Association of Anti-Human Leukocyte Antigen and Anti-Angiotensin II Type 1 Receptor Antibodies With Liver Allograft Fibrosis After Immunosuppression Withdrawal

BACKGROUNDMany pediatric patients who receive a living-donor liver transplant undergo withdrawal of immunosuppression (IS). For them, the high incidence of long-term progressive graft fibrosis is of particular concern. METHODSWe conducted a cross-sectional study including 81 pediatric patients who underwent IS withdrawal after living-donor liver transplant at Kyoto University Hospital and whose serum samples and pathological data could be obtained during the analysis period. We examined the association of donor-specific anti-human leukocyte antigen (HLA) antibody (DSA) and angiotensin II type 1 receptor antibody (anti-AT1R Ab) with posttransplant graft fibrosis. Normalized mean fluorescence intensity (MFI) 5,000 or higher and anti-AT1R Ab concentrations 17 U/mL or higher were both considered high level. The patients were classified into an advanced fibrosis group (AFG) (Ishak score≥3) and a control group (CG) (Ishak score≤2). RESULTSOnly one patient demonstrated DSA class I. Among those who demonstrated DSA class II, more AFG patients than CG patients demonstrated high-level mean fluorescence intensity, although the difference was not significant (64% vs. 39%; P=0.053). The incidence of high-level DSA-DRB1, however, was significantly higher in the AFG than that in the CG (40% vs. 4%; P