EFFECTS OF CYCLOSPORINE-A ON PLASMA-CELLS IN EXPERIMENTAL GINGIVITIS IN DOGS

The aim of the present investigation was to evaluate the effect of Cyc losporine A (CsA) on the inflammatory lesion formed in the gingival ti ssues during de novo plaque formation. 5 beagle dogs were used. On day 0, all teeth of the 5 dogs were scaled and polished. A 6-week period of plaque control including daily tooth cleaning with toothbrush and d entifrice was initiated. A clinical examination regarding plaque and g ingivitis was performed, and :he plaque control measures were abandone d on the right side of mandible. 3 weeks later, the clinical examinati on was repeated, samples of subgingival plaque harvested and biopsies obtained from the 3rd and 4th right mandibular premolar regions. The t ooth cleaning measures on the left side of the mandible were terminate d al this interval. During the following 3 weeks, the animals formed p laque in the lower left premolar regions, and received, Ix daily, a su bcutaneous injection of CsA. At the end bf this 2nd plaque formation p eriod (test), the clinical examination was repeated, subgingival plaqu e was sampled and biopsies from the 3rd and 4th left mandibular premol ar regions harvested. The biopsies were prepared for histometric and m orphometric analyses. The clinical and histological examinations demon strated that plaque formation resulted in a gingival lesion (ICT) whic h, in the 2 periods, had similar size and apical extension. The ICT fo rmed during the CsA administration period, however, harbored an increa sed number of plasma cells and a reduced macrophage density than the c ontrol lesion. It is suggested that CsA administration may result in a Th-2 (T-helper 2-cell) dependent activation of B-lymphocytes.