Proto-oncogene expression in peripheral blood mononuclear cells in IgA nephropathy

Proto-oncogene expression in peripheral blood mononuclear cells in IgA nephropathy. We have investigated the expression of proto-oncogenes in mononuclear cells obtained from patients with IgA nephropathy using a RNA hybridization technique. Patients with IgA nephropathy expressed more c-myc, c-raf, c-fos, and c-jun proto-oncogene RNA than did normal controls. However, no significant expression of c-N-ras, c-mos or c-myb genes was found in the mononuclear cells of these patients. When the amount of urinary protein excretion was used as an indicator of disease activity (> 1 g/day), a positive correlation was found between c-myc, c-raf, c-fos, and c-jun expression and urinary protein excretion (P < 0.01). The expression of these genes correlated also with the serum IgA concentration (P < 0.01), IgA immune complex (P < 0.01), and histopathological changes in renal tissues obtained from patients with IgA nephropathy (P < 0.01). The results of this survey suggest that abnormally regulated proto-oncogene expression in mononuclear cells may play an important role in the progression of IgA nephropathy and may be useful as an indicator of disease activity and/or prognosis