Adult-Onset Still’s Disease (AOSD)—On the Basis of Own Cases

Introduction: Adult-onset Still’s disease (AOSD) is a rare chronic autoinflammatory condition characterized by a spiking fever, arthritis, a rash, hepatosplenomegaly, lymphadenopathy, leucocytosis, and hyperferritinemia. It is sometimes accompanied by life-threatening complications like macrophage activation syndrome/hemophagocytic lymphohistiocytosis (MAS/HLH). Treatment options for AOSD include glucocorticoids (GCs), immunosuppressive drugs, biological medications, and Janus kinase (JAK) inhibitors. The features that differentiate MAS/HLH from AOSD are: in MAS/HLH, a different type of fever, which is persistent, a sharp decrease in the number of leukocytes and thrombocytes, a further increase in the level of transaminases and ferritin, significant hepatosplenomegaly, lymphadenopathy, symptoms of the central nervous system (CNS), disseminated intravascular coagulation (DIC) and hemophagocytosis in the bone marrow. This study aimed to evaluate the course of AOSD, which results in MAS/HLD. Patients and methods: Nine AOSD patients, four of whom developed MAS/HLH, were treated at the Rheumatology Clinic in the Central Clinical Hospital of the Ministry of Interior Affairs from 1 January 2015 to 15 March 2020 and at the Rheumatology Clinic in the National Institute of Geriatric, Rheumatology and Rehabilitation from 1 September 2021 to 1 March 2024. Medical history, clinical data, demographic data, laboratory data, imaging data, Hscore, and treatment data were collected. Results: All the patients with MAS and an Hscore above 150 recovered. Discussion: MAS/HLH requires rapid diagnosis as well as treatment with methylprednisolone pulses, cyclosporine A, and etoposide. When comparing patients who developed MAS/HLH with those who did not, possible risk factors were identified: the presence of pregnancy (two cases) and an aggressive course of AOSD. The Hscore is a useful tool for identifying patients with MAS/HLH.