A Case of Cytomegalovirus-Induced Hemophagocytic Lymphohistiocytosis in a Patient with an Underlying Rheumatic Disease

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition caused by overproduction of inflammatory cytokines and overactivation of macrophages that can progress to multiorgan dysfunction and failure. Although there are guidelines that attempt to recognize the condition in its early stage, diagnosis can be very challenging due to heterogeneous presentations of HLH. Symptoms and clinical findings include fever, neurologic complaints, respiratory issues, liver dysfunction, cytopenias, amongst others most of which are not specific to HLH. In addition, response to treatment can be highly variable, necessitating an individualized treatment plan based on the presentation. We present a case of a 21-year-old female with a history of biopsy-proven inflammatory myositis on azathioprine and prednisone who presented with fever, hypotension, and pancytopenia. Additional imaging studies showed multiorgan involvement, including pneumonia, pyelonephritis, and splenomegaly. A bone marrow biopsy of her iliac crest showed hemophagocytosis and the infectious workup confirmed cytomegalovirus (CMV) infection, which led to the diagnosis of CMV-induced HLH. She was treated initially with anakinra for macrophage activation syndrome (MAS) in addition to dexamethasone and ganciclovir. Unfortunately, she did not respond to anakinra and was subsequently switched to etoposide with dexamethasone and valganciclovir, which subsequently helped our patient to recover clinically. Our case highlights the challenging nature of HLH and the importance of early detection and a personalized treatment plan in achieving optimal outcomes in patients with HLH.