Acute graft-vs.-host disease correlates with the disparity for the PECAM-1 S536N polymorphism only in the HLA-B44-like positive Tunisian recipients of HSCs

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 [Gly908Arg], 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.

Role of non-HLA gene polymorphisms in graft-versus-host disease

A large number of reports have associated various non-HLA gene polymorphisms with the risk and severity of graft-versus-host disease (GVHD). To date, candidate gene studies and genome-wide association studies have been performed to investigate such non-HLA gene polymorphisms in relation to GVHD. Candidate gene studies are hypothesis-driven and cost-effective, whereas genome-wide association studies have the potential to discover new gene polymorphisms, including possible biomarkers and therapeutic targets. Some gene polymorphisms have the potential to affect protein function or gene expression, or to encode minor histocompatibility antigens. Non-HLA genotyping for genes influencing GVHD prior to transplantation should provide useful information that will facilitate choosing the donor, type of graft, conditioning treatment, and GVHD prophylaxis. However, attention should be paid to the need for validation studies and ethical issues.

Do FY antigens act as minor histocompatibility antigens in the graft-versus-host disease paradigm after human leukocyte antigen-identical sibling hematopoietic stem cell transplantation?

FY antigens are candidate minor histocompatibility antigens relevant to renal allograft rejection, but no data have been reported about their role in graft-versus-host disease (GVHD) incidence after human leukocyte antigen (HLA)-identical siblings hematopoietic stem cell transplantation (HSCT). The aim of this study was to examine the effect of donor/recipient disparity at FY antigens on the incidence of GVHD in Tunisian patients receiving an HLA-identical HSCT. This work enrolled 105 Tunisian pairs of recipients and their HLA-identical sibling donors of HSCs. FY genotyping was performed with the polymerase chain reaction-sequence-specific primer method and donor/recipient disparity for these antigens was analyzed at two levels: incompatibility and nonidentity. The case-control analyses showed no significant correlation between FY disparity and the incidence of either acute or chronic GVHD. Sample size calculation showed that 572 cases and 1716 controls would be necessary to be able to detect a significant association with 80% power and two-sided type I error level of 5% (α=0.05). The lack of association in the studied cohort may be explained by the low immunogenicity of FY antigens in HSCT context, compared with other antigens such as HA-1 and CD31.