RT Journal Article
SR Electronic
T1 ELISA is the superior method for detecting antineutrophil cytoplasmic antibodies in the diagnosis of systemic necrotising vasculitis.
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 670
OP 676
DO 10.1136/jcp.52.9.670
VO 52
IS 9
A1 A Harris
A1 G Chang
A1 M Vadas
A1 D Gillis
YR 1999
UL http://jcp.bmj.com/content/52/9/670.abstract
AB BACKGROUND: Antineutrophil cytoplasmic antibodies (ANCA) have been used as a diagnostic marker for systemic necrotising vasculitis, a disease classification which includes Wegener granulomatosis, microscopic and classic polyarteritis nodosa, and Churg Strauss disease. OBJECTIVE: To compare the diagnostic value of the two methods for detecting these antibodies--immunofluorescence and enzyme linked immunosorbent assay (ELISA)--with respect to biopsy proven active systemic necrotising vasculitis in a clinically relevant population. METHODS: A prospective study to ascertain the patient's diagnosis at the time of each of the 466 requests for ANCA received at one laboratory over a nine month period, and allocate each to one of five diagnostic groups: active and inactive biopsy proven systemic necrotising vasculitis, suspected systemic necrotising vasculitis, low probability systemic necrotising vasculitis, and not systemic necrotising vasculitis. RESULTS: ELISA was superior to immunofluorescence in the diagnosis of systemic necrotising vasculitis because it was less likely to detect other diseases. This was reflected in its specificity of 97% and positive predictive value of 73%, compared with 90% and only 50% for immunofluorescence (p = 0.0006 and p = 0.013, respectively). ELISA had a negative predictive value of 98% which was not significantly different to immunofluorescence. ELISA was technically superior. CONCLUSIONS: ELISA is the superior method of ANCA detection in the diagnosis of systemic necrotising vasculitis and should be used in conjunction with a compatible clinical picture and histological evidence.