913 IMMUNE COMPLEXES IN SLIPPED CAPITAL FEMORAL EPIPHYSIS

Abstract

Serum, synovial fluid, and synovial biopsy material were examined in 9 patients with slipped capital femoral epiphysis (SCFE), in 7 controls, and in 3 patients with acute toxic synovitis (ATS) for the presence of immune complexes (IC), immunoglobulins, and complement components. The serum was assayed for IC by the Raji cell indirect fluorescent method and by the Clq binding assay (Clq-BA). Total hemolytic complement (CH100), C3, and C4 were quantitated by radial diffusion, and quantitative immunoglobulins (IgG,A, and M) were measured by laser nephelometry. Biopsies of the synovium and the junction of the femoral neck and articular cartilage were studied by light microscopy and direct immunofluorescence. IC in the synovial fluid were demonstrated in 6 of 7 SCFE patients by Raji cell method and 5 of 7 by Clq-BA, in 3 of 3 ATS patients by Raji cell method and Clq-BA, and in 1 control by Raji cell method, but not by Clq-BA. Fluorescent staining for deposition of immunoglobulins and complement on synovial tissue was negative in all study cases. All serum immunologic parameters(IgG, IgA, IgM, C3, C4, and CH100) were normal in patients with SCFE, and IC were not detected in SCFE patients' serum by either the Raji cell method or Clq-BA. However, the serum from 1 of 3 ATS patients had IC by Raji cell method. Immunoglobulins and complement of the synovial fluid were comparable in all 3 groups(SCFE, ATS, and control). This preliminary data suggest that immune complexes may play a pathologic role in SCFE and ATS.