Skip to main content
2024 AABB Annual Meeting Main banner
Icon Legend
This session is not in your favorites.
This session is in your favorites. Click again to remove it.
Presentation Icons
Live Stream Sessions
Live Stream Sessions

Immunohematology and Genetic Testing (red cells, leukocytes and platelets)

(P-IG-42) Use of a Lab Developed Test as a Cost-Effective Alternative to Screen for RH Variant Donors within a Blood Center

Sunday, October 20, 2024
12:00 PM - 1:00 PM  
Background/Case Studies: The immunohematology reference laboratory (IRL) uses an algorithm based on a commercial genotyping assay to identify potential donors with rare RH alleles. These potential donors are then confirmed with a commercial RHCE genotyping assay. Testing volume is limited due to the high cost associated with the commercial assay. RH allele-matched unit requests at this IRL are becoming more common and difficult, as there is a major shortage of donors nationwide to fulfill patient needs. To address this, a laboratory-developed test (LDT) was developed and compared to the commercial assay to evaluate the concordance of results and potential cost savings.

Study

Design/Methods:

EDTA whole blood samples were selected from donors of African descent who had historically tested C- and E-, or C+ E- by serology for the LDT over a 12-month period. DNA extractions were performed on the donor samples using a laboratory detergent method of DNA isolation, followed by a two-stage multiplex polymerase chain reaction. The LDT interrogated the following single nucleotide polymorphisms (SNPs): RHCE*ce733C >G, RHCE*ce712A >G, and RHCE*ce48G >C. The SNP results of each donor tested were determined using gel electrophoresis of the post-PCR products. Donors found homozygous or compound heterozygous for these SNPs had reflex testing with a commercial RHCE assay. The cost of testing for the LDT was $4.33 US dollars per sample, not including technologist time, compared to the cost of the commercial assay, which was $144.20 per sample, not including technologist time.

Results/Findings: Between February 2023 and February 2024, the LDT evaluated 2,167 donors. Overall, 116 donors were eligible for RHCE genotype confirmation. Upon RHCE genotype confirmation, 73 (62.9%) had matching SNP results; 102 were confirmed homozygous for RHCE*ce733C >G which encodes partial c and e antigens, and altered hrB (+, very weak, to negative) antigen expression; 5 of the donors were found to be homozygous for the RHCE*(C)ceS haplotype encoding the rare hrB- phenotype. The total cost of the LDT screening test was $9,383.11, and the total cost of the commercial assay was $16,727.20.

Conclusions:

The LDT allowed the IRL to prescreen a large volume of donors at a lower cost rather than testing them directly with the commercial genotyping assay. This resulted in a higher likelihood of detecting rare donors with RHCE variants. The LDT’s total cost to screen donors was much lower than the $312,481.40 price if the alternative commercial assay was used. The LDT proved a cost-effective screening method to aid the blood center’s IRL in identifying possible RH variant donors, allowing it to fulfill difficult RH allele match requests for its patient population.