Bone marrow harvest from unrelated donors-up-to-date methodology

Development of an in-house bone marrow collection kit: The Catalan bone marrow transplantation group experience

BACKGROUND AND OBJECTIVES

Bone marrow (BM) harvesting is one of the essential sources of stem cells for haematopoietic stem cell transplantation. In 2019, commercial BM collection kits became unavailable in Europe. Consequently, we created an in-house BM collection kit as an alternative.

MATERIALS AND METHODS

We compared two groups of BM collections. The first collections were taken using an in-house kit from June 2022 through February 2023 and the second with a commercial kit from February 2021 through May 2022. These all took place at seven collection centres (CC). We analysed the harvest quality (cell blood count, CD34+ cells, viability, potency and sterility), the incidents occurring with each kit and the time to neutrophil and platelet engraftment in recipients.

RESULTS

A total of 23 donors underwent BM harvesting with the in-house kit and 23 with the commercial one. Both cohorts were comparable regarding donor characteristics, CC and time to procedure. No statistical differences were found in harvest quality between the in-house and commercial kits. A new transfusion set was required in three BM harvests (13%) with the in-house kit because of filter clogging. The median time to neutrophil and platelet engraftment was 21 days for both cohorts and 29 days (in-house) and 33 days (commercial), p = 0.284, respectively.

CONCLUSION

The in-house BM collection kit offers a real approach to solve the diminished supply of commercial kits. A higher risk of filter clogging was observed compared with commercial kits due to the lack of 850 and 500 μm filters.

Worries and Psychological Well-Being in Potential Hematopoietic Stem Cell Donors Before Donation-A Swedish National Study

BACKGROUND

The physical risks involved in donating hematopoietic stem cells have been thoroughly studied, but little is known about the psychological risks potential donors might face before donation. The aim of this study was to describe potential the pre-donation worries and psychological well-being of hematopoietic stem cell donors and investigate possible associations between donor characteristics and psychological well-being.

METHODS

In a cross-sectional, national cohort study, we describe pre-donation worries and psychological well-being and investigate possible associations between donor characteristics and psychological well-being. A questionnaire was sent to prospective adult hematopoietic stem cells donors.

RESULTS

The study included 210 participants, 47% of whom were related and 53% unrelated to the recipient. Of the participants, 39% reported great worry about the recipient and 12% great worry about themselves as potential donors. Symptoms of anxiety were expressed by 21%, whereas symptoms of depression were uncommon and perceived general mental health was slightly lower than in the Swedish population. Great worry about oneself, lower age, and female sex were related to increased anxiety and lower mental health.

CONCLUSION

This study highlighted that some potential donors report high levels of pre-donation worry and that greater worry about oneself, lower age, and female sex are associated with lower psychological well-being. Although further studies are needed to investigate this psychological risk over time, it is clear that some potential donors are particularly vulnerable.

Bone Marrow versus Peripheral Blood Grafts for Haploidentical Hematopoietic Cell Transplantation with Post-Transplantation Cyclophosphamide

In the coronavirus disease 19 (COVID-19) pandemic era, the number of haploidentical hematopoietic cell transplantations (HCTs) with peripheral blood (PB) grafts increased significantly compared with HCTs with bone marrow (BM) grafts, which may be associated with adverse outcomes. We compared outcomes of HCT in BM graft and PB graft recipients age ≥18 years with hematologic malignancies who underwent T cell- replete haploidentical HCT and received graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide, tacrolimus, and mycophenolate mofetil. Among the 264 patients, 180 (68%) received a BM graft and 84 (32%) received a PB graft. The median patient age was 50 years in both groups. The majority (n = 199; 75%) received reduced-intensity conditioning. The rate of acute leukemia or myelodysplastic syndrome was higher in the BM graft recipients compared with the PB graft recipients (85% [n = 152] versus 55% [n = 46]; P < .01). The median times to neutrophil and platelet engraftment and the incidence of grade II-IV and grade III-IV acute GVHD (aGVHD) were comparable in the 2 groups. Among the patients with grade II-IV aGVHD, the rate of steroid-refractory aGVHD was 9% (95% confidence interval [CI], 5% to 18%) in the BM group versus 32% (95% CI, 19% to 54%) in the PB group (hazard ratio [HR], 3.7, 95% CI, 1.5 to 9.3; P = .006). At 1 year post-HCT, the rate of chronic GVHD (cGVHD) was 8% (95% CI, 4% to 13%) in the BM group versus 22% (95% CI, 14% to 36%) in the PB group (HR, 3.0; 95% CI, 1.4-6.6; P = .005), and the rate of systemic therapy-requiring cGVHD was 2.5% (95% CI, 1% to 7%) versus 14% (95% CI, 7% to 27%), respectively (HR, 5.6; 95% CI, 1.7 to 18; P = .004). The PB group had a significantly higher risk of bacterial and viral infections, with no appreciable advantage in the duration of hospitalization, immune reconstitution, relapse, nonrelapse mortality, or survival. Our data suggest a benefit of the use of BM grafts over PB grafts for haplo-HCT.

Should We Stop Collecting the Preoperative Autologous Blood before Bone Marrow Harvest?

Preoperative autologous blood donation (PAD) in bone marrow (BM) donors is performed to meet potential post-harvest transfusion needs and to avoid the risk of allogeneic transfusions. We reviewed retrospectively bone marrow harvests in 216 healthy donors during a ten-year period to determine the use of autologous blood. All donors except four had undergone PAD. The initial hemoglobin level of 153 g/L (male donors) and 135 g/L (female donors), respectively, decreased by about 8 g/L after preoperative blood donation and by 23 g/L after bone marrow harvest (medians). Autologous blood was administered to 70% of donors, 30% of the units remained unused. The evaluation of the risk of reaching transfusion threshold (<115 g/L males, <105 g/L females) revealed that donors with initial hemoglobin above 145 g/L and those weighing above 75 kg have minimal risk of requiring blood substitution (about 10%). A larger volume of bone marrow was obtained from male compared to female donors (1300 vs. 1100 mL) because of their higher body weight, which resulted in a higher number of procured nucleated cells (362 vs. 307 × 10⁶/kg TNC, ns). The donor-recipient weight difference predicted the probability of sufficient collection. Only 1.5% of donors weighing ≥ 20 kg more than recipients failed to reach ≥3 × 10⁸/kg TNC recipient. Our findings affirm previous data that PAD is unnecessary for healthy marrow donors and may be indicated individually after considering the pre-collection hemoglobin level, donor and recipient weight, and expected blood loss. Reasonable substitution cut-offs have to be set together with clinical symptom evaluation. The effective use of PAD also requires an adequate time interval between PAD and BM harvest.

Preoperative autologous blood donation in adult bone marrow donors: reappraisal of a single-centre experience

To avoid risk for allogeneic transfusions in healthy bone marrow (BM) donors, 1-2 preoperative autologous blood donations (PAD) are usually collected before the BM harvest. We analysed the haematological parameters in BM donors before and after the harvest, to assess the efficacy of this practice in limiting the postharvest anaemia. Overall, 102 consecutive donors underwent BM harvest preceded by one (26 cases) or two PAD (76 cases), which were infused during BM collection. We analysed the parameters related to donors, PAD timing and BM graft characteristics. PAD induced a significant decrease in Hb (from 14·6 g/dl, IQ range 13·3-15·5 to12·9 g/dl, IQ range 11·8-13·9; P < 0·0001) in all donors, with a median Hb loss at day -1 of 10·9% (IQ range 6·8-14·2). The PAD-related Hb decrease was independent of sex or number of PAD, and was inversely related to the time elapsed from first or last PAD. In comparison with values recorded at day-1, BM harvest produced an additional Hb decrease, accounting for a median Hb loss of 18·9% (IQ range 14·9-24·4). Overall, in comparison with pre-PAD values, Hb levels at day +1 were reduced of 28·9% (IQ range 23·6-32·2), independently if donors had 1 or 2 PAD reinfused. In conclusion, these data show that two PAD do not carry any advantage over one PAD. An eventual benefit of PAD can be achieved only if an adequate interval between PAD and BM harvest elapses. Prospective randomized studies could be worth to establish if any role for PAD does exist in BM donors.

Pre- and post-bone marrow harvest anaemia is associated with lower CD34+ stem cell collection, high harvest volume and female gender

BACKGROUND

Donor safety is paramount when performing bone marrow stem cell harvest. The incidence of full blood count (FBC) abnormalities among donors and variables associated with anaemia after marrow harvest are not well established.

AIMS

To describe the frequency of FBC abnormalities prior to bone marrow stem cell harvest and to identify variables associated with post harvest anaemia.

METHODS

Outcomes of 80 consecutive adult marrow harvests performed at our centre were analysed retrospectively.

RESULTS

FBC abnormalities were present in 28% of donors prior to marrow harvest with normocytic anaemia the most common abnormality in 13%. Reduced donor haemoglobin (Hb) was independently correlated with lower CD34+ cell count per kg of recipient body weight. Anaemia (Hb < 100 g/L) was seen in 20% of donors after harvest with median decrease in Hb of 19 g/L. Variables independently associated with anaemia after harvest included donor to recipient weight ratio (P = 0.011), high collection volume (P = 0.044) and female gender (P = 0.023). Total nucleated cell and CD34 concentration in the final collected product were associated with the inverse of harvested marrow volume (P < 0.001).

CONCLUSIONS

Pre-harvest anaemia should be corrected where possible particularly in female donors. Marrow collection volume should be minimised to reduce post-harvest anaemia, optimise CD34+ cell number and improve nucleated and stem cell concentrations in the harvest product.

The Concentration of Total Nucleated Cells in Harvested Bone Marrow for Transplantation Has Decreased over Time

Bone marrow (BM) is an essential source of hematopoietic stem cell grafts for many allogeneic hematopoietic cell transplant (HCT) recipients, including adult patients (for specific diseases and transplantation strategies) and the majority of pediatric recipient. However, since the advent of granulocyte colony-stimulating factor-mobilized peripheral blood stem cell (PBSC) grafts, there has been a significant decrease in the use of BM in HCT, thought to be due mainly to the increased logistical challenges in harvesting BM compared with PBSCs, as well as generally no significant survival advantage of BM over PBSCs. The decreased frequency of collection has the potential to impact the quality of BM harvests. In this study, we examined >15,000 BM donations collected at National Marrow Donor Program centers between 1994 and 2016 and found a significant decline in the quality of BM products, as defined by the concentration of total nucleated cells (TNCs). The mean TNC concentration in BM donations dropped from 21.8 × 10⁶ cells/mL in the earliest era (1994 to 1996) to 18.7 × 10⁶ cells/mL in the most recent era (2012 to 2016) (means ratio, .83; P < .001). This decline in BM quality was seen despite the selection of more donors perceived to be optimal (eg, younger and male). Multivariate regression analysis showed that higher-volume centers (performing >30 collections per era) had better-quality harvests with higher concentrations of TNCs collected. In conclusion, we have identified a significant decrease in the quality of BM collections over time, and lower-volume collection centers had poorer-quality harvests. In this analysis, we could not elucidate the direct cause for this finding, suggesting the need for further studies to investigate the key factors responsible and to explore the impact on transplant recipients.

Bone marrow harvest in donors with anaemia

BACKGROUND

Bone marrow harvest (BMH) for haematopoietic stem cell transplantation is a well-established procedure. The guidelines of World Marrow Donor Association provide information on donor selection. However, some of the guidelines regarding donors with anaemia prior to harvest lack in supporting data from clinical studies. With this study, we aimed to provide such data.

MATERIAL AND METHODS

In this retrospective, single-centre study, we analysed the interplay between haemoglobin levels and BMH and BMH impact on haemoglobin levels in a cohort of 149 unrelated BM donors, including 13 subjects with mild anaemia.

RESULTS

The BMH led to significantly lower decrease in haemoglobin levels in donors with anaemia than in control group (1·79 g/dl vs. 2·56 g/dl, P < 0·0001). The following parameters: BMH volume (ml), BMH volume/donor body weight (ml/kg), total nucleated cells (TNC) in product (×10⁸ ) and TNC/kg recipient body weight in product (×10⁸ /kg) did not differ significantly between those two analysed groups (P > 0·05). Median BM volume harvested from anaemic donors was 16·34 ml/kg; none of them required blood transfusion after BMH.

CONCLUSION

Mild anaemia prior to BMH does not significantly impact the collection results. The BMH is safe and feasible in donors with mild anaemia.