Course and resolution of the coagulopathy in nephrotic children.

Blood coagulation function was serially studied in 84 children with nephrotic syndrome. Fifty-eight had minimal change disease, six had focal glomerulosclerosis and 20 had other forms of renal disease associated with the nephrotic syndrome. Qualitatively similar abnormalities in fibrinogen metabolism were present in all groups with clinically overt nephrotic syndrome; plasma fibrinogen concentration and high molecular weight fibrin(ogen) complexes (HMWFC) were grossly elevated (P less than 0.001 in most groups). With disease remission fibrinogen and HMWFC concentrations decreased to the normal range, usually with concomitant transient increase in plasma fibrinolytic activity (P less than 0.02). Alterations in concentrations of other proteins involved in coagulation and fibrinolysis differed depending on the underlying cause for the nephrotic syndrome. Antithrombin III concentration was normal except in the focal glomerulosclerosis group. The results demonstrate that a coagulopathy characterized by pathological degree of thrombin action on fibrinogen complicates the nephrotic state and may be initiated by different mechanisms. It is suggested that this coagulopathy, which remits with clinical improvement, is consequent upon local intrarenal activation of the blood coagulation system.