Red blood cell alloimmunisation in multi-transfused patients from an haemodialysis service in Burkina Faso.

Background: In Burkina Faso, red blood cell (RBC) transfusion remains the crucial anaemia treatment following chronic renal failure (CRF) as erythropoietin and its analogues are unavailable. However, blood group matching beyond the ABO and Rhesus is not common in Burkina Faso. Thus, alloimmunisation is a potential issue for transfused patients. Objective: Our study aimed to identify anti-erythrocyte antibodies in multi-transfused CRF patients at the Yalgado Ouedraogo Teaching Hospital, Ouagadougou, Burkina Faso. Methods: This cross-sectional study, conducted from October 2018 to November 2019, included CRF patients who had received at least two RBC units. We screened patients for the presence of RBC antibodies using three commercial Cells panels and identified antibody specificities for positive screenings using 11 Cells panels for an indirect antiglobulin test (IAT) in a low ionic strength microcolumn gel-card system. Results: Two hundred and thirty-five patients (45.1% female; average age: 41.5 years) were included. The median number of blood units received per patient was 10 (interquartile range: 5-20). The overall alloimmunisation rate was 5.9% (14/235). Antibodies identified included: anti-D (1 case), anti-C (1 case), anti-D+C (4 cases), anti-CW (1 case), anti-E (1 case), anti-S (1 case) and anti-Lea (1 case). In four positive patients, the specificity of the antibodies was indeterminate. No risk factors were associated with alloimmunisation. Conclusion: In Burkina Faso, screening for RBC alloantibodies should be mandated for patients at risk. The high rate of indeterminate antibodies suggests the need to develop a local RBC antibody panel adapted to the local population.

Chronic Granulomatous Disease with the McLeod Phenotype: a French National Retrospective Case Series.

BACKGROUND: X-linked chronic granulomatous disease (CGD) is a primary immunodeficiency caused by mutations in the CYBB gene (located on Xp21.1). Patients with large deletions on chromosome Xp21.1 can present with the McLeod phenotype and also Duchenne muscular dystrophy or retinitis pigmentosa. The objective of the present study was to describe a series of French patients with CGD and the McLeod phenotype. METHODS: We retrospectively collected data from the medical records of 8 patients with CGD and the McLeod phenotype registered at the French National Reference Center for blood types. RESULTS: The median age at diagnosis of CGD was 1.2 years, the median age at diagnosis of the McLeod phenotype was 4.5 years, and the median length of follow-up was 15.2 years. Four patients displayed allo-immunization, with anti-KEL20 and anti-XK1 (formerly known as anti-KL) antibodies. Five of the 6 patients with available blood smears had acanthocytosis. Neuropsychiatric, muscle-related, and ocular manifestations were present in 4, 2, and 1 of the patients, respectively. Three of the 4 patients having undergone allogeneic hematopoietic stem cell transplantation (HSCT) are alive. Overall, 5 patients are alive, and 3 are alive and well. CONCLUSION: This is the largest yet descriptive study of a series of patients with X-linked CGD and the McLeod phenotype. Although this disease combination is rare, the timely, accurate diagnosis of the McLeod phenotype is critical because of the serious post-transfusion complications. However, HSCT can be considered in these patients.

Antibodies to co-trimoxazole (trimethoprim and/or sulfamethoxazole) related to the presence of the drug in a commercial low-ionic-strength solution.

BACKGROUND: Drug-dependent antibodies have been associated with approximately 10% of acquired immune hemolytic anemia cases. These antibodies are a rare cause of interference in pretransfusion red blood cell (RBC) serologic testing. The aim of this work was to report three cases of subjects developing antibodies against co-trimoxazole, a combination of trimethoprim (TMP) and sulfamethoxazole (SMX). CASE REPORT AND METHODS: Blood samples of donor/patients were referred to our laboratory for the exploration of a positive antibody detection test. There was no recent history of drug taking. Antibody identification was performed by gel test using an indirect antiglobulin test, with reagent RBCs in low-ionic-strength solutions (LISS) containing co-trimoxazole or not. RESULTS: All three sera showed positive reactions when RBCs were resuspended in LISS containing co-trimoxazole, but negative reactions when RBCs were resuspended in LISS without antibiotic. We detected antibodies against co-trimoxazole showing three different antibody patterns: anti-TMP plus anti-SMX, anti-TMP alone, or anti-SMX alone. Anti-TMP showed an apparent anti-Ku specificity in the two cases where it was present. Anti-SMX showed an apparent anti-H specificity in one of the two cases described. The drug-dependent antibodies were not associated with acquired hemolytic anemia or other pathologies. CONCLUSION: Antibodies against co-trimoxazole may only be detected when using a diluent for reagent RBCs containing the drug in question. Antibody pattern (anti-TMP and/or anti-SMX) may vary according to individuals' immune response. Drug-dependent antibodies may react as antibodies against a high-prevalence antigen, supporting the hypothesis of antibodies to drug and membrane components. Drug-dependent antibodies such as anti-co-trimoxazole may be a serologic finding without clinical features.

Anti-U-like as an alloantibody in S-s-U- and S-s-U+(var) black people.

BACKGROUND: S, s, and U antigens belong to the MNS system. They are carried by glycophorin B (GPB), encoded by GYPB. Black people with the low-prevalence S-s- phenotype, either U- or U+(var), can make a clinically significant anti-U. Anti-U-like, a cold immunoglobulin G autoantibody quite commonly observed in S-s+U+ black persons, was previously described to be nonreactive with ficin-, α-chymotrypsin-, and pronase-treated red blood cells (RBCs); nonreactive or weakly reactive with papain-treated RBCs; and reactive with trypsin-treated RBCs. Here we describe, in S-s- people from different molecular backgrounds, an alloantibody to a high-prevalence GPB antigen, which presents the same pattern of reactivity with proteases as autoanti-U-like. STUDY DESIGN AND METHODS: Four S-s- patients with an alloantibody to a high-prevalence GPB antigen were investigated by serologic and molecular methods. RESULTS: An alloantibody was observed in two S-s-U-/Del GYPB, one S-s-U+(var)/GYPB(P2), and one S-s-U+(var)/GYPB(NY) patients. As this alloantibody showed the same pattern of reactivity with proteases as autoanti-U-like, we decided to name it "anti-U-like." Anti-U-like made by the two S-s-U- patients was reactive with the S-s-U+(var) RBCs of the two other patients. CONCLUSION: S-s-U-/Del GYPB, S-s-U+(var)/GYPB(P2), and S-s-U+(var)/GYPB(NY) patients can make an alloanti-U-like. Anti-U-like made by S-s-U- people appears reactive with GYPB(P2) and GYPB(NY) RBCs, which both express a weak and partial U-like reactivity. We recommend transfusing S-s-U- RBCs in S-s-U- patients showing alloanti-U-like. Our study contributes to a better understanding of alloimmunization to GPB in black people and confirms importance of genotyping in S-s- patients, especially those with sickle cell disease to be frequently transfused.

Identification and characterization of a novel XK splice site mutation in a patient with McLeod syndrome.

BACKGROUND: McLeod syndrome is a rare X-linked neuroacanthocytosis syndrome with hematologic, muscular, and neurologic manifestations. McLeod syndrome is caused by mutations in the XK gene whose product is expressed at the red blood cell (RBC) surface but whose function is currently unknown. A variety of XK mutations has been reported but no clear phenotype-genotype correlation has been found, especially for the point mutations affecting splicing sites. STUDY DESIGN AND METHODS: A man suspected of neuroacanthocytosis was evaluated by neurologic examination, electromyography, muscle biopsy, muscle computed tomography, and cerebral magnetic resonance imaging. The McLeod RBC phenotype was disclosed by blood smear and immunohematology analyses and then confirmed at the biochemical level by Western blot analysis. The responsible XK mutation was characterized at the mRNA level by reverse transcription-polymerase chain reaction (PCR), identified by genomic DNA sequencing, and verified by allele-specific PCR. RESULTS: A novel XK splice site mutation (IVS1-1G>A) has been identified in a McLeod patient who has developed hematologic, neuromuscular, and neurologic symptoms. This is the first reported example of a XK point mutation affecting the 3' acceptor splice site of Intron 1, and it was demonstrated that this mutation indeed induces aberrant splicing of XK RNA and lack of XK protein at the RBC membrane. CONCLUSION: The detailed characterization at the molecular biology level of this novel XK splice site mutation associated with the clinical description of the patient contributes to a better understanding of the phenotype-genotype correlation in the McLeod syndrome.