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Bakchoul T, Bassler D, Heckmann M, Thiele T, Kiefel V, Gross I, Arnold DM, DiTomasso J, Smith JW, Paes B, Greinacher A. Management of infants born with severe neonatal alloimmune thrombocytopenia: the role of platelet transfusions and intravenous immunoglobulin. Transfusion 2013; 54:640-5. [DOI: 10.1111/trf.12336] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 05/10/2013] [Accepted: 05/22/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Tamam Bakchoul
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Dirk Bassler
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Matthias Heckmann
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Thomas Thiele
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Volker Kiefel
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Isabel Gross
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Donald M. Arnold
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Julie DiTomasso
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - James W. Smith
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Bosco Paes
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
| | - Andreas Greinacher
- Institute for Immunology and Transfusion Medicine; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital, Universitätsmedizin Greifswald; Greifswald Germany
- Department of Neonatology; University Children's Hospital; Tuebingen Germany
- Department of Transfusion Medicine; University of Rostock; Rostock Germany
- Department of Medicine; McMaster University; Hamilton Ontario Canada. Department of Pediatrics, Neonatal Division; McMaster University; Hamilton Ontario Canada. Canadian Blood Services; Hamilton Ontario Canada
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102
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Strong NK, Eddleman KA. Diagnosis and management of neonatal alloimmune thrombocytopenia in pregnancy. Clin Lab Med 2013; 33:311-25. [PMID: 23702120 DOI: 10.1016/j.cll.2013.03.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Neonatal alloimmune thrombocytopenia (NAIT) is the most common cause of severe thrombocytopenia in the healthy newborn, occurring in 1 in 1000 live births. NAIT is analogous to rhesus alloimmunization in pathophysiology; however, it often presents unexpectedly in first pregnancies. Presentation of NAIT varies from mild thrombocytopenia to life-threatening intracranial hemorrhage. It has been observed to be more severe in subsequent affected pregnancies. It is important that the diagnosis of NAIT be considered in the work-up of all cases of neonatal thrombocytopenia to determine the risk to future pregnancies and corresponding management plans. This article discusses the pathogenesis and incidence of NAIT and the antenatal and postnatal management of this condition.
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Affiliation(s)
- Noel K Strong
- Icahn School of Medicine at Mount Sinai, Department of Obstetrics, Gynecology and Reproductive Science, New York, NY 10029, USA.
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103
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Allen DL, Metcalfe P, Kaplan C, Kekomaki R, de Haas M, Yusuf R, Ouwehand WH. Sensitivity of assays for the detection of HPA-1a antibodies: results of an international workshop demonstrating the impact of cation chelation from integrin αIIbβ3 on three widely used assays. Vox Sang 2013; 105:167-73. [PMID: 23662600 DOI: 10.1111/vox.12043] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 02/22/2013] [Accepted: 03/24/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND OBJECTIVES HPA-1a antibodies account for 70-80% of cases of fetal-neonatal alloimmune thrombocytopenia (FNAIT) in Caucasians. However, numerous workshops have demonstrated variability in their detection. We recently showed that exposure of αIIbβ3 to ethylene diamine tetraacetic acid (EDTA) affected binding of many anti-αIIbβ3 monoclonal, and HPA-1a allo-, antibodies; this adversely affected sensitivity of the monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay and indirect platelet immunofluorescence test (PIFT). This study presents results from an international workshop studying the impact of cation chelation on HPA-1a antibody detection in routine diagnostic laboratories. MATERIALS AND METHODS Serum and EDTA-anticoagulated plasma samples containing anti-HPA-1a were distributed to 39 laboratories. Participants were asked to detect and identify any HPA antibodies present. RESULTS 2/39 (5.1%) participants were able to detect and identify anti-HPA-1a in the serum, but not in the plasma sample. EDTA plasma reduced MAIPA assay sensitivity by ≥ 20% in 17/24 (70.8%) laboratories and by ≥ 50% in 9/24 (37.5%) when using HPA-1a1a platelets (mean: 27.7%, range 0-85.1%); when using HPA-1a1b platelets 3/4 (75%), participants reported ≥ 50% loss of sensitivity (mean 65.6%, range 0-96.6%). A small but significant increase in optical densities was observed in antigen capture ELISA assays when using plasma (mean difference: 0.081, P < 0.01). Insufficient PIFT data were returned to draw firm conclusions. CONCLUSION Use of EDTA plasma significantly affects the sensitivity of the MAIPA assay and can affect detection of even potent, FNAIT-causing examples of anti-HPA-1a. These data highlight the importance of use of αIIbβ3 in an appropriate conformation for the sensitive detection of anti-HPA-1a.
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Affiliation(s)
- D L Allen
- Nuffield Department of Clinical Laboratory Sciences, University of Oxford, Oxford, UK.
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104
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Recombinant HPA-1a antibody therapy for treatment of fetomaternal alloimmune thrombocytopenia: proof of principle in human volunteers. Blood 2013; 122:313-20. [PMID: 23656729 DOI: 10.1182/blood-2013-02-481887] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fetomaternal alloimmune thrombocytopenia, caused by the maternal generation of antibodies against fetal human platelet antigen-1a (HPA-1a), can result in intracranial hemorrhage and intrauterine death. We have developed a therapeutic human recombinant high-affinity HPA-1a antibody (B2G1Δnab) that competes for binding to the HPA-1a epitope but carries a modified constant region that does not bind to Fcγ receptors. In vitro studies with a range of clinical anti-HPA-1a sera have shown that B2G1Δnab blocks monocyte chemiluminescence by >75%. In this first-in-man study, we demonstrate that HPA-1a1b autologous platelets (matching fetal phenotype) sensitized with B2G1Δnab have the same intravascular survival as unsensitized platelets (190 hours), while platelets sensitized with a destructive immunoglobulin G1 version of the antibody (B2G1) are cleared from the circulation in 2 hours. Mimicking the situation in fetuses receiving B2G1Δnab as therapy, we show that platelets sensitized with a combination of B2G1 (representing destructive HPA-1a antibody) and B2G1Δnab survive 3 times as long in circulation compared with platelets sensitized with B2G1 alone. This confirms the therapeutic potential of B2G1Δnab. The efficient clearance of platelets sensitized with B2G1 also opens up the opportunity to carry out studies of prophylaxis to prevent alloimmunization in HPA-1a-negative mothers.
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105
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Inhibition of HPA-1a alloantibody-mediated platelet destruction by a deglycosylated anti-HPA-1a monoclonal antibody in mice: toward targeted treatment of fetal-alloimmune thrombocytopenia. Blood 2013; 122:321-7. [PMID: 23645838 DOI: 10.1182/blood-2012-11-468561] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fetal/neonatal alloimmune thrombocytopenia (FNAIT) is often caused by maternal alloantibodies against the human platelet antigen (HPA)-1a, which opsonizes fetal platelets (PLTs). Subsequent PLT destruction is mediated via the Fc part of the alloantibodies. The monoclonal antibody (mAb) SZ21 binds to the HPA-1a epitope and inhibits the binding of maternal alloantibodies. However, it also promotes complement activation and phagocytosis. Deglycosylation of antibodies abrogates the Fc-related effector functions. We modified the N-glycan of SZ21 by endoglycosidase F. The in vivo transplacental transport of N-glycan-modified (NGM)-SZ21 was not impaired. When injected into pregnant mice, both native-SZ21 and NGM-SZ21 were transported equally into fetal circulation (8.9% vs 8.7%, respectively, P = .58). Neither the binding properties of NGM-SZ21 to HPA-1a in surface plasmon resonance, nor the inhibition of anti-HPA-1a-induced PLT phagocytosis, were affected by N-glycan modification. NGM-SZ21 prevented PLT destruction induced by maternal anti-HPA-1a antibodies in vivo in a mouse model (PLT clearance after 5 hours; 18% vs 62%, in the presence or absence of NGM-SZ21, respectively, P = .013). Deglycosylation of SZ21 abrogates Fc-effector functions without interfering with placental transport or the ability to block anti-HPA-1a binding. Humanized, deglycosylated anti-HPA-1a mAbs may represent a novel treatment strategy to prevent anti-HPA-1a-mediated PLT destruction in FNAIT.
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106
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Skaik Y, Battermann A, Hiller O, Meyer O, Figueiredo C, Salama A, Blasczyk R. Development of a single-antigen magnetic bead assay (SAMBA) for the sensitive detection of HPA-1a alloantibodies using tag-engineered recombinant soluble β3 integrin. J Immunol Methods 2013; 391:72-80. [DOI: 10.1016/j.jim.2013.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 02/21/2013] [Indexed: 10/27/2022]
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Sainio S, Javela K, Tuimala J, Koskinen S. Usefulness of maternal anti-HPA-1a antibody quantitation in predicting severity of foetomaternal alloimmune thrombocytopenia. Transfus Med 2013; 23:114-20. [DOI: 10.1111/tme.12018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 12/18/2012] [Accepted: 01/29/2013] [Indexed: 11/29/2022]
Affiliation(s)
- S. Sainio
- Finnish Red Cross Blood Service; Platelet Immunology laboratory; Helsinki; Finland
| | - K. Javela
- Finnish Red Cross Blood Service; Platelet Immunology laboratory; Helsinki; Finland
| | - J. Tuimala
- Finnish Red Cross Blood Service; Platelet Immunology laboratory; Helsinki; Finland
| | - S. Koskinen
- Finnish Red Cross Blood Service; Platelet Immunology laboratory; Helsinki; Finland
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Peterson JA, McFarland JG, Curtis BR, Aster RH. Neonatal alloimmune thrombocytopenia: pathogenesis, diagnosis and management. Br J Haematol 2013; 161:3-14. [PMID: 23384054 DOI: 10.1111/bjh.12235] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Neonatal alloimmune thrombocytopenia, (NAIT) is caused by maternal antibodies raised against alloantigens carried on fetal platelets. Although many cases are mild, NAIT is a significant cause of morbidity and mortality in newborns and is the most common cause of intracranial haemorrhage in full-term infants. In this report, we review the pathogenesis, clinical presentation, laboratory diagnosis and prenatal and post-natal management of NAIT and highlight areas of controversy that deserve the attention of clinical and laboratory investigators.
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Affiliation(s)
- Julie A Peterson
- Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, WI 53226-3548, US.
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109
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Pina-Cabral LB, Carvalhais V, Mesquita B, Escórcio C, Salgado P, Santos A, Ruivães E, Monteiro MC, Arrieta I, O’Connor E, Almeida-Dias A, Criado B. Allelic and genotypic frequencies of platelet glycoprotein polymorphisms in a Portuguese population. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2013. [DOI: 10.1016/j.repce.2013.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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110
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Pina-Cabral LB, Carvalhais V, Mesquita B, Escórcio C, Salgado P, Santos A, Ruivães E, Monteiro MC, Arrieta I, O’Connor E, Almeida-Dias A, Criado B. Allelic and genotypic frequencies of platelet glycoprotein polymorphisms in a Portuguese population. Rev Port Cardiol 2013; 32:111-5. [DOI: 10.1016/j.repc.2012.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 08/02/2012] [Indexed: 11/25/2022] Open
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Bakchoul T, Bertrand G, Krautwurst A, Kroll H, Bein G, Sachs UJ, Santoso S, Kaplan C. The implementation of surface plasmon resonance technique in monitoring pregnancies with expected fetal and neonatal alloimmune thrombocytopenia. Transfusion 2012; 53:2078-85. [PMID: 23278334 DOI: 10.1111/trf.12051] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 10/09/2012] [Accepted: 10/30/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND Maternal anti-HPA-1a alloantibodies are responsible for most cases of severe fetal and neonatal alloimmune thrombocytopenia (FNAIT). The presence of HPA-1a alloantibodies in maternal blood alone does not predict the fetal platelet (PLT) count, and the predictivity of antibody titers determined by enzyme immunoassays (EIAs) is debated. In contrast to EIA, surface plasmon resonance (SPR) provides information on antibody-binding properties. STUDY DESIGN AND METHODS Sequential sera from pregnant women with expected FNAIT were assessed for HPA-1a alloantibodies using SPR. Group I (n = 6) was treated with intravenous immunoglobulin (IVIG) and steroids beginning at 19 weeks of gestation (w.g.), and Group II (n = 4) received intrauterine PLT transfusions (IUT) beginning at 22 w.g. Maternal alloantibodies were quantified using an HPA-1a monoclonal antibody (MoAb) as a standard. Antibody avidity was determined as the ratio of B700 (end of the dissociation phase) to B350 (end of the association phase); the area under the curve (AUC) was calculated to determine overall antibody binding. RESULTS After 22 w.g., alloantibody characteristics remained stable in both groups, while there was a steep decrease in B700 and B350 values between 16 and 22 w.g. (assessed only in Group I), indicating a decrease in anti-HPA-1a alloantibody concentrations. Interestingly, the AUCs of the last maternal sample before elective delivery appeared to be correlated with fetal and neonatal PLT counts (p = 0.014 and 0.017, respectively). CONCLUSION SPR provides quantitative information on HPA-1a alloantibody characteristics in addition to monoclonal antibody-specific immobilization of platelet antigens. SPR results can be calibrated using a MoAb standard and should be further assessed for a potential correlation with fetal PLT count.
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Affiliation(s)
- Tamam Bakchoul
- Institute for Clinical Immunology and Transfusion Medicine, Justus-Liebig University, Giessen, Germany; Institute for Immunology und Transfusion Medicine, Ernst-Moritz-Arndt University, Greifswald, Germany; the Platelet Immunology Unit and the Immunology Transfusion Unit, INTS, Paris, France; Institute for Transfusion Medicine Dessau, Red Cross Blood Transfusion Service, Dessau, Germany
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114
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Towards a prophylactic treatment of HPA-related foetal and neonatal alloimmune thrombocytopenia. Curr Opin Hematol 2012; 19:469-74. [DOI: 10.1097/moh.0b013e328358f86c] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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115
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116
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Madani K, Kamphuis MM, Lopriore E, Porcelijn L, Oepkes D. Delayed diagnosis of fetal and neonatal alloimmune thrombocytopenia: a cause of perinatal mortality and morbidity. BJOG 2012; 119:1612-6. [DOI: 10.1111/j.1471-0528.2012.03503.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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117
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Kumpel BM. Would it be possible to prevent HPA-1a alloimmunization to reduce the incidence of fetal and neonatal alloimmune thrombocytopenia? Transfusion 2012; 52:1393-7. [PMID: 22780891 DOI: 10.1111/j.1537-2995.2012.03700.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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118
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Crosstalk between Platelets and the Immune System: Old Systems with New Discoveries. Adv Hematol 2012; 2012:384685. [PMID: 23008717 PMCID: PMC3447344 DOI: 10.1155/2012/384685] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 08/15/2012] [Indexed: 11/17/2022] Open
Abstract
Platelets are small anucleate cells circulating in the blood. It has been recognized for more than 100 years that platelet adhesion and aggregation at the site of vascular injury are critical events in hemostasis and thrombosis; however, recent studies demonstrated that, in addition to these classic roles, platelets also have important functions in inflammation and the immune response. Platelets contain many proinflammatory molecules and cytokines (e.g., P-selectin, CD40L, IL-1β, etc.), which support leukocyte trafficking, modulate immunoglobulin class switch, and germinal center formation. Platelets express several functional Toll-like receptors (TLRs), such as TLR-2, TLR-4, and TLR-9, which may potentially link innate immunity with thrombosis. Interestingly, platelets also contain multiple anti-inflammatory molecules and cytokines (e.g., transforming growth factor-β and thrombospondin-1). Emerging evidence also suggests that platelets are involved in lymphatic vessel development by directly interacting with lymphatic endothelial cells through C-type lectin-like receptor 2. Besides the active contributions of platelets to the immune system, platelets are passively targeted in several immune-mediated diseases, such as autoimmune thrombocytopenia, infection-associated thrombocytopenia, and fetal and neonatal alloimmune thrombocytopenia. These data suggest that platelets are important immune cells and may contribute to innate and adaptive immunity under both physiological and pathological conditions.
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Abstract
Neonatal alloimmune thrombocytopenia (NAIT), with an incidence of one in 1000 live births, is the most common cause of severe thrombocytopenia and intra-cerebral haemorrhage in term neonates. NAIT results from trans-placental passage of maternal antibodies against a paternally derived fetal platelet alloantigen. Clinical presentation varies from unexpected thrombocytopenia on a blood film in a well newborn to intracranial haemorrhage (ICH). In contrast to haemolytic disease of the newborn, NAIT can present in a first pregnancy, and subsequent pregnancies are usually more severely affected. The role of antenatal screening for maternal alloantibodies instead of fetal blood sampling to identify at-risk fetuses remains uncertain, but there is a trend towards less invasive maternally directed treatment for at-risk pregnancies. Neonatal management is aimed at preventing or limiting thrombocytopenic bleeding with transfusion of antigen-matched platelets.
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Affiliation(s)
- David C Risson
- Grantley Stable Neonatal Unit, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.
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120
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Husebekk A, El Ekiaby M, Gorgy G, Killie MK, Uhlin-Hansen C, Salma W, Navarrete C, El Afandi M, Skogen B, Ahlen MT. Foetal/neonatal alloimmune thrombocytopenia in Egypt; human platelet antigen genotype frequencies and antibody detection and follow-up in pregnancies. Transfus Apher Sci 2012; 47:277-82. [PMID: 22640833 DOI: 10.1016/j.transci.2012.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 02/17/2012] [Accepted: 04/30/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND OBJECTIVES Foetal and neonatal alloimmune thrombocytopenia (FNAIT) is studied mainly in Caucasian populations. Severe thrombocytopenia (<50×10(9)/L) gives risk of haemorrhage and the most feared complication is intracranial haemorrhage (ICH). In Caucasian populations anti-human platelet antigen (HPA)-1a antibodies are the cause of FNAIT in >80% of the cases. The aims of this project were to study the gene frequencies of HPA-1-5 and 15 alleles in an Egyptian population (Arabic), and to determine the frequency of HPA-1a and -5b immunisations in a cohort of Egyptian pregnant women. MATERIALS AND METHODS Altogether 6974 pregnant women were included in the study. Genotyping was performed by polymerase chain reaction and antibodies were detected by flow cytometry and enzyme-linked immunosorbent assay. HPA-1-5 and 15 alleles were studied in 367 individuals. RESULTS The HPA genotypes differed from genotypes published from different Caucasian and Chinese (Han) populations in HPA-1, -2, -3, and -5 systems with significant higher frequency of HPA-1b, -2b and -5b. The rate of HPA-1a alloimmunisation was found comparable to Caucasian populations. Severe thrombocytopenia was found in two newborns. No bleeding complication was reported. Anti-HPA-5b antibodies were detected in 4.4% of the pregnant women. Clinical consequences of these antibodies were not studied. CONCLUSION The HPA-1bb and -5bb genotypes are more frequent in the Egyptian Arabic population studied compared to Caucasian populations. FNAIT due to anti-HPA-1a and -5b antibodies must be suspected in cases of neonatal thrombocytopenia. Further large prospective studies are needed to increase the knowledge of clinical complications related to HPA alloantibodies in populations with different genetic backgrounds.
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Affiliation(s)
- A Husebekk
- Institute of Medical Biology, University of Tromsø, Tromsø, Norway.
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121
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Arinsburg SA, Shaz BH, Westhoff C, Cushing MM. Determination of human platelet antigen typing by molecular methods: Importance in diagnosis and early treatment of neonatal alloimmune thrombocytopenia. Am J Hematol 2012; 87:525-8. [PMID: 22345051 DOI: 10.1002/ajh.23111] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 12/22/2011] [Indexed: 11/07/2022]
Abstract
Neonatal alloimmune thrombocytopenia (NAIT) is the most common cause of severe thrombocytopenia and intracranial hemorrhage in the perinatal period. While the gold standard for making a diagnosis of NAIT is detection of a human platelet antigen (HPA)-specific antibody in maternal serum, together with identifying an incompatibility between the parents for the cognate HPA antigen, platelet genotyping is the gold standard method for HPA typing. Platelet genotyping is critical in screening at-risk fetuses for the presence ofthe HPA corresponding to the maternal antibody. In addition, platelet genotyping may play a role in population screening to identify women at risk for sensitization, and thus, fetuses at risk for NAIT. The most commonly used methods of platelet genotyping are sequence-specific primer-polymerase chain reaction (PCR-SSP), restriction fragment length polymorphism-PCR (PCR-RFLP), and TaqMan real-time PCR. PCR-SSP and PCR-RFLP are relatively inexpensive and technically simple methods, but they are not easily automated and require expertise for reliable interpretation of results. Newer methods that allow for multiplexing, automation, and easily interpretable results, such as bead arrays, are currently in development and available for research purposes.
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Affiliation(s)
- Suzanne A Arinsburg
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
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Cook TJ, Qiu CC, Dickinson JE. A review of the contemporary management of fetal and neonatal alloimmune thrombocytopenia in an Australian tertiary obstetric hospital. Aust N Z J Obstet Gynaecol 2012; 52:321-6. [PMID: 22510050 DOI: 10.1111/j.1479-828x.2012.01438.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 03/14/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is the most common cause of severe perinatal thrombocytopenia, arising from the transplacental passage of maternal antibodies directed at paternally inherited antigens on fetal platelets. AIM To review the occurrence, management and perinatal outcomes of pregnancies complicated by FNAIT from a single tertiary obstetric hospital in Western Australia. MATERIALS AND METHODS The study was conducted as a retrospective review of cases with prenatally recognised FNAIT between 2001 and 2011, with the treatment modalities and outcomes analysed. RESULTS Over the 10-year period, 20 cases of clinically significant FNAIT in 13 women were managed at our centre. Three cases were complicated by antenatal intracranial haemorrhage (15%), and in all 3, this was the presenting feature leading to diagnosis. In 17/20 (85%) cases, anti-HPA 1a was the responsible antibody, with the remainder being anti-HPA 5b. In 16/17 cases with pre-pregnancy recognition, intravenous gammaglobulin (IVGG) was administered antenatally (gestation at commencement ranging from 13 to 26 weeks) with adjuvant prednisolone in three cases. Postnatal treatment (IVGG or platelet transfusion) was provided in 4/16 cases. There was no intracranial haemorrhage or demise in any case receiving prenatal therapy. CONCLUSIONS FNAIT is a rare and serious condition. In our small single-centre study, there was variability in the therapeutic strategies, although IVGG was central to all prenatally managed pregnancies. None of the treated pregnancies was complicated by intracranial haemorrhage or fetal death. There is a need for ongoing refinement of FNAIT management protocols, both in the prenatal and in the postnatal period.
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Affiliation(s)
- Timothy J Cook
- School of Women's and Infants' Health, The University of Western Australia, Perth, Western Australia, Australia
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123
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Preimplantation Genetic Diagnosis for Fetal Neonatal Alloimmune Thrombocytopenia Due to Antihuman Platelet Antigen Maternal Antibodies. Obstet Gynecol 2012; 119:338-43. [DOI: 10.1097/aog.0b013e318242a11d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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124
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Egbor M, Knott P, Bhide A. Red-cell and platelet alloimmunisation in pregnancy. Best Pract Res Clin Obstet Gynaecol 2012; 26:119-32. [DOI: 10.1016/j.bpobgyn.2011.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 09/20/2011] [Accepted: 10/11/2011] [Indexed: 10/14/2022]
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125
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Tiller H, Killie MK, Chen P, Eksteen M, Husebekk A, Skogen B, Kjeldsen-Kragh J, Ni H. Toward a prophylaxis against fetal and neonatal alloimmune thrombocytopenia: induction of antibody-mediated immune suppression and prevention of severe clinical complications in a murine model. Transfusion 2012; 52:1446-57. [DOI: 10.1111/j.1537-2995.2011.03480.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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126
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The Bruised Newborn. Transfus Med 2012. [DOI: 10.1007/978-1-4471-2182-4_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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127
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Holzhauer S, Zieger B. Diagnosis and management of neonatal thrombocytopenia. Semin Fetal Neonatal Med 2011; 16:305-10. [PMID: 21835709 DOI: 10.1016/j.siny.2011.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thrombocytopenia is the most common haematological abnormality in newborns admitted to neonatal care units and serves as an important indicator of underlying pathological processes of mother or child. In most cases thrombocytopenia is mild to moderate and resolves within the first weeks of life without any intervention. However, in some neonates thrombocytopenia is severe or may reflect an inborn platelet disorder. As clinical course and outcome of thrombocytopenia depend on the aetiology of thrombocytopenia, an appropriate work-up is essential to guide therapy in neonates with thrombocytopenia and to avoid severe bleeding.
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Affiliation(s)
- Susanne Holzhauer
- Department of Paediatric Oncology and Haematology, Charité - University of Berlin, Berlin, Germany
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128
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Sachs UJ, Bakchoul T, Eva O, Giptner A, Bein G, Aster RH, Gitter M, Peterson J, Santoso S. A point mutation in the EGF-4 domain of β(3) integrin is responsible for the formation of the Sec(a) platelet alloantigen and affects receptor function. Thromb Haemost 2011; 107:80-7. [PMID: 22116617 DOI: 10.1160/th11-08-0542] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Accepted: 10/06/2011] [Indexed: 11/05/2022]
Abstract
Neonatal alloimmune thrombocytopenia (NAIT) is caused by fetomaternal platelet incompatibility with maternal antibodies crossing the placenta and destroying fetal platelets. Antibodies against human platelet antigen-1a (HPA-1a) and HPA-5b are responsible for the majority of NAIT cases. We observed a suspected NAIT in a newborn with a platelet count of 25 G/l and petechial haemorrhages. Serological analysis of maternal serum revealed an immunisation against αIIbβ3 on paternal platelets only, indicating the presence of an antibody against a new rare alloantigen (Sec(a)) residing on αIIbβ3. The location of Sec(a) on αIIbβ3 was confirmed by immunoprecipitation. Nucleotide sequence analysis of paternal β3 revealed a single nucleotide exchange (G(1818)T) in exon 11 of the β3 gene (ITGB3), changing Lys(580) (wild-type) to Asn(580) (Sec(a)). Two additional members of the family Sec were typed Sec(a) positive, but none of 300 blood donors. Chinese hamster ovary cells expressing Asn(580), but not Lys(580) αIIbβ3, bound anti-Sec(a), which was corroborated by immunoprecipitation. Adhesion of transfected cells onto immobilised fibrinogen showed reduced binding of the Asn(580) variant compared to wild-type αIIbβ3. Analysis of transfected cells with anti-LIBS and PAC-1 antibody showed reduced binding when compared to the wild-type. No such effects were observed with Sec(a) positive platelets, which, however, are heterozygous for the Lys(580)Asn mutation. In this study, we describe a NAIT case caused by maternal alloimmunisation against a new antigen on αIIbβ3. Analysis with mutant transfected cells showed that the Lys(580)Asn mutation responsible for the formation of the Sec(a) antigenic determinant affects αIIbβ3 receptor function.
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Affiliation(s)
- Ulrich J Sachs
- Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Langhansstr. 7, D-35385 Giessen, Germany
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129
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Li C, Piran S, Chen P, Lang S, Zarpellon A, Jin JW, Zhu G, Reheman A, van der Wal DE, Simpson EK, Ni R, Gross PL, Ware J, Ruggeri ZM, Freedman J, Ni H. The maternal immune response to fetal platelet GPIbα causes frequent miscarriage in mice that can be prevented by intravenous IgG and anti-FcRn therapies. J Clin Invest 2011; 121:4537-47. [PMID: 22019589 PMCID: PMC3204841 DOI: 10.1172/jci57850] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 08/26/2011] [Indexed: 11/17/2022] Open
Abstract
Fetal and neonatal immune thrombocytopenia (FNIT) is a severe bleeding disorder caused by maternal antibody-mediated destruction of fetal/neonatal platelets. It is the most common cause of severe thrombocytopenia in neonates, but the frequency of FNIT-related miscarriage is unknown, and the mechanism(s) underlying fetal mortality have not been explored. Furthermore, although platelet αIIbβ3 integrin and GPIbα are the major antibody targets in immune thrombocytopenia, the reported incidence of anti-GPIbα-mediated FNIT is rare. Here, we developed mouse models of FNIT mediated by antibodies specific for GPIbα and β3 integrin and compared their pathogenesis. We found, unexpectedly, that miscarriage occurred in the majority of pregnancies in our model of anti-GPIbα-mediated FNIT, which was far more frequent than in anti-β3-mediated FNIT. Dams with anti-GPIbα antibodies exhibited extensive fibrin deposition and apoptosis/necrosis in their placentas, which severely impaired placental function. Furthermore, anti-GPIbα (but not anti-β3) antiserum activated platelets and enhanced fibrin formation in vitro and thrombus formation in vivo. Importantly, treatment with either intravenous IgG or a monoclonal antibody specific for the neonatal Fc receptor efficiently prevented anti-GPIbα-mediated FNIT. Thus, the maternal immune response to fetal GPIbα causes what we believe to be a previously unidentified, nonclassical FNIT (i.e., spontaneous miscarriage but not neonatal bleeding) in mice. These results suggest that a similar pathology may have masked the severity and frequency of human anti-GPIbα-mediated FNIT, but also point to possible therapeutic interventions.
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MESH Headings
- Abortion, Spontaneous/etiology
- Abortion, Spontaneous/immunology
- Abortion, Spontaneous/prevention & control
- Animals
- Blood Platelets/immunology
- Disease Models, Animal
- Female
- Histocompatibility Antigens Class I/immunology
- Histocompatibility, Maternal-Fetal/immunology
- Humans
- Immunoglobulins, Intravenous/therapeutic use
- Integrin beta3/genetics
- Integrin beta3/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Platelet Glycoprotein GPIb-IX Complex/genetics
- Platelet Glycoprotein GPIb-IX Complex/immunology
- Pregnancy
- Receptors, Fc/antagonists & inhibitors
- Receptors, Fc/immunology
- Thrombocytopenia, Neonatal Alloimmune/etiology
- Thrombocytopenia, Neonatal Alloimmune/immunology
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Affiliation(s)
- Conglei Li
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Siavash Piran
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Pingguo Chen
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Sean Lang
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Alessandro Zarpellon
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Joseph W. Jin
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Guangheng Zhu
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Adili Reheman
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Dianne E. van der Wal
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Elisa K. Simpson
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Ran Ni
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Peter L. Gross
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Jerry Ware
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Zaverio M. Ruggeri
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - John Freedman
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
| | - Heyu Ni
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
Toronto Platelet Immunobiology Group and Department of Laboratory Medicine, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael’s Hospital, Toronto, Ontario, Canada.
Canadian Blood Services, Toronto, Ontario, Canada.
Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California, USA.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Department of Medicine and
Department of Physiology, University of Toronto, Ontario, Canada
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130
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Allen DL, Abrahamsson S, Murphy MF, Roberts DJ. Human platelet antigen 1a epitopes are dependent on the cation-regulated conformation of integrin α(IIb)β(3) (GPIIb/IIIa). J Immunol Methods 2011; 375:166-75. [PMID: 22036924 DOI: 10.1016/j.jim.2011.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 09/18/2011] [Accepted: 10/07/2011] [Indexed: 11/17/2022]
Abstract
BACKGROUND The HPA-1a (Leu(33)) polymorphism of platelet integrin αIIbβ3 is the target of alloantibodies in 70-80% cases of neonatal alloimmune thrombocytopenia (NAIT) in Caucasians and reliable detection of these antibodies is essential for appropriate clinical management. However, the ability to detect such antibodies is highly variable between laboratories and, in a number of clinical cases where there is a HPA-1 genotype mismatch between mother and neonate, HPA-1a antibodies are undetectable. Furthermore, some studies have not shown a consistent relationship between maternal anti-HPA-1a level and neonatal platelet count. Since the integrity and conformation of the αIIbβ3 complex are dependent on divalent cations, we investigated whether HPA-1a epitope integrity and/or conformation might be affected by the presence of the cation chelator EDTA in patient samples or in assay buffers, thus providing a possible explanation for the variable sensitivity of current assays. PRINCIPLE FINDINGS Exposure of the αIIbβ3 complex to EDTA resulted in reduced reactivity of three anti-HPA-1a mAbs (B2, 19-7 and 23-15). More significantly, cation chelation adversely affected detection of polyclonal anti-HPA-1a, not only in the platelet immunofluorescence assay, where alloantibody binding was reduced compared to control platelets (mean MFI reduction 44.5%, range 17.3-69.7%, n=4), but also in the commonly used monoclonal antibody specific immobilisation of platelet antigens assay (MAIPA) where both alloantibody and monoclonal capture antibody binding were reduced (mean OD reduction 82.8%, range 68.3-96.6%, n=9). CONCLUSIONS These data show that HPA-1a antibodies recognise epitopes on αIIbβ3 that are sensitive to EDTA treatment and that cation chelation grossly reduces the sensitivity of the MAIPA assay by diminishing not only HPA-1a alloantibody binding but also 'capture' monoclonal antibody binding. These findings may, in part, explain the current variability in antibody measurement and will guide the development of more sensitive tests for anti-integrin antibodies in NAIT and other conditions.
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Affiliation(s)
- David L Allen
- NHS Blood and Transplant, John Radcliffe Hospital, Oxford, UK.
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131
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TILLER HEIDI, KILLIE METTEKJAER, HUSEBEKK ANNE, SKOGEN BJØRN, NI HEYU, KJELDSEN-KRAGH JENS, ØIAN PÅL. Platelet antibodies and fetal growth: maternal antibodies against fetal platelet antigen 1a are strongly associated with reduced birthweight in boys. Acta Obstet Gynecol Scand 2011; 91:79-86. [DOI: 10.1111/j.1600-0412.2011.01269.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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132
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Abstract
Although neonatal thrombocytopenia (platelet count < 150×10(9) /l) is a common finding in hospital practice, a careful clinical history and examination of the blood film is often sufficient to establish the diagnosis and guide management without the need for further investigations. In preterm neonates, early-onset thrombocytopenia (<72h) is usually secondary to antenatal causes, has a characteristic pattern and resolves without complications or the need for treatment. By contrast, late-onset thrombocytopenia in preterm neonates (>72h) is nearly always due to post-natally acquired bacterial infection and/or necrotizing enterocolitis, which rapidly leads to severe thrombocytopenia (platelet count<50×10(9) /l). Thrombocytopenia is much less common in term neonates and the most important cause is neonatal alloimmune thrombocytopenia (NAIT), which confers a high risk of perinatal intracranial haemorrhage and long-term neurological disability. Prompt diagnosis and transfusion of human platelet antigen-compatible platelets is key to the successful management of NAIT. Recent studies suggest that more than half of neonates with severe thrombocytopenia receive platelet transfusion(s) based on consensus national or local guidelines despite little evidence of benefit. The most pressing problem in management of neonatal thrombocytopenia is identification of safe, effective platelet transfusion therapy and controlled trials are urgently needed.
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Affiliation(s)
- Subarna Chakravorty
- Centre for Haematology, Imperial College London, London Department of Paediatrics, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
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133
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Response: prediction of the fetal status in noninvasive management of alloimmune thrombocytopenia. Blood 2011. [DOI: 10.1182/blood-2011-07-364927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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134
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Stuge TB, Skogen B, Ahlen MT, Husebekk A, Urbaniak SJ, Bessos H. The cellular immunobiology associated with fetal and neonatal alloimmune thrombocytopenia. Transfus Apher Sci 2011; 45:53-9. [PMID: 21708486 DOI: 10.1016/j.transci.2011.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is caused by maternal antibodies that cross the placenta in connection with pregnancy and destroy fetal platelets. Recently, maternal T cell responses associated with FNAIT have been studied at the clonal level. These T cell clones recognize an integrin β3 epitope, which is anchored to the HLA-DRB3∗0101-encoded MHC molecule DR52a. The same MHC allele is strongly associated with FNAIT. As the production of pathological antibodies reactive with fetal platelets is likely dependent on these T cell responses, there exists a potential for preventing FNAIT by targeting these T cells.
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Affiliation(s)
- Tor B Stuge
- Laboratory Medicine, University Hospital of North Norway, Tromsø, Norway.
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135
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Skogen B, Killie MK, Kjeldsen-Kragh J, Ahlen MT, Tiller H, Stuge TB, Husebekk A. Reconsidering fetal and neonatal alloimmune thrombocytopenia with a focus on screening and prevention. Expert Rev Hematol 2011; 3:559-66. [PMID: 21083473 DOI: 10.1586/ehm.10.49] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Uncertainty regarding the pathophysiology of fetal and neonatal alloimmune thrombocytopenia (FNAIT) has hampered the decision regarding how to identify, follow-up and treat the women and children with this potentially serious condition. Since knowledge of the condition is derived mainly from retrospective studies, understanding of the natural history of this condition remains incomplete. General screening programs for FNAIT have still not been introduced, mainly because of a lack of reliable risk factors and effective treatment. Now, several prospective screening studies involving up to 100,000 pregnant women have been published and the results have changed the understanding of the pathophysiology of FNAIT and, thereby, the approach toward diagnostics, prevention and treatment in a more appropriate way.
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Affiliation(s)
- Bjørn Skogen
- Laboratory Medicine, University Hospital of North Norway, N-9038 Tromsø, Norway.
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136
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Bakchoul T, Kubiak S, Krautwurst A, Roderfeld M, Siebert HC, Bein G, Sachs UJ, Santoso S. Low-avidity anti-HPA-1a alloantibodies are capable of antigen-positive platelet destruction in the NOD/SCID mouse model of alloimmune thrombocytopenia. Transfusion 2011; 51:2455-61. [DOI: 10.1111/j.1537-2995.2011.03171.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rayment R, Brunskill SJ, Soothill PW, Roberts DJ, Bussel JB, Murphy MF. Antenatal interventions for fetomaternal alloimmune thrombocytopenia. Cochrane Database Syst Rev 2011:CD004226. [PMID: 21563140 DOI: 10.1002/14651858.cd004226.pub3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Fetomaternal alloimmune thrombocytopenia results from the formation of antibodies by the mother which are directed against a fetal platelet alloantigen inherited from the father. The resulting fetal thrombocytopenia (reduced platelet numbers) may cause bleeding, particularly into the brain, before or shortly after birth. Antenatal treatment of fetomaternal alloimmune thrombocytopenia includes the administration of intravenous immunoglobulin (IVIG) and/or corticosteroids to the mother to prevent severe fetal thrombocytopenia. IVIG and corticosteroids both have short-term and possibly long-term side effects. IVIG is also costly and optimal regimens need to be identified. OBJECTIVES To determine the optimal antenatal treatment of fetomaternal alloimmune thrombocytopenia to prevent fetal and neonatal haemorrhage and death. SEARCH STRATEGY We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2011) and bibliographies of relevant publications and review articles. SELECTION CRITERIA Randomised controlled studies comparing any intervention with no treatment, or comparing any two interventions. DATA COLLECTION AND ANALYSIS Two review authors independently assessed eligibility, trial quality and extracted data. MAIN RESULTS We included four trials involving 206 people. One trial involving 39 people compared a corticosteroid (prednisone) versus IVIG alone. In this trial, where analysable data were available, there was no statistically significant differences between the treatment arms for predefined outcomes. Three trials involving 167 people compared IVIG plus a corticosteroid (prednisone in two trials and dexamethasone in one trial) versus IVIG alone. In these trials there was no statistically significant difference in the findings between the treatment arms for predefined outcomes (intracranial haemorrhage; platelet count at birth and preterm birth). Lack of complete data sets and important differences in interventions precluded the pooling of data from these trials. AUTHORS' CONCLUSIONS The optimal management of fetomaternal alloimmune thrombocytopenia remains unclear. Lack of complete data sets for two trials and differences in interventions precluded the pooling of data from these trials which may have enabled a more developed analysis of the trial findings. Further trials would be required to determine optimal treatment (the specific medication and its dose and schedule). Such studies should include long-term follow up of all children and mothers.
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Affiliation(s)
- Rachel Rayment
- Arthur Bloom Haemophilia Centre, University Hospital of Wales, Cardiff and Vale NHS Trust, Heath Park, Cardiff, UK, CF14 4XW
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Lee AI, Kaufman RM. Transfusion Medicine and the Pregnant Patient. Hematol Oncol Clin North Am 2011; 25:393-413, ix. [DOI: 10.1016/j.hoc.2011.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Shehata N, Denomme GA, Hannach B, Banning N, Freedman J. Mass-scale high-throughput multiplex polymerase chain reaction for human platelet antigen single-nucleotide polymorphisms screening of apheresis platelet donors. Transfusion 2011; 51:2028-33. [DOI: 10.1111/j.1537-2995.2011.03082.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kroll H, Feldmann K, Zwingel C, Hoch J, Bald R, Bein G, Bayat B, Santoso S. A new platelet alloantigen, Swi(a) , located on glycoprotein Ia identified in a family with fetal and neonatal alloimmune thrombocytopenia. Transfusion 2011; 51:1745-54. [PMID: 21332723 DOI: 10.1111/j.1537-2995.2010.03038.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a bleeding disorder caused by transplacental passage of maternal antibodies to fetuses whose platelets (PLTs) express the corresponding human PLT antigen (HPA). STUDY DESIGNS AND METHODS We observed a fetus with FNAIT who died from a severe intracranial hemorrhage. Analysis of maternal serum in antigen capture assay with paternal PLTs showed reactivity with PLT glycoprotein (GP)IIb/IIIa (α(IIb) β(3) ) and GPIa/IIa (α(2) β(1) integrin), indicating the presence of anti-HPA-1a and an additional alloantibody against GPIa (termed anti-Swi(a) ). RESULTS By immunochemical studies, the localization of the Swi(a) antigen on GPIa/IIa could be confirmed. Analysis of paternal GPIa full-length cDNA showed a single-nucleotide substitution C(3347) T in Exon 28 resulting in a Thr(1087) Met amino acid substitution. Testing of family members by polymerase chain reaction-restriction fragment length polymorphism using MslI endonuclease showed perfect correlation with phenotyping. Extended family and population studies showed that 4 of 10 members of the paternal family but none of 500 unrelated blood donors were Swi(a) carriers. Expression studies on allele-specific transfected Chinese hamster ovary (CHO) cells confirmed that the single-amino-acid substitution Thr(1087) Met was responsible for the formation of the Swi(a) epitope. Adhesion of CHO cells expressing the Swi(a) alloantigen to immobilized collagens was not impaired compared to the wild-type control and was not inhibited by anti-Swi(a) alloantibodies. CONCLUSION In this study we defined a new PLT alloantigen Swi(a) that was involved in a case of additional immunization against HPA-1a. Our observations demonstrate that combinations of PLT-specific alloantibodies may comprise low-frequency alloantigens.
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Affiliation(s)
- Hartmut Kroll
- Institute for Transfusion Medicine Dessau, Red Cross Blood Transfusion Service NSTOB, Dessau, Germany.
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McQuilten ZK, Wood EM, Savoia H, Cole S. A review of pathophysiology and current treatment for neonatal alloimmune thrombocytopenia (NAIT) and introducing the Australian NAIT registry. Aust N Z J Obstet Gynaecol 2011; 51:191-8. [PMID: 21631435 DOI: 10.1111/j.1479-828x.2010.01270.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fetomaternal or neonatal alloimmune thrombocytopenia (NAIT) is a rare but serious condition associated with significant fetal and neonatal morbidity and mortality. The most useful predictor of severe disease is a history of a sibling with an antenatal intracranial haemorrhage. However, NAIT can occur during the first pregnancy and may not be diagnosed until the neonatal period. Antenatal treatment options include maternal intravenous immunoglobulin (IVIG) and corticosteroid treatment, fetal blood sampling (FBS) and intrauterine platelet transfusion (IUT) and early delivery. FBS (with or without IUT) can be used to direct and monitor response to therapy, and to inform mode and timing of delivery. However, this procedure is associated with significant risks, including fetal death, and is generally now reserved for high-risk pregnancies. This review highlights the current understanding of the epidemiology and pathophysiology of NAIT and summarises current approaches to investigation and management. It also introduces the newly established Australian NAIT registry. Owing to the relative rarity of NAIT, accruing sufficient patient numbers for studies and clinical trials at an institutional level is difficult. This national registry will provide an opportunity to collect valuable information and inform future research on this condition.
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Affiliation(s)
- Zoe K McQuilten
- Transfusion Medicine Services, Australian Red Cross Blood Service, South Melbourne, Victoria 3205, Australia.
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Giers G, Wenzel F, Riethmacher R, Lorenz H, Tutschek B. Repeated intrauterine IgG infusions in foetal alloimmune thrombocytopenia do not increase foetal platelet counts. Vox Sang 2011; 99:348-53. [PMID: 20624268 DOI: 10.1111/j.1423-0410.2010.01367.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND AND OBJECTIVES Foetal alloimmune thrombocytopenia (FNAIT) is often treated transplacentally with maternally administered i.v. immunoglobulins, but not all foetuses show a consistent platelet increase during such treatment. MATERIALS AND METHODS We retrospectively analysed data from a cohort of ten foetuses with FNAIT treated by direct foetal immunoglobulin infusion. Foetal treatment was begun between 17 and 25 weeks and continued until 36 weeks with weekly cordocenteses and foetal immunoglobulin infusions. RESULTS While foetal IgG levels increased steadily during weekly IgG infusions, foetal platelet counts remained unchanged. CONCLUSION Our retrospective study presents a unique analysis of a historical cohort, contributing to the ongoing debate about the treatment of choice for foetal alloimmune thrombocytopenia.
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Affiliation(s)
- G Giers
- Clinical Hemostaseology and Transfusion Medicine, Düsseldorf, Germany.
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Abstract
Fetal/neonatal alloimmune thrombocytopenia is the most common cause of severe thrombocytopenia in the fetus and in an otherwise healthy newborn. To counter the consequences of severe fetal thrombocytopenia, antenatal therapies have been implemented. Predictive parameters for fetal severe thrombocytopenia are important for the development of noninvasive strategy and tailored intervention. We report here data concerning 239 pregnancies in 75 HPA-1bb women. Analysis of the index cases (diagnosis of fetal/neonatal alloimmune thrombocytopenia) did not show any significant correlation between the severity of the disease and the maternal genetic background (ABO blood group and HLA-DRB3 allele). Subsequent pregnancies were managed, and therapy effectiveness was evaluated. The highest mean newborn platelet count was observed for a combination of intravenous immunoglobulin and steroids (135 × 10⁹/L; 54 newborns) compared with intravenous immunoglobulin alone (89 × 10⁹/L; 27 newborns). The maternal anti-HPA-1a antibody concentration measured before any treatment and before 28 weeks of gestation was predictive of the fetal status. The weighted areas under curves of the maternal alloantibody concentrations were predictive of therapy response. To conclude, this large retrospective survey gives new insights on maternal predictive parameters for fetal status and therapy effectiveness allowing noninvasive strategies.
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Abstract
Fetal/neonatal alloimmune thrombocytopenia (FNAIT) resulting from fetal platelet destruction by maternal alloantibodies is the most common cause of severe fetal thrombocytopenia and of neonatal thrombocytopenia in maternity wards. The pathophysiology is largely unknown. The fetus has long been considered as an "innocent bystander."
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Animal model of fetal and neonatal immune thrombocytopenia: role of neonatal Fc receptor in the pathogenesis and therapy. Blood 2010; 116:3660-8. [DOI: 10.1182/blood-2010-05-284919] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Fetal and neonatal immune thrombocytopenia (FNIT) is a severe bleeding disorder in which maternal antibodies cross the placenta and destroy fetal/neonatal platelets. It has been demonstrated that the neonatal Fc receptor (FcRn) regulates immunoglobulin G (IgG) homeostasis and plays an important role in transplacental IgG transport. However, the role of FcRn in the pathogenesis and therapy of FNIT has not been studied. Here, we developed an animal model of FNIT using combined β3 integrin–deficient and FcRn-deficient (β3−/−FcRn−/−) mice. We found that β3−/−FcRn−/− mice are immunoresponsive to β3+/+FcRn−/− platelets. The generated antibodies were β3 integrin specific and were maintained at levels that efficiently induced thrombocytopenia in adult β3+/+FcRn−/− mice. FNIT was observed when immunized β3−/−FcRn+/+ females were bred with β3+/+FcRn+/+ males, while no FNIT occurred in β3−/−FcRn−/− females bred with β3+/+FcRn−/− males, suggesting that FcRn is indispensable for the induction of FNIT. We further demonstrated that fetal FcRn was responsible for the transplacental transport of various IgG isotypes. We found that anti-FcRn antibody and intravenous IgG prevented FNIT, and that intravenous IgG ameliorated FNIT through both FcRn-dependent and -independent pathways. Our data suggest that targeting FcRn may be a potential therapy for human FNIT as well as other maternal pathogenic antibody-mediated diseases.
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Killie MK, Salma W, Bertelsen E, Skogen B, Husebekk A. Quantitative MAIPA: Comparison of different MAIPA protocols. Transfus Apher Sci 2010; 43:149-54. [PMID: 20675194 DOI: 10.1016/j.transci.2010.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION In a screening setting, maternal anti-HPA 1a antibody level has been found to be a good prognostic tool to identify newborns at risk for severe NAIT. AIM Identify the optimal MAIPA protocol for quantitation of anti-HPA 1a antibodies. MATERIALS AND METHODS Plasma were analysed for anti-HPA 1a antibodies using different monoclonal antibodies, lyophilized or fresh platelets and MAIPA protocols. RESULTS The anti-HPA 1a antibody level varied significantly when different monoclonal antibodies were used. However, there was a strong correlation between maternal anti-HPA 1a antibody level and platelet count in the newborn. The sensitivity of the assay depended on the adopted MAIPA protocol. CONCLUSION Consistent tests results are of importance for the clinical impact of the test.
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Affiliation(s)
- Mette Kjær Killie
- Department of Immunology and Transfusion Medicine, University Hospital of North Norway, 9038 Tromsø, Norway.
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Piotrowski A, Dabrowska-Wojciak I, Mikinka M, Fendler W, Walas W, Sobala W, Kuczkowski KM. Coagulation abnormalities and severe intraventricular hemorrhage in extremely low birth weight infants. J Matern Fetal Neonatal Med 2010. [DOI: 10.3109/14767050903229614] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Nomura ML, Couto E, Martinelli BM, Barjas-Castro ML, Barini R, Passini Júnior R, Castro V. Fetal genotyping for platelets antigens: a precise tool for alloimmune thrombocytopenia: case report and literature review. Arch Gynecol Obstet 2010; 282:573-5. [DOI: 10.1007/s00404-010-1415-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 02/18/2010] [Indexed: 10/19/2022]
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Brouk H, Halle L, Bertrand G, Neche FZ, Ouelaa H, Kaplan C. Human platelet antigen allele frequencies in different Algerian populations. ACTA ACUST UNITED AC 2010; 75:673-8. [DOI: 10.1111/j.1399-0039.2009.01429.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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