Comparison of Outcomes After Second Allogeneic Hematopoietic Cell Transplantation Versus Donor Lymphocyte Infusion in Allogeneic Hematopoietic Cell Transplant

Allogeneic hematopoietic cell transplantation is potentially curative for hematological diseases however relapse and graft failure remains major causes of treatment failure. We examined the outcomes of DLI and second-HCT for each entity; we observed second-HCT demonstrates superior survival for relapse compared to DLI. Donor mismatch, KPS and time from first-HCT to intervention are predominant independent prognostic factors influencing survival. Background: Allogeneic hematopoietic cell transplantation (HCT) is potentially curative for hematological disease however can be complicated by relapse or graft failure (GF), for which second-HCT and donor lymphocyte infusions (DLI) are performed. This study aimed to compare outcomes following the two interventions. Methods: We retrospectively investigated 89 patients with relapse or GF after first-HCT, 50 (56%) underwent second HCT and 39 (44%) received (DLI), from June 2011 to September 2020. Results: Median age at intervention was 55 years (19-72). Second-HCT was performed for relapse in 19 patients and for GF in 31 patients (primary GF in 11 and secondary in 20 patients), same donor was used in 25 (50%) patients. DLI was performed for relapse in 20 and for secondary GF in 19 patients. Median number of DLI administered was 2 (range 1-11). Univariate analysis demonstrated 2 year overall survival (OS) for second-HCT was superior when performed for relapse (65%) compared to GF (44%) (P = .03). For DLI patients, 2 year OS was 49% for GF and 45% for relapse patients (P = .49). For relapse as an indication, second-HCT demonstrated border line superiority compared to DLI (P = .07). Multivariable analysis demonstrated for OS for the entire cohort demonstrated donor mismatch (HR 0.50, 95% CI 0.26%-0.94%, P = .03), KPS at time of intervention (HR 2.10, 95% CI 1.14%-3.85%, P = .02) and time from first-HCT to intervention (HR 0.51, 95% CI 0.28%-0.93%, P = .03) as significant variables. Conclusion: Second-HCT may improve outcomes when performed for relapse post-transplant if patients achieve remission again, while DLI may be reserved for patients with active disease.

Automated summary

Allogeneic hematopoietic cell transplantation is a potential cure for hematological diseases, but relapse and graft failure remain major causes of treatment failure. This study compared the outcomes of donor lymphocyte infusions (DLI) and second-HCT for patients with relapse or graft failure after the first transplantation. The results showed that second-HCT had better survival rates for relapse patients compared to DLI. Donor mismatch, Karnofsky Performance Status (KPS), and time from first-HCT to intervention were identified as independent prognostic factors for survival.