Bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation: The effect of NOD2/CARD15 mutations in a Tunisian population

Bronchiolitis obliterans (BO) is a serious lung complication that can develop after allogenic stem cell transplantation. It has been suggested that single nucleotide polymorphisms (SNPs) that affect the NOD2/CARD15 gene impair its function and result in an uncontrolled innate immune response in the recipient, thereby leading to BO. One hundred eighty-one donor-recipient pairs were analyzed for the association between NOD2 gene variants (SNP8 [Arg702Trp], SNP12 [Gly908Ara and SNP13 [Leu1007fsinsC]) and the occurrence of BO. Ten patients (2.8%) developed this complication. The incidence of BO increases in recipient variant patient group from 4.7% to 23% in donor Wild-type group in SNP8 (p < 0.001). The incidence rose to 19% when the recipient carried the SNP12 variant (p < 0.001) in the Tunisian population. Analyses demonstrated that recipient NOD2CARD15 variants (SNP8 and SNP12) present a greater risk in developing BO than recipients without mutation. Our study demonstrated that NOD2/CARD15 typing may be useful in identifying patients at high risk for BO.