Immne response to bacterial antigens indicates recurrent acute anterior uveitis

A Finnish study has provided evidence that recurrent acute anterior uveitis (AAU) is linked with raised antibody responses possibly related to repeated infections, persistence of bacterial antigens, or a naturally heightened immune reactivity.

Most patients with AAU were positive for HLA-B27 (86% versus 9% controls) and 84% had recurrent AAU. Spondyloarthropathy (SpA) was diagnosed for 25% of patients; 27% had eye complications in one or both eyes.

Serum antibodies to a range of bacteria associated with SpAs did not differ significantly in their presence or titres between patients and controls. However, recurrent AAU (≤10/>10 recurrences) was the only variable associated with positive responses against one or several bacteria. No persistence of bacterial antigens could be shown in peripheral blood mononuclear cells, but Chlamydia pneumoniae DNA was found in an antibody negative patient.

Sixty four patients with AAU first examined between 1993 and 1996 and then in September-December 1999 and 64 age and sex matched healthy controls were compared for serum antibodies to a range of bacteria by ELISA (Salmonella, Yersinia spp, Klebsiella pneumoniae, Proteus mirabilis, Campylobacter jejuni, and Borrelia burgdorferi) or microimmunofluorescence (Clamydia spp). Salmonella and yersinia antigens were looked for by immunofluorescence of purified blood mononuclear cells and C pneumoniae DNA by PCR.

AAU occurs in SpA but its cause is unknown. It seems to be associated with HLA-B27 and infections. In many ways its characteristics mirror those of reactive arthritis, but whether bacterial antigens persist in AAU, as they do in reactive arthritis, was not known.