Plasma exchange in immune complex glomerulonephritis: clinical and immunological correlations.

22 patients with immune complex (IC) glomerulonephritis (GN) were treated with plasma exchange (PE), corticosteroids and immunosuppressors, in 4 cases also as a long treatment. We evaluated circulating IC and some neutrophils (PMN) functions such as phagocytosis, aggregation and platelet activating factor (PAF) release. In extracapillary GN improvement was observed in 3/9 patients, concomitantly with IC decrease: in 6/9 patients no renal amelioration occurred, despite IC decrease in two. In all Lupus Nephritis and mixed IgG/IgM cryoglobulinemia, IC were highly positive and the disappearance of IC in 5/6 Lupus Nephritis and 4/4 cryoglobulinemia heralded systemic and renal amelioration. PMN functions were hampered in acute Lupus Nephritis and mixed cryoglobulinemia, but constantly improved along with IC decrease and clinical amelioration. Thus in extracapillary GN the decrease of IC by PE may not eventuate in renal improvement. In Lupus Nephritis and cryoglobulinemia a better correlation exits between IC, PMN function and clinical course.