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

The nephrotoxic potential of alpha-interferon (IFN alpha-2b) was analysed in 21 patients with chronic myeloid leukemia. As particularly sensitive parameters in the detection of subclinical renal injury we measured the excretion of the following urinary enzymes: lactate dehydrogenase (LDH), gamma-glutamyltransferase (GGT), leucine arylaminidase (LAP), beta-galactosidase (GAL) and N-acetyl-beta-glucosaminidase (NAG). Additionally, protein excretion and urinary sediment were analysed. In 18 of 21 patients a significant increase in the excretion of LDH, LAP, GGT and NAG was found, in 6 patients there was an additional rise in the output of GAL. Eleven patients developed proteinuria up to 2 g/l, one patient excreted up to 9 g/l. Enzymuria and protein excretion decreased in all patients after reduction of the IFN alpha-2b dosage and disappeared in two patients following cessation of therapy. The high incidence of nephrotoxic events in patients with CML during IFN alpha-2b therapy might be mostly due to immunological or substance-specific effects.