In order to determine the immunologic status and possible susceptibility to bacterial infection in children with juvenile rheumatoid arthritis (JRA), titers of hemagglutinating antibodies to E coli 055, E coli 086, common antigen, and Shigella polyvalent antigen were measured. Immunoglobulin G was the predominant antibody. IgA antibodies were found in higher titers in children with J RA. No significant differences were found between children with JRA and matched controls. These data show that children with JRA do not have any deficit in antibody production to specific bacterial antigens, and any increased appearance of infection in these children is more probably due to deficiencies in cellular factors.An increased susceptibility to systemic and often fatal infections has been reported in both JRA and adult rheumatoid arthritis (1,2). However relatively little is