Impact of age and diagnosis on viability during centrifugation and cryopreservation of peripheral blood stem cell products

Loss of CD34+ Cells and Effect of the Number of Viable Cryopreserved CD34+ Cells in the Infused Blood Grafts on Hematologic Recovery, Progression-Free Survival and Overall Survival in NHL Patients After Autologous Stem Cell Transplantation

PATIENTS

This post-hoc study aimed to find out factors affecting graft viable CD34+ cell loss during processing and cryopreservation in 129 non-Hodgkin lymphoma (NHL) patients receiving autologous stem cell transplantation (auto-SCT) and the impact of a low (< 2.0 × 106/kg, group A) and a decent number (≥ 2 × 106/kg, group B) of viable CD34+ cells infused on the hematologic recovery, progression-free survival (PFS) and overall survival (OS) after auto-SCT.

RESULTS

The median loss of viable CD34+ cells during cryopreservation was higher in group A (47% vs. 19%, p < .001). A higher yield of CD34+ cells at the first apheresis in group B (p = .002) was linked with greater loss of viable graft CD34+ cells after cryopreservation. Filgrastim (FIL) use for mobilization seemed to associate with higher viable CD34+ cell loss compared to pegfilgrastim (PEG) or lipegfilgrastim (LIPEG) in both groups (in group A FIL 66 vs. PEG 35%, p = .006; in group B FIL 37 vs. PEG 15 vs. LIPEG 13%, p < .001). Hematologic recovery after auto-SCT was faster in group B. Neither viable CD34+ cell loss during storage nor viable CD34+ cell number < 2.0 × 106/kg infused affected on PFS or OS.

CONCLUSIONS

G-CSF type used in mobilization and mobilization capacity were found to correlate with viable CD34+ cell loss during processing and storage. Most importantly, low infused viable CD34+ cell count did not seem to impact on PFS or OS.

FACTORS INFLUENCING POST- CRYOPRESERVED CD34+ CELLS VIABILITY IN THE HARVESTED PRODUCTS OF AUTOLOGOUS HAEMATOPOIETIC STEM CELLS

The cryopreservation process of stem cells potentially cause the loss of CD34+ cells. The aim of this study is to evaluate association of patient, graft and technical characteristics with post cryopreserved CD34+ cells viability among lymphoproliferative disease namely multiple myeloma (MM) and lymphoma patients at Hospital Universiti Sains Malaysia (USM). This retrospective study was conducted in the Transplant Unit. A search of the hospital data (2008-2018) to identify 132 patients for both MM and lymphoma who underwent autologous peripheral blood haematopoietic stem cells (APBSC) mobilisation, and were successfully harvested and cryopreserved. Selected patients' profile as well as selected parameters of stem cell mobilization and cryopreservation were obtained from laboratory information system (LIS), record unit and the Transplant Unit. Multiple logistic regression (MLR) was used to find significant associated factors and p <0.05 was considered significant. The mean age of the patients was 39 years old with almost equal gender distribution and majority were lymphoma patients, 96 (72.7%) while 36 (27.3%) were multiple myeloma (MM) patients. The significant influencing factors of post-cryopreserved CD34+ cells viability were pre-cryopreserved CD34+ cell viability, total nucleated cells (TNC), and anti-platelet and antibiotics usage. Patients who are not on anti-platelet and have higher pre-cryopreserved CD34+ cells viability have higher chance for good post-cryopreserved CD34+ cells viability. While, those patients with higher TNC and on antibiotics have lower chance for good post cryopreserved CD34+ cells viability. This study showed patients who are not on anti-platelet and antibiotics will have higher probability of achieving good post cryopreserved CD34+ cells viability. The APBSC products with higher pre-cryopreserved CD34+ cells viability and lower TNC will achieve better post-cryopreserved CD34+ cells viability. The addition of extra plasma to the APBSC products is recommended to reduce the TNC.

Comparison of the methods evaluating post thawing viability of peripheral blood stem cell graft

OBJECTIVE

Reliable and pratique methods are essential for rapid and accurate determination of post thawing viability of peripheral blood stem cell (PBSC) graft before hematopoietic stem cell transplantation. In this study, Trypan Blue (TP) Eosin Y (EO), and Acridine-orange-ethidium bromide (AO/EB), which are of the methods commonly used for the assessment of viability in clinic practice, were compared with the flow cytometry-7AAD (7AAD) method, which is a more sensitive method. The aim of this study is to examine which method evaluates postthawing viability in a more compatible manner with 7AAD.

MATERIALS-METHODS

Postthawing viability rates were examined simultaneously by means of four different methods before hematopoietic stem cell transplantation in a total of 20 PBSC graft. The results obtained from the AO/EB, TP, EO methods were evaluated with the flow cytometry-7AAD in terms of concordance.

RESULTS

The AO / EB was determined to be the method having the best concordance with the flow cytometry-7AAD method. Although, at a lower level compared to the AO/EB method, the EO method had a statistically significant concordance with the flow cytometry-7AAD method. No statistically significant concordance was detected between the TP method and 7AAD method in terms of viability results.

CONCLUSION

The AO/EB method was identified to be the method having the best compatibility with the flow cytometry -7AAD method in showing the viability of the cryopreserved PBSC graft. In the viability assessment of PBCS graft using light microscopy, the EO may be preferred since is more sensitive compared to the TP method.