Infections in patients with systemic lupus erythematosus

Despite the availability of newer therapeutic interventions of improve clinical outcome in patients with Systemic Lupus Erythematosus (SLE), the incidence of infections as a cause of morbidity and mortality has not changed over the past 30 years. SLE itself increases the risk of infection, due to genetic (complement deficiencies) and acquired factors such as functional asplenia (humoral immunodepression) and the use of immunosuppressive drugs. These medications increase the risk of opportunistic infections that are associated with an altered cellular immune response. The main etiologic infectious agents in SLE patients are common bacterial pathogens, especially capsulated ones. The most common sites are lung, skin, bladder, brain and systemic infections. The main risk factor for infection is the history of a previous one. The clinical approach to SLE patients with suspected infectious diseases must consider the possibility of a flare up of the underlying disease, posing an additonal problem to the clinician (Rev Med chile 2009; 137: 1367-74).