Macrophage Activation Syndrome (MAS) in a Recently Released Prisoner with Systemic Lupus Erythematosus (SLE).

BACKGROUND Systemic lupus erythematosus (SLE) has myriad manifestations that can affect any organ system in the body. Macrophage activation syndrome (MAS) is a disease of uncontrolled lymphocyte and macrophage proliferation and activation, which has various triggers, including autoimmune disorder, viral infection, and malignancy. We report here on MAS as a complication of adult SLE, a rare association in the literature, in a patient with an unknown past medical history. CASE REPORT A 38-year-old male patient presented with severe muscle weakness, diffuse abdominal cramps with vomiting and incontinence of stool, confusion, cough, and sweating increasing in severity for about 1 week. He was unable to give a coherent history and according to his family had been released from prison 3 weeks prior, having been in the corrections system for much of his adult life. The diagnosis of new-onset fulminant SLE complicated by MAS was made, noting the profound degree of bone marrow involvement, neuropsychiatric changes, and hyperferritinemia. CONCLUSIONS Many of the symptoms, signs, and laboratory findings of SLE overlap with those of MAS, and concomitant presence of both of these disease poses unique diagnostic challenges as well as extreme risk to the patient. A robust set of criteria for identifying MAS in the setting of a confounding underlying rheumatological illness does not exist in the adult population; this case illustrates the approach taken by our team to come to this diagnosis.