Prevalence, Predictors, and Prognosis of Serious Infections in Takayasu Arteritis: A Cohort Study.

Objective: To describe the incidence, risk factors, and outcomes associated with serious infections in patients with Takayasu arteritis (TA).

Methods: Serious infections, defined as infections resulting in hospitalization or death or unusual infections like tuberculosis, were identified from a cohort of patients with TA. Corticosteroid and disease-modifying antirheumatic drug (DMARD) use at the time of serious infection was noted. Demographic characteristics, clinical presentation, angiography, and disease activity at presentation, and the use of DMARDs during follow-up were compared between patients with TA with or without serious infections. Mortality in patients with TA who developed serious infections was compared to those who did not using hazard ratios (HR; with 95% CI).

Results: Of 238 patients with TA, 38 (16%) had developed serious infections (50 episodes, multiple episodes in 8; 3 episodes resulted in death). Among the 38 initial episodes, 11/38 occurred in those not on corticosteroids and 14/38 in those not on DMARDs. Pneumonia (n = 19) was the most common infection, followed by tuberculosis (n = 12). Patients with TA who developed serious infections vs those who did not had higher disease activity at presentation (active disease 97.4% vs 69.5%, mean Indian Takayasu Arteritis Activity Score 2010 12.7 (SD 7.3) vs 10.2 (SD 7.0), mean Disease Extent Index in Takayasu Arteritis 11.2 (SD 6.1) vs 8.8 (SD 6.1) and were more frequently initiated on corticosteroids or DMARDs. HRs calculated using exponential parametric regression survival-time model revealed increased mortality rate in patients with TA who developed serious infections (HR 5.52, 95% CI 1.75-17.39).

Conclusion: Serious infections, which occurred in the absence of immunosuppressive treatment in approximately one-fifth of patients with TA, were associated with increased mortality in patients with TA.