Infections in newly diagnosed systemic lupus erythematosus patients with high disease activity: a retrospective cohort study / 中华风湿病学杂志

ABSTRACT

Objective:To determine the characteristics of hospitalized newly diagnosed systemic lupus erythematosus (SLE) patients with high disease activity, and identify the risk factors.Methods:Data from 194 newly diagnosed SLE patients at Shanghai Renji Hospital between May 2013 and December 2018 were collected retrospectively. All patients were followed up for 1 year or until death. Patients' demographic, clinical, and laboratory characteristics on admission and medication history were retrospectively collected as baseline data. Patients were divided into two groups, lupus patients with infection (51 cases) and lupus patients without infection (143 cases). The method of univariate analysis of data depended on the data distribution type. Variables that suggested association in the univariate analysis ( P<0.05) were entered into Cox regression model. Results:Among 194 patients with newly diagnosed SLE, 21 cases (11%) died and 51 cases (26%) were infected during 1-year follow-up. Regarding the infection site, 34 cases (67%) had lung infection, 9 cases (18%) had central nervous system infection and 9 cases (18%) had blood stream infection. Common bacteria were identified in 19 cases (45%), followed by fungal infection in 18 cases (43%) and mycobacterium infection in 7 cases (17%). Among the 51 patients with infection, 38 patients (75%) had infection within the first 3 months after diagnosis, and mortality in this group was significantly higher than that in the uninfected group (39%, 15/38 vs 2%, 3/143 , P<0.01). Comparing baseline parameters between patients with 3-month infection and without, significant differences ( P<0.05) were detected in age (≥40 years), systemic lupus erythematosus disease activity index (SLEDAI) score (>10 points), Systemic Lupus International Collaborating Clinic (SLICC)/American College of Rheumatology(ACR) systemic lupus erythematosus damage index (SDI) (≥1 point), pericardial effusion, nephritis, gastrointestinal vasculitis, diabetes, lymphocyte count <0.8×10 9/L platelet count <100×10 9/L, serum creatinine >104 mmol/L and serum globulin level <20 g/L. Finally, clinically meaningful candidate predictors were included in the Cox regression model and it showed that lymphocyte count <0.8×10 9/L, nephritis and gastrointestinal vasculitis were independently predictive for 3-month infection in new-onset lupus patients. Conclusion:Understanding disease spectrums and risk factors of infection in newly diagnosed SLE patients will help clinicians to manage those patients with infection effectively to achieve favorable prognosis.