Moiseev IS, Tsvetkova T, Aljurf M, Alnounou RM, Bogardt J, Chalandon Y, Drokov MY, Dvirnyk V, Faraci M, Friis LS, Giglio F, Greinix HT, Kornblit BT, Koelper C, Koenecke C, Lewandowski K, Niederwieser D, Passweg JR, Peczynski C, Penack O, Peric Z, Piekarska A, Ronchi PE, Rovo A, Rzepecki P, Scuderi F, Sigrist D, Siitonen SM, Stoelzel F, Sulek K, Tsakiris DA, Wilkowojska U, Duarte RF, Ruutu T, and Basak GW
Transplant-associated thrombotic microangiopathy (TA-TMA) is a life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT). This study evaluated clinical and morphological practices of TA-TMA diagnosis in EBMT centers. Two questionnaires, one for transplant physician and one for morphologist, and also a set of electronic blood slides from 10 patients with TA-TMA and 10 control patients with various erythrocyte abnormalities, were implemented for evaluation. Seventeen EBMT centers participated in the study. Regarding criteria used for TA-TMA diagnosis, centers reported as follows: 41% of centers used the International Working Group (IWG) criteria, 41% used "overall TA-TMA" criteria and 18% used physician's decision. The threshold of schistocytes to establish TA-TMA diagnosis in the participating centers was significantly associated with morphological results of test cases evaluations (p = 0.002). The mean number of schistocytes reported from blood slide analyses were 4.3 ± 4.5% for TA-TMA cases (range 0-19.6%, coefficient of variation (CV) 0.7) and 1.3 ± 1.6% for control cases (range 0-8.3%, CV 0.8). Half of the centers reported schistocyte levels below 4% for 7/10 TA-TMA cases. The intracenter variability was low, indicating differences in the institutional practices of morphological evaluation. In conclusion, the survey identified the need for the standardization of TA-TMA morphological diagnosis.