Vol.23 No.5

Original Article

Clinical features of patients with anti-neutrophil cytoplasmic autoantibodies targeting native myeloperoxidase antigen

Authors

Yuji Yamanishi1 , Toshiko Ito-Ihara2, 3 , Tomokazu Nagao4 , Kazuko Uno5 , Shigeto Kobayashi6 , Eri Muso3 , Peter Y. Shane7 , Gary S. Firestein8 , Hiroshi Hashimoto9 , Tomio Okazaki10 , Kazuo Suzuki4, 11

  • Department of Rheumatology, Hiroshima Rheumatology Clinic, Hacchobori-Ito-Kyuhodo-Bldg. 3F, 10-13 Teppo-cho, Naka-ku, Hiroshima 733-0017, Japan
  • Department of Clinical Innovative Medicine, Translational Research Center, Kyoto University Hospital, Kyoto, Japan
  • Department of Nephrology and Dialysis, Kitano Hospital, Tazuke Kofukai Medical Research Institute, Osaka, Japan
  • Department of Immunology, Inflammation Program, Chiba University Graduate School of Medicine, Chiba, Japan
  • Division of Basic Research, Louis Pasteur Center for Medical Research, Kyoto, Japan
  • Department of Internal Medicine, Juntendo University Koshigaya Hospital, Saitama, Japan
  • Department of Medicine and Rheumatology, Tokyo Medical and Dental University, Tokyo, Japan
  • Division of Rheumatology, Allergy and Immunology, UCSD School of Medicine, La Jolla, CA, USA
  • Department of Internal Medicine and Rheumatology, Juntendo Tokyo Koto Geriatric Center, Tokyo, Japan
  • Kure-Kyosai Hospital, Hiroshima, Japan
  • National Institute of Infectious Diseases (NIID-NIH), Tokyo, Japan
Received:

5 April 2012

Accepted:

28 September 2012

Published online:

21 October 2012

Full Text

PDF　(member's only)

Abstract

Objectives Anti-neutrophil cytoplasmic autoantibodies
(ANCA) are useful diagnostic markers in systemic vasculitic
disorders with small-vessel involvement, but depending
on the particular test used, the myeloperoxidase
(MPO)-ANCA results are variable. In the present study, we
performed a comparative analysis between our originally
developed nMPO-ANCA assay that targets the native MPO
antigen and other commercially available assays using sera
of patients with clinical features of ANCA-associated
vasculitis (AAV).
Methods Sera of 24 patients strongly suspected of having
AAV were examined for the presence of MPO-ANCAs by
our nMPO-ANCA assay and by other commercial-based
MPO-ANCA assays. These results were correlated to
indirect immunofluorescence microscopy staining patterns
and patient clinical parameters.
Results Eighteen out of 24 patients (75 %) were positive
for nMPO-ANCA, compared with 13 out of 24 patients
(54 %) by one of the most frequently used commercialbased
MPO-ANCA enzyme-linked immunosorbent assays
(ELISAs) in Japan. Interestingly, the patients who tested
positive with our nMPO-ANCA assay alone showed clinical
features of AAV marked by continuous fever, polyarthritis,
and mild nephritis. The titers of nMPO-ANCA decreased in
association with clinical improvement after treatment.

Key words

ANCA-associated vasculitis, ELISA, MPO-ANCA, Native MPO, PR3-ANCA