Prognostic Factors on Survival After Hematopoietic Stem Cell Transplantation for Adult Over 40 Years In Aplastic Anemia.
Authors: Kim Hawk , Kwak Jae-Yong , Kim Byung Soo , Kim Sung Hyun , Bae Sung-Hwa , Sohn Sang Kyun , Shin Ho-Jin , Won Jong-Ho , Yoon Sung-Soo , Jo Deog-Yeon , Joo Young-Don , Choi Jung Hye , Hyun Myung Soo , Lee Kyoo Hyung 
Published: October 2019

Abstract
Abstract 1315
Younger age is an important favorable prognostic factor to undergo HSCT in adult patients with AA, however what makes the poor survival in elderly patients is not well known. In this study we analyzed the age factor on HSCT in adult AA. A total 225 adult AA patients who had undergone HSCT were enrolled in this study. The age at the time of HSCT in 57 patients were over 40 yrs (elderly group) and 168 patients were less than 40 years (younger group). Adult over than 40 years had poor survival (5 year survival rate [5YSR] 55.1% vs. 76%; p=0.003) and this tendency maintained not only in MRD setting (5YSR 58.2 vs. 82.1%; p=0.003) but also in AD setting (4YSR 43.2% vs. 63.2%; p=0.109). We explored the prognostic factors of age over 40 years. Gender (p=0.642), prior IST (p=1.0), time from diagnosis to HSCT (p=0.348), donor type (p=0.479), HLA matching (p=0.311), ABO incompatibility (p=0.504), conditioning regimen (p=0.412), use of BM as stem cell source (p=0.456), infused CD34+ cells (p=0.478) were not different between elderly and younger groups. Compared with younger group, patients in elderly group had similar HSCT results in terms of engraft failure (p=0.848), neutrophil engraftment (p=1.0), platelet engraftment (p=0.104), SOS (p=0.591), aGvHD (p=0.445), cGvHD (p=0.105), grade of cGvHD (p=0.321), resolution of cGvHD (p=0.503) and relapse after HSCT (p=0.754). The causes of death had no statistical differences between 2 groups; infection (84.2% vs. 69.7%; p=0.328), engraft failure (5.3% vs. 21.2%; p=0.232), GvHD (20.0% vs. 18.2%; p=1.0). The more units of PC transfusion (p=0.061), more female to male matching (p=0.089), delayed time to ANC>500/μ(median 17 vs. 15 days; p=0.012) and delayed time to ANC>1000/μ(median 19 vs. 17 days; p=0.008) were noted in elderly group. Days for platelet engraftment were not different (p=0.485). Univariate analysis for survival in elderly group showed followings: gender (p=0.406); prior IST (p=0.104); donor type (p=0.475); HLA matching (p=0.052); female to male (p=0.857); ABO incompatibility (p=0.943); BM as a stem cell source (p=0.697); TBI as conditioning (p=0.467); ATG as conditioning (p=0.989); engraft failure (p=0.006); SOS (p=0.001); aGvHD (p=0.689); G3/4 aGvHD (p=0.024); cGvHD (p=0.545); extensive cGvHD (0.701). Mutivariate analysis revealed engraft failure (HR 2.839, 95% CI 1.012–7.967; p=0.047) and VOD (HR 5.972, 95% CI 1.597–22.331; p=0.008) were significant prognostic factors for survival.
No prior IST, HLA full matching, successful engraftment, no SOS and no grade 3/4 aGvHD were the predictors of favorable survival in patients over 40 years old with AA. In conclusion, to prolong the HSCT survival for adult over 40 years in AA, HSCT without IST, full HLA matching, the prevention of engraft failure by using PB as a stem cell source and active management of SOS and effective GvHD prevention should be considered.

Disclosures:
No relevant conflicts of interest to declare.