Fibrinolysis in Glomerulonephritis Treated With Ancrod: Renal Functional, Immunologic and Histopathologic Effects

Abstract

The effects of a 14-day course of ancrod on fibrinolysis, renal function and structure, and immunologic findings are reported in 37 patients with glomerulonephritis. Patients were divided into two groups. In the first, the level of fibrin degradation products within 48 h was relatively low (less than 1 mg/ml). In these patients there was a linear relationship between changes in levels of fibrin degradation products and fibrinogen, suggesting that fibrin degradation products derived from ancrod-cleaved-fibrinogen in the circulating pool; in most, level of plasma alpha 2-antiplasmin before treatment was elevated. In the second, the level of fibrin degradation products within 48 h was high (greater than 1 mg/ml). Compared with the change in fibrinogen, a disproportionate increase in levels of fibrin degradation products suggested that a significant amount derived from sources other than plasmin digested ancrod-cleaved-fibrinogen, thus reflecting effective fibrinolysis, perhaps also in tissues; in most, the level of plasma alpha 2-antiplasmin was normal before treatment. In those with initial high levels of fibrin degradation products, higher levels persisted throughout treatment, changes in other fibrinolysis components were greater, and plasminogen activator inhibitor levels became normal. In patients with initial high but not with initial low response in fibrin degradation products renal function improved within 24 to 48 h and continued to improve thereafter; there was an immediate but temporary increase in proteinuria. Microvascular thrombosis decreased significantly, indicating effective removal of fibrin from glomeruli. The relation of early fibrinolysis to changes in immunologic and histopathologic findings was analyzed in patients with lupus nephritis. With ancrod, there was an increase toward normal of serum C3 and C4, a decrease in serum Igs, gamma globulin and anti-dsDNA antibody and in glomerular C3 and Ig deposits, suggesting that ancrod had favorable effects on immunologic factors. There were no clinical differences in patients with initial high and low responses, but the relationship of microvascular and inflammatory indexes before treatment differed. Initial renal biopsies and those after treatment were carried out on average 28 days apart. Inflammatory and microvascular indexes and glomerular thrombi decreased in patients with initial high levels of fibrin degradation products; fibrosclerosis index and glomerular sclerosis increased in patients with initial low levels of fibrin degradation products. Fibrinolysis expressed as the 48 h (fibrin degradation products/fibrinogen) ratio, correlated inversely with change in fibrosclerosis index and glomerular sclerosis in the whole group, and especially in those with initial high levels of fibrin degradation products.(ABSTRACT TRUNCATED AT 400 WORDS)