The minimum number of cord blood units needed for Koreans is 51,000

Umbilical Cord Blood Units Cryopreserved in the Public Cord Blood Bank: A Breakthrough in iPSC Haplobanking?

The use of induced pluripotent stem cells (iPSCs) is an emerging therapeutic option for precision medicine. Cord blood (CB) cells with lower immunogenicity, fewer genomic changes, and persistent epigenetic memory might be ideal candidates for iPSC production. Based on the human leukocyte antigen (HLA) distribution of cord blood units (CBUs) in the public CB bank, we estimated the coverage of the Korean population with HLA-homozygous iPSCs to repurpose cryopreserved CBUs. We analyzed a total of 27,904 Korean CBUs donated to the public CB bank. Low-to-intermediate resolution typing was performed for HLA-A, -B, and -DRB1 alleles, and individuals possessing homozygous HLA haplotypes were identified by direct counting. Moreover, the matching probabilities for zero-mismatch transplantation were calculated for 27,904 CBUs and 50,000,000 potential Korean patients. Among the preserved CBUs, 15 HLA-A, 40 HLA-B, and 13 HLA-DRB1 alleles as well as 48 homozygous HLA-A-B-DRB1 haplotypes were identified at serological equivalents (2 digits). The 48 identified homozygous haplotypes cumulatively matched 78.18% of the 27,904 Korean CB donors as zero HLA-mismatch iPSC sources. Among the combinations of 1,699 haplotypes with frequencies greater than 0.001%, assuming a population of 50 million, those 48 haplotypes can provide a match for 78.37% of potential Korean recipients. A practicable number of HLA-A, -B, and -DRB1 homozygous iPSC lines derived from CBUs may be an efficient option in allogeneic iPSC therapy because this type of haplobanking may provide cell lines with optimal HLA matching for up to three-quarters of the Korean population.

Total nucleated cell counts are driving clinician's choice rather than cryopreservation period: Lesson for cord blood banks

According to the increase in both the number of cryopreserved cord blood (CB) units and the cryopreservation period for each CB unit in the largest public CB bank in Korea, we are pursuing greater efficiency in CB bank management. Thus, we analyzed whether the cryopreservation period has a negative impact on the selection of CB units for CB transplantation (CBT). Until December 2019, 468 CB units were used for transplantation. The cryopreservation period, total nucleated cell (TNC), and CD34+ cell counts were analyzed among the CB units according to the CBT-year and the donation year. The results showed that the cryopreservation period was increased in recent CBT-year groups. The transplanted CB units showed similar TNC counts irrespective of the donation year, and the mean TNC count was 13.9 × 108/unit. CB units cryopreserved for a relatively long period were transplanted consistently. The mean TNC count of CB units cryopreserved for over 10 years was 16.4 × 108/unit. The mean CD34+ cell counts were not significantly different among the CB units transplanted after CBT-2013 and among the CB units donated after CBT-2011. Through an analysis of the CB units selected by clinicians for CBT, this study revealed that clinicians placed more weight on the TNC counts than on the cryopreservation period of cryopreserved CB units. Therefore, the minimum TNC count of CB units suitable for cryopreservation should be increased up to 13.0 × 108/unit to balance the satisfaction of clinicians' needs with the efficiency of the CB bank.

Usefulness of the Hematopoietic Stem Cell Donor Pool as a Source of HLA-Homozygous Induced Pluripotent Stem Cells for Haplobanking: Combined Analysis of the Cord Blood Inventory and Bone Marrow Donor Registry

Induced pluripotent stem cells (iPSCs) have opened up unprecedented opportunities for novel therapeutic options for precision medicine. Hematopoietic stem cell (HSC) donor pools with previously determined HLA types may be ideal sources for iPSC production. Based on the HLA distribution of cryopreserved cord blood units (CBUs) and registered bone marrow (BM) donors, we estimated how much of the Korean population could be covered by HLA-homozygous iPSCs. We analyzed a total of 143,866 Korean HSC donors (27,904 CBUs and 115,962 BM donors). Each donor sample was typed for the HLA-A, -B, and -DRB1 alleles at low to intermediate resolution by DNA-based molecular techniques: PCR sequence-specific oligonucleotide (PCR-SSOP), PCR with sequence-specific primers (PCR-SSP) and PCR with sequence-based typing (PCR-SBT). We also identified individuals possessing homozygous HLA haplotypes by direct counting. The matching probabilities for zero-mismatch transplantation were calculated for 143,866 Koreans and 50 million potential Korean patients. Among the HSC donor pool, 17 HLA-A alleles, 41 HLA-B alleles, and 13 HLA-DRB1 alleles, as well as 128 homozygous HLA-A-B-DRB1 haplotypes, were identified at serologic equivalents, and those haplotypes cumulatively matched 93.20% of the 143,866 Korean donors as zero HLA-mismatch iPSC sources. Among the combinations of 2,056 haplotypes with frequencies ≥ 0.001% in a population of 50 million, those 128 homozygous haplotypes can provide 93.65% coverage for potential Korean recipients. Haplobanking of a reasonable number of HLA-A, -B, and -DRB1 homozygous iPSC lines derived from CBUs and cells of registered BM donors may be an efficient option for allogenic iPSC therapy.

A cost analysis of public cord blood banks belonging to the Italian Cord Blood Network

BACKGROUND

Public cord blood banking is currently managed in Italy by a network of 19 regional cord blood banks coordinated by the National Blood Centre and the National Transplant Centre. A cost analysis was carried out within the Italian network to determine the relationship between cost of cord blood collection and banking and size of the bank inventory, which ranged from 106 to 9,341 units on December 31^st, 2012.

MATERIALS AND METHODS

The 19 banks were invited to report costs incurred in 2012 related to cord blood unit collection, transportation, biological validation, characterisation, manipulation, cryopreservation, storage, data management, and general costs. Missing information on selected items was replaced with standardised costs represented by average data obtained from the reporting banks. Eight banks (52%) participated in the study. Average costs were determined in the three banks with inventories of >3,000 units vs the three banks with inventories of <1,000 units.

RESULTS

Both cord blood collection and cord blood banking costs per unit were lower in the larger banks than in the smaller banks (average collection costs: € 119.25 and € 151.31, respectively; average banking costs: € 3,614.15 and € 8,158.37, respectively).

DISCUSSION

The study outlined an inverse relationship between the costs of cord blood collection and banking and the size of the bank inventory, suggesting that scale economies could be obtained through centralisation of banking activities.

Excluding Anti-cytomegalovirus Immunoglobulin M-Positive Cord Blood Units Has a Minimal Impact on the Korean Public Cord Blood Bank Inventory

Cord blood units (CBUs) for transplantation should be free of communicable disease and must contain a specific amount of total nucleated cells and CD34+ cells. Although posttransplantation cytomegalovirus (CMV) infections are from latent infection in patients, ensuring CMV-free CBUs by performing CMV-specific IgM and nucleic acid amplification testing (NAT) is one of the mandatory procedures for the safety of CBUs. However, the exclusion policies (based on these test results) vary among nations and institutions. We tested 28,000 processed CBUs between May 2006 and June 2014. The cord blood leukocytes from CMV IgM-positive samples were then subjected to NAT. The total nucleated cell and CD34+ cell counts were measured for each CBU, and the results were compared to the CMV IgM and IgG results. The seroprevalence of CMV among pregnant women was 98.1% (18,459/18,818) for IgG and 1.7% (441/25,293) for IgM. The concentration and the total number of CD34+ cells were significantly higher in CBUs from IgM-negative mothers compared to those from IgM-positive mothers (72.4/μl vs. 57.2/μl, respectively, p < 0.0001; 1.45 × 106/unit vs. 1.15 × 106/unit, respectively, p < 0.0001). Among CBUs with positive CMV IgM in their mothers' plasma or cord blood plasma, only 0.58% of the samples (3/517) had a positive NAT. The number of excluded CBUs from inventory due to positive CMV IgM in the cord blood was 54 of 18,326 (0.3%). For inventory purposes, it is appropriate to remove CBUs with positive cord blood CMV IgM findings irrespective of the NAT status as well as positive maternal CMV IgM in South Korea.

Current status of cord blood banking during first two years of 'National Government-Assigned Public Cord Blood Banks Operation' in Korea

Cord blood (CB) has become a viable stem cell source for hematopoietic stem cell transplantation (HSCT), and public cord blood banks (CBBs) have been established to manage donated cord blood units (CBUs) for unrelated HSCT. As the potential uses for CB continue to grow, there is a global tendency to encourage public CBBs. The aim of this study was to investigate the current status of public CBBs that were designated and supported by the Korean national government. We analyzed 6,168 CBUs preserved at the 3 Government-Assigned Public CBBs during their first two years of operation (2012-2013) and the standard operating procedures for CB processing at each CBB. CBU inventories at ALLCORD, Catholic HSC Bank and Fatima Public CBB were 4,022, 1,207 and 939 units, respectively. Total nucleated cell (TNC) counts per unit were 11.0 × 10(8) at ALLCORD, 10.7 × 10(8) at Fatima and 9.8 × 10(8) at Catholic, and all far exceeded the requirement for cryopreservation under the law (7.0 × 10(8)). CD34(+) cell counts and % were as follows: 3.5 × 10(6) (0.31 %) in ALLCORD, 2.2 × 10(6) (0.20 %) in Fatima and 2.2 × 10(6) (0.22 %) in Catholic. All the three banks observed the 'CB Act' in dealing with CBUs, including collection, processing, laboratory tests and cryopreservation. Government supported and strictly law-abiding public CBBs in Korea have considerable CBU inventories of high quality in terms of efficacy and safety. Legislation and accompanying government-support will be helpful for establishing CB standardization, vitalizing CBT and improving clinical outcomes.

Estimation of size of cord blood inventory based on high-resolution typing of HLAs

Methods for estimating the cord blood (CB) inventory size required vary according to the ethnic diversity of the HLA, degree of HLA matching and HLA-typing resolution. We estimated the CB inventory size required using 7190 stored CB units (CBU) and 2450 patients who were awaiting or underwent allogeneic hematopoietic stem cell transplantation. With high-resolution typing of HLA-A, B and DRB1, 94.6% of Korean patients could find CBUs in 100 000 CBUs with a 5/6 match, and 95.7% could find CBUs in 5000 CBUs with a 4/6 match. With low-resolution typing of HLA-A and B and high-resolution typing of leukocyte antigen-DRB1, 95% of patients could find CBUs in 50 000 CBUs with a 5/6 match, and 96.7% could find CBUs in 3000 CBUs  with a 4/6 match. With additional high-resolution typing for HLA-A and B, which could improve transplantation outcome, the size of the CB inventory would need to increase twofold for Koreans.

Roles of obstetricians in quality management of cord blood collection and informing potential donors: a survey on obstetricians' understanding of cord blood in Korea

BACKGROUND

The obstetrician's role in vitalizing cord blood (CB) banking is important in both informing donors and beginning CB processing. The aim of the study was to investigate obstetricians' understanding of CB and their roles in informing donors and collection management.

STUDY DESIGN AND METHODS

Questionnaires examining the management and awareness of CB were distributed to collection centers, and we analyzed 57 respondents who had collection experience.

RESULTS

All respondents were experienced, and 82.5% had CB collection experience of at least 4 years. If patients asked for information, one-third provided information about CB themselves, and two-thirds provided CB banks' (CBBs') contact information. Less than half of the respondents knew the legal regulations and had a collection manual. Regarding the awareness of transportation and storage of CB, 58% rated their knowledge as minimal, and respondents who knew the legal regulations rated their knowledge at a higher level. One-fifth of the participants felt that CB collection distracted the labor process, and 16% were concerned about delayed bleeding control. The probability of autologous CB transplantation was overestimated, and the matching probability in public CBBs was underestimated. Approximately 82.7% of the respondents correctly rated the therapeutic use of CB, and 54% rated their knowledge level about CB usefulness as average.

CONCLUSION

Obstetricians' understanding of CB was lower than expected, considering that they are associated with CB collection centers. Obstetricians who provide information and recognize regulations seem to collect CB in compliance with the regulations better. These results will be helpful in CB collection management and education planning for obstetricians.