in addition to the changes mentioned before, LAP activity was significantly elevated and the specific gravity decreased. However, in all experiments the wet weight of the kidneys remained normal as compared to controls. The results thus show dose-dependent changes in several renal parameters, indicating a slight-to-moderate and reversible renal impairment.