IgA antibodies to myeloperoxidase in patients with eosinophilic granulomatosis with polyangiitis (Churg-Strauss).

Abstract

OBJECTIVES:

To determine the prevalence of anti-myeloperoxidase (MPO) antibodies of IgA (IgA anti-MPO) isotype in patients with eosinophilic granulomatosis with polyangiitis (EGPA), and the association of the IgA antibodies with IgG anti-MPO and with disease activity.

METHODS:

Serum samples from patients with EGPA followed in a multicenter longitudinal cohort were tested by ELISA for the presence of IgA anti-MPO and IgG anti-MPO antibodies. Sera from 87 healthy controls were used to define a positive test. Sera from 168 patients with EGPA (298 samples) were tested. Frequencies of positive testing for IgA anti-MPO were compared between patients with active EGPA, patients in remission, and controls.

RESULTS:

IgA anti-MPO was detected in 10 of 168 (6%) patients with EGPA (11 of 298 serum samples) compared to 1 of 87 (1%) healthy controls (p=0.10). All 11 samples testing positive for IgA anti-MPO also tested positive for IgG anti-MPO. Ninety samples tested positive for IgG anti-MPO but negative for IgA. Samples taken during active EGPA were positive for IgA anti-MPO in 6/72 cases (8%), compared to 5/226 (2%) during remission (p=0.03). Among samples taken during moderate or high disease activity, 5/41 were positive (12%, p=0.01 compared to remission).

CONCLUSIONS:

Although IgA anti-MPO antibodies are detectable in some patients with EGPA and may be detectable more frequently during active disease, their presence seems unlikely to provide information beyond what is obtained from conventional IgG anti-MPO.

• Authors: Esha Oommen, Amber Hummel, Lisa Allmannsberger, David Cuthbertson, Simon Carette, Christian Pagnoux, Gary S Hoffman, Dieter E Jenne, Nader A Khalidi, Curry L Koening, Carol A Langford, Carol A McAlear, Larry Moreland, Philip Seo, Antoine Sreih, Steven R Ytterberg, Peter A Merkel, Ulrich Specks, Paul A Monach, Vasculitis Clinical Research Consortium
• Journal: Clinical and experimental rheumatology (Clin Exp Rheumatol) 2017 Mar-Apr Vol. 35 Suppl 103 Issue 1 Pg. 98-101 ISSN: 0392-856X [Print] Italy
• PMID: 28281453 (Publication Type: Journal Article, Multicenter Study)

Chemical References

• Antibodies, Antineutrophil Cytoplasmic
• Biomarkers
• Immunoglobulin A
• Immunoglobulin G
• Immunosuppressive Agents
• Peroxidase

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Antibodies, Antineutrophil Cytoplasmic (blood)
• Biomarkers (blood)
• Canada
• Case-Control Studies
• Churg-Strauss Syndrome (blood, diagnosis, drug therapy, immunology)
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Immunoglobulin A (blood)
• Immunoglobulin G (blood)
• Immunosuppressive Agents (therapeutic use)
• Male
• Middle Aged
• Peroxidase (immunology)
• Predictive Value of Tests
• Remission Induction
• Treatment Outcome
• United States
• Young Adult