Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (720 page)

   Crohn disease (10–40%)

   Bacterial enteritis (rare)

   Autoimmune liver diseases

   Primary sclerosing cholangitis

   Autoimmune hepatitis

   Infections

   Chromomycosis

   HIV-1

   Acute malaria

   Five percent healthy controls

   Limitations

   There is a subjective component to the interpretation of IFA, because the tests are based on visual interpretation of the IF pattern, which is not straightforward. It depends on the experience of the individual who performs the assay.

   ANCA testing is not standardized; the sensitivity and specificity will vary with the laboratory. The cANCA pattern has a greater specificity than the pANCA pattern for vasculitis. However, even positive cANCA IFA results were associated with vasculitis in only 50% of patients.