From the Guidelines
Macrophage Activation Syndrome (MAS) is characterized by symptoms such as fever, multiorgan dysfunction, and CNS issues, including headaches, vision disturbances, and issues related to walking, as well as laboratory abnormalities like elevated CRP, hyperferritinemia, cytopenias, hypofibrinogenemia, and coagulopathy 1. The clinical features of MAS can have substantial overlap with Cytokine Release Syndrome (CRS), making a clear diagnosis challenging. However, patients with MAS may not exhibit hepatosplenomegaly or evidence of hemophagocytosis, which can help differentiate it from other conditions. Some key symptoms and laboratory findings associated with MAS include:
- Fever
- Multiorgan dysfunction
- CNS issues (eg, headaches, vision disturbances, and issues related to walking)
- Elevated CRP
- Hyperferritinemia
- Cytopenias
- Hypofibrinogenemia
- Coagulopathy
- Elevated levels of several serum cytokines, including IL-6, INFg, sIL-2Ra, and granulocyte macrophage colony-stimulating factor. It is essential to recognize MAS promptly, as it can rapidly progress to multi-organ failure and death if not treated promptly with immunosuppressive therapy, typically including anti-IL-6 therapy and aggressive use of corticosteroids 1.
From the Research
Symptoms of Macrophage Activation Syndrome (MAS)
The symptoms of Macrophage Activation Syndrome (MAS) include:
- Persistent high-grade fever 2, 3
- Hepatosplenomegaly (enlargement of the liver and spleen) 2, 3, 4
- Lymphadenopathy (enlargement of the lymph nodes) 2, 3, 4
- Hemorrhagic manifestations (bleeding) 2
- Sepsis-like condition 2
- Skin rash 3, 4
- Neurological involvement 3
- Swelling of the feet and ankle joints 5
- Petechiae (small spots on the skin due to bleeding) 5
Laboratory Features
Laboratory features of MAS include:
- Leukopenia (low white blood cell count) 3
- Anemia (low red blood cell count) 3
- Thrombocytopenia (low platelet count) 3
- Jaundice (yellowing of the skin and eyes) 3
- Hypofibrinogenemia (low fibrinogen level) 3
- Elevated liver enzymes 3
- Elevated lactate dehydrogenase (LDH) 3
- Elevated ferritin 3, 6
- Elevated triglycerides 3
- Elevated C-reactive protein (CRP) 3
- Elevated plasma D-dimer 3
- Hemophagocytosis in bone marrow (destruction of blood cells in the bone marrow) 3
Other Features
Other features of MAS include: