Prevalence of antineutrophil cytoplasmic antibodies during treatment with benzylthiouracil.
BACKGROUND
Drug induced antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis is a rare complication associated especially with propylthiouracil (PTU). Prevalence of ANCA in patients receiving PTU is well established. Few cases of vasculitis were also reported with benzylthiouracil (BTU). The objective of this study is to clarify the prevalence of ANCA in patients receiving BTU.


METHODS
ANCA were investigated by indirect immunofluoresence and enzyme linked immunosorbant assay in 159 patients with Graves' disease (86 untreated and 73 treated with BTU).


RESULTS
ANCA were positive in three (3.5%) untreated patients and 27 (37%) treated ones. Titres of ANCA varied between 1:20 and 1:200. There was a significant association between BTU treatment and ANCA (p<0.001). ANCA were directed against myeloperoxidase (MPO) in 28 (93.3%) patients. Median treatment duration was 24 months (ranges 0.5 to 144 months). There was no significant association between treatment duration and ANCA. Vasculitis was found in two (2.7%) treated patients. One patient has developed isolated cutaneous vasculitis and the other one a pulmonary vasculitis with diffuse alveolar haemorrhage.


CONCLUSIONS
BTU therapy is characterised by a high prevalence of ANCA mainly but not exclusively directed against MPO. However, vasculitis remains a rare complication.
Sghiri
R
R
Laboratory of Immunology, Farhat Hached Hospital, Ibn El Jazzar, 4000 Sousse, Tunisia. sghiririm@yahoo.com
Ouertani
M
M
Ben Hsine
H
H
Slim
I
I
Chaieb
L
L
Ghedira
I
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D013956:Antithyroid Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001324:Autoantigens / Q000276:immunology; D001327:Autoimmune Diseases / Q000139:chemically induced* / Q000276:immunology; D002648:Child; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006111:Graves Disease / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology; D013889:Thiouracil / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D014657:Vasculitis / Q000139:chemically induced* / Q000276:immunology; D055815:Young Adult
D019268:Antibodies, Antineutrophil Cytoplasmic; D013956:Antithyroid Agents; D001324:Autoantigens; D013889:Thiouracil; D009195:Peroxidase; C019269:benzylthiouracil