Abstract

Stem cell transplantation from unrelated cord blood (CB) donors is nowadays a standard practice for treatment of both malignant and non-malignant haematological disorders. The degree of HLA disparities, the cell dose and the prompt availability of the CB unit strongly influence the donor choice. According to FACT Netcord standards, HLA A, B and DRB1 shall be determined on a pre-cryopreservation sample from each CB. Once a CB unit is identified for potential use, a sample is tested to verify HLA type and confirmation of maternal haplotype is provided. The recipient’s HLA typing and its matching to the donor are confirmed as well prior to CB release for transplant. Quality of the stem cell product represents a basic assumption for the final success of transplant and an essential requirement for CB Banks (CBB). Each CBB shall establish a program of quality assurance that includes identification and traceability. The protection of confidentiality of mother and infant donors and the maintenance of linkage of a particular CB to its mother/neonate pair is of the highest priority. For this purpose each CB is assigned a unique numeric identifier that accompanies the unit in all steps of management and by which it is related to its maternal/infant data and reference samples. At the Pavia CBB, all CB donations are routinely typed for both HLA class I and class II by molecular techniques (low resolution for A and B loci and high resolution for DRB1). The mother haplotype is also assessed by molecular methods at time of banking. Therefore each CB/mother pair is checked before inclusion in the inventory. We retrospectively evaluate the impact of such a strategy on ensuring both identification and linkage of our CB repository. We review the data referring to the CBs stored in our Bank, all typed by LR-DNA for class I loci and by LR/HR-DNA for class II loci. Our inventory consists of 1987 units available for donor selection. In 2 pairs (0.1%) the mother’s typing was found fully disparate as respect to the supposed corresponding CB/neonate. The identification cannot be confirmed leading to discard of the unit. We also review the data pertinent to the 45 units released for transplant by our CBB: in all cases the cord’s confirmatory typing was coherent to the previous typing thus confirming the identity of the product ready for shipment. In our hands, the practice of confirming maternal haplotype at time of banking provides the final evidence of correct assignment and identification before inclusion in the inventory, ensuring the highest quality of the product supplied. This strategy also optimizes the time for the search requests management contributing to prompt availability of the graft.

Disclosure: No relevant conflicts of interest to declare.

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