Hemophagocytic Lymphohistiocytosis in Early Infancy- Pitfall of Differentiation between Hereditary and Infectious Reasons

Hemophagocytic Lymphohistiocytosis (HLH) is characterized by pathologic immune activation which occurs either as a familial disorder or as an acquired condition. The diagnosis of HLH requires the presence of five out of nine criteria: fever, splenomegaly, pancytopenia, hypertriglyceridemia, hypofibrinogenemia, hemophagocytosis in bone marrow, hyperferritinemia, low or absent natural killer cell activity and high level of soluble interleukin-2 receptor.Here we present a 6-month-old girl with parents from Southern Italy. She suffered from hepatosplenomegaly and a recurrent high fever for 3 months' duration. On admission, she showed neurological symptoms including irritability and neck stiffness. Blood analysis revealed bicytopenia, namely anemia and thrombocytopenia. The first bone marrow aspirate was indicative for neither malignancies nor HLH. At this time, additional investigations indicated macrophage activation syndrome with elevated ferritin value (11.741ng/ml), soluble interleukin-2 receptor (CD25) levels (16.018U/ml), hypertriglyceridemia (582mg/dl) supportive of the diagnosis of HLH. Because of the worsening of her clinical condition, a second bone marrow aspirate and biopsy was performed 5 days later when the child became pancytopenic. The second bone marrow aspirate still did not show morphological signs of HLH, but microorganisms were detected in at least one macrophage, which were consecutively diagnosed as Leishmania amastigotes within macrophages by positive Leis...
Source: Blood - Category: Hematology Authors: Tags: 203. Lymphocytes, Lymphocyte Activation, and Immunodeficiency, including HIV and Other Infections Source Type: research