Authors of a review examining global IgA nephropathy (IgAN) patterns propose that the timing of primary Epstein-Barr virus (EBV) infection may contribute to differences in disease frequency. The hypothesis is based partly on similarities between the galactose-deficient polymeric IgA1 found in circulating immune complexes and mesangial deposits in IgAN and IgA produced by EBV-infected B cells. Across countries with available data, EBV seropositivity by age 9 was higher where IgAN frequency was low, with a median of 90% versus 60.7% in countries with higher IgAN frequency (P=.001), and earlier EBV infection correlated inversely with IgAN frequency (r=–0.6; P=.001). The authors propose that infection during early childhood, before full maturation of the IgA system, may generate immune responses that reduce later EBV infection of IgA-positive B cells. Infection delayed until adolescence may provide greater opportunity for EBV to affect the mature IgA compartment.
Socioeconomic conditions may also be central to the observed pattern. Higher IgAN frequency was associated with higher national income, while earlier EBV infection tended to occur in populations with lower socioeconomic status and different living and hygiene conditions. However, these findings are ecological and hypothesis-generating rather than proof that EBV causes IgAN. The analysis combined historical data collected with different serologic methods and at different times, lacked individual-level EBV and socioeconomic information in patients with IgAN, and showed attenuation of the EBV association after adjustment for national income. The proposed EBV–IgAN connection therefore offers a novel mechanistic framework for further study, but prospective studies are needed before infection timing can be considered a clinical risk factor or treatment target.
Reference: Novak Z, Raška M, Mestecky J. IgA nephropathy: a novel pathway in immunopathogenesis dependent on the timing of Epstein-Barr virus infection. Front Immunol. 2026 Jun 2;17:1792410. doi: 10.3389/fimmu.2026.1792410.
