Circulating hematopoietic progenitors and CD34+ cells predicted successful hematopoietic stem cell harvest in myeloma and lymphoma patients: experiences from a single institution

Abstract

BackgroundPrevious studies have shown that the numbers of both circulating hematopoietic progenitor cell (HPC) and CD34+ cell are positively correlated with CD34+ cell harvest yield. However, the minimal numbers of both circulating HPCs and CD34+ cells required for performing an efficient hematopoietic stem cell (HSC) harvest in lymphoma and myeloma patients have not been defined in our institution.Patients and methodsMedical records of 50 lymphoma and myeloma patients undergoing peripheral blood HSC harvest in our institution were retrospectively reviewed. The minimal and optimal HSC harvest yield required for the treatment was considered to be ≥2×106 CD34+ cells/kg and ≥5×106 CD34+ cells/kg, respectively.ResultsThe minimally required or optimal HSC yield obtained was not influenced by age (≥60 years), sex, underlying malignancies, disease status, multiple rounds of chemotherapy, or history of radiotherapy. The numbers of both circulating HPC and CD34+ cell were higher in patients with minimally required HSC yields (P=0.000 for HPC and P=0.000 for CD34+ cell) and also in patients with optimal HSC yields (P=0.011 for HPC and P=0.006 for CD34+ cell). The cell count cutoff for obtaining minimally required HSC harvest was determined to be 20/mm3 for HPCs and 10/mm3 for CD34+ cells. Furthermore, the cell count cutoff for obtaining optimal HSC harvest was determined to be 60/mm3 for HPCs and 35/mm3 for CD34+ cells.ConclusionA total of 60/mm3 of HPCs and 35/mm3 of CD34+ cells in peripheral blood predicted optimal HSC harvest in lymphoma and myeloma patients.

Determination of mononuclear cell count using peripheral smear and flow cytometry in peripheral blood stem cell products

“…predicted that circulating 60 HPCs/μl and 35 CD34+ cells/μl were estimated to be the probably cutoff cell counts for predicting optimal (CD34 ≥5 × 10 6 /kg) hematopoietic stem cell collection. [ 8 ] From our results, it was clear that only CD34+ cell counts and not MNC counts in peripheral blood reliably predict the number of CD34+ cells in the harvest [ Table 3 ]. Peripheral blood CD34 cell count of 37 cells/μl best correlated with CD34 yield of ≥2 × 10 6 in PBSC product and was comparable with other published literature.…”

“…As correlation methods study only the relationship between one variable over another and not their differences, regression analysis was preferred to study the data distribution and to look for constant or proportional difference between two methods. [ 8 ] The peripheral smear and flow cytometry methods had a moderate positive correlation level ( r = 0.52), but with a significant deviation from the linearity in regression methods, as shown in Figure 3 . There was a significant systematic difference, that flow cytometry method constantly under- or overestimates MNC count enumeration compared to peripheral smear method ( P = 0.04) in the study.…”

“…[ 9 ] Few studies had tried circulating hematopoietic progenitor cells (HPCs), an estimate by counting immature cells using Sysmex automated hematology analyzer as an alternate surrogate for PBSC harvest prediction. [ 8 ] Yu JT et al . predicted that circulating 60 HPCs/μl and 35 CD34+ cells/μl were estimated to be the probably cutoff cell counts for predicting optimal (CD34 ≥5 × 10 6 /kg) hematopoietic stem cell collection.…”

“…Peripheral blood CD34 cell count of 37 cells/μl best correlated with CD34 yield of ≥2 × 10 6 in PBSC product and was comparable with other published literature. [ 8 ]…”

Study of stem cell homing & self-renewal marker gene profile of ex vivo expanded human CD34+ cells manipulated with a mixture of cytokines & stromal cell-derived factor 1

“…Others have reported importance of absolute numbers of CD34 + cells for successful engraftment in human transplant cases 4 32 . A significant increase has been observed in absolute numbers of CD34 in ex vivo expanded cultures and human CD45 in in vivo model in our study.…”