Analysis of Erythrocyte C4d to Complement Receptor 1 Ratio: Use in Distinguishing between Infection and Flare-Up in Febrile Patients with Systemic Lupus Erythematosus

Clinical characteristics and risk factors of infections in patients with systemic lupus erythematosus

To investigate the clinical characteristics of infection in SLE patients and analyze the risk factors of infection. A retrospective analysis method was used and the data were collected from 173 case times of 142 hospitalized patients. We found the incidence rate of infections in SLE was 50.7%. The most common infection sites were lungs, followed by upper respiratory tracts and urinary tracts. The most common pathogens were bacteria, followed by fungi. The infection-associated risk factors were duration of hospitalization, lupus activity state, the use of high-dose corticosteroids and immunosuppressive agents, the low serum level of complements 3 and 4 (C3 and C4), fever, the high level of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), the abnormality of white blood cell (< 4 × 10⁹/L or > 10 × 10⁹/L), and the low level of albumin (P < 0.05 or P < 0.001). The independent risk factors for SLE patients with infection consist of the abnormality of white blood cells, the high level of CRP, the low serum level of C4, and longtime hospitalization. Attention should be paid to the risk factors of infection, and treatment to enhance immunity should be carried out to reduce the chance of infection.

Vaccine-preventable infections in Systemic Lupus Erythematosus

Systemic Lupus Erythematosus (SLE) is characterized by abnormal autoantibody production and clearance. Infections are among the most important causes of morbidity and mortality in SLE patients; they have an increased frequency of severe bacterial and viral infections possibly due to inherited genetic and immunologic defects and to immunosuppressive therapies. In addition, infectious agents can switch on lupus disease expression and activity. Among the strategies to reduce the risk of infection, vaccination can be considered the most reliable option. Most vaccines are effective and safe in SLE patients, although in certain cases immunogenicity may be sub-optimal and vaccination can trigger a flare. Although these issues are currently unresolved, the risk benefit balance is in favor for vaccination to reduce the risk of infection in SLE patients. In the present review we discuss the preventive strategies currently recommended to reduce bacterial and viral infections in SLE.