Chronic anemia patients (such as thalassemia) often rely on long-term red blood cell transfusion to sustain life. However, alloimmune reactions against blood group antigens can pose serious risks to the patients' clinical treatment and survival. The regulatory mechanisms of transfusion-related alloimmunity are not yet well understood. For example, some patients, despite long-term transfusions, do not develop alloimmune reactions, while others produce alloantibodies against multiple blood group antigens, making transfusion therapy increasingly difficult. Red blood cell blood group alloimmunity involves various immune cells, including antigen-presenting cells and different T cells. Many studies are exploring the regulatory roles and even potential interventions. This article reviews the correlation between cellular immunity and red blood cell blood group antigens in alloimmune responses, and explores the interaction between the two, as well as their impact on immune responses.
Humans ; Immunity, Cellular/immunology* ; Erythrocytes/immunology* ; Blood Group Antigens/immunology* ; Animals ; Isoantibodies/immunology* ; T-Lymphocytes/immunology*

OBJECTIVE: To report the blood group antigen and antibody specificity identification methods for a patient with high-frequency antibodies, and the process of finding and providing compatible blood for the patient. METHODS: A patient sent from the Blood Transfusion Department of Shanxi Provincial People's Hospital to Blood Transfusion Technology Research Laboratory of Taiyuan Blood Center in November 2022 was selected for the study. Classical serological methods were used to determine the patient's blood type, screen for unexpected antibodies, identify antibodies, and perform crossmatching. High-frequency antibody identification was carried out using red blood cells treated with various enzymes. Blood group genotyping was conducted using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF) and Sanger sequencing. Multiple strategies were employed to address the patient's blood source problem. The study was approved by the Medical Ethics Committee of Taiyuan Blood Center [Ethics No. 2024 Ethics Review No.(2)]. RESULTS: The patient's blood type was B, RhD positive. Initial screening of the patient's serum with multiple screening cells and antibody identification cells in saline medium was negative, but positive in antiglobulin medium. The patient's serum showed varying reaction intensities with red blood cells treated with different enzymes. MALDI-TOF mass spectrometry and Sanger sequencing revealed a homozygous nonsense variant c.376C>T (p.Gln126Ter) in the ABCG2 gene, resulting in the Jr(a-) phenotype. During family donor selection, the patient's son was found to have a heterozygous variant c.376C>T (p.Gln126Ter), and another heterozygous variant c.421C>A (p.Gln141Lys), which predicted a Jr(a+w) phenotype. Crossmatch tests confirmed the compatibility of blood from the patient's son, which was used to address the urgent blood requirement. Later, rare blood from a Jr(a-) donor from the Guangzhou Blood Center was used for the patient's ongoing treatment, saving the patient's life. CONCLUSION Combining classic serological testing with blood group gene typing techniques successfully identified the rare Jr(a-) blood type and high-frequency anti-Jra antibodies. Enzyme-treated red blood cell identification methods confirmed the presence of anti-Jra antibodies. By searching within the family and seeking help from other blood centers, compatible blood was found. This approach may provide insights for resolving similar complex blood matching problems in the future.
Humans ; Blood Grouping and Crossmatching/methods* ; Blood Group Antigens/immunology* ; Blood Transfusion ; Male ; Isoantibodies/blood* ; Female ; Genotype

OBJECTIVE: To retrospectively analyze the identification results of irregular antibodies, to clarify the distribution features and to explore the relation of alloantibodies and autoantibodies with the immunized history of patients and disease kinds. METHODS: 49 820 patients who applied for red blood transfusion during Sep 1st 2017 to Sep 1st 2018 were selected. All the specimens were screened for the antibody by microcolumn gel antiglobulin technique, which then were identified for irregular antibody. RESULTS: Antibodies were found in 861 (1.73%) of all 49 820 transfused samples. The alloimmunization history of the patients with antibodies was significantly different between male and female (χ=18.54，P＜0.01). The alloantibody was the most common, accounting for 59.50% in all of the antibodies. Warm autoantibody, anti-E, anti-M, anti-cE and anti-Ce accounted for 68.5% of the antibodies. The blood group of Rh, MNS and Lewis were responsible for 92.40% of alloantibody, especially anti-E accounted for the largest percentage(38.60%) of alloantibody. Patients with alloantiboies experienced much more the alloimmunization and transfusion history (χ=20.13，P＜0.01；χ=5.40，P＜0.05) . The distribution of auto and alloantibody was very significantly different among the ddifferent isease (χ=51.8，P＜0.01), Hematopathy, solid tumor and osteoarthropathy were often associated with alloantibody, otherwise, autoantibodies often occurred in hematopathy and autoimmune disease. CONCLUSION The most important factor that results in antibody-screening positive is alloantibody, in which anti-E antibody from Rh blood group system in most common.
Antibodies ; immunology ; Blood Group Antigens ; Blood Transfusion ; Erythrocytes ; Female ; Humans ; Isoantibodies ; Male ; Retrospective Studies

BACKGROUND: Duffy (FY) blood group genotyping is important in transfusion medicine because Duffy alloantibodies are associated with delayed hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. In this study, FY allele frequencies in Thai blood donors were determined by in-house PCR with sequence-specific primers (PCR-SSP), and the probability of obtaining compatible blood for alloimmunized patients was assessed. METHODS: Five hundred blood samples from Thai blood donors of the National Blood Centre, Thai Red Cross Society, were included. Only 200 samples were tested with anti-Fy(a) and anti-Fy(b) using the gel technique. All 500 samples and four samples from a Guinea family with the Fy(a-b-) phenotype were genotyped by using PCR-SSP. Additionally, the probability of obtaining antigen-negative red blood cells (RBCs) for alloimmunized patients was calculated according to the estimated FY allele frequencies. RESULTS: The FY phenotyping and genotyping results were in 100% concordance. The allele frequencies of FY*A and FY*B in 500 central Thais were 0.962 (962/1,000) and 0.038 (38/1,000), respectively. Although the Fy(a-b-) phenotype was not observed in this study, FY*B(ES)/FY*B(ES) was identified by PCR-SSP in the Guinea family and was confirmed by DNA sequencing. CONCLUSIONS: Our results confirm the high frequency of the FY*A allele in the Thai population, similar to that of Asian populations. At least 500 Thai blood donors are needed to obtain two units of antigen-negative RBCs for the Fy(a-b+) phenotype.
Adult ; Alleles ; Asian Continental Ancestry Group/genetics ; Base Sequence ; Blood Donors ; DNA/chemistry/genetics/metabolism ; Duffy Blood-Group System/*genetics/immunology ; Female ; Gene Frequency ; Genotype ; Humans ; Isoantibodies/blood/immunology ; Male ; Middle Aged ; Phenotype ; Polymerase Chain Reaction ; Receptors, Cell Surface/genetics/*immunology ; Sequence Analysis, DNA ; Thailand ; Young Adult

BACKGROUND: Although single antigen bead assays (SAB) are approved qualitative tests, the median fluorescence intensity (MFI) values obtained from SAB are frequently used in combination with quantitative significances for diagnostic purposes. To gauge the reproducibility of SAB results, we assessed the interlaboratory variability of MFI values using identical kits with reagents from the same lot and the manufacturer's protocol. METHODS: Six serum samples containing HLA-specific antibodies were analyzed at five laboratories by using Lifecodes LSA Class I and Class II SAB kits (Immucor, USA) from the same lot, according to the manufacturer's protocol. We analyzed the concordance of qualitative results according to distinct MFI cutoffs (1,000, 3,000, 5,000, and 10,000), and the correlation of quantitative MFI values obtained by the participating laboratories. The CV for MFI values were analyzed and grouped by mean MFI values from the five laboratories (<1,000; 1,000-2,999; 3,000-4,999; 5,000-9,999; and > or =10,000). RESULTS: The categorical results obtained from the five laboratories exhibited concordance rates of 96.0% and 97.2% for detection of HLA class I and class II antibodies, respectively. The Pearson correlation coefficients for MFI values of class I and class II antibodies were between 0.947-0.991 and 0.992-0.997, respectively. The median CVs for the MFI values among five laboratories in the lower MFI range (<1,000) were significantly higher than those for the other MFI ranges (all P<0.01). CONCLUSIONS: Analysis of SAB performed in five laboratories using identical protocols and reagents from the same lot resulted in high levels of concordance and strong correlation of results.
Analysis of Variance ; HLA Antigens/immunology ; Histocompatibility Testing ; Humans ; Isoantibodies/*blood ; Laboratories ; Reagent Kits, Diagnostic ; Reproducibility of Results

OBJECTIVETo detect platelet anti-HPA-1a and -1b antibodies using recombinant GPIIIa fragments coupled to Luminex beads.

METHODSThe sensitivity of 2 techniques, monoclonal antibody specific immobilization of platelet antigen (MAIPA) and Luminex bead assay, was compared using 12 twofold-serial dilutions (from neat to 1 in 2048) of an anti-HPA-1a WHO international standard. The specificity of Luminex assay to identify anti-HPA-1a and -1b antibodies was assessed using 8 negative or positive controls and 36 blinded samples provided by WHO Platelet Workshop.

RESULTSThe sensitivity of MAIPA and Luminex bead assay to detect anti-HPA-1a was dilution 1/64 (i.e. 1.56 IU/ml) and far more than dilution 1/2048 (i.e. 0.049 IU/mL), respectively. The Luminex bead assay could specifically identify negative and positive controls of anti-HPA-1a and -1b. All results of 36 blinded samples by Luminex assay were accordant to reference results except one sample which contained high concentration antithetical antibody and resulted in false positive of anti-HPA-1b. Cross-reactivity was also not observed with the samples containing HLA, ABO or other platelet antibodies.

CONCLUSIONThe Luminex beads coupled with recombinant GPIIIa fragments can be used to detect HPA-1 system antibodies with sufficient sensitivity and specificity, that is suitable for the detection of platelet alloantibodies in clinical alloimmune thrombocytopenia.

Antibodies, Monoclonal ; Antigens, Human Platelet ; immunology ; Blood Platelets ; Humans ; Integrin beta3 ; chemistry ; Isoantibodies ; blood ; Purpura, Thrombocytopenic, Idiopathic ; diagnosis ; Recombinant Proteins ; chemistry ; Sensitivity and Specificity

No abstract available.
Aged ; False Positive Reactions ; *Histocompatibility Testing ; Humans ; Isoantibodies/immunology ; Keratoplasty, Penetrating ; Male ; Transplantation, Homologous

OBJECTIVETo explore the diagnosis and treatment of a case of neonatal alloimmune thrombocytopenia purpura (NAITP) caused by anti HPA-3a antibody.

METHODSThe platelet counts and purpuric symptom in the newborn were clinical examined. The HPA-1-21bw genotypes of the newborn and his parents were detected by multiple DNA-PCR, gene sequencing and genotyping. The HPA specificity antibody in the sera of newborn and his mother were detected by flow cytometry (FCM), and the HPA specificity antibody was identified by monoclonal antibody-specific immobilization of platelet antigens (MAIPA).

RESULTSThe newborn had the typical symptom of NAITP, multiple subcutaneous petechia, hematuria and coffee-like vomitus. The HPA genotype of the newborn was HPA-3ab, while that of his mother and his father were HPA-3bb and HPA-3aa, respectively. The sera of newborn and his mother existed antibody against the platelet of newborn's father. The HPA antibody of the newborn and his mother were identified as anti HPA-3a. The newborn was approved a patient of NAITP caused by anti HPA-3a antibody.

CONCLUSIONThe diagnosis and treatment for NAITP newborn caused by anti HPA-3a antibody in this study was the first domestic report. It could provide successful experiences and references for the similar cases.

Antibody Specificity ; immunology ; Antigens, Human Platelet ; immunology ; Genotype ; Humans ; Infant, Newborn ; Isoantibodies ; adverse effects ; immunology ; Male ; Thrombocytopenia, Neonatal Alloimmune ; etiology ; immunology

To determine the approximate incidence and clinical features of pernicious anemia in a Korean population, we retrospectively analyzed clinical data for patients with pernicious anemia who were diagnosed between 1995 and 2010 at five hospitals in Chungnam province. Ninety-seven patients were enrolled, who accounted for 24% of patients with vitamin B12 deficiency anemia. The approximate annual incidence of pernicious anemia was 0.3 per 100,000. The median age was 66 (range, 32-98) yr, and the male/female ratio was 1.25. Anemia-associated discomfort was the most common symptom (79.4%), followed by gastrointestinal and neurological symptoms (78.4% and 38.1%, respectively). Pancytopenia was found in 36 patients (37.1%), and autoimmune disorders were found in 15 patients (15.5%). Antibody to intrinsic factor was detected in 62 (77.5%) of 80 patients examined, and antibody to parietal cells was detected in 35 (43.2%) of 81 patients examined. Of the 34 patients who underwent tests for Helicobacter pylori, 7 (12.5%) were positive. The anemia-associated and gastrointestinal symptoms resolved completely in all patients after intramuscular injection of cobalamin, whereas neurological symptoms remained in some. In conclusion, pernicious anemia is less frequent in Koreans than in Western populations; however, the clinical features of this disorder in Koreans do not differ from those of Western cases.
Adult ; Aged ; Anemia, Pernicious/complications/*diagnosis/epidemiology ; Asian Continental Ancestry Group ; Autoimmune Diseases/complications/epidemiology ; Female ; Gastrointestinal Diseases/complications/drug therapy/epidemiology ; Helicobacter Infections/diagnosis ; Helicobacter pylori ; Humans ; Isoantibodies/blood ; Male ; Middle Aged ; Nervous System Diseases/complications/epidemiology ; Parietal Cells, Gastric/immunology ; Republic of Korea/epidemiology ; Retrospective Studies ; Vitamin B 12/blood/therapeutic use

Blood Coagulation Factor Inhibitors ; antagonists & inhibitors ; blood ; Factor VIII ; administration & dosage ; antagonists & inhibitors ; immunology ; Hemophilia A ; drug therapy ; genetics ; immunology ; Humans ; Immune Tolerance ; Isoantibodies ; blood ; immunology ; Recombinant Proteins ; adverse effects ; immunology ; therapeutic use ; Risk Factors ; Time Factors