History of Hepatitis B Infection Is the Most Common Risk Factor Impacting Eligibility in Minority Donors for Cord Blood

Background:

Cord blood (CB) is an accepted allogeneic hematopoietic stem cell source and has increased access to transplantation particularly for minority patients (Barker et al, BBMT 2010; 16: 1541-48). As a result, one of the aims of the CB Banks is to increase collections from minority donors.

Before the acceptance of any Cord Blood Unit (CBU) in the searchable inventory for potential use in clinical transplantation, FDA requires donor eligibility assignment, as mandated by the 2005 published guidelines, and licensure.

Objective and Methods:

We performed a retrospective analysis of the eligibility assignment on the CBU collected during the period 4/2013-3/2014 (one fiscal year) in six collection sites of the National Cord Blood Program (NCBP) at the New York Blood Center. Three of the collection sites are located in the New York area, and the other three in each of the following states: Atlanta, GA, Cleveland, OH, and Fairfax, VA. All CBU that met criteria for banking were evaluated for eligibility; CBU with positive maternal infectious disease markers for HIV, HCV, HBV and HTLV were discarded according to the FDA Guidelines.

We grouped the reasons for ineligibility in six risk factor categories, as listed in Table 1. We further looked at race/ethnic background of the mothers and the various risk factors and impact on donor eligibility.

Results:

From a total of 1826 CBU placed in the NCBP searchable inventory during the study period, 1597 (87%) were qualified as eligible, whereas 237 (13%) were assigned as ineligible. 1567 eligible CBU (85.5%) met all other FDA licensure criteria and became licensed HEMACORD®, whereas the ineligible CBU, or eligible with parameters below the FDA specifications were Investigational New Drug (IND) products (N=259 or 14%).

Note: HBV PCR was performed using Procleix Ultrio assay (Gen Probe, Inc.)

Results and discussion:

In our cohort of 237 ineligible CBU, the racial distribution was as follows: 49% came from White donors, 16% from Asian, 18% from African American and 17% from Multi-Race donors. The two leading causes for donor’s ineligibility in our cohort were the risk of vCJD associated with maternal immigration/extended residence in a European country, or in American military base in Europe (51% of the cases), and presence of anti-HB Core Ab with HBV DNA negative results (24.5%).

The percentage of ineligible CBU within total number of donations from each individual racial group was as follows: White: 12%; Asian: 17%; African American: 11% and Multi Race: 16%. This finding is in contrast with published data where African American donors were significantly less likely to be eligible to donate whole blood (Shaz BH et al, Transfusion 2012 52(5); 1050-61). It is important to note that the presence of positive anti-HB Core Ab was the leading cause for ineligibility among Asian (54%), and African American donors (36%). None of these donors were positive for HBV DNA indicating absence of viremia.

Conclusion:

In contrast to blood donors, CBU from ineligible donors can be used for transplantation as IND products, rather than being deferred, provided there is an urgent medical need. History of hepatitis B infection is a common risk factor in minority donors but viremia has not been demonstrated. On the other hand, “reluctance” to use these CBU in clinical practice impacts primarily minority patients.