STRUCTURAL AND FUNCTIONAL ALTERATIONS OF LYMPH NODES IN STRESS-RELATED IMMUNODEFICIENCY

Oktabr, 2025-Yil 293 STRUCTURAL AND FUNCTIONAL ALTERATIONS OF LYMPH NODES IN STRESSRELATED IMMUNODEFICIENCY Azimova Dilora Alijon qizi Asian International University. [email protected] https://doi.org/10.5281/zenodo.17446969 Reasurch relevance: Chronic stress disrupts immune homeostasis through neuroendocrine pathways and leads to increased susceptibility to infectious, inflammatory, and autoimmune disorders. Lymph nodes, as the main peripheral immune organs, are directly affected by stress hormones such as glucocorticoids and catecholamines. Identifying histological alterations in lymph nodes is essential for predicting immunodepression and designing prophylactic measures. Objective: To assess the morphological changes in lymph nodes under experimentally induced stress-related secondary immunosuppression. Materials and Methods Rodent models were exposed to:  Noise and light stress,  Nutritional restriction,  High-dose corticosteroids,  Sleep disturbance.  The duration of exposure varied between 7 and 28 days. Lymph nodes were examined using:  Hematoxylin–eosin staining,  Sudan III and Van Gieson methods,  PAS reaction,  Phase-contrast and electron microscopy,  Immunohistochemical markers (CD8+, caspase-3, Ki-67). Results The following pathological alterations were identified:  Regression or disappearance of cortical follicles  Reduced germinal center proliferation  Atrophy of T-cell zones in the paracortex  Delay in plasma cell differentiation  Early stromal sclerosis in the reticular framework  Decreased numbers of macrophages in lymphatic sinuses  Venous and capillary stasis  Partial replacement of lymphoid follicles by adipose tissue. These changes confirm the suppressive effect of stress mediators on lymphopoiesis, immune surveillance, and lymphatic microcirculation. The findings indicate a direct role of apoptosis, stromal collapse, and inhibited proliferation in the pathogenesis of secondary immunodeficiency. Oktabr, 2025-Yil 294 References 1. Khaitov R., Pinegin B. (2020). Pathogenesis of Stress-Induced Immunodeficiency. Immunology Journal. 2. Karimova D. (2022). Lymph Node Histology and Stress Impact. Uzbek Medical Journal. 3. Sapolsky R. (2018). Neuroendocrine Stress Mechanisms. J Neuroimmunol.