Rational requesting or rationing testing?
- Correspondence to: Mr R J Lock North Bristol NHS Trust, Southmead Hospital, Bristol BS10 5NB, UK; boblock75hotmail.com
The appropriate use of antineutrophil cytoplasm antibody (ANCA) tests
The UK government has acknowledged that up to 70% of medical diagnoses now rely on pathology laboratory analyses.1 One consequence of such reliance is an ever increasing laboratory workload, usually, in National Health Service laboratories, at a rate in excess of the financial resources to support it. It follows that this demand can only be serviced by increased efficiency.
One area where demand has risen sharply in the past decade is in the field of antineutrophil cytoplasmic antibody (ANCA) testing. Since the association of ANCA with Wegener’s granulomatosis (WG) in 1985,2 an increasing number of autoimmune, drug induced, and infectious disorders have been shown to have an association with ANCA.3–8 However, overall, the data suggest that these ANCA do not help to elucidate the diagnosis or prognostic features of these disorders (reviewed in Savige et al, 20009). In addition, there is increasing evidence to suggest that ANCA may be of help, albeit limited, in categorising inflammatory bowel disease.10,11 Low sensitivity limits the diagnostic use of ANCA in this area.12,13
As indicated in the consensus document,14 the principle use of ANCA testing remains as an aid to diagnosis in the necrotising vasculitides (such as WG, microscopic polyangiitis, Churg-Strauss, and pauci-immune crescentic glomerulonephritis). Untreated, these conditions have considerable morbidity and mortality.
In this issue of the Journal of Clinical Pathology, Sinclair et al have reviewed their experience over a six month period of a “gating policy”, based on clinical information given to the laboratory at the time of …
