Macrophage Activation Syndrome Flashcards
MAS is caused by excessive activation & expansion of what cells
Macrophages and T cells (predominantly CD8+)
Pathognomonic feature of MAS
Pathological hemophagocytosis
T/F Pathological hemophagocytosis is sensitive for overall diagnosis of MAS
F
T/F Pathological hemophagocytosis is specific for MAS
F
Rheumatic disease where MAS is seen most commonly
sJIA
Other common rheumatic diseases associated with MAS other than sJIA
SLE and KD
T/F MAS occurring at initial presentation of a rheumatic disease is not uncommon
T
MC trigger of MAS in patients with rheumatic disease
Viral illnesses, particularly EBV and other members of the herpes family
Drugs most commonly implicated as triggers for MAS in patients with rheumatic disease
Gold, MTX, sulfasalazine
Cells with deficient function in MAS
NK cell
Cytotoxic T cell
Cytokines implicated in MAS pathophysiology
IFN-γ and IL-18
Cytokine implicated in MAS which is a well-known macrophage activator
IFN-γ
Anti-IFN-γ monoclonal antibody approved in the US (2018) for treatment of pediatric HLH
Emapalumab
T/F MAS is often associated with a flare of underlying sJIA rather than infection
T
IL-18 is known for its ability to
Amplify lymphocyte production of IFN-γ
Patients with sJIA and high levels of this cytokine more often have systemic manifestations rather than arthritis, and are also more likely to develop MAS
IL-18
There is high expression of this scavenger receptor in hemophagocytic macrophages in MAS
CD163
Receptor expressed by hemophagocytic macrophages in MAS whose best known function is related to its ability to bind hemoglobin-haptoglobin complexes and initiate pathways important for adaptation to oxidative stress induced by free heme and iron
CD163
Receptor expressed by hemophagocytic macrophages in MAS associated with hyperferritinemia
CD163
Decrease in this cell count is usually an early finding in MAS
Platelet
T/F Cytopenias in MAS is due to decreased production
F, increased destruction peripherally
T/F Liver involvement is not common in MAS
F, common
T/F Significant hepatomegaly is frequently present in MAS
T
