Human leukocyte antigen compatibility and incidence of donorspecific antibodies in pediatric liver transplant recipients

BACKGROUND Antibody-mediated rejection following liver transplantation(LT)has been increasingly recognized,particularly with respect to the emergence of de novo donor-specific antibodies(DSAs)and their impact on graft longevity.While substantial evidence for adult populations exists,research focusing on pediatric LT outcomes remains limited.AIM To investigate the prevalence of human leukocyte antigen(HLA)mismatches and DSA and evaluate their association with rejection episodes after pediatric LT.METHODS A cohort of pediatric LT recipients underwent HLA testing at Santa Casa de Porto Alegre,Brazil,between December 2013 and December 2023.Only patients who survived for>30 days after LT with at least one DSA analysis were included.DSA classes I and II and cross-matches were analyzed.The presence of de novo DSA(dnDSA)was evaluated at least 3 months after LT using the Luminex®single antigen bead method,with a positive reaction threshold set at 1000 MFI.Rejection episodes were confirmed by liver biopsy.RESULTS Overall,67 transplanted children were analyzed;61 received grafts from living donors,85%of whom were related to recipients.Pre-transplant DSA(class I or II)was detected in 28.3%of patients,and dnDSA was detected in 48.4%.The median time to DSA detection after LT was 19.7[interquartile range(IQR):4.3-35.6]months.Biopsyproven rejection occurred in 13 patients at follow-up,with C4d positivity observed in 5/13 Liver biopsies.The median time to rejection was 7.8(IQR:5.7-12.8)months.The presence of dnDSA was significantly associated with rejection(36%vs 3%,P<0.001).The rejection-free survival rates at 12 and 24 months were 76%vs 100%and 58%vs 95%for patients with dnDSA anti-DQ vs those without,respectively.CONCLUSION Our findings highlight the importance of incorporating DSA assessment into pre-and post-transplantation protocols for pediatric LT recipients.Future implications may include immunosuppression minimization strategies based on this analysis in pediatric LT recipients.

Managing gastroesophageal reflux disease in children: The role of endoscopy

Gastroesophageal reflux disease (GERD) is a growing problem in the pediatric population and recent advances in diagnostics and therapeutics have improved their management, particularly the use of esophago-gastroduodenoscopy (EGD). Most of the current knowledge is derived from studies in adults; however there are distinct features between infant onset and adult onset GERD. Children are not just little adults and attention must be given to the stages of growth and development and how these stages impact the disease management. Although there is a lack of a gold standard test to diagnose GERD in children, EGD with biopsy is essential to assess the type and severity of tissue damage. To date, the role of endoscopy in adults and children has been to assess the extent of esophagitis and detect metaplastic changes complicating GERD; however the current knowledge points another role for the EGD with biopsy that is to rule out other potential causes of esophagitis in patients with GERD symptoms such as eosinophilic esophagitis. This review highlights special considerations about the role of EGD in the management of children with GERD.