Spectrum of anti-neutrophil cytoplasmic antibodies in patients with pulmonary tuberculosis overlaps with that of Wegener's granulomatosis
Pradhan, V.D.; Badakere, S.S.; Ghosh, K.; Pawar, A.R.
Indian Journal of Medical Sciences 58(7): 283-288
2004
ISSN/ISBN: 0019-5359 PMID: 15286419 Document Number: 239977
Mycobacterial infections are known to induce the development of autoantibodies and a few of these antibodies are also known to be diagnostic markers for some other diseases and it is uncertain whether these autoantibodies play a role in the pathogenesis of autoimmune disorders. This study was undertaken to determine the prevalence of autoantibodies like anti-neutrophil cytoplasmic antibodies (ANCA), anti-nuclear antibodies (ANA), anti-double stranded antibodies (anti-dsDNA) and anti-histone antibodies (AHA)in pulmonary Tuberculosis. Seventy consecutive pulmonary TB patients, 30 patients of interstitial lung disease and 100 normal individuals were studied. ANCA and ANA were detected by indirect immunofluorescence test (IIF). Anti-dsDNA and AHA were tested by ELISA. ANCA was detected in 30% cases, and of these 52.4% showed perinuclear pattern (p-ANCA), 38.1% cytoplasmic (c-ANCA) and 9.5% showed an "atypical" pattern. ANCA specificities by ELISA revealed that, 47.6% had anti-Myeloperoxidase (anti-MPO), 28.6% had anti-Proteinase3 (anti-PR3) and 19.1% had anti-Lactoferrin (anti-LF) antibodies. ANA and AHA were present in 24.3% and 21.4% cases respectively whereas anti-ds DNA antibodies were absent. Normal controls showed 4% and 2% positivity for ANA and ANCA whereas disease control group of ILD showed 7% of ANA and ANCA posititivy. The presence of autoantibodies in TB patients could have a multifactorial etiology. Clinically relevant is the presence of anti-PR3 antibodies. This finding along with pulmonary and renal manifestations could lead to a false diagnosis of Wegener's granulomatosis or vice versa because these autoantibodies may be present in both diseases.