IMMUNOMODULATING ACTIVITY OF ALLOPURINOL IN EXPERIMENTAL LENS-INDUCEDUVEITIS

Purpose: The aim of this study was to evaluate the immunomodulating ac tivity of allopurinol using a model of lens-induced uveitis (LIU) and to compare these effects to those of steroids. Methods: We tested the sera of both LIU and control rats against western blots (WE) of SDS-PA GE separations of protein fractions from normal and LIU rat lenses. Th ese blots were scanned using digital image analysis. A newly developed technique was used to compare the complex autoantibody (AAB) repertoi res. Five groups of LIU rats were investigated: no treatment; single d oses of methylprednisolone (MPR; 7.5 mg/kg body wt. i.v.); allopurinol (AL; 50 mg/kg body wt. i.v.); a combination of both drugs (AT and MRP ); repeated application of AL (ALFR; 50 mg/kg body wt. i.v. every 2 we eks during the immunization period and a daily dose of approx. 25 mg/k g body wt. orally). Results: Immunization induced complex antibody rep ertoires against lens proteins. Antibody repertoires of LIU rats were identical, regardless of whether the proteins were obtained from contr ol, uveitis eyes, or corresponding healthy eyes of the same individual . AL showed a dose-dependent immunological effect in LIU treatment. Gi ven as a single dose, AL revealed no significant change in the AAB rep ertoire; however, ALFR showed very clear modification of the AAB reper toires compared to both controls and rats receiving steroids. Conclusi ons: These results suggest dose-dependent effects of allopurinol in LI U treatment. Repeated application during the immunization period induc ed a strong immunomodulating effect of AL that was not observed after single doses.