Density of CD1a-labeled Langerhans' cells in normal human gingiva and in nifedipine- and immunosuppressive medication-induced gingival overgrowth

Background: The purpose of this study was to compare the distribution of La ngerhans' cells in normal human gingiva and in nifedipine- and immunosuppre ssive medication-induced gingival overgrowth by means of an immunohistochem ical study. Methods: Gingival samples were collected from II nifedipine-medicated cardi ac patients, 22 triple-medicated (azathioprine, prednisolone, and cyclospor in A) renal transplant recipients, and 28 generally healthy individuals. Pa tients were grouped into the immunosuppression group, the combined immunosu ppression and nifedipine group, the nifedipine group, and the generally hea lthy control group. Five mu m-thick cryostat sections were stained with mon oclonal antibody (mAb) for CD1a using an avidin-biotin-enzyme complex (ABC) method. Numbers of CD1a-labeled cells/mm(2) were determined in 6 areas: or al epithelium, oral sulcular epithelium, sulcular epithelium, middle connec tive tissue, connective tissue beneath the oral epithelium, and connective tissue beneath the sulcular epithelium. Significances of differences betwee n the groups were tested by means of the Kruskall-Wallis test, and signific ances of differences between pairs of results by the Mann-Whitney U-test an d the t test. Results: Numbers of CD1a-labeled cells were significantly lower in the medi cated groups than in controls in all 3 epithelial areas (P <0.0001) and in the connective tissue beneath the sulcular epithelium (P <0.0021). There we re significantly fewer CD1a-labeled cells in the sulcular epithelium in the nifedipine group than in the other medication groups. Conclusions: The reduced numbers of CD1a-labeled cells found in nifedipine- induced gingival overgrowth were similiar to the reduced numbers of CD1a-la beled cells in gingival overgrowth associated with immunosuppressive medica tion.