Fig. 1

Overview of the study design. We aimed to identify specific epigenetic marks in peripheral blood of healthy graft donors that delineate aGVHD severity in HLA-matched sibling recipients prior to HSCT. At the discovery stage, we assessed genome-wide DNA methylation levels in peripheral blood of 85 HSCT donors, matched to recipients with various transplant outcomes, that is, ‘severe’ aGVHD (grades III + IV; n = 9) and ‘no/mild’ aGVHD (grades 0, I + II; n = 76). HSCT recipients received reduced-intensity (non-myeloablative) T cell-depleted conditioning using in vivo alemtuzumab. At the replication stage, we used a semi-quantitative DNA methylation assay, MethyLight, which can be easily used in a clinical setting. We validated the top-ranked differentially methylated positions associated with aGVHD severity status in donors in the context of both T cell-depleted and T cell-replete conditioning regimens for HSCT