Immunohematology最新文献

The ABO blood group system includes phenotypes, or subgroups, that differ in the amount of A and B antigens present on the red blood cells (RBCs). These subgroups also differ in the A, B, or H substances present in secretions (for individuals who have the secretor phenotype). B subgroups are very rare and are less frequently reported than A subgroups. Usually, B subgroups are discovered during serologic testing when there is a discrepancy between RBC and serum grouping results. Subgroups of B are usually identified by a reference laboratory using molecular and adsorption-elution methods. This report details a case of a young, healthy, pregnant woman with a B subgroup detected by a small transfusion service using adsorption-elution methods. Serology and genotyping of the ABO gene was performed at a reference laboratory where the serology was consistent with a B subgroup, but no changes were identified in ABO gene sequencing. It is important to correctly identify B subgroups in donors and recipients to help resolve ABO discrepancies and potentially prevent ABO incompatibility in blood transfusion, thus minimizing transfusion reactions.

The ABO blood group system includes phenotypes, or subgroups, that differ in the amount of A and B antigens present on the red blood cells (RBCs). These subgroups also differ in the A, B, or H substances present in secretions (for individuals who have the secretor phenotype). B subgroups are very rare and are less frequently reported than A subgroups. Usually, B subgroups are discovered during serologic testing when there is a discrepancy between RBC and serum grouping results. Subgroups of B are usually identified by a reference laboratory using molecular and adsorption-elution methods. This report details a case of a young, healthy, pregnant woman with a B subgroup detected by a small transfusion service using adsorption-elution methods. Serology and genotyping of the ABO gene was performed at a reference laboratory where the serology was consistent with a B subgroup, but no changes were identified in ABO gene sequencing. It is important to correctly identify B subgroups in donors and recipients to help resolve ABO discrepancies and potentially prevent ABO incompatibility in blood transfusion, thus minimizing transfusion reactions.

The Lewis blood group system is unique because antigens are neither alleles of the same gene nor are they synthesized by red blood cells (RBCs); rather, they are adsorbed onto the RBC membrane from plasma as glycolipids. Antibodies against Lewis antigens are predominantly naturally occurring immunoglobulin (Ig)M type that sometimes react at 37°C and the antihuman globulin phase. Lewis compound antigens, ALe^b and BLe^b, have been described that were confirmed because of the presence of antibodies against them. These compound antigens are the result of an interaction between ABO, H, SE, and LE genes.

The Lewis blood group system is unique because antigens are neither alleles of the same gene nor are they synthesized by red blood cells (RBCs); rather, they are adsorbed onto the RBC membrane from plasma as glycolipids. Antibodies against Lewis antigens are predominantly naturally occurring immunoglobulin (Ig)M type that sometimes react at 37°C and the antihuman globulin phase. Lewis compound antigens, ALe^b and BLe^b, have been described that were confirmed because of the presence of antibodies against them. These compound antigens are the result of an interaction between ABO, H, SE, and LE genes.

ABO incompatibility is the most common cause of immune hemolytic disease of the fetus and newborn (HDFN). The American Academy of Pediatrics lists blood group incompatibility as one of the major risk factors for severe hyperbilirubinemia in newborns. We have estimated the risk of ABO HDFN to determine the need for its routine screening. Blood group data from all blood donors who donated in the last 10 years were collected and analyzed. The population prevalence of ABO blood group genes using the phenotype data of blood donors was estimated. This information was further used to calculate an incidence of ABO HDFN requiring intervention in the population. ABO blood group typing was analyzed in 425,743 blood donors. The ABO phenotypes of A, B, O, and AB were 22.48, 36.73, 31.59, and 9.2 percent, respectively. The gene frequencies were 0.1733, 0.2647, and 0.5620 for A, B, and O, respectively. It was estimated that 13.84 percent of group O women would give birth to a non-group O baby and that approximately 2.77 percent of deliveries would likely have ABO HDFN in the study population. In India, the estimated risk of ABO HDFN is 2.9 percent, with a daily 2196 babies at risk of ABO HDFN requiring intervention. This analysis estimates the overall burden of ABO HDFN in the population, which could aid in the decision-making of policymakers, physicians, and community health practitioners to improve neonatal care.

ABO incompatibility is the most common cause of immune hemolytic disease of the fetus and newborn (HDFN). The American Academy of Pediatrics lists blood group incompatibility as one of the major risk factors for severe hyperbilirubinemia in newborns. We have estimated the risk of ABO HDFN to determine the need for its routine screening. Blood group data from all blood donors who donated in the last 10 years were collected and analyzed. The population prevalence of ABO blood group genes using the phenotype data of blood donors was estimated. This information was further used to calculate an incidence of ABO HDFN requiring intervention in the population. ABO blood group typing was analyzed in 425,743 blood donors. The ABO phenotypes of A, B, O, and AB were 22.48, 36.73, 31.59, and 9.2 percent, respectively. The gene frequencies were 0.1733, 0.2647, and 0.5620 for A, B, and O, respectively. It was estimated that 13.84 percent of group O women would give birth to a non–group O baby and that approximately 2.77 percent of deliveries would likely have ABO HDFN in the study population. In India, the estimated risk of ABO HDFN is 2.9 percent, with a daily 2196 babies at risk of ABO HDFN requiring intervention. This analysis estimates the overall burden of ABO HDFN in the population, which could aid in the decision-making of policymakers, physicians, and community health practitioners to improve neonatal care.

This update of the Ok (OK) blood group system (Smart EA, Storry JR. The OK blood group system: a review. Immunohematology 2010;26:124-6) focuses on new information on the role of basigin (BSG), the carrier molecule of the Ok blood group antigens. No further antigens have been identified since the original review. However, the role of BSG in malaria continues to be explored. Immunohematology 2021;37:18-19.

This update of the Ok (OK) blood group system (Smart EA, Storry JR. The OK blood group system: a review. Immunohematology 2010;26:124–6) focuses on new information on the role of basigin (BSG), the carrier molecule of the Ok blood group antigens. No further antigens have been identified since the original review. However, the role of BSG in malaria continues to be explored. Immunohematology 2021;37:18–19.

Many patients with anti-Yt^a receive multiple transfusions of Yt(a+) red blood cells (RBCs) with no ill effects. However, anti-Yt^a has been implicated in hemolytic transfusion reactions. Antibody identification typically determines specificity of antibodies and their clinical significance to justify blood requirements for antigen-negative blood when clinically significant antibodies are involved. Occasionally, specificity of antibody is of variable significance. Variability in clinical significance is a characteristic of anti-Yt^a that may affect the clinical management of such patients. This case reports the outcome of an incompatible transfusion in an 83-year-old female patient with anti-Yt^a, -D, -C, -Le^ab, and -HI who was admitted to the hospital for a severe urinary tract hemorrhage and fever. The patient was transfused with 1 crossmatch-incompatible group A, Yt(a+), D-, C-, E-, S- RBC unit in an emergency medical event. During that time, the patient exhibited chills, shivering, and tachycardia. Decreases in hemoglobin and hematocrit were noted. Laboratory parameters for hemolysis, such as total bilirubin, direct bilirubin, and lactate dehydrogenase, were increased. Based on clinical and laboratory evaluation, it was concluded that the patient had an acute hemolytic transfusion reaction caused by anti-Yt^a. The patient was successfully treated with antipyretics, antihistamines, and corticosteroids. Urinary tract hemorrhaging was stopped. Anemia was additionally improved with parenteral iron supplementation, and further transfusion was not required. Immunohematology 2021;37:13-17.

Many patients with anti-Yt^a receive multiple transfusions of Yt(a+) red blood cells (RBCs) with no ill effects. However, anti-Yt^a has been implicated in hemolytic transfusion reactions. Antibody identification typically determines specificity of antibodies and their clinical significance to justify blood requirements for antigen-negative blood when clinically significant antibodies are involved. Occasionally, specificity of antibody is of variable significance. Variability in clinical significance is a characteristic of anti-Yt^a that may affect the clinical management of such patients. This case reports the outcome of an incompatible transfusion in an 83-year-old female patient with anti-Yt^a, -D, -C, -Le^ab, and -HI who was admitted to the hospital for a severe urinary tract hemorrhage and fever. The patient was transfused with 1 crossmatch-incompatible group A, Yt(a+), D–, C–, E–, S– RBC unit in an emergency medical event. During that time, the patient exhibited chills, shivering, and tachycardia. Decreases in hemoglobin and hematocrit were noted. Laboratory parameters for hemolysis, such as total bilirubin, direct bilirubin, and lactate dehydrogenase, were increased. Based on clinical and laboratory evaluation, it was con

The red blood cell (RBC) antigen Wr^a is a low-prevalence antigen first described in 1953 by Holman and assigned to the Diego system in 1995. Because of its low prevalence, Wr^a is usually absent on commercial screening RBCs and antibody identification panels. When Wr(a+) screening RBCs are available, the corresponding antibody, anti-Wr^a, is often found in sera from healthy individuals, patients, and pregnant women. Anti-Wr^a can cause both hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. We describe a fatal acute hemolytic transfusion reaction caused by anti-Wr^a in a patient with no other RBC alloantibodies. Serologic investigation showed that one of the RBC units the patient received was Wr(a+). Immunohematology 2021;37:20-24.

The red blood cell (RBC) antigen Wr^a is a low-prevalence antigen first described in 1953 by Holman and assigned to the Diego system in 1995. Because of its low prevalence, Wr^a is usually absent on commercial screening RBCs and antibody identification panels. When Wr(a+) screening RBCs are available, the corresponding antibody, anti-Wr^a, is often found in sera from healthy individuals, patients, and pregnant women. Anti-Wr^a can cause both hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. We describe a fatal acute hemolytic transfusion reaction caused by anti-Wr^a in a patient with no other RBC alloantibodies. Serologic investigation showed that one of the RBC units the patient received was Wr(a+). Immunohematology 2021;37:20–24.

D- red blood cells (RBCs), always in short supply, and Rh immune globulin (RhIG) are not needed for patient care if D+ RBCs can safely be transfused. According to a recent work group recommendation, patients with the RHD*weak D type 4.0 allele can be considered D+. We report an African American woman who presented for delivery at the end of the third trimester, at which time anti-U and a serologic weak D phenotype were recognized, requiring U-, D- RBC units. We obtained 3 U- RBC units, including 1 D- unit. Later, the RHD*weak D type 4.0 allele was determined by RHD genotyping, only 6 days before delivery. The patient had an uneventful vaginal delivery of a D+ baby. No transfusion was needed for mother or baby. In this case, a pregnant woman with the RHD*weak D type 4.0 allele can safely be managed as D+, relaxing the unnecessary D- restriction for the limited U- RBC supply. The procured U-, D- RBC unit was frozen with 14 days of shelf-life remaining. To conserve D- RBC units, not limited to U-, for patients with a definite need, we recommend molecular analysis of a serologic weak D phenotype before a transfusion becomes imminent. The best time to resolve a serologic weak D phenotype with RHD genotyping is early in a pregnancy. Immunohematology 2021;37:1-4 .

D– red blood cells (RBCs), always in short supply, and Rh immune globulin (RhIG) are not needed for patient care if D+ RBCs can safely be transfused. According to a recent work group recommendation, patients with the RHD*weak D type 4.0 allele can be considered D+. We report an African American woman who presented for delivery at the end of the third trimester, at which time anti-U and a serologic weak D phenotype were recognized, requiring U–, D– RBC units. We obtained 3 U– RBC units, including 1 D– unit. Later, the RHD*weak D type 4.0 allele was determined by RHD genotyping, only 6 days before delivery. The patient had an uneventful vaginal delivery of a D+ baby. No transfusion was needed for mother or baby. In this case, a pregnant woman with the RHD*weak D type 4.0 allele can safely be managed as D+, relaxing the unnecessary D– restriction for the limited U– RBC supply. The procured U–, D– RBC unit was frozen with 14 days of shelf-life remaining. To conserve D– RBC units, not limited to U–, for patients with a definite need, we recommend molecular analysis of a serologic weak D phenotype before a transfusion becomes imminent. The best time to resolve a serologic weak D phenotype with RHD genotyping is early in a pregnancy. Immunohematology 2021;37:1–4 .

This study aims to determine the most frequent titers of anti-A and anti-B (both presumed immunoglobulin [Ig]M and IgG) in Iranian group O blood donors and to compare these titer values with those found in other studies. In addition, alloantibody production and plasma levels of four IgG subclasses were compared between the high-titer and non-high-titer study groups. This study investigated anti-A and anti-B titers in 358 plasma samples. Based on these results, two study groups (high-titer and non-high-titer) were formed. Antibody detection tests were performed to detect unexpected antibodies to D, C, c, E, e, K, k, Fy^a, Fy^b, Jk^a, Jk^b, M, N, S, s, P1, Le^a, and Le^b. Four IgG subclasses were also evaluated through nephelometry assay. The most frequent titer obtained by room temperature and indirect antiglobulin tube tests was 256. The frequency of titers ≥512 was 31.5 percent. None of the cases showed unexpected RBC alloantibodies. IgG2 levels were significantly higher in the high-titer group. Evaluation of isoagglutinin titers in group O Iranian blood donors can provide insight into the frequency of isoagglutinin titers both within the Iranian population and as compared with other populations. A significant difference in IgG2 levels between the high-titer and non-high-titer groups was identified. More investigation needs to be conducted on the root cause of this finding. Immunohematology 2021;37:5-12 .

This study aims to determine the most frequent titers of anti-A and anti-B (both presumed immunoglobulin [Ig]M and IgG) in Iranian group O blood donors and to compare these titer values with those found in other studies. In addition, alloantibody production and plasma levels of four IgG subclasses were compared between the high-titer and non–high-titer study groups. This study investigated anti-A and anti-B titers in 358 plasma samples. Based on these results, two study groups (high-titer and non–high-titer) were formed. Antibody detection tests were performed to detect unexpected antibodies to D, C, c, E, e, K, k, Fy^a, Fy^b, Jk^a, Jk^b, M, N, S, s, P1, Le^a, and Le^b. Four IgG subclasses were also evaluated through nephelometry assay. The most frequent titer obtained by room temperature and indirect antiglobulin tube tests was 256. The frequency of titers ≥512 was 31.5 percent. None of the cases showed unexpected RBC alloantibodies. IgG2 levels were significantly higher in the high-titer group. Evaluation of isoagglutinin titers in group O Iranian blood donors can provide insight into the frequency of isoagglutinin titers both within the Iranian population and as compared with other populations. A significant difference in IgG2 levels between the high-titer and non–high-titer groups was identified. More investigation needs to be conducted on the root cause of this finding. Immunohematology