The target antigens of antineutrophil cytoplasmic antibodies (ANCA) induced by propylthiouracil.
OBJECTIVE
Antineutrophil cytoplasmic antibody (ANCA) has been well documented in association with propylthiouracil (PTU), and some patients with PTU-induced ANCA also develop clinical vasculitis. The aim of the current study was to detect ANCA specificities in sera from patients with PTU-induced ANCA with and without clinical vasculitis.


METHODS
Sera from 65 patients with PTU-induced ANCA were collected, and 27 of these patients were diagnosed with PTU-induced ANCA associated systemic vasculitis (AASV). Indirect immunofluorescence assay and antigen-specific ELISAs were used to detect ANCA and their antigen specificities. The seven known target antigens included myeloperoxidase (MPO), proteinase 3, human leukocyte elastase, lactoferrin, cathepsin G, azurocidin and bactericidal/permeability-increasing protein (BPI).


RESULTS
In IIF assay, P-ANCA was found in 58/65 (89.2%) sera, C-ANCA in two, both P-ANCA and C-ANCA in five, respectively. MPO (60%) and lactoferrin (63.1%) were the two most common target antigens detected in sera from all the patients. 25/27 sera from patients with PTU-induced AASV recognized multiple target antigens, which was significantly higher than those (13/38) from patients without (P<0.001). Except anti-BPI antibodies, the prevalence of antibodies against the other six target antigens was significantly higher in patients with clinical vasculitis than that in patients without (P<0.05, respectively).


CONCLUSIONS
Antibodies against multiple ANCA specific antigens, especially the antigens rather than MPO and PR3, might be the characteristic of PTU-induced ANCA. Patients with antibodies against more ANCA specific antigens might be at increased risk of developing overt clinical vasculitis. The mechanism of ANCA production in PTU-induced cases was different from that in primary AASV.
Gao
Ying
Y
Department of Nephrology, Peking University First Hospital, Beijing 100034, PR China.
Chen
Min
M
Ye
Hua
H
Guo
Xiao-Hui
XH
Zhao
Ming-Hui
MH
Wang
Hai-Yan
HY
D000293:Adolescent; D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood / Q000276:immunology*; D000941:Antigens / Q000276:immunology*; D013956:Antithyroid Agents / Q000009:adverse effects*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011441:Propylthiouracil / Q000009:adverse effects*; D014657:Vasculitis / Q000097:blood / Q000139:chemically induced / Q000276:immunology*
D019268:Antibodies, Antineutrophil Cytoplasmic; D000941:Antigens; D013956:Antithyroid Agents; D011441:Propylthiouracil