Validation of recently proposed consensus criteria for thrombotic microangiopathy after allogeneic hematopoietic stem-cell transplantation.
BACKGROUND
The lack of an accepted definition of transplantation-associated thrombotic microangiopathy (TMA) has led the Blood and Marrow Transplants Clinical Trials Network (CTN) and International Working Group (IWG) to propose a definition for TMA with some differences. However, there have been few studies validating and comparing both newly proposed criteria for TMA.


METHODS
To validate recently proposed criteria for TMA by CTN and IWG, we analyzed 672 patients who underwent allogeneic stem-cell transplantation between January 2002 and December 2006.


RESULTS
The cumulative incidences of TMA by CTN and IWG were 6.1% and 2.5%, respectively. The cumulative incidence of overall TMA (O-TMA) including probable-TMA defined as meeting CTN criteria without renal or neurologic dysfunction, as well as TMA by CTN (definite-TMA), was 12.7%. Sixty-six percent of TMA by CTN did not have any degree of schistocytosis by IWG criteria (≥4%), and 18% of TMA by IWG criteria did not have renal or neurologic dysfunction. On multivariate analyses, probable-TMA as well as definite-TMA adversely affected the survival of a cohort including all patients. In patients with O-TMA, the degree of schistocytosis (≥4% or not) failed to show prognostic significance, whereas renal involvement was a significant prognostic factor associated with poor survival.


CONCLUSIONS
Both proposed consensus criteria have major pitfalls in their use as uniformly accepted diagnostic criteria for TMA. The use of O-TMA as a broad definition for TMA and the grading system by the presence of renal involvement may be a counterproposal for future trials.
Cho
Byung-Sik
BS
Department of Internal Medicine, Catholic Blood and Marrow Transplantation Center, Seoul, Korea.
Yahng
Seung-Ah
SA
Lee
Sung-Eun
SE
Eom
Ki-Seong
KS
Kim
Yoo-Jin
YJ
Kim
Hee-Je
HJ
Lee
Seok
S
Min
Chang-Ki
CK
Cho
Seok-Goo
SG
Kim
Dong-Wook
DW
Lee
Jong-Wook
JW
Min
Woo-Sung
WS
Park
Chong-Won
CW
D000293:Adolescent; D000328:Adult; D000368:Aged; D003245:Consensus Statements as Topic; D005260:Female; D006086:Graft vs Host Disease / Q000453:epidemiology / Q000209:etiology / Q000401:mortality; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006650:Histocompatibility Testing; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010976:Platelet Count; D015203:Reproducibility of Results; D013921:Thrombocytopenia / Q000209:etiology; D057049:Thrombotic Microangiopathies / Q000453:epidemiology* / Q000209:etiology; D014184:Transplantation, Homologous / Q000009:adverse effects*
D007770:L-Lactate Dehydrogenase