Clinicopathological Characteristics of Acute Antibody-Mediated Rejection in Pediatric Liver Transplantation-A...

Introduction: Presently, liver transplantation is becoming a more common treatment option for adults and children suffering from liver failure. Antibody-mediated rejection (AMR), a phenomenon that is exceedingly uncommon and inadequately comprehended, may induce graft dysfunction. The objective of the investigation was to evaluate the clinical and histopathological manifestations of AMR in pediatric patients. Material and methods: The retrospective study comprised sixty-two liver core biopsies from forty-two pediatric patients. In a total of 10 biopsies, 7 children were diagnosed with AMR, while 35 of them exhibited features of acute T-cell-mediated rejection (TCMR) in 52 biopsies. The C4d binding assay was conducted in all biopsies using the immunohistochemical (IHC) method. Bilirubinostasis, steatosis and acute and chronic rejection were re-assessed in all specimens. The 6-grade Ishak scale was employed to evaluate fibrosis. The TCMR activity was established using the Banff classification. AMR was assessed according to a novel histopathological grading system that was developed by the authors. Depending on the type of rejection, the relationship between histopathological grading, morphological characteristics, and laboratory parameters was established for each group. Standard methods were implemented to conduct statistical analysis. Results: At the time of biopsy, the median age of patients was 47.6 months (15.03-98.83) and the median time from transplantation was 0.9 months (0.3-7.6). The study's findings provided evidence that histopathological lesions were the least specific manifestation, which supported the presence of AMR. A positive C4d staining statistically increases the likelihood of AMR diagnosis, whether or not there are associated morphological abnormalities. The type of rejection and laboratory tests did not exhibit any statistically significant correlation. Conclusions: The diagnosis of AMR in a transplanted liver is intricate and requires a multifaceted approach. However, the proposed histopathological grading may be a helpful method for selecting patients who should be assessed for donor-specific antibodies (DSAs) or in whom AMR should be suspected when DSAs cannot be determined.