Objectives
To compare the clinical and laboratory characteristics of pediatric-onset systemic lupus erythematosus (pSLE), pSLE with macrophage activation syndrome (MAS), and pSLE with recurrent MAS, and to find biomarkers for the differential diagnosis of these diseases.
Methods
Demographic, clinical, laboratory and radiological data were analysed for three groups of patients: 18 cases of pSLE with MAS, 48 age- and sex-matched cases of active pSLE without MAS and 40 age- and sex-matched cases of pSLE with inactive disease. One case of a 9-year-old girl with recurrent MAS as the primary manifestation of SLE also was recorded.
Results
IL-10 and IFN-γ levels were significantly higher in pSLE patients with MAS than in pSLE patients without MAS, and were significantly correlated with SLE and MAS laboratory features. Levels of IL-10 > 7.25 pg/ml had a high sensitivity and levels of IFN-γ > 6.7 pg/ml had a high specificity for predicting MAS in pSLE. Constitutional symptoms were evident in the case of recurrent MAS in pSLE, and traditional immunosuppressive therapies were unable to prevent the next MAS episode.
Conclusion
Compared with pSLE and pSLE-MAS with a single episode, pSLE with recurrent MAS has different clinical manifestations and responses to treatment, requiring intensive studies to elucidate the underlying pathogenic mechanisms. Elevated serum levels of IL-10 and IFN-γ may be correlated with pSLE with MAS and can serve as serum biomarkers for pSLE with MAS.