To evaluate the clinical significance of the 2016 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR)/Pediatric Rheumatology International Trials Organization (PRINTO) classification criteria for macrophage activation syndrome (MAS) in patients with febrile systemic lupus erythematosus (SLE).
We performed a retrospective analysis of SLE patients with fever, who were admitted to Severance Hospital between December 2005 and May 2016. Patients were evaluated for MAS using the 2016 classification criteria for MAS. Clinical features and laboratory findings were compared and overall survival rate was analyzed. Forward and backward stepwise logistic regression analysis was used to evaluate the factors associated with in-hospital mortality.
Among 157 patients with SLE, 54 (34.3%) were considered to have MAS on admission (n = 42) and during admission (n = 12). For patients who already have MAS on admission, their baseline laboratory findings demonstrated lower CRP, platelets, total protein, albumin, complement C3, fibrinogen and higher AST, ALT, total bilirubin, ferritin, and triglyceride. The overall survival rate was significantly lower in patients with MAS than without MAS (64.8% vs. 97.0%, p < 0.001). Multivariate analysis showed that the presence of MAS was significantly associated with in-hospital mortality in febrile SLE patients (OR = 64.5; 95% CI: 7.6-544.4; p < 0.001).
The 2016 classification criteria for MAS is useful to identify febrile SLE patients at high risk for in-hospital mortality. Monitoring febrile SLE patients with the new 2016 classification criteria might aid in the early detection of MAS.