Association between Regimen Related Toxicity and Acute-Graft-Versus-Host Disease.

Tissue injury resulting from preparative therapy for transplantation is integral to the development of acute graft-versus-host disease (GVHD) according to current theory. If toxicity to normal tissues is a critical factor in the pathophysiology of GVHD, greater degrees of regimen related toxicities should be associated with a higher incidence and greater severity of GVHD. We analyzed 438 patients who underwent allogeneic transplantation from related (n=360) or unrelated (78) donors and who survived > 100 days following transplantation. Patients had received preparative regimens of BuCy (n=340) or BuCyVP16 (n=98). Median age was 36 (range 4–66). There were 263 males and 175 females. This cohort survived a median of 35 months (range 3 months to 20 years).

Sixty-eight of these patients had developed (Bearman) grade 3-4 regimen related toxicities. These patients had a 50% incidence of acute GVHD > grade II and a 26% incidence of developing GVHD ≤ grade II, compared to significantly lower incidences of 33% (P=.01) and 14% (P=.02) respectively in the group experiencing < grade 3 regimen related toxicity. Exclusion of patients whose GVHD prophylactic regimens were significantly altered because of toxicity did not significantly influence these results.

This data suggest that patients who develop severe regimen related toxicity are significantly more likely to develop severe acute GVHD, supporting a potential pathophysiologic role for tissue injury in the development of acute GVHD.