COAGULATION STUDIES ON PATIENTS WITH SICKLE CELL DISEASES

Repeated measurements of coagulation factor activities were done on blood from 16 patients with Sickle Cell Disease over a one year period. Sixty-two coagulation profiles were available for analysis during well periods and 12 profiles on 6 patients were obtained during painful crisis. The profiles included measurements of the prothrombin time, partial thromboplastin time, thrombin time, platelet count, quantitation of Factors I, II, V, VII, VIII, IX, X, XI, XII, measurement of fibrin split products, fibrin monomer, and platelet aggregation with collagen ADP and epinephrine. Factor II was significantly lower than normal, platelet counts were significantly increased, and platelet aggregation with collagen epinephrine and ADP were impaired in approximately one-third of patients in. the absence of known injestion of platelet active drugs. Fibrin monomer as measured by radioactive amine incorporation (JCI 50:2235, 1971) was increased once in each of 4 patients but there were no increased levels of fibrin split products in the serum and no significant differences in results during well and painful crisis periods. Therefore, no evidence of chronic intravascular coagulation was found. The decreased concentration of prothrombin may be a result of liver impairment. The increased platelets and abnormal aggregation are unexplained.