Parvovirus B19 and parvovirus V9 are not associated with Henoch-Sch?nlein purpura in children.

BACKGROUND: Based on single case reports, parvovirus B19 (B19) has repeatedly been proposed as an etiologic agent in patients with Henoch-Sch?nlein purpura (HSP), perhaps causing vasculitis by direct invasion of vascular endothelial cells because of the tissue distribution of the cellular B19 receptor. A cohort of children with HSP and other vasculitic diseases was investigated and compared with healthy control children to assess the role of B19 as well as parvovirus V9 (a putative emerging B19-like virus). PATIENTS AND METHODS: Serum samples from 36 children with HSP (n = 29) or other vasculitic diseases (n = 7) were examined, and 38 healthy bone marrow donors were used as controls. The presence of specific B19 and V9 IgM and IgG antibodies was determined with a recently developed enzyme-linked immunosorbent assay, and viral DNA was detected by a novel nested PCR. RESULTS: Specific IgM was not present in any of the patient or control serum samples. B19 DNA was detected in one patient, a previously healthy 8-year-old boy diagnosed with HSP, whereas none of the controls was B19-positive. V9 was not detected in any of the clinical or control samples. It seems likely that B19 infection might have triggered the development of HSP in the B19-positive patient, because B19 viremia is otherwise uncommon. CONCLUSIONS: Although causality is difficult to construe in single cases, the data indicate that B19 is not a common contributing factor in the pathogenesis of vasculitis and that this pathogen is only rarely associated temporally with HSP or vasculitic diseases in children.