Transplant Conditioning Intensity (TCI) score

The Transplant Conditioning Intensity (TCI) score was developed to determine the intensity of conditioning regimen given before allogeneic hematopoietic cell transplantation (allo-HCT). The Acute Leukemia Working Party (ALWP) of European Society for Blood and Marrow Transplantation (EBMT) assigned intensity weight scores for frequently used components in the conditioning regimen, used their sum to generate the transplant conditioning intensity (TCI) score, and built a discrete 3-category stratification index (low, intermediate, high) according to the calculated TCI score ([1-2], [2.5-3.5], [4-6], respectively). In the discovery cohort of 8,255 patients with AML allografted between 2005-2017, TCI grouping was highly and better predictive for early (day 100 and 180) non-relapse mortality (NRM), 2-year NRM and relapse (REL) as compared with the classical myeloablative conditioning (MAC) and reduced intensity conditioning (RIC) classification (Bone Marrow Transplantation 2020; 55:1114). In a validation cohort of more than 4,000 patients transplanted in the most recent period (2018-2021), TCI could stratify the 48 different conditioning regimens particularly finely based on their impact on d100 and d180 NRM, and TCI group assignment was also a strong and independent predictor both for overall NRM and REL. Thus, TCI reflects the conditioning regimen related morbidity and anti-leukemic efficacy highly satisfactorily and across other established prognostic factors.