Poster (download) Abdalova A.M.1, Shurlygina A.V.2, Dergacheva T.I.3, Klimontov V.V.4, Letyagin A.Yu.51Research Institute of Clinical and Experimental Lymphology – Branch of the Institute of Cytology and Genetics SB RAS, arzuabd@mail.ru2Research Institute of Clinical and Experimental Lymphology – Branch of the Institute of Cytology and Genetics SB RAS, anna_v_s@mail.ru3Research Institute of Clinical and Experimental Lymphology – Branch of the Institute of Cytology and Genetics SB RAS, dr-tanja@yandex.ru4Research Institute of Clinical and Experimental Lymphology – Branch of the Institute of Cytology and Genetics SB RAS, klimontov@mail.ru5Research Institute of Clinical and Experimental Lymphology – Branch of the Institute of Cytology and Genetics SB RAS, letyagin-andrey@yandex.ru The circadian temporary organization of the dynamic processes occurring at the level of the cellular compartment of the immune system ensures their clear time sequence, the optimal ratio of cellular elements in organs and tissues at any given time/ Any pathological process leads to biorhythmological disorders of varying severity, which begin at the very early stages of the disease, when clinical signs are not yet manifested. However, in the literature there is very little information about the daily biorhythms of the immune system in violation of its functions, in particular, in the chronic inflammatory process. We found that with inflammation in the thymus, spleen and lymph nodes, the nature of the diurnal fluctuations in the content of large, medium and small lymphocytes, monocytes / macrophages, CD8 +, CD25 + cells changes. Thus, with the development of inflammation in the uterine mucosa in rats, desynchronosis in the immune system is observed. This allows us to talk about the need to take into account circadian rhythms in the diagnosis and treatment of inflammatory diseases.