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A3384 - What Lies Beneath: Hemophagocytic Lymphohistiocytosis Complicating a Case of Disseminated Histoplasmosis
Author Block: S. Sangli1, R. Carr2, P. D. Scanlon3; 1Critical Care, Mayo Clinic, Rochester, MN, United States, 2Internal Medicine, Mayo Clinic, Rochester, MN, United States, 3Mayo Clinic, Rochester, MN, United States.
Background Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune activation syndrome resulting in an uncontrolled inflammatory response and cytokine storm resulting in multi-organ failure and death. It can occur at any age with no identified familial associations. We describe a patient with disseminated histoplasmosis who developed secondary HLH. Case 71 year old woman with a history significant for rheumatoid arthritis (RA) on methotrexate and hydroxychloroquine along with infliximab, coronary artery disease, coming in with a history of few weeks of diarrhea and recurrent fevers. She recently travelled to South Dakota and Missouri where she noted some mosquito bites. Her recent medical history included knee injections for RA and had no other localizing symptoms. Her labs were significant for anemia, thrombocytopenia, transaminitis, hyperbilirubinemia, lactic acidosis and acute kidney injury. Ultrasound of liver was consistent with hepatic steatosis. Computed tomography of the abdomen and pelvis revealed severe atherosclerosis with possible high-grade stenosis of the superior mesenteric artery. In the setting of recent immunocompromising therapies, recent travel, fevers, peripheral blood cytopenia of 2 lines and liver dysfunction, we performed a tick-borne illness workup and given the recent infliximab use, fungal studies were performed. Histoplasma urine antigen reported to be positive. She was found to have high inflammatory markers including CRP (94.2mg/L) and ferritin levels which peaked at 13,850 mcg/L. Further evaluation showing significantly low fibrinogen 170mg/L was consistent with disseminated intravascular coagulation. She was confirmed to have disseminated histoplasmosis on blood cultures. She was promptly started on liposomal amphotericin 4 milligrams/kilogram along with itraconazole. Meanwhile, she also developed multiple episodes of hypoglycemia over a 24-hr period despite administering dextrose 50% injection and continued oral intake. Since this suggested adrenal involvement she was begun on hydrocortisone therapy for several days to which, she responded. The progressive peripheral cytopenias, the markedly elevated serum ferritin led to a high suspicion for secondary hemophagocytic lymphohistiocytosis (HLH). Bone marrow biopsy was performed which was consistent with HLH. She was successfully managed with antifungal therapy for the disseminated histoplasmosis and ruxolitinib for HLH. Conclusion Histoplasmosis is an important complication in patients on TNF alpha inhibitors especially, infliximab. In patients with risk factors such as immunosuppressed states, certain infections and rheumatological diseases, high index of suspicion for secondary HLH is essential to diagnosis. Prompt treatment of underlying cause is critical for the resolution of HLH.