Light and electron-microscopic study of epithelium covering free gingiva at various stages of chronic gingivitis in patients with β-thalassemia major

Aim. Study of the nature and severity of reorganization of the structural elements of gingival epithelium in remission and exacerbation of chronic catarrhal sclerosing gingivitis in patients with β-thalassemia major at the light-microscopic and ultrastructural levels. Methods. From araldite-epon blocks of gingival biopsy specimens taken from 18 patients with β-thalassemia major, the semithin (1-2 μm) and ultrathin (35-70 nm) sections were obtained by means of ultramicrotome. Semi-thin sections were stained by trichrome. Viewing of stained and unstainted ultrathin sections was performed on an electron microscope at an accelerating voltage of 80-120 kV. Results. The increase of ferritin molecules in the intercellular space and in cytoplasm of all cellular elements (except for neutrophils) of the epithelial coverage of the gingiva, as well as the presence of siderophages in the exudative phase demonstrate that one of the main causes of exacerbation of chronic catarrhal sclerosing gingivitis in patients with β-thalassemia major is an increase of congestion of their body with iron-containing elements. The widened slit-like spaces of various shapes and sizes existing in gingival epithelium especially in the acute stage, should be considered as a sign of intercellular edema - spongiosa, and not acantholysis. Disruption of tonofilament-desmosomal complexes of gingival epithelial cells and increased accumulation of glycogen granules in developed hypoxia can be considered the main factors involved in altering the cytodifferentiation of gingival epitheliocytes in the exudative phase of chronic catarrhal sclerosing gingivitis that results in occuring in stratum corneum of light cells without any signs of keratinization, as well as the absence of an epithelial barrier. Conclusion. Identification of molecular mechanisms of disorders of neutrophil and epithelial barriers of gingival mucous membrane can be used in the diagnosis and development of new principles of treatment of inflammatory processes in patients with β-thalassemia major.