Haemophagocytic syndrome in Systemic Lupus Erythematosus - clues to an early diagnosis.

Macrophage activation syndrome (MAS) is a rare life-threatening condition that involves excessive activation of inflammatory cells and overproduction of different cytokines. It is characterized by persistent fever, hepatosplenomegaly, cytopenias and coagulopathy. Other prominent features are hyperferritinemia and findings of activated macrophages in haemopoietic organs, often associated with multi-organ impairment. Its occurrence has been linked to numerous triggers such as viral agents, malignancy and rheumatic diseases. With overlap of clinical features, distinguishing MAS from autoimmune disease flare or sepsis can represent a major challenge. Therefore, a high degree of suspicion is necessary to prompt diagnosis and treatment. Our purpose is to highlight important clinical aspects for an early and differential recognition of this syndrome.