Wegener’s granulomatosis is characterized by granulomatous inflammation containing foci of vasculitis involving the nasopharynx plus crescentic glomerulonephritis (proliferative vascular lesions obliterating a focal area of Bowman’s capsule space). Laboratory test abnormalities include substantial hematuria and proteinuria, and reflect a culture-negative ongoing inflammatory process. The WBC count and ESR are usually elevated when the disease is active.

Limited forms of this syndrome also occur, most often confined to the nasopharynx or less often, the lower respiratory tract. Diagnosis is made when possible by biopsy of clinically affected areas. In addition, a serologic test called the anti-neutrophil cytoplasmic (ANCA) test is now available in larger reference laboratories and medical school centers. This uses a fluorescent antibody method that demonstrates fluorescent antibody localization in the cytoplasm of neutrophils having a granular appearance throughout the cytoplasm (C-ANCA; although there is a minor tendency toward perinuclear accumulation), C-ANCA has been reported in about 90%-95% (range, 84%-100%) of active classic Wegener’s cases, in about 30% (range, 13%-41%) when the disease is inactive, and in about 65% (range, 60%-85%) when the disease is limited to the respiratory tract. Most, but not all, of patients with Wegener’s granulomatosis localized only to the kidneys have negative C-ANCA results.

Even more recently, it was found that using a different fixative for the cells used for antigen in the fluorescent antibody technique produced reaction with a different ANCA, one that predominantly localized next to the cell nucleus (perinuclear; p-ANCA). Perinuclear ANCA has been reported to react with myeloperoxidase, and is detected in 50%-80% of localized Wegener’s centered in the kidneys as crescentic glomerulonephritis or a similar condition known as idiopathic crescentic glomerulonephritis. p-ANCA is also found in other conditions associated with inflammation; in one study it could be detected in about 75% of patients with ulcerative colitis, 75% of patients with primary sclerosing cholangitis, 50% of patients with autoimmune hepatitis, 50% of patients with Churg-Strauss vasculitis, 5%-7% of patients with hepatitis virus B or C active infection, and 8% of patients with Crohn’s disease.