Treatment of acute graft versus host disease with low dose-alternate day anti-thymocyte globulin

The efficacy of antithymocyte globulin (ATG) in the treatment of graft-versus-host disease (GvHD) is controversial. In the present study we report on the use of low dose ATG (thymoglobuline, Sangstat) and steroids in 28 patients with moderate to severe acute GvHD.

Fifteen patients received ATG as first-line treatment within 14 days of the diagnosis of GvHD (median 8 days, range 4-13). Twelve patients received ATG as second-line therapy, more than 14 days after diagnosis (median 32 days, range 14 to 98). The proportion of patients with severe (grade III-IV) GvHD at the time of ATG therapy was 4/15 in the former group and 7/13 in the latter (p=0.1).

On day 30 after ATG the overall proportion of responders was 80% in the group administered ATG early and 38% in those given it later (p=0.03). The overall actuarial 3-year transplant-related mortality was 40% vs 74% for the early vs late ATG groups (p=0.03); the actuarial 3-year survival was, respectively, 49% vs 23% (p=0.04). For patients with GvHD grade III-IV the actuarial 1-year TRM was 47% for those given ATG early, 87% for the late ATG group and 82% for a concurrent control group of 26 patients not treated with ATG.

In conclusion, ATG may be considered for early treatment of acute GvHD, within a few days from the onset of the disease. A prospective trial has been started to test whether, in this setting, low dose ATG with steroids is superior to steroids alone.