Detection of enteroviruses in renal biopsies from patients with immunoglobulin A nephropathy

Viruses have been suspected to be one of the causes of IgA nephropathy (IgAN). Recent studies have detected viruses in renal tissues of patients with IgAN. Enteroviruses have been reported as pathogenic agents in some renal diseases. We previously reported that group B coxsackieviruses cause pathological changes in experimentally infected mouse kidney. The aim of the present study was to examine the participation of enteroviruses in the pathogenesis of renal diseases including IgAN. Renal biopsies of ten patients with IgAN (group 1) and of 19 patients with non-IgAN renal disease (group 2) were analyzed by polymerase chain reaction (PCR) for the presence of enteroviral RNA. Positive PCR results were obtained for three patients (30%) of group 1. We confirmed by sequencing that the positive PCR products were derived from strains of enteroviruses. One of these three patients also had a positive result for lymphocytes from peripheral blood. In contrast, enteroviral RNA was detected in none of the 19 patients of group 2. The incidence of enteroviral RNA detection in patients of group 1 was higher than that in group 2 (P<0.05). Our findings suggest that enteroviral infection may have the possibility of becoming one of the factors involved in the mechanism of onset or evolution of IgAN.