Differences in the composition of inflammatory cell infiltrate in lens-induced uveitis under therapy with allopurinol or steroids

PURPOSE. The aim of this study was to compare the qualitative changes in th e composition of inflammatory cell infiltrate in lens-induced uveitis (LIU) under treatment with allopurinol (Allo), methylprednisolone (Pred) or the two drugs combined (Allo/Pred). METHODS. Twenty male Wistar rats were sensitized with lens proteins for eig ht weeks. Intravenous (IV) therapy was started after anterior capsule disru ption in one eye of each animal. Five rats were randomly assigned to each o f the four groups: controls, Allo (50 mg/kg bw), Pred (7.5 mg/kg bw) and Al lo/Pred (50 mg/7.5 mg per kg bw). Eyes were enucleated 24 hours later and f ixed in paraformaldehyde/glutaraldehyde. Sections at three levels were stai ned with Giemsa and examined using a 0 to 4+ score for each type of inflamm atory cell. Granulocytes were seen as neutrophils and eosinophils. Neutroph ils were divided into polymorphs and "others", and graded with lymphocytes. RESULTS. In all therapy groups there was a significant reduction of polymor phs (p <0.05) in comparison to the control group. There was also a signific ant reduction in lymphocytes (p <0.05) in the Pred and Allo/Pred groups as compared to the control group and the Allo group. CONCLUSIONS. Single-dose IV allopurinol significantly reduced the overall n umber of polymorphonuclear leucocytes In LIU. Unlike methylprednisolone, al lopurinol did not have any significant impact on lymphocytes.