Anti-HLA and Anti-MICA Antibodies in Liver Transplant Recipients: Effect on Long-Term Graft Survival

OBJECTIVE Presence of anti-HLA antibodies has a well-known impact on kidney grafts survival; however their role in liver transplantation has not been fully elucidated. We conducted a 7-year prospective study to show correlation between presence of anti-HLA and anti-MICA antibodies and liver graft survival. METHODS Blood samples from 123 liver transplant recipients were collected during patients routine visits. Time from transplantation to blood sample collection was different for each patient. Blood samples were tested for anti-HLA (separately class I and II) and MICA antibodies using Luminex assays. RESULTS There were 32 (26%) patients with positive anti-HLA and 37 (30%) with positive anti-MICA antibodies. Graft loss occurred in 7 cases (23%) in anti-HLA positive group compared to 20 (22%) in anti-HLA negative group (P = ns) and in 8 cases (22%) in anti-MICA positive group but 19 (23%) in anti-MICA negative group (P = ns). No correlations were detected between presence of antibodies and acute graft rejection (AGR). Presence of any antibodies (anti-HLA or anti-MICA antibodies) correlated with late graft rejection (P = 0.04). CONCLUSION Presence of anti-HLA or anti-MICA had no impact on long-term liver graft survival; however, detection of any antibodies was correlated with episodes of late graft rejection.