To determine the prevalence of human parvovirus B19 infection in patients with juvenile idiopathic arthritis (JIA) by detection of specific IgM, IgG, and viral DNA.
Serum samples of 50 patients with diagnosis of JIA and 39 healthy controls were analyzed by ELISA to detect IgG and IgM anti-B19-specific antibodies. The parvovirus B19 genome was detected by nested polymerase chain reaction (PCR). The average age of the patients was 9.6 years (2-14 yrs); 30 were female (60%) and 20 male (40%). The definitive diagnoses of these patients corresponded to 19 systemic forms (38%), 11 to the oligoarticular variety (22%) and 20 to the polyarticular (40%). The average age of the control group was 7.8 years (2-16 yrs); the distribution by sex was 25 females (64%) and 14 males (36%).
IgM against parvovirus B19 was detected in 20% of the cases (10 patients) and B19 DNA genome by PCR in 48% (24 patients); in 10% of the cases (5 patients), both markers were detected. IgG was found in 32% (16 patients). In the control group neither IgM nor the viral genome was detected. However, 43.5% of the controls (17/39) had IgG against parvovirus B19, indicating past infection by the virus.
Our study confirms recent observations regarding a high prevalence of viral DNA in JIA patients and a possible role of this viral infection in JIA pathogenesis.