Immune disorders in pediatric Edwards’ syndrome

Edwards’ syndrome (trisomy 18) is the second most common autosomal trisomy after Down syndrome and is characterized by pronounced multiorgan pathology affecting virtually all body systems, including the immune system. Although immune disturbances are frequently observed in this chromosomal syndrome and may substantially influence the clinical course of the disease, an insufficient attention was paid to morphological diagnosis of these changes in pediatric pathology. As a result, important structural alterations in immune organs are often underestimated being rarely considered as a distinct and clinically relevant component of the underlying pathogenesis. The aim of this study was to perform a detailed analysis of morphological changes in immune organs in children diagnosed with Edwards syndrome. The study was carried out at the Sverdlovsk Regional Pathology Bureau (SOPAB) in Yekaterinburg, Russia, and included examination of autopsy materials from 10 children who died between 2019 and 2025. A review of their medical records demonstrated that, despite comprehensive clinical evaluations, none of the patients received a premortem diagnosis of immunodeficiency, and this condition was not mentioned in the final clinical diagnoses. The postmortem pathological evaluation revealed significant abnormalities of immune organs in 70% of the children. The thymic gland exhibited various pathological changes, including hypoplasia (30%), hypoplastic dysplasia with areas of fatty degeneration and lymphoid depletion (10%), and large-cystic hypoplastic dysplasia (10%). Their spleen also exhibited alterations in both the quantity and architecture of its lymphoid components. Infectious complications were documented in six children (60%), either as competing conditions or as the direct cause of death. One child presented only with prolonged recurrent pneumonias, while in the remaining cases the infections were generalized. In all instances, the infectious conditions were associated with severe inborn malformations of organs and systems and/or pronounced structural abnormalities of thymus gland. These findings highlight the importance of further research into immunopathology in patients with chromosomal abnormalities, aiming to enhance diagnostic accuracy at both clinical and pathological stages.