The protean presentations of XK disease (McLeod syndrome): a case series with new observations and updates on previously reported families.

XK disease is a very rare, multi-system disease, which can present with a wide spectrum of symptoms. This disorder can also be identified pre-symptomatically with the incidental detection of serological abnormalities when typing erythrocytes in peripheral blood, or on other routine laboratory testing. Increasing awareness of this disorder and improved access to genetic testing are resulting in increasing identification of affected patients and families.

Genotyped RhD+ red cells for D-positive patients with sickle cell disease with conventional RHD and unexpected anti-D.

Anti-D can occur in D-positive patients who inherit RHD genetic variants encoding partial D antigen expression, but unexpected anti-D is also found in the plasma of patients with sickle cell disease who have conventional RHD gene(s) and are transfused with units from Black donors. These anti-D are likely stimulated by variant Rh expressed on donor cells; however, patients with anti-D, regardless of cause, are transfused for a lifetime with D-negative (Rh-negative) blood. This results in significant increased use of Rh-negative units, especially for those requiring chronic transfusion, which can strain Rh-negative blood inventories.

Three novel Er blood group system alleles and insights from protein modeling.

Background: The Er blood group system was recently shown to be defined by PIEZO1. The system consists of high prevalence antigens Er, Er3, ERSA, and ERAMA; and low prevalence antigen Er. Er/Er are antithetical with Er(a-b+) defined by the ER*B allele [c.

RH genotypes and red cell alloimmunization rates in chronically transfused patients with sickle cell disease: A multisite study in the USA.

Background: Red cell alloimmunization remains a challenge for individuals with sickle cell disease (SCD) and contributes to increased risk of hemolytic transfusion reactions and associated comorbidities. Despite prophylactic serological matching for ABO, Rh, and K, red cell alloimmunization persists, in part, due to a high frequency of variant RH alleles in patients with SCD and Black blood donors.

Study Design And Methods: We compared RH genotypes and rates of alloimmunization in 342 pediatric and young adult patients with SCD on chronic transfusion therapy exposed to >90,000 red cell units at five sites across the USA.

Blood Group Serology and "Race": Looking Back to Move Forward.

Less than a decade after the discovery of the ABO antigens as a Mendelian inherited trait, blood group antigen frequencies were first used to define racial groups. This approach, known as seroanthropology, was the basis for collecting large amounts of blood group frequency data in different populations and was also sometimes used for racist purposes. Ultimately, population geneticists used these data to disprove race as a biological construct.

Variant RHD alleles and Rh immunization in patients with sickle cell disease.

RH diversity among patients and donors contributes to Rh immunization despite serologic Rh-matched red cell transfusions. Anti-D can occur in D+ patients with RHD variants that encode partial D antigens. Anti-D has also been reported in patients with conventional RHD transfused primarily with units from Black donors who frequently have variant RHD.

A novel high-prevalence antigen in the Lutheran system, LUGA (LU24), and an updated, full-length 3D BCAM model.

Background: The basal cell adhesion molecule (BCAM) carries the antigens of the Lutheran (LU, ISBT005) system. We report a novel Lutheran antigen and propose an updated, full-length 3D model of BCAM.

Study Design And Methods: Red blood cell testing, antibody identification, and BCAM genomic DNA sequencing were done by standard methods.

ABO Genotyping finds more A to B kidney transplant opportunities than lectin-based subtyping.

ABO compatibility is important for kidney transplantation, with longer waitlist times for blood group B kidney transplant candidates. However, kidneys from non-A (eg, A) subtype donors, which express less A antigen, can be safely transplanted into group B recipients. ABO subtyping is routinely performed using anti-A lectin, but DNA-based genotyping is also possible.

Two new Scianna variants causing loss of high prevalence antigens: ERMAP model and 3D analysis of the antigens.

Background: Scianna (Sc) antigens, seven high and two of low prevalence, are expressed on erythrocyte membrane-associated protein (ERMAP). We investigated SC (ERMAP) in individuals who made antibodies to high prevalence Scianna antigens, and propose a 3D model for ERMAP to precisely localize the residues associated with the known antigens.

Methods: Serological testing and DNA sequencing was performed by standard methods.

YTGT: A new high-prevalence antigen in the Yt blood group system in two unrelated Native Americans and transfusion management.

Background: The Yt system consists of five antigens: antithetical Yt /Yt and the high-prevalence antigens YTEG, YTLI, and YTOT. We investigated a sample from a Native American (NA) female with post-operative anemia and an unidentified antibody who developed rigors, tachycardia, and hypotension on transfusion of incompatible RBCs.

Methods And Materials: Serologic testing methods included LISS, PEG, and IgG gel.

Accurate long-read sequencing allows assembly of the duplicated RHD and RHCE genes harboring variants relevant to blood transfusion.

Next-generation sequencing (NGS) technologies have transformed medical genetics. However, short-read lengths pose a limitation on identification of structural variants, sequencing repetitive regions, phasing of distant nucleotide changes, and distinguishing highly homologous genomic regions. Long-read sequencing technologies may offer improvements in the characterization of genes that are currently difficult to assess.

Anti-Emm, a rare specificity to the high-incidence antigen Emm in an Indian patient defining the new blood group system EMM (ISBT042).

A transfusion recipient lacking a high-incidence antigen (HIA) and has corresponding alloantibody pose a problem in providing compatible blood unit. We encountered a patient with an antibody to an HIA that required identification to assess if compatible blood could be organized. A 65-year-old male was posted for coronary artery bypass grafting surgery.

PIGG defines the Emm blood group system.

Emm is a high incidence red cell antigen with eight previously reported Emm- probands. Anti-Emm appears to be naturally occurring yet responsible for a clinically significant acute hemolytic transfusion reaction. Previous work suggests that Emm is located on a GPI-anchored protein, but the antigenic epitope and genetic basis have been elusive.