Two Edges of Immune Dysregulation: Adult Onset Still’s Disease in a Patient with a History of Kaposi Sarcoma

We describe a very unique case of emergence AOSD in a patient with a history of KS. A 52-years old woman presented with fever, arthralgia, sore throat and skin rash that started 1 year ago. Patient’s medical history was noteworthy because 1.5 years ago she was diagnosed with Kaposi’s sarcoma where she presented with a low extremity rash and swollen lymph nodes. Lymph node biopsy demonstrated HHV-8 positivity and atypical vascular proliferation and atypical endothelial cells that were interpreted as Kaposi sarcoma. She receieved paclitaxel chemotherapy and with this treatment Kaposi sarcoma was in remission. Current physical examination revealed a fever of 38.5⁰ C, salmon colored rash in anterior chest wall, pharyngeal erythema, cervical and axillary lymphadenopathy and polyarthralgia in wrists, ankles and small joints of hand and feet. Laboratory examinations revealed neutrophilic leukocytosis, anemia, a very high ferritin level (16815 mcg/l) and elevated acute phase reactants. Rheumatoid factor and antinuclear antibody were negative. Infections and mlaignancies were ruled out and patient was diagnosed with adult onset Still’s disease. Patient responded dramatically to the combination treatment of 2*16 mg methylprednisolone and 15 mg/week oral methotrexate. Clinical symptoms improved dramatically, acute phase reaactants and ferritin normalized and hemoglobin increased. As soon as the symptoms were controlled, methylprednisolone tapering was initiated and it was eventually stopped. Patients continues to receive methotrexate. She is under follow up for 27 months with both her Kaposi sarcoma and adult onset Still’s disease in remission. To our knowledge, this is the first case of AOSD that developed in a patient with KS history. The patient whose immune system initially succumbed to opportunistic pathogen HHV-8 and suffered from KS received chemotherapy. Once KS was in remission, a different form of immune dysregulation- this time immune system hyperactivation, with a predominant innate immune system activation occurred and she suffered form AOSD.