Insufficiency of the immune system in fetuses and infants with sepsis: Morphological and morphometric studies

The pathology of lymphoid organs was studied with morphological, morphometric, and immunohistochemical methods in 73 fetuses and newborns who died of different diseases, including sepsis. Gestation ages ranged from 22 to 42 weeks and death had occurred no later than 28 days after birth. We have found previously that in fetuses and newborns with pneumonia the immune response to microbial effects is manifested in specific morphological features different from those in children and adults. Such immune response was meant as insufficiency. In fetuses and newborns with sepsis, the signs of decompensation of the lymph system were found to be the main peculiarities in the immune response of these organisms to infection. Decompensation manifested by a significant decrease in the number of cells, especially B and T lymphocytes. As a result, the number of follicles in the spleen decreased, and devastation of lymph nodes was observed. The thymus showed weak morphological changes, especially in low-birth-weight fetuses and newborns. Sepsis is discussed in terms of the outcome of general decompensation of the immune system under conditions of bacterial aggression.