Objectives This study aimed to investigate the incidence rate and risk factors of bloodstream infection (BSI) in patients with systemic lupus erythematosus (SLE) exposed to medium to high doses of glucocorticoids. Methods This study included 1109 treatment episodes with prolonged (≥4 weeks) medium-to-high-dose glucocorticoids (≥15 mg/day prednisolone) in 612 patients with SLE for over 14 years. Clinical features regarding systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K), immunosuppressant use, and laboratory results were obtained from the electronic medical database. The primary outcome of this study was the 1-year incidence of BSI. The effect of clinical factors on the outcome was investigated using a generalized estimating equation. Results During a total of 1078.64 person-years, 30 cases of BSI occurred, with an incidence rate of 2.78 (95% confidence interval (CI) 1.88–3.97) per 100 person-years. Mortality rate of the treatment episodes with BSI was 16.7%, which was significantly higher than that in the other episodes (incidence rate ratio (IRR) 19.59, 95% CI 7.33–52.44). When the incidence rate of BSI was stratified by baseline glucocorticoid dose and SLEDAI-2K score, a higher incidence rate of BSI occurred as disease activity or baseline glucocorticoid dose increased. In the multivariable analysis, SLEDAI-2K ≥20 (adjusted IRR (aIRR) 4.66, 95% CI 2.17–10.00), initial baseline prednisolone ≥ 60 mg/day (aIRR 2.42, 95% CI 1.11–5.32), and cumulative prednisolone dose ≥15 mg/day during the previous 6 months (aIRR 2.13, 95% CI 1.03–4.40) significantly increased the risk of BSI. Conclusion In patients with SLE exposed to prolonged medium-to-high-dose glucocorticoids, the 1-year incidence rate of BSI was significantly higher than previously reported in the general patients with SLE. Severe disease activity, and high-dose glucocorticoid treatment previously or at baseline increased the risk of BSI.

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening hematological disorder characterized by uncontrolled activation of CD8+ T and natural killer cells, leading to a cytokine storm and severe organ dysfunction. Although secondary HLH related to autoimmune diseases usually demonstrates a good treatment response to immunosuppressive therapy for underlying conditions, there is no consensus regarding the treatment in case of unresponsiveness to the treatment. Herein, we present a case of HLH that was unresponsive to high-dose glucocorticoid and cyclosporine treatment in a patient with newly diagnosed systemic lupus erythematosus. The patient's clinical features and laboratory abnormalities rapidly improved with ruxolitinib, an oral Janus kinase 1 and 2 (JAK1/2) inhibitor. This result suggests that blocking JAK-STAT pathway may be a potential treatment option in patients with refractory HLH secondary to autoimmune diseases.