Acute graft-versus-host disease (GVHD)
Despite adequate posttransplantation immunosuppressive therapy, acute GVHD remains a major cause of morbidity and mortality in this setting, even when HLA-identical siblings are used as stem cell donors. Up to 30% of the recipients of stem cells or BMT from HLA-identical related donors and most patients receiving cells from other sources (matched unrelated, non-HLA-identical siblings, cord blood) will develop grade ≥2 acute GVHD (Basara et al., 2001; Chao et al., 1993; Goker et al., 2001; Martin et al., 2011; Pidala, 2011).
In this section we will review clinical aspects relevant to the care of patients with this complication.
Definition and staging
Traditionally, the definition of acute and chronic GVHD has followed a chronological approach. Arbitrarily, day 100 posttransplantation has been the dividing line between acute and chronic GVHD. Indeed, the majority of acute and chronic GVHDs occur before and after day 100, respectively. However, because we have gained new insights on these diseases and have become more aware of the existence of acute GVHD after day 100, these two diseases are best differentiated clinically (Couriel et al., 2005; Mielcarek et al., 2003).