ORAL PROTEIN-INTAKE AND THE RISK OF ACUTE GRAFT-VERSUS-HOST DISEASE AFTER ALLOGENEIC MARROW TRANSPLANTATION

The possibility that antigenically active protein macromolecules affect the risk of developing acute graft-versus-host disease (aGVHD) was investigated in a cohort of patients who underwent allogeneic marrow transplantation for hematologic malignancy (n = 575). Daily records of food intake from transplant through discharge or death were evaluated for grams of total protein and summed over consecutive 4-day intervals. The day of onset of aGVHD was partitioned into 4-day time intervals such that assessments of food intake preceded onset of aGVHD by 3-6 days. Acute GVHD developed in 308 (54%) patients. The cumulative incidence of aGVHD among patients eating any amount of protein was lower (4-13%) than that of patients not eating protein (8-19%) for each of the time intervals through day 21 post-transplant; the relative risk associated with protein intake, adjusted for patient and transplant characteristics that are correlated with the occurrence of aGVHD, ranged from 0.23 (95% confidence interval (CI) 0.09, 0.63) to 0.83 (CI 0.46, 1.51). A proportional hazards regression analysis, using protein intake as a time-dependent covariate, confirmed these results. The findings of this study provide no support for the hypothesis that intake of protein-containing foods during the first 3 weeks after marrow transplantation increases the risk of aGVHD.