ACTIVE JUVENILE DERMATOMYOSITIS (JDMS) IS ASSOCIATED WITH COMPLEMENT AND COAGULATION ACTIVATION, AND INCREASED TITERS TO ANTINUCLEAR (ANA) AND COXSACKIE B VIRAL (COX-B) ANTIGENS:

Seven active JDMS children had increased complement activation products (C3d and C4d), endothelial cell perturbation (increased factor VIII related antigen), and intravascular thrombosis (generation of fibrinopeptide A), despite normal routine coagulation studies. When 12 JDMS sera obtained within 4 months of disease onset were tested for complement fixing antibody to Cox-B, 83% were positive to at least one antigen, compared to 25% of controls matched for age/sex/date of visit. In contrast, assays for antibody to 15 other possible viral antigens, including Mycoplasma pneumonia, did not give greater than expected titers. When neutralizing antibody was measured, an increase in Cox-B2 (58%), B4 (58%), B5 (67%), was seen vs a maxima of 26% in control sera. Finally, when these sera were tested for ANA, 50% were positive. We conclude that newly diagnosed JDMS is associated with increased antibody to Cox-B and ANA; active disease perturbs the coagulation and complement systems. We speculate that these events may be related to the pathophysiology of this chronic illness. Supported in part by grants from Illinois Chapter Arthritis Foundation, Marlene Apfelbaum Memorial Foundation, and AM-21589.