Sensitivity of assays for the detection of HPA-1a antibodies: results of an international workshop demonstrating the impact of cation chelation from integrin αIIbß3 on three widely used assays.
Vox Sang
; 105(2): 167-73, 2013 Aug.
Article
en En
| MEDLINE
| ID: mdl-23662600
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 αIIbß3 to ethylene diamine tetraacetic acid (EDTA) affected binding of many anti-αIIbß3 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 ANDMETHODS:
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 αIIbß3 in an appropriate conformation for the sensitive detection of anti-HPA-1a.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Quelantes
/
Antígenos de Plaqueta Humana
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Ácido Edético
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Integrina alfa2
/
Integrina beta3
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Trombocitopenia Neonatal Aloinmune
/
Isoanticuerpos
Tipo de estudio:
Diagnostic_studies
Límite:
Female
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Humans
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Male
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Newborn
Idioma:
En
Revista:
Vox Sang
Año:
2013
Tipo del documento:
Article
País de afiliación:
Reino Unido