METHODS: MC3T3-E1 cells were seeded on HA and treated with recombinant IL-6 or rIL-17A or combination of the two cytokines. Cell proliferation and differentiation activity were measured by MTS and alkaline phosphatase assays respectively. Observation of cell adhesion and proliferation was examined by scanning electron microscopy. Gene and protein expressions were performed on RANKL and OPG using qPCR, Western blot and ELISA.

CASE PRESENTATION: An 8-year-old and an 11-year-old were admitted separately to the hospital with fever for 7 and 14 days, respectively. In the younger child, a generalized rash preceded the fever. Both had been well, with no significant past medical history prior to the onset of the illness. In both girls, abdominal ultrasonography showed multiple small hypoechoic lesions suggestive of abscesses scattered throughout the spleen. Their C-reactive protein and blood cultures were negative, and symptoms persisted despite intravenous antibiotics. Fulfilling the clinical and immunologic criteria for diagnosis, both were ultimately diagnosed with childhood-onset SLE. Rapid recovery of symptoms and complete resolution of the abscesses ensued with corticosteroids and immunosuppressive therapy.