[Evaluation of the gingival status by quantification of the T6 (CD1a) and HLA-DR antigens].

The number/mm2 of sections of Langerhans cells (LC's) expressing antigens T6 and/or HLA-DR was determined in eight human gingival samples which consisting of normal gingivae, contraceptive induced hyperplastic, traumatic, inflammatory and diphenylhydantoin hyperplasic gingivae. All samples, except those from normal gingivae, showed inflammatory and/or hyperplasic histopathological patterns. In the immunostained samples, LC's appeared in variable numbers and were randomly distributed between the keratinocytes. All pathological samples, except the inflammatory gingiva showed HLA-DR+ keratinocytes. Wilcoxon and Mann-Whitney statistical tests suggested the existence of three subpopulations of LC's: T6+/DR+; T6-/DR+ and T6+/DR-. The subpopulation T6+/DR+ was predominant in conditions of normal immune response. The subpopulation T6-/DR+ suggested the presence of newly incorporated LC's from the lamina propia. T6+/DR- subpopulations could indicate the existence of a system to avoid overstimulation. It is concluded that quantitative evaluation of T6 and HLA-DR expression was representative of the gingival conditions and the disease activity.