Morphological study of dendritic cells in human cervix by zinc iodide osmium method

Dendritic cells (DCs) are a heterogeneous population of antigen presenting cells that have been identified in several tissues including the female reproductive organs. The aim of the present study is to demonstrate the morphological differences of dendritic cells in normal human exocervix using the Zinc Iodide Osmium (ZIO) procedure.

Normal cervical tissues obtained from nine patients who underwent abdominal hysterectomies for various ailments were processed for histochemical study. Six microns thick serial sections were taken and viewed under a light microscope. The diameters of the cells were measured under a magnification of 40x using the Cellsens image analysing software and analysed using SPSS version 16.

In the normal human exocervix, a greater density of ZIO-positive DCs was noted in the epithelium and subepithelium and their distribution was not uniform. In some areas of epithelium, the ZIO-positive cells in the basal layer showed a typical dendritic morphology, while the cells in the intermediate and superficial layers were nondendritic polygonal cells. Intraepithelial capillaries were noted, which were surrounded by ZIO-positive nondendritic polygonal cells. There was significant difference in the mean diameters of typical DCs (8.61±1.86 μm) and nondendritic polygonal cells (10.97±1.93 μm). In the subepithelium the DCs had typical morphology and their distribution varied. ZIO positive DCs were noted in the epithelium and cervical glands of endocervix also. In conclusion, the human cervix has different subsets of ZIO positive DCs with varied distribution. Their functional role has yet to be defined.