Desiccating Stress Significantly Increases the Risk for Chronic Ocular Graft-versus-Host-Disease.

Desiccating stress (DS) is known to induce dry eye disease but has not been studied in the context of ocular graft-versus-host disease (oGVHD). Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) are exposed to DS on transplantation wards, which are highly climate-regulated for hygienic purposes. Because oGVHD demonstrates features of dry eye disease, this retrospective study aimed to analyze DS as a risk factor for chronic oGVHD. A total of 444 patients undergoing allo-HSCT were investigated with a maximum follow-up of 5.8 years post-transplantation. Relative humidity (%rH) on the transplantation ward was monitored, and data were correlated with the occurrence, severity, and onset of chronic oGVHD, as well as the occurrence of acute skin GVHD. A logistic regression model was used to predict the development of oGVHD. One hundred three of 213 surviving patients developed oGVHD. oGVHD was significantly correlated with a lower %rH (r = .2; P = .03), and more patients (73%) developed oGVHD after transplantation under DS compared with patients after transplantation under high-humidity conditions (30%; P = .02). Reduced humidity increased the relative risk for oGVHD by 4% for each %rH, but it did not affect the severity or time of first diagnosis of oGVHD. In this study, we demonstrate that DS is an independent risk factor for oGVHD. Adjusting air humidity during allo-HSCT has the potential to serve as a preventive measure with clinical relevance.