Immunoassay for human serum hemojuvelin.

Abstract

BACKGROUND:

Hemojuvelin, a critical regulator of iron homeostasis, is involved in the regulation of hepcidin expression and iron homeostasis. It is expressed both as a membrane-bound form and as a soluble one. Serum hemojuvelin can be produced by secretion following furin cleavage or by proteolytic cleavage of the membrane-bound form by matriptase 2 (TMPRSS6). These forms contribute to down-regulation of hepcidin expression upon iron deficiency or hypoxia. This study describes the development and validation of the first enzyme-linked immunosorbent assay for hemojuvelin in human serum.

DESIGN AND METHODS:

This assay is based on the use of a recombinant human repulsive guidance molecule-c peptide and a polyclonal antibody against hemojuvelin able to recognize the recombinant peptide and the native soluble hemojuvelin by immunoprecipitation.

RESULTS:

The enzyme-linked immunosorbent assay was validated and appeared to be a robust method with intra- and inter-coefficients of variance ranging from 2.6% to 15%. The assay was able to quantify hemojuvelin levels in a control population within a range from 0.88 to 1.14 mg/L. Patients with iron-refractory iron-deficiency anemia with a mutation in the TMPRSS6 gene were found to have lower levels of circulating hemojuvelin than those in healthy patients. The enzyme-linked immunosorbent assay also showed that soluble hemojuvelin levels were significantly higher in patients with anemia of chronic disease than in control individuals.

CONCLUSIONS:

This enzyme-linked immunosorbent assay has a good specificity and sensitivity for the quantification of soluble hemojuvelin in human serum and could be a valuable aid to understanding the physiological role of this protein.

• Authors: Carole Brasse-Lagnel, Maura Poli, Céline Lesueur, Bernard Grandchamp, Alain Lavoinne, Carole Beaumont, Soumeya Bekri
• Journal: Haematologica (Haematologica) Vol. 95 Issue 12 Pg. 2031-7 (Dec 2010) ISSN: 1592-8721 [Electronic] Italy
• PMID: 20713458 (Publication Type: Journal Article)

Chemical References

• GPI-Linked Proteins
• HJV protein, human
• Hemochromatosis Protein
• Membrane Proteins
• Iron
• Serine Endopeptidases
• TMPRSS6 protein, human

Topics

• Adolescent
• Adult
• Anemia (blood)
• Anemia, Iron-Deficiency (blood, drug therapy, genetics)
• Blotting, Western
• Child
• Child, Preschool
• Enzyme-Linked Immunosorbent Assay (methods)
• Female
• GPI-Linked Proteins (blood)
• Hemochromatosis Protein
• Humans
• Iron (metabolism, therapeutic use)
• Male
• Membrane Proteins (genetics)
• Middle Aged
• Mutation
• Reproducibility of Results
• Serine Endopeptidases (genetics)