MEASUREMENT OF URINARY IL-6 IN HUMAN CHRONIC GLOMERULONEPHRITIS

IL-6 is closely associated with the pathogenesis of human mesangial proliferative glomerulonephritis (mesPGN). We have previously shown that the measurement of urinary IL-6 is a helpful tool for monitoring the progression of IgA nephropathy. In this study, IL-6 activity of both 24-hour urine and spot urine from the same patients was measured to determine which urine sample functions better as a sample for the measurement of urinary IL-6. Urine samples were collected from 131 patients with primary and secondary glomerular diseases followed at Nara Medical University Hospital. Spot urine samples were collected and stored immediately at -20℃ until use. Twenty-four-hour urine samples were collected at room temperature and also stored at -20℃ until use. Urinary IL-6 was measured by using IL-6 dependent hybridoma clone, MH60. BSF2, as well as enzyme-linked immunosorbent assay (ELISA). When the spot urine was used for the measurement of IL-6, IL-6 activity became undetectable in 15 out of 20 patients, while 24-hour urine samples from all 20 patients showed significant IL-6 activity. In addition, urinary IL-6 activity was not diminished by 24-hour storage of urine samples at room temperature. These data indicate that IL-6 was not excreted continuously. Thus, the 24-hour urine sample was a better sample for the measurement of urinary IL-6. The levels of urinary IL-6 measured by using MH60. BSF2 were positively correlated with those measured by ELISA system. However, urinary IL-6 in about 53% of patients whose urinary IL-6 activity could be determined by using MH60. BSF2 became undetectable when using ELISA system. As a sample for the measurement of urinary IL-6, we should use the 24-hour urine sample. Urinary IL-6 could be measured easily by using ELISA system.