Early Deaths After Allogeneic Stem Cell Transplantation in Adult T Cell Leukemia/Lymphoma (ATLL) Patients - A Single Institute Retrospective Analysis
Authors: Takeuchi Shogo , Nakano Nobuaki , Kubota Ayumu , Takatsuka Yoshifusa , Tokunaga Mayumi , Itoyama Takahiro , Utsunomiya Atae , Yonekura Kentarou 
Published: October 2019

Abstract
Abstract 4503

Backgrand
Adult T cell leukemia/lymphoma (ATLL) is a highly aggressive hematological malignancy caused by a human T cell lymphotropic virus type 1 (HTLV-1), and has a poor prognosis. In order to improve the outcome, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is increasingly used as a curative option. However, 3-year overall survival rate is low with approximately 30% and incidence of non-relapse mortality is so high that incidence of early deaths would be increased. Therefore, it is necessary to consider its indication. Here we clarify the factors of early deaths within 100 days after allo-HSCT retrospectively in our single institute located in endemic area of ATLL.

Methods
There were 59 ATLL patients underwent allo-HSCT at Imamura Bun-in Hospital from June 1998 to March 2011. We analyzed the clinical characteristics of 13 patients died within 100 days after allo-HSCT compared with 46 patients alive over 100 days retrospectively.

Results
In 13 patents, median age was 52 (range: 40–59) years. Eight patients were male and 5 female. All patients diagnosed as acute type ATLL. ECOG performance status at HSCT were 1 in 11 patients and 2 in 2 patients. Disease status at HSCT was CR in 3 patients and non-CR in 10 patients (SD 2, PD 8). HCT-CI scoring was 0 in 3 patients, 1 in 3 patients, 2 in 4 patients, and over 3 in 3 patients, included 2 CR, respectively. Six patients received BMT, 6 PBSCT, and 1 CBT, respectively. Nine patients underwent HSCT from HLA-identical siblings. Six out of 9 had received conventional stem cell transplantation (CST) and 3 reduced-intensity stem cell transplantation (RIST). Four of 9 were transplanted from HTLV-1-carrier donors. HLA matching were 6/6 in 5 patients, 5/6 in 5 patients, and 4/6 or 3/6 in 3 patients, respectively. Eleven patients could evaluate acute GVHD (a-GVHD). Four patients out of 11 complicated with grade 0–1 a-GVHD, 4 grade 2, 2 grade 3, and 1 grade 4, respectively.The causes of death were TMA in 4 patients, disease progression of ATLL in 3 patients, acute GVHD in 3 patients, sepsis in 2 patients, GI bleeding in 1 patient, respectively. Median time to HSCT from initial chemotherapy was 187 (100–294) days and median survival time after HSCT was 54 (10–98) days, respectively. In univaiate analysis, significant factors contributed to early death were HLA mismatched donors (p<0.001) and high value of soluble IL-2 receptor at HSCT (p<0.001). PD status at HSCT (P=0.12), over 3 HCT-CI score (P=0.47), RIST (P=0.85), grade II-IV of a-GVHD (P=0.46), and high levels of LDH were not contributed to incidence of early death, respectively.

Conclusion
Although our study was based on relatively small number of patients, high incidence of early death, within 100 days after allo-HSCT, have shown. HLA disparity and high value of soluble IL-2 receptor at HSCT contributed to incidence of early death. Our results suggest that it should be considered not only disease status, including value of soluble IL-2 receptor at HSCT, but also HLA matching when planning to undergo HSCT for ATLL recipients.

Disclosures:
No relevant conflicts of interest to declare.