"Lupus in fabula": Systemic lupus erythematosus complicated by macrophage activation syndrome with a fatal outcome

Abstract

Introduction/Objective: Macrophage activation syndrome (MAS) is a hyperinflam-matory syndrome and an extremely rare but potentially life-threatening complication of systemic lupus erythematosus (SLE), other systemic autoimmune and autoinflammatory diseases, infections, and malignancies. Case report: A 33-year-old female patient with a history of recurrent cholangitis since childhood and persistently positive antinuclear antibodies (ANA) for several years was treat-ed symptomatically in December 2022 for fever and gastrointestinal symptoms interpreted as a recurrent episode of cholangitis, despite the presence of pancytopenia, consumptive coagulopathy, and impaired renal function. In January 2023, she developed recurrent fever accompanied by peripheral lymphadenopathy, splenomegaly, progression of pancytopenia, and hypocomplementemia, at which point a diagnosis of SLE was established and treatment with methylprednisolone was initiated. Due to newly developed changes in mental status with hallucinations and prominent nightmare content, neuropsychiatric lupus was consid-ered; however, it was not confirmed because of the absence of an adequate neuroradiologi-cal correlate. Subsequently, progressive deterioration of liver and kidney function and wors-ening pancytopenia occurred, accompanied by extreme hyperferritinemia (> 33,511 µg/L), hypofibrinogenemia, and hypertriglyceridemia, leading to the diagnosis of macrophage activation syndrome as a complication of active, previously unrecognized systemic lupus ery-thematosus (H-score 266). Cyclosporine was introduced, resulting in transient improvement; however, despite immunomodulatory doses of intravenous immunoglobulins along with the other therapy, anasarca, respiratory, cardiac, and renal failure developed. Therapeutic plasma exchange and intensive ultrafiltration resulted in short-term clinical, laboratory, and echocardiographic improvement, followed by worsening of the multiple organ dysfunction syndrome. Despite all treatment modalities employed, the patient had a fatal outcome. Conclusion: The overlap of the clinical and laboratory manifestations of active systemic lupus erythematosus and macrophage activation syndrome significantly complicates timely diagnosis. Monitoring ferritin concentrations is of particular diagnostic impor-tance, with values > 10,000 µg/L considered highly suggestive of MAS.