A novel enzyme-linked immunosorbent assay method for the detection of human neutrophil antigen-2a antibodies.

Abstract

BACKGROUND:

Antibodies to human neutrophil antigen (HNA)-2a are responsible for a number of immune-mediated neutropenia disorders. Although several methods exist for the identification of anti-HNA-2a, all these methods have several limitations. In this study, a solid-phase enzyme-linked immunosorbent assay (ELISA) using recombinant HNA-2a antigen (rHNA-2a) allowing rapid detection of HNA-2a antibodies was developed.

STUDY DESIGN AND METHODS:

Soluble rHNA-2 was generated by transfection of insect cells with CD177 vector. Purified rHNA-2a was immobilized on microtiter wells coated with anti-CD177 and was applied to analyze 10 sera containing HNA-2a antibodies. For the evaluation of the ELISA method, results were compared with the standard assay, MAIGA (monoclonal antibody antigen capture assay) for detection of neutrophil antibodies.

RESULTS:

The specificity of HNA-2a antibodies in all sera was confirmed by immunoblotting. Sera were then tested simultaneously in ELISA and MAIGA assays. Nine of 10 sera showed positive reactions in ELISA, whereas only 9 of 10 sera reacted in the standard MAIGA assay. All HNA-2a antibodies were detectable in MAIGA when diluted sera were applied. No reaction was observed with different sera containing neutrophil-reactive antibodies (6 anti-HNA-1a, 4 anti-HNA-1b, and 20 anti-HLA Class I and II) in ELISA. All HNA-2a antibodies were detectable in MAIGA when diluted sera were applied. Notably, sera containing anti-proteinase 3 (PR3) from patients with Wegener's granulomatosis reacted in MAIGA. In contrast, this antibody showed no reaction in ELISA with purified rHNA-2a.

CONCLUSIONS:

These results demonstrated that ELISA with rHNA-2a provides a good method for detecting HNA-2a antibodies in human serum. This assay enables to exclude the presence of autoantibody against PR3 in patient's sera, which cannot be differentiated from anti HNA-2a with current serologic methods.

• Authors: Behnaz Bayat, Silke Werth, Ulrich J H Sachs, Sentot Santoso
• Journal: Transfusion (Transfusion) Vol. 49 Issue 9 Pg. 1819-24 (Sep 2009) ISSN: 1537-2995 [Electronic] United States
• PMID: 19497055 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies
• CD177 protein, human
• GPI-Linked Proteins
• Isoantigens
• Membrane Glycoproteins
• Receptors, Cell Surface
• neutrophil-specific antigen NA1, human
• neutrophil-specific antigen NA2
• Myeloblastin

Topics

• Antibodies (immunology)
• Enzyme-Linked Immunosorbent Assay (methods)
• GPI-Linked Proteins
• Humans
• Isoantigens (immunology)
• Membrane Glycoproteins (immunology)
• Myeloblastin (immunology)
• Neutrophils (immunology)
• Receptors, Cell Surface (immunology)