The nitrobule tetrazolium (NBT) test in endemic benign (epidemic) nephropathy

NBT test values in blood samples from 25 cases of endemic benign (epidemic) nephropathy (EBN) were high, i.e. more than 19% NBT-positive neutrophils, in 22 (88%) of the patients, intermediate, i.e. 13-19%, in two (8%) and normal in one patient (4%); in eight patients (32%) the NBT test values were 50% or more. The test values remained elevated, i.e. 13% or more, for more than one month after the onset of illness in three of ten patients on whom serial tests were performed. Among 18 patients with kidney diseases other than EBN and 16 with kidney transplant, high NBT test values, 20 and 22%, respectively, were found in two (5.9%), intermediate values in two and normal test values in 30 patients (88.2%). This paper is the first published report on NBT test values in cases of EBN. The test was rated to be of diagnostic value in patients in whom EBN might be suspected, highly elevated test values (larger than or equal to 50% NBT-positive neutrophils) lending support to the diagnosis.