Fragmented Red Cell as a Possible Favorable Prognostic Marker of Hematopoietic Stem Cell Transplantation Associated Thrombotic Microangiopathy

Background: Fragmented red cell (FRC) by automated hematologic analyzer is known to detect schistocyte. In this study, it is noted that FRC might be a favorable prognostic marker of hematopoietic stem cell transplantation associated thrombotic microangiopathy (TA-TMA). Methods: The peripheral blood samples and clinical data of 89 patients were collected. The diagnosis of TA-TMA was defined by the Blood and Marrow Transplant Clinical Trials Network's criteria and schistocyte or both schistocyte- and FRC-positive cases and other parameters fulfilled are regarded as TA-TMA. Results: Schistocyte and FRC displayed a correlation coefficient of 0.461 (P < 0.001) by Spearman's method. The diagnostic concordance of TA-TMA using schistocyte and FRC was 92.1% with kappa index of 0.531 (P < 0.001). The number of diagnosed patients and mean survival month were as follows: TA-TMA by schistocyte, 8 (8.9%), 13.5 month; TA-TMA by schistocyte and FRC, 7 (7.8%), 40.4 month; No TMA, 74 (83.1%), 38.3 month, respectively. Kaplan-Meier survival analysis by log-rank method of the patient with TA-TMA by schistocyte and rest of the group showed statistical significance (P < 0.01). Conclusion: As evidenced by the data, FRC might be a favorable prognostic marker for TA-TMA, but additional studies with larger patients groups are required for validation of clinical applications.