[Usefulness of analyzing ANCA changes for diagnosis of Wegener's granulomatosis]

ANCA were described in 1982 as sensitive and specific markers for active Wegener's granulomatosis (WG). We analysed the results of ANCA test performed in 298 patients hospitalized in Institute of Tuberculosis and Lung Diseases in the period 1990-1998 because of different symptoms and syndromes of respiratory system which could be symptoms of WG. Presence of c-ANCA, p-ANCA and other not well defined types of ANCA in the titer greater than 1:40 in the serum was regarded as positive result of test. We found it in 60 patients. In 47 WG pts ANCA were present in 40 of 42 pts with active disease and 1 of 5 in remission. Further 19 positive results were found in a group of 251 patients with other diseases: 1 of 4 pts with Churg-Strauss syndrome, 1 of 2 with pulmonary renal syndrome, 5 of 28 with connective tissue diseases, 1 of 21 with tuberculosis, 1 of 23 with sarcoidosis, 1 of 6 with histiocytosis, 3 of 11 with hypersensitivity pneumonitis, 1 (lymphoma) of 34 with neoplasms, 1 of 20 with pulmonary fibrosis, 1 of 8 with cardiac failure, 1 of 5 with pleural fluid, 1 of 10 pneumoconiosis and toxic reactions (after furagin), 1 of 6 with BOOP. Sensitivity of ANCA test in our material is 87%, specificity = 95%, and positive prevalence accuracy is 68%. It means that 32% of the patients with positive results could be inappropriate treated as WG.

ANCA test could be not used as a screening test. Results of ANCA test alone cannot be used as basis for treatment. ANCA test is a helpful tool in diagnosing of WG.