COMPARATIVE CHARACTERISTICS OF TONSILLAR LYMPHOID COMPONENT IN FETUSES WITH INTRAUTERINE GROWTH RETARDATION AND NORMAL BODY WEIGHT IN LATE PRENATAL PERIOD

Abstract

The aim of this work is to identify the morphological and functional features of the lymphoid component of the tonsils in foetuses with intrauterine growth retardation (IUGR) in the late prenatal period. Material and Methods. The autopsy material of the study was tonsils from 10 full-term stillborn foetuses of average body weight (3.0-3.5 kg) (comparison group hereinafter CG) and 11 stillborn foetuses weighing 2.1-2.5 kg (hereinafter IUGR). The morphological material was stained by histological, histochemical methods, followed by morphometry on an Olympus BX-41 microscope with subsequent processing with Olympus DP-soft version 3.1 program. Immunohistochemical study was carried out using the direct Coons technique. The paraffin slices were treated with monoclonal antibodies (mAb) to Thy-1, CD3, CD4, CD5, CD8, CD19, CD22, HLA-Dr. The specimens were studied with the help of Carl Zeiss Axioskop 40 FL luminescent microscope and photographed with a CANON A520 digital camera. The light intensity was analyzed, determining the optical density of immunofluorescence of the immune cells using the original method. Results. Lymphoid follicles average diameter in IUGR group was 35.45±1.507 μm, which is significantly less than the value in CG group – 54.90±1.286 μm, (p ≤0.05). The relative volume of lymphoid tissue in the tonsils of the foetuses with IUGR was also significantly lower, amounting to 63.36±2.110% compared to 72.20±2.898% in CG group (p ≤0.05), the density of cellular elements in ×600 field of vision (IUGR group – 112.63±2.284, CG – 123.40±3.392; p ≤0.05). In IUGR group, the number of CD5 lymphocytes was significantly higher, amounting to 15.63±1.286 c.u. (in CG group, 12.30±1.159 c.u.) (p ≤0.05). The population of mature CD19 lymphocytes was significantly reduced in IUGR group (IUGR – 62.09±2.625 c.u., CG – 77.0±2.660 c.u.; p ≤0.05). The luminescence intensity of the areas, where CD3-mature T-lymphocytes were localized, was significantly reduced in IUGR group in comparison with the indicator of CG group (group CG – 55.70±1.828 c.u., IUGR – 51.72±1.190 c.u.; p ≤0.05). In IUGR group, CD4 population was significantly reduced – 33.72±2.101 c.u., vs. 45.80±1.813 c.u. in CG group (p ≤0.05), while CD8 population was enlarged (41.90±1.578 vs. 33.0±1.632 c.u. in CG group) (p ≤0.05). Conclusion. The results of the quantitative and qualitative assessment of the lymphoid component of the palatine tonsils of foetuses with IUGR revealed signs of hypoplasia and delayed maturation of both Tand B-lymphoid populations against the background of increased suppressor activity. Complete maturation may occur in the early stages of the postnatal development of the child, at the same time, an increase in the population of B-1 lymphocytes, as well as an increase in the suppressor activity of CD8, which has already been formed in utero, can later play the role of an important link in the morphogenesis of immunopathological reactions of various origins.