POS1013 HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS IN SYSTEMIC LUPUS ERYTHEMATOSUS: A NATIONWIDE POPULATION-BASED STUDY
Authors: J. Lee, C. H. Yoon
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Hemophagocytic lymphohistiocytosis (HLH) is an extremely rare but potentially life-threatening immune dysregulation disorder [1]. Immunosuppression and chronic inflammation also increase susceptibility to HLH [2,3]. Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease characterized by dysregulated immune responses affecting various organs and systems requiring immunosuppressive treatment. It is thought that the incidence of HLH is likely to significantly increase in patients with SLE, but no such investigation has been reported in previous studies. <h3>Objectives:</h3> We investigated the incidence of HLH and risk factors for HLH in SLE patients. <h3>Methods:</h3> Using the Korean nationwide insurance claim data during 2005-2018, we identified 17,989 newly-diagnosed SLE patients. The patients of SLE and HLH were identified using the ICD-10 codes in admission data. Age- and sex-matched non-SLE controls were randomly sampled in a 5:1 ratio (n = 89,945). We excluded patients aged less than 20 years and other combined autoimmune rheumatic disease. We used the Kaplan-Meier method for survival analysis and the log rank test to compare the risk of HLH between the SLE and control cohorts. The risk of HLH was assessed by determining hazard ratio (HR) with 95% confidence intervals (CI) by using multivariable conditional logistic regression. <h3>Results:</h3> The SLE patients had a higher incidence of HLH compared to controls (p &lt; 0.001) (Figure 1). Among the total 17,989 SLE patients, 99 patients (0.6 %) were diagnosed with HLH (Table 1). Of these, 10 patients (10.1 %) died. Among the total 89,945 controls, 6 patients (0.01 %) were diagnosed with HLH. SLE patients exhibited significantly higher prevalence rates of hypertension, diabetes, congestive heart failure, chronic renal disease, interstitial lung disease, malignancy, and stroke compared to the control group (p &lt; 0.001). Patients with SLE who developed HLH had a significantly younger mean and median age at diagnosis of SLE compared to non-HLH patients (p &lt; 0.001). In multivariable analysis, older age (over 65 years) (HR 0.24, p = 0.016), females (HR 0.5, p = 0.03) and higher BMI (HR 0.38, p = 0.012) were associated with lower risk of HLH in SLE patients. <h3>Conclusion:</h3> This study demonstrated development of HLH in patients with SLE was associated with males, younger age, and lower BMI. <h3>REFERENCES:</h3> [1] Grifn G, Shenoi S, Hughes GC (2020) Hemophagocytic lymphohistiocytosis: an update on pathogenesis, diagnosis, and therapy. Best Pract Res Clin Rheumatol 34(4):101515. [2] Parikh SA et al (2014) Prognostic factors and outcomes of adults with hemophagocytic lymphohistiocytosis. Mayo Clin Proc 89(4):484–492. [3] Rouphael NG et al (2007) Infections associated with haemophagocytic syndrome. Lancet Infect Dis 7(12):814–822. <b>Table 1.</b> Baseline characteristics in SLE and controls <h3>Acknowledgements:</h3> This study is based on the data from the NHID and provided through the Korea Health Industry Development Institute (KHIDI). <h3>Disclosure of Interests:</h3> <b>None declared.</b>