ASPECTS OF ACCIDENTAL INVOLUTION (AI) OF THE THYMUS IN CHILDREN WHO DIED FROM INFECTIOUS AND NON-INFECTIOUS CAUSES, AS WELL AS WITH SUDDEN INFANT DEATH SYNDROME (SIDS)

Abstract

Over the long period of existence of SIDS as a diagnosis, many questions have accumulated, one of which is the bewilderment about the lack of adequate research into the problem of its immunological causes. In this work, an attempt was made to identify the features of pathomorphological transformations (AI) of the thymus, in the context of its connection with SIDS and other verified causes of death. Research objectives: to identify the features and possible consequences of accidental thymus involution, in the context of its connection with SIDS and other causes of death, including intrathymic infection (maybe intrauterine). Materials and methods: a single-center, observational retrospective cohort continuous study was conducted, a total of 112 autopsy reports of children of different ages who died from infectious and non-infectious causes, as well as with SIDS, were analyzed. 24 protocols were received from the Kuzbass Clinical Bureau of Forensic Medicine (2013-2023), the remaining 88 were provided by the Department of Pediatric Pathology of the Kemerovo Regional Pathological Anatomy Bureau (2022-2024). Results of the study: children who died from infectious causes are significantly more likely to have thymus AI in its final phases (3, 4, 5), than children who died from non-infectious causes (chi-square 34.782, p < 0.001, Se 87.5%, Sp 78.4%) and children with a posthumous diagnosis of SIDS (chi-square 9.980, p = 0.002, Se 75%, Sp 79.2%). And if the children who died from non-infectious causes in the overwhelming majority did not have signs of AI (79%), then in the latter outcome thymomegaly prevailed (chi-square 18.039, p < 0.001, Se 45.8%, Sp 97.4%), and to a lesser extent - degenerative involutional pathomorphosis of the thymus gland, especially in children with intrauterine involution (chi-square 8.362, p = 0.004., Se 64.7%, Sp 100%). Conclusions: the dominant influence of infectious stressors (including intrauterine) on the features of the involutional pathomorphosis of accidental involution was determined. The peculiarity of AI in children with SIDS had a contradictory nature. In most cases, these changes were minimal (AI 1), while in others, there was significant involutional pathomorphosis, which was statistically significantly associated with the presence of a history of intrauterine infections, which to a certain extent could have influenced the fatal outcome. This assumption dictates the need to conduct an ultrasound of the thymus within certain decreed timeframes.

Keywords

• тимус
• иммунодефицитные состояния
• акцидентальная инволюция тимуса
• синдром внезапной детской смерти