Pre-transplant comorbidity burden and post-transplant chronic graft-versus-host disease.

The Haematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) was designed as a predictor of non-relapse mortality after HCT. Chronic graft-versus-host disease (GVHD) contributes to mortality after HCT. Here, we investigated whether the HCT-CI could predict development of chronic GVHD or post-chronic GVHD mortality. We retrospectively analysed data from 2909 patients treated with allogeneic HCT for malignant and non-malignant haematological conditions at four institutions. In Cox regression models adjusted for potential confounders, increasing HCT-CI was not statistically significantly associated with the development of chronic GVHD [hazard ratio (HR) = 1·02, P = 0·34]. Yet, the index was associated with an increased risk of non-relapse mortality (HR = 1·29, P < 0·0001) as well as overall mortality (HR = 1·25, P < 0·001) following the development of chronic GVHD. The association between HCT-CI and post-chronic GVHD mortality was similar regardless of donor type or stem cell source. HCT-CI scores could be incorporated in the design of clinical trials for treatment of chronic GVHD.