[Nephritis and complement].

Abstract

There are many cases in which renal biopsies show glomerular complement accumulation. Some of these cases have low serum complement levels, but the extent to which the complement system participates in the pathogenesis of glomerulonephritis is unknown. We examined the activation system in acute poststreptococcal glomerulonephritis (PSGN). Ordinarily in PSGN an alternative pathway is activated. In the early stage of the disease, both C3 and C4 serum complement levels were depressed in one fourth. This suggested that the classical pathway is also activated in PSGN. Serum complement levels are very important in the diagnosis of the type and severity of lupus nephritis. Serum complement levels and activity index of lupus nephritis were very well correlated in our cases. The improvement of serum complement levels may corresponds to the improvement of the pathological activity of the disease.