REDUCED THYMIC FUNCTIONALITY IN PEDIATRIC PATIENTS AFTER LIVER TRANSPLANTATION

FLORENCIA B GONZÁLEZ; BRENDA DINATALE; ITAUÁ LESTON ARAUJO; WILSON SAVINO; ANA R PÉREZ; OSCAR BOTTASSO; ALEJANDRO COSTAGUTA; GUILLERMO COSTAGUTA; CAROLINA RUMBO; GABRIEL GONDOLESI

Congreso; 27th annual meeting, Society of Pediatric Liver Trasplantation SPLIT 2023; 2023

Society of Pediatric Liver Transplantation

Background: Children´s thymic functional capacity may be profoundly disturbed by immunosuppressive therapies. Since there are no current global reliable strategies to evaluate thymic function after solid organ transplantation, we aimed to explore by non-invasive techniques, how the functionality of the thymus is affected in pediatric patients undergoing immunosuppressive therapies after liver transplantation. Methods: Eight (8) pediatric patients undergoing liver transplantation were included in the study (mean ± SEM; 6,25±1.8 years). Immunosuppressive protocols included calcineurin inhibitors, meprednisone, and basiliximab with mycophenolate eventually added if needed. Blood samples were assessed for recent thymic emigrants (RTEs, detected as CD4+CD45RA+CD31+ by flow cytometry) and T-cell receptor excision circles quantification (signal-joint TRECs by qPCR), before and 1 month after transplantation. Thymus size was also established by ultrasonography. Results: We found an inverse association between age and RTEs levels, but not TRECs, at any time point. Reduced thymus size was also recorded in all patients. RTE levels were significantly decreased in 4/5 patients (80%) after 1 month of the liver transplant, and TRECs levels were significantly decreased in 5/8 patients (62.5%) at the same time point.Conclusions: Immunosuppressive treatment might affect thymus size and functionality. This may have an impact on the frequency of infections and graft tolerance.