Raised IgM antibodies to parvovirus B19 in juvenile rheumatoid arthritis.

To delineate the role of human parvovirus B19 in the etiopathogenesis of juvenile rheumatoid arthritis (JRA), IgM and IgG antibodies specific for parvovirus B19 surface protein antigen(s) were estimated in the sera using commercial ELISA kits. Sera of 69 JRA patients (median age 16 yr, male : female ratio 1.1:1) satisfying the criteria of American Rheumatism Association along with 26 sera of rheumatoid arthritis (RA) and 12 sera of healthy children as disease and normal controls respectively were screened. Of the 69 patients with JRA, 19 (27.5%), 35 (50.7%) and 9 (13%) were positive for IgM, IgG and both IgG and IgM antibodies respectively. Of the 26 disease control sera, 11 (42.3%) were positive for IgG antibodies while none had elevated IgM antibodies. Among 12 healthy controls, 7 (58.3%) were positive for IgG and 1 was positive for both IgG and IgM antibodies. Thus, a statistically significant proportion of children with JRA had evidence of parvovirus B19 infection.