Antilymphocyte/Thymocyte Globulin for the Treatment of Steroid-Refractory Acute Graft-Versus-Host Disease: 20-Year Experience at a Single Center.

Abstract

Although there is currently no consensus regarding the treatment of steroid-refractory acute graft-versus-host disease (GvHD) after hematopoietic stem cell transplantation (HSCT), antithymocyte globulin (ATG) is one of the most widely used immunosuppressive drugs in this setting. We retrospectively summarized our transplant center’s experience with 35 steroid-resistant acute GvHD patients who were treated with three different ATG preparations. Severe (grade III-IV) acute GvHD was observed either during the posttransplantation period (n= 32) or after donor lymphocyte infusion (n= 3). For secondary treatment of acute GvHD, rabbit Jurkat cell linereactive ATG (ATG Fresenius®) (n= 22), rabbit thymus cell-reactive ATG (Thymoglobulin®) (n= 9) or equine antilymphocyte globulin (ALG) (Lymphoglobulin®) (n= 4) was administered at a dose of 2-10 mg/kg/day for five consecutive days. The median time from the diagnosis of acute GvHD to the first day of infusion of ATG or ALG was 15 days (3-70 days). An overall response was observed in 15 patients (42%), with similar response rates among patients treated with any of the three ATG preparations. The overall survival (OS) of the patients did not increase in any treatment group, though the severity of GvHD and the disease status before HSCT were shown to negatively impact OS. Although responses could be achieved in steroid-refractory acute GvHD using rabbit or horse ATG, survival rates did not increase because of high mortality rates due to infection during treatment.