This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal  disorders, Subject name: Pediatrics
Macrophage activation syndrome is characterized by all except __________ 
Select and explain. 
A. Hemophagocytosis, B. Hypofibrinogenemia, C. Hyperiglycidemia, D. Hypoferritenemia
D: Hypoferritenemia
Answer: D: Hypoferritenemia 
Explanation: Macrophage activation syndrome is characterised by all if the listed feature except Hypoferritenemia . Macrophage activation syndrome(MAS) is rare but potentially fatal complication of systemic JIA. It is characterized by the following: Macrophage hemophagocytosis in the bone marrow Hypofibrinogenemia (paradoxical fall in erythrocyte sedimentation rate ) (ESR) Hyperiglyceridemia Extreme hyperferritinemia Fever > 38.5oC Splenomegaly Cytopenia affecting atleast two or three cell lineages. Reference : nelson textbook of pediatrics 21st edition Pgno: 1262