Tuberculosis in people with rheumatic disease in Finland 1995–2007: a nationwide retrospective register study

OBJECTIVES: RA and its medication, especially TNF-α inhibitors, increase the risk of clinical tuberculosis (TB) infection. We aimed to investigate the clinical manifestations, incidence and temporal changes in TB occurring concurrently with rheumatic diseases (RDs) between 1995 and 2007. METHODS: We combined the register of the Social Insurance Institution of Finland and the National Infectious Disease Register to find adult patients with reimbursed DMARDs and with a TB notification between 1995 and 2007. After reviewing the medical records, we described their clinical manifestations and medications, explored TB incidence trends using Poisson regression, and compared the incidence of TB with that of the general population. RESULTS: We identified 291 patients with both TB and rheumatic disease (RD), 196 of whom had RA. Between 1995 and 2007, the incidence of TB in adult RD decreased from 58.8 to 30.0 per 100 000 (trend P < 0.001, average marginal effect −3.4/100 000 per year, 95% CI −4.4, −2.4). Compared with the general population, the incidence was ∼4-fold. Among RD patients, pulmonary TB was the most common form of TB (72.6%). Disseminated TB was present in 56 (19.6%) patients. CONCLUSION: The incidence of TB among RD patients was ∼4-fold that of the general population, and it declined between 1995 and 2007. Disseminated TB was present in nearly 20% of patients.