Significance of anti-HLA immunization in lung transplantation

Objectives: HLA immunization is triggered by pregnancy, blood transfusion or organ transplantation. It is recognized factor for graft dysfunction after kidney transplantation. This study explores influence of HLA antibodies on occurrence and severity of Bronchiolitis Obliterans Syndrome (BOS), and survival after lung transplantation (LT). Methods: Retrospective study from January 2004 to June 2010 including 99 LT in 96 patients. We determined 3 groups: specifically immunized against their pulmonary graft (group 1, n=16), non-specifically immunized (group 2, n=19), non-immunized (group 3, n=64). We compared FEV1 evolution curves at 1, 3, 6 months and every 6 months, survival with and without BOS (Kaplan Meier and Log rank), incidences of acute cellular rejection (ACR), lower respiratory infections and bronchial stenosis (Chi-2 and ANOVA). Results: Specific immunization (group 1) appeared 15 months (±14) after LT. Non-specific immunization (group 2) was detected 9 months (±32) before LT. A decrease of FEV1 was observed in group 1 at 24 and 30 months after LT (compared to group 3: p < 0,05). There was a linear relationship between antibodies rates and FEV1 decrease in group 1. Mean delays between LT and BOS diagnosis were 20 (±14), 14 (±13), and 25 (± 11) months for group 1, group 2, and group 3 respectively. Incidences of BOS 0p and ACR were increased in group 2 compared to group 3 (p < 0,05). Conclusion: Anti-HLA immunization is related to early onset of BOS. Specific antibodies probably lead to humoral rejection. Non specific antibodies indicated sensitized status with increased incidence of ACR.