Interleukin-4 expression in mesangial proliferative glomerulonephritis.

Several cytokines are known to play roles in the pathogenesis of human glomerulonephritis. Recently, some studies proposed a possible relationship between interleukin-4 (IL-4) and glomerulonephritis. To investigate the involvement of IL-4 in human glomerulonephritis, we evaluated renal biopsy specimens using immunohistochemical procedures. Our study revealed that the glomeruli in immunoglobulin A nephropathy and lupus nephritis (World Health Organization grades II and IV) contained IL-4-positive cells, which were CD-3- and CD-4-positive T lymphocytes. CD-8-, CD-14-, CD-19-, or CD-56-positive cells did not react with anti-IL-4. CD-23-positive cells were not observed in the sections used in this study. Interleukin-4-positive cells were not found in the normal control kidney tissues. The degree of the glomerular IL-4-positive cell index correlated well with the glomerular hypercellularity index, but not with any other clinical or histopathologic parameters. Therefore, the present study offers more reliable evidence concerning the association between IL-4 and human glomerulonephritis.