INTERCURRENT INFECTION AS A RISK FACTOR FOR DISEASE FLARES IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: N. Jourde-Chiche et al.
Infections are potential triggers of SLE flares although most of the evidence is obtained from a limited number of observational studies. To determine whether intercurrent infections are a risk factor for SLE flares 203 SLE patients were followed prospectively. 52% of patients received corticosteroids and 37% immunosuppressants other than antimalarials. Clinical data were collected at baseline, and at the start of an intercurrent infection that either was, or was not followed by a flare within three months.
Major infections were defined as infections for which hospital admission or intravenous antibiotic therapy was required. Minor infections were defined as infections (proven or not proven, but highly likely based on clinical symptoms and/or response to therapy) for which hospital admission was not warranted. SLE flares were defined as an increase in disease activity requiring intensification of immunosuppressive therapy.
The incidence rates of major and minor infections were 5.3 per 100 patient years and 63.9 per 100 patient years, respectively. The incidence rate of major SLE flares was 3.6 per 100 patient years and 15.1 per 100 patient years for minor flares.
The incidence rates of, major infections followed by a flare within three months were 0.7 per 100 patient years, and 2.3 per 100 patient years for minor infections. Intercurrent infections (major and minor) are associated with SLE flares (major and minor; HR 1.9, 95% CI:1.3 – 2.9). The hazard ratio for a major SLE flare following a major infection was 7.4.
This study confirms a high frequency of infections in SLE patients suggesting that intercurrent infection is a risk factor for SLE flares. These findings underline the importance of prevention and treatment of infections in SLE patients.