Response-guided therapy for steroid-refractory acute GVHD starting with very-low-dose antithymocyte globulin

Treatment for steroid-refractory acute graft-versus-host disease (GVHD) has not been established yet. In this article, we report a single-center experience with rabbit antithymocyte globulin (ATG) for the treatment of steroid-refractory acute GVHD. We retrospectively analyzed 11 consecutive patients between December 2009 and December 2013. ATG was given at an initial dose of 1.0 mg/kg for all but one patient with gradual dose escalation while assessing responses. The overall improvement at day 28 was 55% after a median of two treatments (range: 1-5), and a median dose of 3 mg/kg (range: 1.0-11.75 mg/kg) of ATG. Patients with skin (100%, 3/3) and gut (83%, 5/6) responded favorably, whereas the cases with liver involvement showed poor responses (25%, 1/4). The overall survival and transplant-related mortality at 1 year were 55% and 45%, respectively. There were no patients who had developed a post-transplant lymphoproliferative disorder. We suggest that response-guided ATG therapy could be an option for patients with steroid-refractory GVHD, without increasing the incidence of opportunistic infections.