Hemophagocytic lymphohistiocytosis (HLH) is a rare disorder characterized by fever, pancytopenia, hyperferritinemia, and phagocytosis of hematopoietic cells in bone marrow, liver, or lymph nodes. HLH can occur during the course of systemic lupus erythematosus (SLE), but can also be a presenting manifestation. Because development of pancytopenia occurs in less than 10 percent of SLE cases, investigation for HLH is necessary when otherwise unexplained pancytopenia persists despite adequate treatment. We experienced three cases of secondary HLH associated with SLE. Among the three patients, two patients devel-oped HLH during the clinical course of SLE. The other patient who presented with pancytopenia was first diagnosed with HLH, and later with SLE. In her case, HLH turned out to be a presenting manifestation of SLE. We report on three successfully treated cases, and discuss the prevalence, characteristics, treatments, and prognosis of secondary HLH associated with SLE. (J Rheum Dis 2015;22:180-185)

Keywords: Hemophagocytic lymphohistiocytosis, Systemic lupus erythematosus, Pancytopenia