Donor Cell Leukemia Following Allogeneic Hematopoietic Stem Cell Transplantation.

Approximately 25,000 allogeneic transplants are performed annually worldwide; a figure that has steadily increased over the past three decades. The study of transplant recipient survivorship has become a cogent topic and post-transplant donor cell pathology warrants further study. Donor cell leukemia (DCL) is a rare but serious complication of allogeneic stem cell transplantation (SCT) where the recipient develops a form leukemia originating from the donor cells used for transplantation. Detection of abnormalities predicting donor cell pathology might inform donor selection, and the design of survivorship programs for early detection of these abnormalities might allow therapeutic intervention earlier in the disease course. We present four recipients of allogeneic hematopoietic stem cell transplant (HSCT) from our institution who developed donor cell abnormalities allogeneic SCT, highlighting their clinical characteristics and challenges.

The Impact of Renal Impairment in Multiple Myeloma Patients Undergoing Autologous Stem Cell Transplantation With Melphalan Conditioning.

Background: There are no standard renal dose adjustments for melphalan conditioning for autologous stem cell transplantation (ASCT) in multiple myeloma (MM) patients. The objective of this study was to evaluate the effect of melphalan dosing and chronic kidney disease (CKD) on transplant-related outcomes, progression-free survival (PFS), and overall survival (OS). Methods: A retrospective chart review was performed, and MM patients who underwent ASCT between February 2016 and September 2021 were included. Melphalan 200 mg/m2 (Mel200) or 140 mg/m2 (Mel140) was administered. The cohort was divided based on renal function: creatinine clearance (CrCl) ≥ 60 mL/min (no-CKD) and CrCl < 60 mL/min (CKD). Outcomes measured include PFS, OS, treatment-related mortality (TRM), incidence of adverse events, hospitalization duration, and hospital readmission within 30 days. Statistical analysis included Chi-square test, t-test, and Kaplan-Meier method. Logistic regression model was used to account for melphalan dose adjustment. Results: A total of 124 patients were included (n = 108 no-CKD, and n = 16 CKD). Median age was 62 years, majority (62%) were male, and 97% had at least a partial response at time of ASCT. Of the 124 patients, nine (7%) received Mel140. Five of these patients had CKD (CrCl range: 26 - 58 mL/min), with one on hemodialysis. Median time to neutrophil engraftment was 13.6 vs. 14.9 days and median time to platelet engraftment was 18.3 vs. 18.5 days in the CKD group vs. no-CKD group, respectively (P = 0.03 and P = 0.8). When adjusting for melphalan dose reduction, the median time to neutrophil engraftment was not statistically significant (P = 0.11). At a median follow-up of 28.7 months, the median PFS for the CKD vs. no-CKD group was 60 vs. 46 months (P = 0.3). One-year OS was 93.8% in the CKD group vs. 97% in the no-CKD group. There was a higher incidence of grade 3 or 4 mucositis in the CKD group vs. no-CKD group (P = 0.013). Conclusions: There is no significant difference in engraftment, PFS, or OS for MM patients with CKD vs. no-CKD receiving melphalan conditioning for ASCT. Severe mucositis was significantly more common in the CKD group, including when accounting for melphalan dose reduction.