Uveitis, vitreous humour, and klebsiella. II. Cross-reactivity studies with radioimmunoassay.

Radioimmunoassay with calf and cow vitreous humour-I125 and rabbit antivitreous humour serum has been employed to investigate the immunological cross-reactivity of vitreous humour with bacterial and mammalian tissue antigens. Klebsiella ultrasonicate preparation at a dose fo 10 000 micrograms/ml was found to inhibit the binding of vitreous humour by 25-100% (p less than 0.001), compared with an inhibition of 5-30% by a similar quantity of E. coli ultrasonicate preparation. Equivalent amounts of Streptococcus pyogenes antigen, bovine haemoglobin, and hyaluronic acid had no inhibitory effect, while horse spleen ferritin was found to inhibit vitreous humour binding between 0 and 10%. These results indicate that klebsiella micro-organisms have antigens which partially resemble some eyeball components. It is suggested that acute anterior uveitis of ankylosing spondylitis may be produced by anti-Gram-negative bacterial antibodies binding to cross-reacting eye antigens.