Red cell genotyping precision medicine: a conference summary

Abstract

This review summarizes the salient points of the symposium 'Red Cell Genotyping 2015: Precision Medicine' held on 10 September 2015 in the Masur Auditorium of the National Institutes of Health. The specific aims of this 6th annual symposium were to: (1) discuss how advances in molecular immunohematology are changing patient care; (2) exemplify patient care strategies by case reports (clinical vignettes); (3) review the basic molecular studies and their current implications in clinical practice; (4) identify red cell genotyping strategies to prevent alloimmunization; and (5) compare and contrast future options of red cell genotyping in precision transfusion medicine. This symposium summary captured the state of the art of red cell genotyping and its contribution to the practice of precision medicine.

Keywords: molecular immunohematology; red cell genotyping; transfusion precision medicine.

Figure 1.

Schematic comparison of two patients’ RH genotypes with the genotype of the respective incompatible red blood cell units. Case 1 represents the patient reported at the conference (upper panel); case 2 has been published previously by Fasano et al. [2010]. Four representative haplotypes carrying distinct amino acid substitutions in the RHD and RHCE exons are shown for comparison (lower panel). A conventional Dce haplotype is depicted for reference; each square corresponds to an exon that is numbered in the Dce haplotype. The variant amino acid substitutions and their locations are indicated by bars (black or white lines in the squares of the representative haplotypes).

Figure 2.

Red cell genotyping across multiple blood centers. All Versiti-affiliated blood centers participate in mass-scale red cell genotyping of donor units (left side) [Flegel et al. 2015a]. Rare units are identified and diverted to rare donor programs worldwide. Antigen-negative information is shared throughout the supply chain via a web-based antigen query portal in the cloud [Flegel et al. 2015b]. A data warehouse is accessible online and offers real-time web-based red cell genotype information on blood units. A blood center queries the data warehouse to fill orders that cannot be met from their current inventory. Units can be shipped between blood centers in a large region and across state lines to meet antigen-negative demands (right side). Versiti is composed of the BloodCenter of Wisconsin (BCW), Michigan Blood (MI), Heartland Blood Centers (HBC) and Indiana Blood Center (IBC).

Figure 3.

The web-based solution for red cell genotype and phenotype data. Hospitals can access such data in the cloud for all blood units in their inventory. The hospital enters patient information (top portion), the blood type and antigen-negative attributes (middle portion) and number of units required (lower left). Blood unit ISBT 128 identification numbers are scanned (not shown) and then the electronic query is sent to the blood center (lower center-left). The query returns the ISBT identification number of the oldest unit(s) with the required attributes (not shown). If the required units are not found, the process can be started again (lower center) by scanning additional inventory, or the hospital can place the order with the blood center (lower center-right).