Auto-antibody profiles in patients with active pulmonary tuberculosis

OBJECTIVES: To determine the prevalence of a wide array of auto-antibodies in patients with tuberculosis (TB) compared with healthy controls. MATERIALS AND METHODS: Forty-seven consecutive patients (age 47 ± 21 years, 29 males) with recently diagnosed active pulmonary tuberculosis (PTB) and 39 healthy controls were enrolled. Data collected on a questionnaire included clinical features of the disease, duration of symptoms, presence of fever, cough, arthralgia, myalgia, sicca symptoms and others. Serum samples were collected from the patients' before initiating TB treatment, frozen at -20°C and tested for antinuclear antibodies (ANA), anti-ds DNA, anti-Sm, anti-RNP, anti-Ro, anti-La, and anti-cardiolipin (ACA) (IgG and IgM). RESULTS: Rheumatic symptoms were relatively rare: arthralgia (n = 2), myalgias (n = 2), and eye (n = 1) and mouth dryness (n = 4). The TB patients' mean serum levels of anti-ds DNA, anti-Sm, anti-RNP, anti-SSA (anti-Ro), and anti-ACA-IgM were significantly increased compared with controls (P < 0.05 for all). A significantly higher proportion of TB patients had increased pathological levels of anti-ds DNA (32% vs. 2.5%), anti-Sm (38% vs. 0%), anti-RNP (15% vs. 0%), anti-Ro (64% vs. 10%), anti-ACA-IgG (59% vs. 0%) and anti-ACA-IgM (47% vs. 7.7%) (P < 0.05 for all). CONCLUSIONS: Patients with active TB have significantly increased titres of various auto-antibodies, including highly specific serological markers, such as anti-Sm. RELEVANCE: Differential interpretation of serological studies of patients with systemic manifestations should consider the possibility of PTB.