OI-02. Organizational and methodological aspects of patient’s selection for transplantation and search for an unrelated donor: Experience of the National Research Center for Hematology

Summary

Introduction

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the therapy of choice for many patients with hematological malignancies and solid tumors. In 2018, according to the EBMT data, 19630 allo-HSCTs were performed, which is a 4-fold increase in transplant activity over two decades [1]. Despite the fact that the number of haploidentical transplants is increasing, about 50% of all allo-HSCTs are performed from unrelated donors [1]. 47% donations of hematopoietic stem cells (HSC) were from unrelated donors, according to the National Research Center for Hematology (NRCH). Preparation for donation of HSC is a multi-stage procedure, including the joint work of many departments, while organizational and methodological aspects were still not well described. Our aim was to demonstrate the structure and efficiency of the procedure of searching and donation of HSC from Russian unrelated donor within the framework of the NRCH searching group.

Materials and methods

Each patient is evaluated by a specialized medical commission for selection of patients for allo-HSCT at the NRCH. If there are indications, and there are no contraindications for allo-HSCT, as well as in the absence of an HLA-identical donor, the patient undergoes procedures for searching of unrelated donor. The algorithm of actions is shown in Figure 1.

Figure 1. Algorithm for searching unrelated HSCT donors

Results

From January to June 2020, 49 patients underwent a search for unrelated donor in the Russian Federation. According to the results of this search, 20 patients were selected for allo-HSCT from related donors (haploidentical, syngeneic); a search for an unrelated donor was started in 25 patients, and 4 patients did not appear for repeated discussion. 122 unrelated donors were activated for 25 patients (median number per a patient was 5 (range 1 to 11)). 56 donors were excluded from further search before requesting blood samples: 31 donors after retyping at a low resolution had the matching result 8/10 or less. 25 donors refused, or were not activated for subsequent processing for other reasons. 66 blood samples from potential donors were requested for screening the blood-borne infections and high-resolution typing. However, only 38 samples were received, 28 requests were denied for various reasons (medical causes, 10; personal refusals, 6 cases; absent contacts with donor for more than 7 days, 8 cases; quarantine for a new coronavirus infection, 4 cases). Among the received 38 blood samples, 35 were subjected to high-resolution typing; donation was cancelled in one donor due to hepatitis B positivity of blood sample; 2 patients did not come for a second discussion. 17 matched donors were found among 35 typed samples of 13 patients (three patients had 2 matched donors). Thus, 12 HSC donations were performed. One donation was postponed with quarantine due to a new coronavirus infection. 12 patients didn’t have unrelated donor, but 3 of them already underwent haploidentical HSCT, 3 patients were planned to undergo haploidentical HSCT, contact was lost with 5 patients, donor search for 1 patient was continued due to the absence of a haploidentical donor. Moreover, we analyzed the time intervals required:
- 3 to 54 days passed from a request to obtaining a blood sample (median of 10 days);
- 10 to 64 days – from obtaining a blood sample to high resolution typing results: (median, 24.5 days);
- 12 to 48 days – from high-resolution typing results to HSC donation (median of 39 days);
- 33 to 108 days from requesting blood sample to HSC donation (median of 73 days). For example, in Japan, the same time interval is 140 days, but this study included 203 patients [2].

Conclusion

Preparation for HSC donation is an important stage that involves complex organizational and methodological aspects. The data presented demonstrate large amounts of work carried out by the searching group.

References

1. Passweg JR, Baldomero H, Chabannon C, et al. The EBMT activity survey on hematopoietic-cell transplantation and cellular therapy 2018: CAR-T’s come into focus. Bone Marrow Transplant. 2020;55(8):1604-13. DOI:10.1038/s41409-020-0826-4.
2. Kawashima N, Nishiwaki S, Shimizu N, et al. Outcomes of strategic alternative donor selection or suspending donor search based on Japan Marrow Donor Program coordination status. Int J Hematol. 2018;107(5):551-8. DOI:10.1007/s12185-018-2413-7.

Keywords

Unrelated donor, search, typing, donation of hematopoietic stem cells, Russian Federation.