DEPOSITION OF IGG ANTIACTIN ANTIBODIES ON KIDNEYS OF GLOMERULAR NEPHROPATHY PATIENTS WITH AN ENHANCED GLOMERULAR ALPHA-SMOOTH MUSCLE ACTIN EXPRESSION

In this study, we have attempted to evaluate by immunohistochemistry a ssay the glomerular alpha smooth muscle actin (ASMA) expression in 53 kidney biopsy specimens obtained from patients with glomerular nephrop athy as compared with 16 histologically normal human kidneys. An enhan ced mesangial ASMA expression was observed in 26 of 53 specimens of pa tients with glomerulonephritis. In contrast, normal glomeruli showed n o ASMA-positive mesangial cells. Furthermore, we have analyzed the spe cificities of antibodies eluted from kidney biopsy specimens from pati ents and controls using an enzyme immunoassay against a panel of self antigens composed of actin, myosin, tubulin and DNA. The antibodies el uted from exclusively renal biopsy specimens of patients with an enhan ced glomerular ASMA expression showed high IgG activity restricted to actin. Our results demonstrated the presence of IgG anti-actin activit y in glomerular nephropathy patients with an enhanced mesangial ASMA e xpression.