Malnutrition and immune cell subsets in children undergoing kidney transplantation.

Background: Malnutrition, including obesity and undernutrition, among children is increasing in prevalence and is common among children on renal replacement therapy. The effect of malnutrition on the pre‐transplant immune system and how the pediatric immune system responds to the insult of both immunosuppression and allotransplantation is unknown. We examined the relationship of nutritional status with post‐transplant outcomes and characterized the peripheral immune cell phenotypes of children from the Immune Development of Pediatric Transplant (IMPACT) study. Methods: Ninety‐eight patients from the IMPACT study were classified as having obesity, undernutrition, or normal nutrition‐based pre‐transplant measurements. Incidence of infectious and alloimmune outcomes at 1‐year post‐transplantation was compared between nutritional groups using Gray's test and Fine‐Gray subdistribution hazards model. Event‐free survival was estimated by Kaplan–Meier method and compared between groups. Differences in immune cell subsets between nutritional groups over time were determined using generalized estimating equations accounting for the correlation between repeated measurements. Results: We did not observe that nutritional status was associated with infectious or alloimmune events or event‐free survival post‐transplant. We demonstrated that children with obesity had distinct T‐and B‐cell signatures relative to those with undernutrition and normal nutrition, even when controlling for immunosuppression. Children with obesity had a lower frequency of CD8 Tnaive cells 9‐month post‐transplant (p <.001), a higher frequency of CD4 CD57 + PD1‐ T cells, and lower frequencies of CD57‐PD1+ CD8 and CD57‐PD1‐ CD8 T cells at 12‐month transplant (p <.05 for all). Conclusions: Children with obesity have distinct immunophenotypes that may influence the tailoring of immunosuppression. [ABSTRACT FROM AUTHOR]