Effect of cryopreservation on a rare McLeod donor red blood cell concentrate.

Units of red blood cell (RBC) concentrates with rare phenotypes are typically not included in method validation studies for cryopreservation processes; rather, they are reserved for patients with rare blood needs. Some rare RBC phenotypes may demonstrate membrane abnormalities, like acanthocytosis as observed for RBCs with the McLeod phenotype, and are specifically banked for these rare attributes; however, the impact that rare RBC phenotypes have on post-thaw quality has not been well studied. To evaluate how a rare RBC phenotype is affected by the cryopreservation process, 4 RBC units, cryopreserved in 1993 using manual methods, were selected for evaluation. These RBCs included one with the McLeod phenotype and three with phenotypes not known to cause significant membrane changes. Post-thaw, an altered deglycerolization protocol, implemented to reduce supernatant glycerol after cryopreservation, was used before processing RBCs on an automated closed system (ACP 215; Haemonetics, Boston, MA) to accommodate the use of a closed system cell processor not available when the RBC units were previously cryopreserved. RBC quality was tested at 24 hours, 7 days, and 14 days post-deglycerolization. Before deglycerolization, an extracted sample from the thawed glycerolized RBC unit was used to obtain genetic material for phenotype confirmation. Genotyping confirmed the McLeod phenotype. When comparing McLeod with non-McLeod units, RBCs from the McLeod donor exhibited acanthocytosis, higher rigidity, and lower morphology scores than RBCs from the non-McLeod units post-deglycerolization. Hemolysis, however, was comparable across all 4 units, meeting regulatory standards. Therefore, McLeod RBCs can withstand cryopreservation, suggesting that units from these donors, glycerolized using older methods, can be deglycerolized using the ACP 215 and stored hypothermically for 14 days. It was also determined that genotyping can be performed on non-leukocyte-reduced cryopreserved RBCs, allowing for confirmation of genetic profiles of donor units banked before the implementation of molecular methods.Units of red blood cell (RBC) concentrates with rare phenotypes are typically not included in method validation studies for cryopreservation processes; rather, they are reserved for patients with rare blood needs. Some rare RBC phenotypes may demonstrate membrane abnormalities, like acanthocytosis as observed for RBCs with the McLeod phenotype, and are specifically banked for these rare attributes; however, the impact that rare RBC phenotypes have on post-thaw quality has not been well studied. To evaluate how a rare RBC phenotype is affected by the cryopreservation process, 4 RBC units, cryopreserved in 1993 using manual methods, were selected for evaluation. These RBCs included one with the McLeod phenotype and three with phenotypes not known to cause significant membrane changes. Post-thaw, an altered deglycerolization protocol, implemented to reduce supernatant glycerol after cryopreservation, was used before processing RBCs on an automated closed system (ACP 215; Haemonetics, Boston, MA) to accommodate the use of a closed system cell processor not available when the RBC units were previously cryopreserved. RBC quality was tested at 24 hours, 7 days, and 14 days post-deglycerolization. Before deglycerolization, an extracted sample from the thawed glycerolized RBC unit was used to obtain genetic material for phenotype confirmation. Genotyping confirmed the McLeod phenotype. When comparing McLeod with non-McLeod units, RBCs from the McLeod donor exhibited acanthocytosis, higher rigidity, and lower morphology scores than RBCs from the non-McLeod units post-deglycerolization. Hemolysis, however, was comparable across all 4 units, meeting regulatory standards. Therefore, McLeod RBCs can withstand cryopreservation, suggesting that units from these donors, glycerolized using older methods, can be deglycerolized using the ACP 215 and stored hypothermically for 14 days. It was also determined that genotyping can be performed on non-leukocyte­reduced cryopreserved RBCs, allowing for confirmation of genetic profiles of donor units banked before the implementation of molecular methods.

Unusual serological findings associated with ceftriaxone-induced immune hemolytic anemia in a child with disseminated low-grade glioma.

Ceftriaxone-induced immune hemolytic anemia (CIHA) is the second most common cause of drug-induced hemolytic anemia. Prompt recognition of this drug reaction is essential because brisk hemolysis can be deadly. The extent to which ceftriaxone antibodies persist after CIHA is unknown; rechallenging patients who have experienced CIHA is not recommended. We report a case of CIHA in a neurooncology patient, which is the first to show anticeftriaxone antibodies with Rh specificity and persisted for 8 months after the drug reaction. These findings have implications for understanding the mechanism of CIHA.

International society of blood transfusion working party on red cell immunogenetics and terminology: report of the Seoul and London meetings.

The Working Party has met twice since the last report: in Seoul, South Korea 2014, and in London, UK 2015, both in association with the International Society of Blood Transfusion (ISBT) Congress. As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. Eleven new blood group antigens were added to seven blood group systems. This brings the current total of blood group antigens recognized by the ISBT to 346, of which 308 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known blood group system.

Microfluidic approach to genotyping human platelet antigens.

Centralised laboratories routinely determine blood types by serological and molecular methods. Current practices have limitations in terms of cost, time and accessibility. Miniaturised microfluidic platforms offer an alternative to conventional genotyping methods, since they consume fewer reagents, provide faster analysis and allow for complete integration and automation. As these 'lab-on-a-chip' devices have been used for bacterial and viral detection, the authors investigated blood group genotyping as a novel application of microfluidic technology. To demonstrate the feasibility of microfluidic chip-based genotyping, the authors compared human platelet antigen 1 (HPA-1) genotype results from conventional and chip-based analysis for 19 blood donor specimens. DNA purification was performed with ChargeSwitch™ magnetic beads, DNA amplification (PCR), restriction length polymorphism (RFLP) and capillary electrophoresis (CE) for identification of the DNA on microfluidic chips. It was found that nine donors were HPA-1a/1a and ten were HPA-1a/1b. Concordance between the conventional and on-chip methods was achieved for all but one sample. All the steps were demonstrated for complete blood group genotyping analysis of patient whole blood specimens on separate microfluidic chips. Future work will focus on integration of all the genotyping protocols on a single microfluidic chip.

Consortium for Blood Group Genes (CBGG): 2009 report.

Consortium for Blood Group Genes is a worldwide organization whose goal is to have a vehicle to interact, establish guidelines, operate a proficiency program, and provide education for laboratories involved in DNA and RNA testing for the prediction of blood group, platelet, and neutrophil antigens. Currently, the consortium operates with representatives from Brazil, Canada, and the United States. Membership is voluntary with the expectation that members actively contribute to discussions involving blood group genetics. This year witnessed a change in the standing committee membership and the institution of a representative for the human platelet antigens group. Looking forward, the consortium sees challenges for the nomenclature of blood group alleles and user-required specifications for laboratory information systems to store genotype information.

Consortium for Blood Group Genes (CBGG): 2008 report.

The Consortium for Blood Group Genes is a worldwide organization whose goal is to have a vehicle to interact, establish guidelines, operate a proficiency program, and provide education for laboratories involved in DNA and RNA testing for the prediction of blood group, platelet, and neutrophil antigens.

Consortium for Blood Group Genes (CBGG): 2007 report.

The Consortium for Blood Group Genes is a worldwide organization whose goal is to have a vehicle to interact, establish guidelines, operate a proficiency program, and provide education for laboratories involved in DNA and RNA testing for the prediction of blood group, platelet, and neutrophil antigens.

High-throughput multiplex single-nucleotide polymorphism analysis for red cell and platelet antigen genotypes.

BACKGROUND: Transfusion recipients who become alloimmunized to red cell or platelet (PLT) antigens require antigen-negative blood to limit adverse transfusion reactions. Blood collection facilities use regulated and unregulated antibodies to phenotype blood, the cost of which can be prohibitive depending on the antisera and demand. An alternative strategy is to screen blood for these antigens with genomic DNA and the associated single-nucleotide polymorphisms (SNPs). STUDY DESIGN AND METHODS: A multiplex polymerase chain reaction (PCR)-oligonucleotide extension assay was developed with genomic DNA and a SNP genotyping platform (GenomeLab SNPstream, Beckman Coulter) to identify SNPs related to D, C/c, E, S/s, K/k, Kp(a/b), Fy(a/b), FY0 (-33 promoter silencing polymorphism), Jk(a/b), Di(a/b), and human PLT antigen (HPA)-1a/1b. A total of 372 samples were analyzed for 12 SNPs. The genotypes were compared to the blood group and PLT antigen phenotypes. RESULTS: Individual sample results varied from 98 to 100 percent for 11 of 12 SNPs. D was correctly identified in 292 of 296 (98.6%) D+ donors. The RHCE exon 5 E/e SNP analysis had the lowest concordance (89.5%). Thirty-three R(1)R(1) and 1 r"r were correctly identified. PCR-restriction fragment length polymorphism (RFLP) on selected samples confirmed the presence of the FY0 silencing polymorphism in nine donors. Homozygous HPA-1b/1b was identified in four donors, which was confirmed by PCR-RFLP (n = 4) and anti-HPA-1a serology (n = 2). The two HPA-1a-negative donors were recruited into the plateletpheresis program. CONCLUSION: The platform has the capacity to genotype thousands of samples per day. The suite of SNPs provides genotype data for all blood donors within 36 hours of the start of testing.

Maternal ABO-mismatched blood for intrauterine transfusion of severe hemolytic disease of the newborn due to anti-Rh17.

BACKGROUND: Clinically significant antibodies to high-incident antigens present a challenge in hemolytic disease of the newborn. Antigen-negative blood may be difficult to obtain for intrauterine transfusion (IUT). In these instances, maternal blood is de facto compatible regardless of an ABO mismatch. CASE REPORT: A group B/D-- woman with a history of hemolytic disease of the newborn due to anti-Rh17 (titer 256) presented to the obstetrical clinic at 12 weeks gestation for management of her third pregnancy. She consented to donate blood for possible IUT. STUDY DESIGN AND METHODS: Washed maternal packed cells were suspended in saline to 75 percent Hct and irradiated before transfusion. The fetus was transfused via the intrahepatic vein. RESULTS: Ultrasound examination at 19 weeks indicated a hydropic fetus. The fetal blood group was O Rh+, direct antiglobulin test 4+, and hemoglobin 22 g per L. A total of 368 mL of maternal blood was transfused during seven procedures. Labor was induced at 38 weeks, and a 2560-g male infant was delivered by Caesarian-section due to fetal distress. The infant grouped as B Rh+, direct antiglobulin test negative. No group O red blood cells were detected. The hemoglobin level was 143 g per L rising to 209 g per L at discharge 3 days later. The indirect bilirubin was 55 micromol/L and remained stable during the hospital stay. Phototherapy was discontinued after 1 day, and the infant was discharged without an exchange or top-up transfusion. CONCLUSIONS: Maternal ABO-mismatched blood is an alternate source for IUT in instances when antigen-compatible allogenic blood is unavailable.

RhD status of a fetus at risk for haemolytic disease with a discrepant maternal DNA-based RhD genotype.

The cloning of the RHD gene has made it possible to determine the RhD status of fetuses at risk for haemolytic disease due to RhD iso-immunization using amniotic fluid or chorionic villi-derived DNA and the polymerase chain reaction. However, some Rh haplotypes are associated with false-positive or negative DNA-based results with the potential for an adverse outcome. We determined the RhD status of a fetus using amniotic fluid-derived DNA for an anti-D iso-immunized woman. Initially, we obtained the ethnic background and the complete RhD and RhCcEe phenotypes of both parents. The mother was RhD negative (Cde/cde) but her DNA was positive for exon 10 of the RHD gene. The fetus was positive for both exons 4 5 and exon 10. Southern analysis confirmed that the maternal DNA contained a portion of the RHD gene with a restriction pattern that was similar to RhD-positive individuals. This report illustrates that, in addition to fetal DNA genotyping, the same PCR assays, complete with RhD and RhCcEe phenotypes, and ethnic background of the parents should be obtained to alert the molecular diagnostic laboratory to the presence of rare Rh haplotypes that are associated with DNA genotyping errors.

An adenine trimer precedes a C/G polymorphism in the 3'-amplimer region of the human platelet glycoprotein IIIa intron 6 CT repeat.

Restriction enzyme and short tandem repeat polymorphisms are often used to link a particular allele with an inheritable disease-related gene in the absence of the information regarding the DNA mutation or defect. Polymorphic markers within the gene in question are particularly useful and can provide sufficient information for genetic counselling to potential carriers of the disease. Using a published method for the CT repeat in intron 6 of the GP3A gene, it was found that a single nucleotide deletion in the published genomic GP3A sequence in the region of the antisense amplimer and a C/G nucleotide polymorphism (allele frequencies, G = 0.883, C = 0.117) immediately adjacent to the deletion were responsible for the lack of PCR amplification. The absence of amplification has important implications for the assignment of a particular CT repeat to a given allele and for the population frequencies of the various CT repeats.

Factor V Leiden and thrombotic complications in heparin-induced thrombocytopenia.

To determine whether factor V Leiden is associated with thrombotic events in patients with heparin-induced thrombocytopenia (HIT), we evaluated 165 patients with serologically confirmed HIT for the presence of factor V Leiden and determined the incidence of venous or arterial thrombosis during the period of HIT. Factor V Leiden was detected in 16 of 165 HIT patients (9.7%). HIT-associated venous thrombosis occurred in 11 of 16 factor V Leiden positive subjects and 94 of 149 factor V Leiden negative subjects (69% vs. 63%; p = 0.79). Arterial thrombosis occurred in 1 of 16 factor V Leiden positive subjects and 21 of 149 factor V Leiden negative subjects (6% vs. 14%; p = 0.70). There was no difference in the incidence of proximal limb DVT, pulmonary embolism, venous limb gangrene, local skin reactions, hemorrhagic adrenal infarction, stroke, or myocardial infarction between the groups. No difference in the severity of venous thrombosis between Leiden positive and negative subjects was detected. Our data suggest that in the acute prothrombotic milieu of HIT, heterozygous factor V Leiden is not an important additional risk factor for thrombosis.

Activation of platelets by sera containing IgG1 heparin-dependent antibodies: an explanation for the predominance of the Fc gammaRIIa "low responder" (his131) gene in patients with heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder caused by heparin-dependent IgG (HIT-IgG) that recognizes a complex of heparin and platelet factor 4 (PF4), leading to platelet activation via the platelet Fc gammaIIa receptors (Fc gammaRIIa). Not all patients who generate HIT-IgG in response to heparin develop HIT, however, possibly because of observed differences in the ability of platelets from healthy individuals to be activated by HIT sera. It is known that a polymorphism in the platelet Fc gammaRIIa plays an important role in determining platelet reactivity to murine platelet-activating monoclonal antibodies of the IgG1 subclass: homozygous arg131 ("high responder" or HR) platelets respond well, and homozygous his131 ("low responder" or LR) platelets respond poorly, respectively, to these murine monoclonal antibodies. We sought to determine whether the differing risk for HIT among patients who receive heparin, as well as the variable platelet reactivity to HIT sera, could be explained by preferential activation by HIT-IgG of platelets bearing a particular Fc gammaRIIa phenotype. We found that the LR Fc gammaRIIa gene frequency was significantly overrepresented among 84 HIT patients, compared with that of 264 control subjects (0.565 versus 0.471; p = 0.03). We studied the subclass distribution of HIT-IgG against its major antigen, heparin/PF4 complexes, and found that 55 of 61 (90%) HIT sera expressed IgG1 antibodies either alone (n = 47) or in combination with IgG2 (n = 5) or IgG3 (n = 3). We then compared the platelet-activating profile of HIT sera with murine platelet-activating monoclonal antibodies. As expected, the murine IgG1 monoclonal antibodies preferentially activated platelets from homozygous HR individuals. In contrast, however, the LR homozygous platelets exhibited the greatest reactivity to HIT sera that contained predominantly anti-heparin/PF4 antibodies of the IgG1 subclass. We conclude that the significant overrepresentation of the LR (his131) gene among patients with HIT may be explained by the preferential activation of LR Fc gammaRIIa platelets by HIT antibodies of the IgG1 subclass, which is the predominant immunoglobulin subclass generated in HIT.

Maternal immunization to Gov system alloantigens on human platelets.

BACKGROUND: Immunization to platelet alloantigens can occur during pregnancy or after the transfusion of blood components. Platelet alloantibodies can cause neonatal alloimmune thrombocytopenia and posttransfusion purpura. Transfusion-induced alloimmunization to a novel platelet alloantigen system, Gov, expressed on the 175-kDa glycosyl phosphatidylinositol-anchored platelet glycoprotein, CD109, was previously described. This report describes three unrelated patients who were alloimmunized to Gov(a) or Gov(b) during pregnancy. STUDY DESIGN AND METHODS: Platelets were typed by using radioimmunoprecipitation for HPA-1a, -3a, -5a, -5b, Gov(a), and Gov(b) and by polymerase chain reaction-restriction fragment length polymorphism for HPA-1a, -1b, -3a, and -3b. Maternal sera were screened for platelet antibodies by using radioimmunoprecipitation and the antigen capture assay. RESULTS: Patients 1 and 2 were investigated after the diagnosis of neonatal alloimmune thrombocytopenia in their children, and alloantibodies specific for Gov(b) and Gov(a), respectively, were detected in maternal serum. Serum from patient 3, who had mild idiopathic thrombocytopenia purpura with no detectable autoantibody, was found to contain alloantibodies to Gov(b) and to HPA-5b, presumably as a result of immunization during pregnancy. Platelet typings confirmed that the patients were at risk for alloimmunization to the respective antigen. CONCLUSION: This report of three cases of maternal alloimmunization to antigens in the Gov system indicates that immunization can occur via placental transfer of antigen and that Gov system alloantibodies may be associated with neonatal alloimmune thrombocytopenia.

A diagnostic test for heparin-induced thrombocytopenia: detection of platelet microparticles using flow cytometry.

Based on our previous observation that heparin-induced thrombocytopenia (HIT) sera can generate platelet microparticles from washed platelets in a heparin-dependent fashion, we developed a test for HIT using flow-cytometry to measure heparin-dependent platelet microparticle formation. During the developmental phase of the assay the optimal physical conditions for microparticle generation were defined. 133 sera were then evaluated using the microparticle assay and the serotonin release assay to determine the threshold for defining a positive result that gave optimal sensitivity and specificity. The microparticle assay was then prospectively evaluated against the serotonin release assay in 202 sera referred to our laboratory for HIT testing. Overall agreement between the two assays was 96% (Cohen's kappa = 0.91). When the clinical data were reviewed on patients whose sera gave discrepant results between the two assays, no case of HIT was detected by one assay and missed by the other. The platelet microparticle assay is as accurate as the serotonin release assay and may be a useful non-radioactive test for HIT.

A simple and rapid competitive enzyme-linked immunosorbent assay to identify HPA-1a (PlA1)-negative donor platelet units.

BACKGROUND: Alloantibodies to HPA-1a (PlA1) are the major cause of neonatal alloimmune thrombocytopenia and posttransfusion purpura and have been implicated in refractoriness to random-donor platelet transfusions. However, most assays used to phenotype platelets are cumbersome or time-consuming for large numbers of samples. STUDY DESIGN AND METHODS: A simple, competitive (inhibition) enzyme-linked immunosorbent assay for HPA-1a phenotyping of donor platelets was developed. A segment from the donor platelet unit transfer line was sealed to obtain a small aliquot of platelets. These platelets were washed once and added to a predetermined dilution of serum containing alloantibodies to HPA-1a. Residual anti-HPA-1a binding to the glycoprotein IIb/IIIa purified by lectin and high-performance liquid chromatography and coated on microtiter wells was detected with a conjugated antihuman IgG. A lack of inhibition equivalent to control (no platelets) was used to determine that the platelets were HPA-1b/b. RESULTS: Of the 557 platelet units tested, 14 (2.5%) were found to be HPA-1a negative, and they were confirmed to be HPA-1b/b by DNA genotyping. Two of the 14 HPA-1b/b units were also HPA-3b/b (approx. 0.35% of the random population). Use of the microtiter format allows 100 to 200 samples to be processed per day. CONCLUSION: This simple and inexpensive assay is useful for identifying HPA-1b/b units for platelet-compatible transfusions or for platelet antibody investigations.