REPRODUCIBILITY IN RETROSPECTIVE GRADING OF ACUTE GRAFT-VERSUS-HOST DISEASE AFTER ALLOGENEIC MARROW TRANSPLANTATION

We have undertaken a formal study to evaluate the reproducibility of r etrospective assessments for grading the severity of acute GVHD, Using criteria previously established by the Seattle group, three reviewers independently assigned GVHD severity grades for a set of 100 marrow t ransplant patients, Significant differences were found in the distribu tion of GVHD grades assigned by one of the reviewers as compared to th e other two reviewers. In only 40% of cases did all three reviewers as sign the same GVHD grade, and in only 68-71% of cases did all three re viewers assign the same grade within 0-I vs II-IV_or 0-II vs III-IV ca tegories, Despite the high rate of disagreement between any two review ers, at least two reviewers assigned the same overall GVHD grade in 93 % of cases, These results suggest that current criteria for assessing the severity of GVHD by a single reviewer are not sufficiently reliabl e for rigorous clinical studies, As an alternative to the original cri teria, we have developed and tested simplified criteria that summarize the clinical course of GVHD as reflected by the progression of diseas e and the amount of immunosuppressive treatment used to control the di sease, Our results suggest that the revised criteria might yield more reproducible retrospective grading than the original criteria, Althoug h the original criteria and the revised criteria might produce differe nt results for individual patients, the overall distributions of grade s with the two systems were similar, The proposed revised criteria cou ld be implemented without disrupting the continuity and consistency wi th previous grading assigned by the original criteria.