Graham Smith | University of Portsmouth (original) (raw)

Papers by Graham Smith

Research paper thumbnail of YS04 Recombinant Mini-?3 Integrin Fragments for the Detection of HPA Antibodies

Transfusion Medicine, 2006

Background The β3 integrin [Glycoprotein (GP) IIIa] gene is highly polymorphic and encodes eight... more Background The β3 integrin [Glycoprotein (GP) IIIa] gene is highly polymorphic and encodes eight of the Human Platelet Antigen (HPA) systems. HPA immunisation is of clinical relevance in neonatal alloimmune thrombocytopenia (NAIT), post‐transfusion purpura (PTP) and platelet refractoriness. However, the current methods of antibody detection are cumbersome and rely upon the use of platelets from genotyped donors. In the case of the rare HPA antigens, obtaining donor platelets is particularly problematic. We therefore set out to develop an antibody screening assay that uses recombinant, soluble β3‐integrin fragments expressing the HPA‐1, –4, –6, –7, –10, –11 and –16 epitopes.

Research paper thumbnail of Donor Deferral Due to Low Hemoglobin—An Updated Systematic Review

Transfusion Medicine Reviews, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of macrothrombocytopenia cosegregates dominantly with abnormal proplatelet formation and integrin and 3 β IIb α membrane-proximal cytoplasmic salt bridge in the gene disrupts the conserved ITGB3 A nonsynonymous SNP in the

Research paper thumbnail of Teicoplanin-induced Thrombocytopenia: The Occurrence and Characterization of Teicoplanin-dependent Antibodies

Research paper thumbnail of Teicoplanin-induced Thrombocytopenia

Research paper thumbnail of A nonsynonymous SNP in the ITGB3 gene dismpts the conserved membrane-proximal cytoplasmic salt bridge in the αIIbβ3 integrin and cosegregates dominantly with abnormal proplatelet formation and macrothrombocytopenia. Commentary

Research paper thumbnail of Oral or parental iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors

Protocols, 2012

... Graham A Smith2, Sheila A Fisher1, Carolyn Doree1, Sally Hopewell3, Susan J Brunskill1, David... more ... Graham A Smith2, Sheila A Fisher1, Carolyn Doree1, Sally Hopewell3, Susan J Brunskill1, David J Roberts1 ... trials (RCTs) of iron supplementation in regular blood donors (Cable 1988; Mackintosh 1988; Gordeuk 1990; Garry 1995; Radtke 2004; Magnussen 2008; Maghsudhu ...

Research paper thumbnail of Management and outcome of 200 cases of fetomaternal alloimmune thrombocytopenia

Transfusion, 2007

Fetomaternal alloimmune thrombocytopenia (FMAIT) is the commonest cause of severe thrombocytopeni... more Fetomaternal alloimmune thrombocytopenia (FMAIT) is the commonest cause of severe thrombocytopenia in term neonates but its management remains controversial. A 7-year prospective observational study of 200 cases of FMAIT evaluated the relationship between human platelet antigen (HPA) antibody specificity, clinical presentation, morbidity, mortality, and therapeutic interventions in the antenatal and postnatal period, with long-term follow-up of neonates with intracranial hemorrhage (ICH). In 1148 referrals for FMAIT, HPA antibodies were confirmed in 200 (17%). The commonest specificities were anti-HPA-1a, 150 (75%); anti-HPA-5b, 31 (15.5%); and anti-HPA-15b, 8 (4%). Of 123 (62%) cases (two sets of twins) with no previous history of FMAIT, intrauterine deaths occurred in 5: anti-HPA-1a alone, 3; in combination with anti-HPA-5b, 1; and anti-HPA-15b, 1. Of the 120 live neonates, 103 had severe thrombocytopenia and 17 (14%) developed ICH (anti-HPA-1a, 13; anti-HPA-5b, 3; anti-HPA-15b, 1...

Research paper thumbnail of Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors

The Cochrane database of systematic reviews, Jan 3, 2014

Iron deficiency is a significant cause of deferral in people wishing to donate blood. If iron rem... more Iron deficiency is a significant cause of deferral in people wishing to donate blood. If iron removed from the body through blood donation is not replaced, then donors may become iron deficient. All donors are screened at each visit for low haemoglobin (Hb) levels. However, some deferred blood donors do not return to donate. Deferred first-time donors are even less likely to return. Interventions that reduce the risk of provoking iron deficiency and anaemia in blood donors will therefore increase the number of blood donations. Currently, iron supplementation for blood donors is not a standard of care in many blood services. A systematic review is required to answer specific questions regarding the efficacy and safety of iron supplementation in blood donors. To assess the efficacy and safety of iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors. We ran the search on 18 November 2013. We searched Cochrane Injuries Group Specialised Register, CENTRA...

Research paper thumbnail of Identification by Immunoblotting of the Erythrocyte Membrane Sialoglycoproteins That Carry the Vw and Mur Antigens

Vox Sanguinis, 1991

Immunoblotting of the separated membrane components of Mi1 erythrocytes with anti-Vw identified a... more Immunoblotting of the separated membrane components of Mi1 erythrocytes with anti-Vw identified a band of Mr 40,000 with a mobility close to that of P-sialoglycoprotein corresponding to the abnormal a-sialoglycoprotein present in Mi1 cells. A comparison of results obtained when MiIII erythrocytes were immunoblotted with anti-Mur, anti-s and the monoclonal antibody R1.3, indicated that the Mur antigen is located on the abnormal b-sialoglycoprotein of Mr 36,000 in MiIII erythrocytes. Prior treatment of Mi1 erythrocytes with neuraminidase resulted in an increase in the intensity of staining of the anti-Vw reactive component. This was consistent with the enhanced reactions observed in haemagglutination tests with neuraminidase-treated erythrocytes. The mobility of the Vw component was reduced when erythrocytes were pre-treated with low concentrations of neuraminidase but increased when higher concentrations of neuraminidase were used.

Research paper thumbnail of The importance of using multiple techniques for detection of platelet antibodies

Vox Sanguinis, 2007

In red cell immunology, it has long been known that no one technique will detect all clinically s... more In red cell immunology, it has long been known that no one technique will detect all clinically significant antibodies. The same appears to be true for platelet immunology, and we highlight this fact by showing four examples of anti-human platelet antigen-1a that were not detected by the monoclonal antibody-specific immobilization of platelet antigen test, the most commonly used technique. Each antibody was found in a case of fetomaternal alloimmune thrombocytopenia in which the fetus or neonate was severely affected.

Research paper thumbnail of The Immunoglobulin V H Gene, V H 4-21, Specifically Encodes Autoanti-Red Cell Antibodies against the I or i Antigens

Vox Sanguinis, 1995

Most autoanti-red cell antibodies found in patients with cold agglutinin disease are specific for... more Most autoanti-red cell antibodies found in patients with cold agglutinin disease are specific for the I or i carbohydrate antigenic determinants. However, antibodies specific for other antigens such as Pr or Sa can also be found, and these are identified by their pattern of reactivity with enzyme-treated red cells. Recently, it has been shown that the vast majority of anti-Ii antibodies react with a monoclonal anti-idiotypic antibody (9G4); this reactivity arises from restriction of the immunoglobulin heavy chains used to encode the antibodies to a single VH4-21 gene, y14-21. The 9G4 antibody appears specific for this gene product, and we have used it to analyse VH4-21 gene involvement in encoding a spectrum of red cell antibodies of various specificities. The results support the strong association between usage of this gene and a n t i 4 specificity and indicate that it is not generally used by other specificities. In particular, it is striking that the unsubstituted type 2 oligosaccharide antigens (I and i) induce a highly restricted autoantibody response very different from that induced by the sialylated type 2 antigens (Sia-b,-1 and Ib). The 9G4 antibody therefore provides a simple tool for discrimination between these autoanti-red cell antibodies, which should be of use in red cell serology.

Research paper thumbnail of Alloantibodies against low-frequency human platelet antigens do not account for a significant proportion of cases of fetomaternal alloimmune thrombocytopenia: evidence from 1054 cases

Transfusion, 2009

BACKGROUND: Maternal alloantibodies against the five common human platelet antigen (HPA) systems ... more BACKGROUND: Maternal alloantibodies against the five common human platelet antigen (HPA) systems (HPA-1 to-3,-5, and-15) are found in only 20% of cases referred for fetal and neonatal thrombocytopenia (FMAIT) investigations. The question asked was whether mismatches for the remaining 11 low-frequency HPAs (HPA-4 and-6bw to-17bw) might in part explain the remaining 80% of cases. STUDY DESIGN AND METHODS: A total of 1054 paternal DNA samples from referred FMAIT cases (among which 223 cases where antibodies against a common HPA were found) were genotyped for 11 lowfrequency HPAs as well as a recently discovered polymorphism (ITGA2B-C2320T). The initial genotyping was carried out by TaqMan and potential heterozygotes were confirmed by DNA sequencing. Clinical and serologic data were collected for each case with a heterozygote father. RESULTS: In total, eight heterozygous fathers were identified: four for HPA-6w, one each for HPA-10w and-11w, and two for HPA-12w. Maternal antibodies against the corresponding antigen were identified in four of the eight cases. In two of these cases, antibodies against HPA-1a and HPA-1b were also found. CONCLUSION: It was concluded that the minor alleles of HPA-4 and-6bw to-17bw are exceptionally rare in the Caucasian population and therefore do not explain the large number of FMAIT referrals which test negative for the common HPA antibodies. M aternal alloimmunization against human platelet antigens (HPAs) can cause fetal and neonatal thrombocytopenia (FMAIT), which can lead to bleeding complications and intracranial hemorrhage (ICH). 1 Specific HPA antibodies are only identified in approximately 20% of all ABBREVIATIONS: CaM = calmodulin; FMAIT = fetal and neonatal thrombocytopenia; HPA(s) = human platelet antigen(s); ICH = intracranial hemorrhage; MAF(s) = minor allele frequency(-ies); MAIPA = monoclonal antibody immobilization of platelet antigen; nsSNP = nonsynonymous single-nucleotide polymorphism; SDM = site-directed mutagenesis; UCN(s) = unique case number(s).

Research paper thumbnail of Microarray-based genotyping for blood groups: comparison of gene array and 5′-nuclease assay techniques with human platelet antigen as a model

Transfusion, 2005

BACKGROUND: Most blood group alloantigens specific for red cells and platelets (PLTs) are based o... more BACKGROUND: Most blood group alloantigens specific for red cells and platelets (PLTs) are based on singlenucleotide polymorphisms (SNPs) in genes encoding relevant membrane proteins. STUDY DESIGN AND METHODS: By use of five human PLT antigen (HPA) systems as a model, the suitability of a fourth-generation microarray technique for SNP typing was investigated. The results of the former were compared with those of a parallel developed thirdgeneration technique (TaqMan assay, Applied Biosystems). Both techniques were validated by use of a unique panel of 71 blinded DNA samples containing at least 15 aa, bb, and ab genotypes for the HPA-1,-2,-3,-5, and-15 systems. RESULTS: Unambiguous and concordant results were obtained with both techniques for all samples. CONCLUSION: The data presented here validate the use of microarray for large-scale SNP typing for clinically relevant blood group alloantigens.

Research paper thumbnail of Molecular characterization of the variable domains of an ?IIb?3-specific immunoglobulin�M ? platelet cold agglutinin in a follicular lymphoma patient with treatment refractory autoimmune thrombocytopenia: idiotypic overlap between ?IIb?3 integrin antibodies

Transfusion, 2007

Molecular characterization of the variable domains of an aIIbb3-specific immunoglobulin M k plate... more Molecular characterization of the variable domains of an aIIbb3-specific immunoglobulin M k platelet cold agglutinin in a follicular lymphoma patient with treatment refractory autoimmune thrombocytopenia: idiotypic overlap between aIIbb3 integrin antibodies

Research paper thumbnail of HPA-1a antibody potency and bioactivity do not predict severity of fetomaternal alloimmune thrombocytopenia

Transfusion, 2007

BACKGROUND: The antenatal management of fetomaternal alloimmune thrombocytopenia (FMAIT) due to H... more BACKGROUND: The antenatal management of fetomaternal alloimmune thrombocytopenia (FMAIT) due to HPA-1a antibodies remains controversial, and a test identifying pregnancies that do not require therapy would be of clinical value. STUDY DESIGN AND METHODS: The statistical correlation was analyzed between clinical outcome and 1) anti-HPA-1a potency in maternal serum samples determined by a monoclonal antibody immobilization of platelet (PLT) antigen assay with an international anti-HPA-1a potency standard and 2) anti-HPA-1a biological activity measured by a monocyte chemiluminescence (CL) assay. RESULTS: A total of 133 pregnancies with FMAIT due to anti-HPA-1a were analyzed. In 97 newly diagnosed cases, there was no difference in antibody potency or CL signal between cases with intracranial hemorrhage (ICH; n = 15), those with no ICH but a PLT count of less than 20 ¥ 10 9 per L (n = 52), and those with a PLT count of at least 20 ¥ 10 9 per L (n = 30). In 22 previously known pregnancies, the positive predictive value of maternal anti-HPA-1a of greater than 30 IU per mL for a PLT count of less than 20 ¥ 10 9 per L was 90 percent, but the negative predictive value was only 66 percent. Antibody potency tended to stay stable throughout pregnancy (n = 16) and from one pregnancy to the next (n = 16). CONCLUSION: Neither severe thrombocytopenia nor ICH in HPA-1a-alloimmunized pregnancies can be predicted with sufficient sensitivity and specificity for clinical application from maternal anti-HPA-1a potency or bioactivity.

Research paper thumbnail of Immunologic and structural analysis of eight novel domain-deletion β 3 integrin peptides designed for detection of HPA-1 antibodies

Journal of Thrombosis and Haemostasis, 2008

Research paper thumbnail of Acquired thrombasthenia due to GPIIbIIIa platelet autoantibodies in a 4-yr-old child

European Journal of Haematology, 2006

Research paper thumbnail of Teicoplanin-dependent antibodies: detection and characterization

British Journal of Haematology, 2005

There are only a few reports of thrombocytopenia associated with clinical doses of teicoplanin, a... more There are only a few reports of thrombocytopenia associated with clinical doses of teicoplanin, a glycopeptide antibiotic used against Gram-positive bacteria. We investigated 39 patients receiving teicoplanin; 31 were thrombocytopenic with platelet counts between 1-105 x 10(9)/l and 8 were not thrombocytopenic. We identified 14 thrombocytopenic cases (45%) and two (25%) non-thrombocytopenic cases with IgG teicoplanin-dependent platelet-reactive antibodies. Use of glycoprotein (GP) capture enzyme-linked immunosorbent assay with platelets and GPIIb/IIIa transfected Chinese Hamster Ovary cells as well as flow cytometry with GP-deficient platelets indicated that the GPIIb/IIIa complex is a major target antigen of these antibodies.

Research paper thumbnail of Provision of platelet support for fetuses and neonates affected by severe fetomaternal alloimmune thrombocytopenia

British Journal of Haematology, 2001

Severe fetomaternal alloimmune thrombocytopenia requires urgent treatment with compatible platele... more Severe fetomaternal alloimmune thrombocytopenia requires urgent treatment with compatible platelet concentrates. As prompt treatment is sometimes delayed owing to the unavailability of compatible platelets, we established an accredited platelet donor panel to provide effective and timely transfusion support for fetal and neonatal therapy. After a mass screening programme of over 60 000 blood donations, 45 HPA-1a-negative donors with no antibodies to HPA, HLA, red cell antigens and granulocytes/lymphocytes, and with low titre anti-A and/or-B were accredited. All accredited donors were fully genotyped for HPA-1,-2,-3 and-5 by PCR-SSP. Ninetyone per cent of the accredited donors were also negative for HPA-5b.

Research paper thumbnail of YS04 Recombinant Mini-?3 Integrin Fragments for the Detection of HPA Antibodies

Transfusion Medicine, 2006

Background The β3 integrin [Glycoprotein (GP) IIIa] gene is highly polymorphic and encodes eight... more Background The β3 integrin [Glycoprotein (GP) IIIa] gene is highly polymorphic and encodes eight of the Human Platelet Antigen (HPA) systems. HPA immunisation is of clinical relevance in neonatal alloimmune thrombocytopenia (NAIT), post‐transfusion purpura (PTP) and platelet refractoriness. However, the current methods of antibody detection are cumbersome and rely upon the use of platelets from genotyped donors. In the case of the rare HPA antigens, obtaining donor platelets is particularly problematic. We therefore set out to develop an antibody screening assay that uses recombinant, soluble β3‐integrin fragments expressing the HPA‐1, –4, –6, –7, –10, –11 and –16 epitopes.

Research paper thumbnail of Donor Deferral Due to Low Hemoglobin—An Updated Systematic Review

Transfusion Medicine Reviews, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of macrothrombocytopenia cosegregates dominantly with abnormal proplatelet formation and integrin and 3 β IIb α membrane-proximal cytoplasmic salt bridge in the gene disrupts the conserved ITGB3 A nonsynonymous SNP in the

Research paper thumbnail of Teicoplanin-induced Thrombocytopenia: The Occurrence and Characterization of Teicoplanin-dependent Antibodies

Research paper thumbnail of Teicoplanin-induced Thrombocytopenia

Research paper thumbnail of A nonsynonymous SNP in the ITGB3 gene dismpts the conserved membrane-proximal cytoplasmic salt bridge in the αIIbβ3 integrin and cosegregates dominantly with abnormal proplatelet formation and macrothrombocytopenia. Commentary

Research paper thumbnail of Oral or parental iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors

Protocols, 2012

... Graham A Smith2, Sheila A Fisher1, Carolyn Doree1, Sally Hopewell3, Susan J Brunskill1, David... more ... Graham A Smith2, Sheila A Fisher1, Carolyn Doree1, Sally Hopewell3, Susan J Brunskill1, David J Roberts1 ... trials (RCTs) of iron supplementation in regular blood donors (Cable 1988; Mackintosh 1988; Gordeuk 1990; Garry 1995; Radtke 2004; Magnussen 2008; Maghsudhu ...

Research paper thumbnail of Management and outcome of 200 cases of fetomaternal alloimmune thrombocytopenia

Transfusion, 2007

Fetomaternal alloimmune thrombocytopenia (FMAIT) is the commonest cause of severe thrombocytopeni... more Fetomaternal alloimmune thrombocytopenia (FMAIT) is the commonest cause of severe thrombocytopenia in term neonates but its management remains controversial. A 7-year prospective observational study of 200 cases of FMAIT evaluated the relationship between human platelet antigen (HPA) antibody specificity, clinical presentation, morbidity, mortality, and therapeutic interventions in the antenatal and postnatal period, with long-term follow-up of neonates with intracranial hemorrhage (ICH). In 1148 referrals for FMAIT, HPA antibodies were confirmed in 200 (17%). The commonest specificities were anti-HPA-1a, 150 (75%); anti-HPA-5b, 31 (15.5%); and anti-HPA-15b, 8 (4%). Of 123 (62%) cases (two sets of twins) with no previous history of FMAIT, intrauterine deaths occurred in 5: anti-HPA-1a alone, 3; in combination with anti-HPA-5b, 1; and anti-HPA-15b, 1. Of the 120 live neonates, 103 had severe thrombocytopenia and 17 (14%) developed ICH (anti-HPA-1a, 13; anti-HPA-5b, 3; anti-HPA-15b, 1...

Research paper thumbnail of Oral or parenteral iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors

The Cochrane database of systematic reviews, Jan 3, 2014

Iron deficiency is a significant cause of deferral in people wishing to donate blood. If iron rem... more Iron deficiency is a significant cause of deferral in people wishing to donate blood. If iron removed from the body through blood donation is not replaced, then donors may become iron deficient. All donors are screened at each visit for low haemoglobin (Hb) levels. However, some deferred blood donors do not return to donate. Deferred first-time donors are even less likely to return. Interventions that reduce the risk of provoking iron deficiency and anaemia in blood donors will therefore increase the number of blood donations. Currently, iron supplementation for blood donors is not a standard of care in many blood services. A systematic review is required to answer specific questions regarding the efficacy and safety of iron supplementation in blood donors. To assess the efficacy and safety of iron supplementation to reduce deferral, iron deficiency and/or anaemia in blood donors. We ran the search on 18 November 2013. We searched Cochrane Injuries Group Specialised Register, CENTRA...

Research paper thumbnail of Identification by Immunoblotting of the Erythrocyte Membrane Sialoglycoproteins That Carry the Vw and Mur Antigens

Vox Sanguinis, 1991

Immunoblotting of the separated membrane components of Mi1 erythrocytes with anti-Vw identified a... more Immunoblotting of the separated membrane components of Mi1 erythrocytes with anti-Vw identified a band of Mr 40,000 with a mobility close to that of P-sialoglycoprotein corresponding to the abnormal a-sialoglycoprotein present in Mi1 cells. A comparison of results obtained when MiIII erythrocytes were immunoblotted with anti-Mur, anti-s and the monoclonal antibody R1.3, indicated that the Mur antigen is located on the abnormal b-sialoglycoprotein of Mr 36,000 in MiIII erythrocytes. Prior treatment of Mi1 erythrocytes with neuraminidase resulted in an increase in the intensity of staining of the anti-Vw reactive component. This was consistent with the enhanced reactions observed in haemagglutination tests with neuraminidase-treated erythrocytes. The mobility of the Vw component was reduced when erythrocytes were pre-treated with low concentrations of neuraminidase but increased when higher concentrations of neuraminidase were used.

Research paper thumbnail of The importance of using multiple techniques for detection of platelet antibodies

Vox Sanguinis, 2007

In red cell immunology, it has long been known that no one technique will detect all clinically s... more In red cell immunology, it has long been known that no one technique will detect all clinically significant antibodies. The same appears to be true for platelet immunology, and we highlight this fact by showing four examples of anti-human platelet antigen-1a that were not detected by the monoclonal antibody-specific immobilization of platelet antigen test, the most commonly used technique. Each antibody was found in a case of fetomaternal alloimmune thrombocytopenia in which the fetus or neonate was severely affected.

Research paper thumbnail of The Immunoglobulin V H Gene, V H 4-21, Specifically Encodes Autoanti-Red Cell Antibodies against the I or i Antigens

Vox Sanguinis, 1995

Most autoanti-red cell antibodies found in patients with cold agglutinin disease are specific for... more Most autoanti-red cell antibodies found in patients with cold agglutinin disease are specific for the I or i carbohydrate antigenic determinants. However, antibodies specific for other antigens such as Pr or Sa can also be found, and these are identified by their pattern of reactivity with enzyme-treated red cells. Recently, it has been shown that the vast majority of anti-Ii antibodies react with a monoclonal anti-idiotypic antibody (9G4); this reactivity arises from restriction of the immunoglobulin heavy chains used to encode the antibodies to a single VH4-21 gene, y14-21. The 9G4 antibody appears specific for this gene product, and we have used it to analyse VH4-21 gene involvement in encoding a spectrum of red cell antibodies of various specificities. The results support the strong association between usage of this gene and a n t i 4 specificity and indicate that it is not generally used by other specificities. In particular, it is striking that the unsubstituted type 2 oligosaccharide antigens (I and i) induce a highly restricted autoantibody response very different from that induced by the sialylated type 2 antigens (Sia-b,-1 and Ib). The 9G4 antibody therefore provides a simple tool for discrimination between these autoanti-red cell antibodies, which should be of use in red cell serology.

Research paper thumbnail of Alloantibodies against low-frequency human platelet antigens do not account for a significant proportion of cases of fetomaternal alloimmune thrombocytopenia: evidence from 1054 cases

Transfusion, 2009

BACKGROUND: Maternal alloantibodies against the five common human platelet antigen (HPA) systems ... more BACKGROUND: Maternal alloantibodies against the five common human platelet antigen (HPA) systems (HPA-1 to-3,-5, and-15) are found in only 20% of cases referred for fetal and neonatal thrombocytopenia (FMAIT) investigations. The question asked was whether mismatches for the remaining 11 low-frequency HPAs (HPA-4 and-6bw to-17bw) might in part explain the remaining 80% of cases. STUDY DESIGN AND METHODS: A total of 1054 paternal DNA samples from referred FMAIT cases (among which 223 cases where antibodies against a common HPA were found) were genotyped for 11 lowfrequency HPAs as well as a recently discovered polymorphism (ITGA2B-C2320T). The initial genotyping was carried out by TaqMan and potential heterozygotes were confirmed by DNA sequencing. Clinical and serologic data were collected for each case with a heterozygote father. RESULTS: In total, eight heterozygous fathers were identified: four for HPA-6w, one each for HPA-10w and-11w, and two for HPA-12w. Maternal antibodies against the corresponding antigen were identified in four of the eight cases. In two of these cases, antibodies against HPA-1a and HPA-1b were also found. CONCLUSION: It was concluded that the minor alleles of HPA-4 and-6bw to-17bw are exceptionally rare in the Caucasian population and therefore do not explain the large number of FMAIT referrals which test negative for the common HPA antibodies. M aternal alloimmunization against human platelet antigens (HPAs) can cause fetal and neonatal thrombocytopenia (FMAIT), which can lead to bleeding complications and intracranial hemorrhage (ICH). 1 Specific HPA antibodies are only identified in approximately 20% of all ABBREVIATIONS: CaM = calmodulin; FMAIT = fetal and neonatal thrombocytopenia; HPA(s) = human platelet antigen(s); ICH = intracranial hemorrhage; MAF(s) = minor allele frequency(-ies); MAIPA = monoclonal antibody immobilization of platelet antigen; nsSNP = nonsynonymous single-nucleotide polymorphism; SDM = site-directed mutagenesis; UCN(s) = unique case number(s).

Research paper thumbnail of Microarray-based genotyping for blood groups: comparison of gene array and 5′-nuclease assay techniques with human platelet antigen as a model

Transfusion, 2005

BACKGROUND: Most blood group alloantigens specific for red cells and platelets (PLTs) are based o... more BACKGROUND: Most blood group alloantigens specific for red cells and platelets (PLTs) are based on singlenucleotide polymorphisms (SNPs) in genes encoding relevant membrane proteins. STUDY DESIGN AND METHODS: By use of five human PLT antigen (HPA) systems as a model, the suitability of a fourth-generation microarray technique for SNP typing was investigated. The results of the former were compared with those of a parallel developed thirdgeneration technique (TaqMan assay, Applied Biosystems). Both techniques were validated by use of a unique panel of 71 blinded DNA samples containing at least 15 aa, bb, and ab genotypes for the HPA-1,-2,-3,-5, and-15 systems. RESULTS: Unambiguous and concordant results were obtained with both techniques for all samples. CONCLUSION: The data presented here validate the use of microarray for large-scale SNP typing for clinically relevant blood group alloantigens.

Research paper thumbnail of Molecular characterization of the variable domains of an ?IIb?3-specific immunoglobulin�M ? platelet cold agglutinin in a follicular lymphoma patient with treatment refractory autoimmune thrombocytopenia: idiotypic overlap between ?IIb?3 integrin antibodies

Transfusion, 2007

Molecular characterization of the variable domains of an aIIbb3-specific immunoglobulin M k plate... more Molecular characterization of the variable domains of an aIIbb3-specific immunoglobulin M k platelet cold agglutinin in a follicular lymphoma patient with treatment refractory autoimmune thrombocytopenia: idiotypic overlap between aIIbb3 integrin antibodies

Research paper thumbnail of HPA-1a antibody potency and bioactivity do not predict severity of fetomaternal alloimmune thrombocytopenia

Transfusion, 2007

BACKGROUND: The antenatal management of fetomaternal alloimmune thrombocytopenia (FMAIT) due to H... more BACKGROUND: The antenatal management of fetomaternal alloimmune thrombocytopenia (FMAIT) due to HPA-1a antibodies remains controversial, and a test identifying pregnancies that do not require therapy would be of clinical value. STUDY DESIGN AND METHODS: The statistical correlation was analyzed between clinical outcome and 1) anti-HPA-1a potency in maternal serum samples determined by a monoclonal antibody immobilization of platelet (PLT) antigen assay with an international anti-HPA-1a potency standard and 2) anti-HPA-1a biological activity measured by a monocyte chemiluminescence (CL) assay. RESULTS: A total of 133 pregnancies with FMAIT due to anti-HPA-1a were analyzed. In 97 newly diagnosed cases, there was no difference in antibody potency or CL signal between cases with intracranial hemorrhage (ICH; n = 15), those with no ICH but a PLT count of less than 20 ¥ 10 9 per L (n = 52), and those with a PLT count of at least 20 ¥ 10 9 per L (n = 30). In 22 previously known pregnancies, the positive predictive value of maternal anti-HPA-1a of greater than 30 IU per mL for a PLT count of less than 20 ¥ 10 9 per L was 90 percent, but the negative predictive value was only 66 percent. Antibody potency tended to stay stable throughout pregnancy (n = 16) and from one pregnancy to the next (n = 16). CONCLUSION: Neither severe thrombocytopenia nor ICH in HPA-1a-alloimmunized pregnancies can be predicted with sufficient sensitivity and specificity for clinical application from maternal anti-HPA-1a potency or bioactivity.

Research paper thumbnail of Immunologic and structural analysis of eight novel domain-deletion β 3 integrin peptides designed for detection of HPA-1 antibodies

Journal of Thrombosis and Haemostasis, 2008

Research paper thumbnail of Acquired thrombasthenia due to GPIIbIIIa platelet autoantibodies in a 4-yr-old child

European Journal of Haematology, 2006

Research paper thumbnail of Teicoplanin-dependent antibodies: detection and characterization

British Journal of Haematology, 2005

There are only a few reports of thrombocytopenia associated with clinical doses of teicoplanin, a... more There are only a few reports of thrombocytopenia associated with clinical doses of teicoplanin, a glycopeptide antibiotic used against Gram-positive bacteria. We investigated 39 patients receiving teicoplanin; 31 were thrombocytopenic with platelet counts between 1-105 x 10(9)/l and 8 were not thrombocytopenic. We identified 14 thrombocytopenic cases (45%) and two (25%) non-thrombocytopenic cases with IgG teicoplanin-dependent platelet-reactive antibodies. Use of glycoprotein (GP) capture enzyme-linked immunosorbent assay with platelets and GPIIb/IIIa transfected Chinese Hamster Ovary cells as well as flow cytometry with GP-deficient platelets indicated that the GPIIb/IIIa complex is a major target antigen of these antibodies.

Research paper thumbnail of Provision of platelet support for fetuses and neonates affected by severe fetomaternal alloimmune thrombocytopenia

British Journal of Haematology, 2001

Severe fetomaternal alloimmune thrombocytopenia requires urgent treatment with compatible platele... more Severe fetomaternal alloimmune thrombocytopenia requires urgent treatment with compatible platelet concentrates. As prompt treatment is sometimes delayed owing to the unavailability of compatible platelets, we established an accredited platelet donor panel to provide effective and timely transfusion support for fetal and neonatal therapy. After a mass screening programme of over 60 000 blood donations, 45 HPA-1a-negative donors with no antibodies to HPA, HLA, red cell antigens and granulocytes/lymphocytes, and with low titre anti-A and/or-B were accredited. All accredited donors were fully genotyped for HPA-1,-2,-3 and-5 by PCR-SSP. Ninetyone per cent of the accredited donors were also negative for HPA-5b.