title: Evidence for intravascular coagulation in systemic onset, but not polyarticular, juvenile rheumatoid arthritis.
abstract: After observing a child with systemic onset juvenile rheumatoid arthritis (S-JRA) who developed purpura fulminans in association with disseminated intravascular coagulation, with subsequent gangrene and autoamputation, we undertook a prospective study of coagulation parameters in children with JRA. Ten consecutive children with S-JRA, 10 children with rheumatoid factor-negative, polyarticular juvenile rheumatoid arthritis (P-JRA), and 10 age- and sex-matched controls were studied. Routine coagulation screening tests were performed, as were tests for plasma fibrinopeptide A (a sensitive measure of intravascular thrombin generation), factor VIII-related antigen (an endothelial cell protein), and platelet factor 4 (a platelet-secreted protein). Our studies suggest that activation of intravascular coagulation is common in systemic onset JRA, but not in rheumatoid factor-negative, polyarticular disease. The coagulopathy may cause severe morbidity. In addition, marked elevations of plasma factor VIII-related antigen suggest perturbation of endothelial cells and vascular involvement in S-JRA, but not in P-JRA. Normal ranges of platelet factor 4 indicate that intravascular platelet consumption does not occur in either type of JRA, despite the thrombocytosis common in both.
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000150:complications* / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004211:Disseminated Intravascular Coagulation / Q000150:complications* / Q000175:diagnosis; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D008297:Male; D013922:Thrombocytosis / Q000503:physiopathology
chemical_list: D005340:Fibrinogen