Development of bronchiolitis obliterans syndrome despite blood chimerism in human lung transplant recipients

Bronchiolitis Obliterans Syndrome (BOS) remains the overwhelming obstacle t o the success of lung transplantations (LTx). The presence of donor-specifi c microchimerism (DSM) and its association with lung allograft function is not well defined. To investigate the relationship between chimerism and BOS , blood was obtained from 21 LTx recipients. Genomic DNA was isolated from patient blood, and PCR-based techniques were used to identify recipient and donor HLADR. Fifty percent of the LTx recipients with BOS exhibited DSM at "T-1" time post transplant, and 40 % at one year follow-up (T-2). However, 54 % exhibited DSM in the BOS-free group at T-1, and 44 % at T-2. Of the B OS-free, DSM-positive patients at T-1, 29 % developed BOS by T-2. In contra st, 50 % of BOS-free DSM-negative patients 50 % developed BOS (P > 0.05). D ouble LTx had a higher prevalence of DSM (73 %) and a lower prevalence of B OS (46 %) than single LTx (50 % and 80 % respectively, P > 0.05). One-HLA-D R-antigen-matched LTx recipients show a low prevalence of DSM compared to n onmatched (P < 0.05). This study demonstrates that the development of BOS i n LTx recipients could also occur in the presence of blood chimerism.