The treatment of Sjögren's disease in NZB/NZW F1 hybrid mice with azathioprine: a two-stage study.

NZB/NZW mice exhibit changes in their salivary and lacrimal glands similar to those occurring in Sjögren's syndrome (SS) in humans. The aim of this study was to determine the efficacy of azathioprine in the treatment of SS in NZB/NZW mice. The experimental animals comprised three groups; the first received the drug daily from 14 weeks of age, the second started therapy at 26 weeks of age and the third group remained untreated. The animals, in groups of five, were killed at four-weekly intervals, up to 42 weeks, using ether. The submandibular and lacrimal glands were assessed for the extent of lymphocytic infiltration using a modified focus scoring system, with light microscopy. During the progression of the disease, azathioprine produced a reduction in the number of lymphocytic foci. This reduction occurred when azathioprine was used both early and late in the condition.