Comparison of Outcomes of Two Preparative Regimens for Lymphoma Patients Who Are Receiving Autologous Hematopoietic Stem Cell Transplantations

Abstract

incidence of infection (median 3 infections vs. RIC median 2 infections, p1⁄40.0001). Infection incidence was significantly increased in patients receiving ATG compared to those not receiving ATG (median 3 vs. 2, p1⁄40.0003). The relative increase in infections with ATG was more pronounced in RIC (+ATG median 3 vs eATG median 1) than in MAC (+ATG median 4 vs. eATG median 3). In both RIC and MAC, ATG use was associated with increased numbers of CMV (112 vs. 61), HHV6 (47 vs. 13), and HSV (32 vs. 8) infections. The relative increase in infection incidence for +ATG patients in RIC (CMV 2.5-fold, HHV6 10.5-fold, HSV 6.5-fold increase) was greater than the increase seen for +ATG patients in MAC (CMV 1.46-fold, HHV6 2.36-fold, HSV 3.17-fold increase). Similar rates of severe (grade 3-4) aGVHD were observed in +ATG patients compared to eATG patients (17.5% vs. 14.95%, p1⁄40.72) through day 180, indicating a potential protective effect of ATG in unrelated/mismatched transplants. In RIC, a nonsignificantly greater proportion of +ATG patients developed severe aGVHD (19.4%) compared toeATG patients (12.9%). The rates of relapse/death were not different between ATG groups (29.91% for eATG and 39.68% for +ATG), and groups had similar mean times to relapse (148 days foreATG and 138 days for +ATG). At 180 days, survival was 83.2% for eATG and 71.4% for +ATG (p1⁄40.0426). Conclusion: Our study demonstrates that ATG use increases infection rates in alloHCT patients, with greater impact in the RIC setting. Although relapse rates were similar between groups, the 180-day mortality for +ATG was significantly greater than eATG, suggesting that infectious complications may impact mortality associated with ATG.