DETECTION OF CYTOKINE MESSENGER-RNA-EXPRESSING CELLS IN PERIPHERAL-BLOOD OF PATIENTS WITH IGA NEPHROPATHY USING NONRADIOACTIVE IN-SITU HYBRIDIZATION

IgA nephropathy (IgA-N) is considered to be an immune-mediated disorde r and several immunological abnormalities have been observed. In the p resent study, we optimized non-radioactive in situ hybridization and a pplied this technique to evaluate the degree of expression of various cytokine mRNAs in peripheral blood mononuclear cells (PBMC) taken from patients with IgA-N on cytospin preparation. Using this method, toget her with image analysis, we examined the expression of mRNA in cells w hich secrete cytokines, such as IL-2, interferon gamma (IFN-gamma), IL -4, IL-5 and IL-6. The expression of these mRNAs was clearly observed in monocytes and lymphocytes at a single-cell level. Compared with hea lthy adults, the expression of IL-4 mRNA, IL-5 mRNA and IL-S mRNA, but not IL-2 mRNA or IFN-gamma mRNA, was significantly enhanced. Our resu lts indicate that non-radioactive in situ hybridization method is a po werful technique for analysis of cytokine mRNAs in PBMC at a cellular level. Our results also suggest that mRNA expression of IL-4, IL-5 and IL-6, produced by Th2 cells, is increased in patients with IgA-N. The abnormal regulatory process involved in cytokine expression may play an important immunopathologic role in IgA-N.