Prevalence of pre-transplant anti-HLA antibodies and their impact on outcomes in lung transplant recipients

BACKGROUND Previous studies have suggested that antibodies against human leukocyte antigen (HLA) are associated with worse outcomes in lung transplantation. However, little is known about the factors associated with outcomes following lung transplantation in Asia. Accordingly, we investigated the prevalence of anti-HLA antibodies in recipients before transplantation and assessed their impact on outcomes in Korea. METHODS A single-center retrospective study was conducted. The study included 76 patients who received a lung transplant at a tertiary hospital in South Korea between January 2010 and March 2015. RESULTS Nine patients (11.8%) had class I and/or class II panel-reactive antibodies greater than 50%. Twelve patients (15.8%) had anti-HLA antibodies with a low mean fluorescence intensity (MFI, 1000-3000), 7 (9.2%) with a moderate MFI (3000-5000), and 12 (15.8%) with a high MFI (> 5000). Ten patients (13.2%) had suspected donor-specific antibodies (DSA), and 60% (6/10) of these patients had antibodies with a high MFI. In an analysis of outcomes, high-grade (≥2) primary graft dysfunction (PGD) was more frequent in patients with anti-HLA antibodies with moderate-to-high MFI values than in patients with low MFI values (39.4% vs. 14.0%, p = 0.011). Of 20 patients who survived longer than 2 years and evaluated for pBOS after transplant, potential bronchiolitis obliterans syndrome (pBOS) or BOS was more frequent in patients with anti-HLA antibodies with moderate-to-high MFI than in patients with low MFI, although this difference was not statistically significant (50.0% vs. 14.3%, p = 0.131). CONCLUSIONS The prevalence of anti-HLA antibodies with high MFI was not high in Korea. However, the MFI was relatively high in patients with DSA. Anti-HLA antibodies with moderate-to-high MFI values were related to high-grade PGD. Therefore, recipients with high MFI before lung transplantation should be considered for desensitization and close monitoring.