Real Time Immunophenotyping of Leukocyte Subsets Early after Double Cord Blood Transplantation Predicts Graft Function.

Cord blood transplantation (CBT) recipients are at increased risk for delayed engraftment and primary graft failure, complications that are often indistinguishable early post-transplantation. Current assays fail to accurately identify recipients with slow hematopoietic recovery and distinguish them from those with pending graft failure. To address this, we prospectively examined the kinetics of immune cell subset recovery in the peripheral blood of 39 patients on days +7 and +14 after double-unit CBT (dCBT) by multiparametric flow cytometry analysis, which we term real-time immunophenotyping (RTIP). RTIP analysis at day +14 revealed distinctive patterns of reconstitution and, importantly, identified patients with slow hematopoietic recovery who went on to engraft. Strikingly, higher absolute numbers of circulating monocytes and natural killer cells at day +14 were predictive of engraftment, but only the absolute number of circulating monocytes was significantly correlated with time to engraftment. This is the first evidence that RTIP on patient peripheral blood mononuclear cells early after dCBT is technically feasible and can be used as a "signature" for predicting the kinetics of hematopoietic recovery. Furthermore, RTIP is a time- and cost-efficient methodology that has the potential to become a clinically feasible diagnostic tool to guide therapeutic interventions in high-risk patients; therefore, its utility should be evaluated in a large cohort of patients.

Re-evaluation of progenitor thresholds and expectations for haematopoietic recovery based on an analysis of 810 autologous transplants: Implications for quality assurance.

Haematological engraftment was assessed in 804 autologous transplants. Neutrophil recovery occurred in over 99% within 14 d but platelet recovery was delayed beyond this time in 14·8%. Time to recovery was dependent on the progenitor cell dose infused. The minimum CD34+ cell threshold adopted in this study (2 × 106 /kg) was safe although recovery was faster with a dose >5 × 106 /kg. CD34+ cell doses of between 1 and 2 × 106 /kg were also acceptable if either the granulocyte-macrophage colony-forming cell dose exceeded 2 × 105 /kg or this dose was due to splitting a higher yield harvest. Prompt neutrophil recovery affords important quality assurance for laboratory processing.

Optimisation and quality control of cell processing for autologous stem cell transplantation.

Clinical practice and the technology of cell processing for autologous stem cell transplantation has continued to evolve over the last two decades and merits review of current quality control expectations. The external regulatory era has improved quality and safety standards but there is still variable practice, with specific risks illuminated by a number of clinical incidents. Viable CD34+ cell assays may fail to indicate significant losses in progenitor function during storage, particularly after cryopreservation, and there is a need to develop an alternative, real time functional assay to replace colony assays. The ultimate guide to potency and successful cell processing for haematopoietic progenitor cell products is prompt and reproducible engraftment and close monitoring is essential for safety and quality control.

Multiple Myeloma: Impact of Time to Transplant on the Outcome.

BACKGROUND: Autologous stem cell transplant (ASCT) is a standard therapy for transplant eligible patients of multiple myeloma (MM). To evaluate impact of time to transplant on subsequent outcomes, we analyzed data on consecutive MM patients who received novel agents-based induction prior to transplant. METHODS: Between 2006 and 2019, 363 MM patients underwent ASCT. Patients' median age was 52 years, ranging from 20 to 72 years, 233 (64.2%) were males. Median interval from diagnosis to transplant was 11.5 months (range, 4-67.5); 201 (55.4%) patients underwent ASCT within 12 months (early) and 162 (44.6%) beyond 12 months since diagnosis (delayed ASCT). Primary objective was progression-free survival. Secondary objectives were-response rate to transplant, overall survival (OS), and transplant-related mortality (TRM). RESULTS: Post-ASCT complete response (CR) (77.1% vs. 64.8%; P < .025) and CR+ very good partial response rate (89% vs. 81.5%; P < .03) was higher for early ASCT cohort. Engraftment characteristics, regimen-related toxicities, and day +100 TRM (3.5% vs 3.7%; P = .564) were similar in 2 cohorts. Median OS for early versus late cohort from date of diagnosis is 127.0 (95% CI, 98.9-155.1) versus 104.5 months (95% CI, 79.3-129.6; P = .356) and from date of transplant is 119.0 (95% CI, 93.4-144.6) versus 89.5 months (95% CI, 57.4-121.6), P < .02. Median PFS is better for early transplant cohort; 69.5 (95% CI, 56.7-82.3) versus 50.0 months (95% CI, 35.6-64.4), P < .05, respectively. CONCLUSION: Early transplant for myeloma is associated with higher response rate and better progression-free survival.

Allogeneic Peripheral Blood Stem Cell Transplant: Correlation of Donor Factors with Yield, Engraftment, Chimerism, and Outcome: Retrospective Review of a Single Institute During a 3-Year Period.

BACKGROUND: Donor factors have a variable correlation with cluster of differentiation (CD)34+ cell dose in allogeneic peripheral blood stem cell (PBSC) harvests. CD34+ cell dose affects the speed of hematopoietic recovery and percentage of donor chimerism in the recipient. METHODS: A total of 25 allogeneic PBSC transplants performed during a 3-year period were included. All donors underwent mobilization with filgrastim. Leukapheresis, flowcytometric CD34+ cell enumeration, and chimerism analysis were performed and correlated with recipient outcome. RESULTS: Besides age, all other donor parameters had a positive correlation with CD34+ cell count. Engraftment kinetics and chimerism had a positive correlation with the CD34+ yield of the PBSC product. Acute graft-vs-host disease (GVHD) was observed in patients with complete chimerism at day 30 after transplantation. CONCLUSION: Adequate CD34+ cell yield happens in healthy donors, independent of donor demographic patterns with G-CSF only. A diverse population of donors can thus be approached for Matched Unrelated Donor (MUD) transplants. An accurate quantitative analysis of early donor chimerism in the recipient (at day 30) is an excellent tool for post-transplant monitoring for acute GvHD.