Diagnosing MAS and biomarkers
For patients with macrophage activation syndrome, prompt diagnosis is crucial
Currently, there is no single set of criteria that has been validated for diagnosing macrophage activation syndrome (MAS) across all patient populations. However, if you suspect MAS in your patients with underlying rheumatic disease, there are a range of laboratory assessments and inflammatory biomarkers that may help you narrow down a diagnosis.
What to consider in the MAS diagnostic workup
For patients with suspected MAS, it is critical to recognize the hyperinflammatory state as quickly as possible. MAS often presents with features that overlap with rheumatic disease flares and infection, but a change from the patient’s expected disease pattern should raise suspicion.1
Clinical trajectory matters
Disease progression and trends in laboratory and clinical findings are often more informative than isolated values.1
Evaluation and management occur simultaneously
Because MAS can progress rapidly, management decisions often begin while the diagnostic evaluation is still underway.2
Early expert consultation is helpful
Specialist input can help guide early evaluation and management in complex cases when the clinical picture is unclear.2
See below for more information about classification criteria and biomarker testing that may be helpful for identifying MAS.
MAS in patients with undiagnosed rheumatic disease
Patients may present with MAS before receiving a rheumatic disease diagnosis.3
It’s important to remain aware of the hallmark features of hyperinflammation and cytokine storm syndromes such as persistent fever, hyperferritinemia, and cytopenia in patients who may have an undiagnosed rheumatic disease.4,5
Diagnostic delays can prove fatal for patients in these instances.1
References: 1. Lerkvaleekul B, Vilaiyuk S. Macrophage activation syndrome: early diagnosis is key. Open Access Rheumatol. 2018;10:117-128. doi:10.2147/OARRR.S151013 2. Shakoory B, Geerlinks A, Wilejto M, et al. The 2022 EULAR/ACR points to consider at the early stages of diagnosis and management of suspected haemophagocytic lymphohistiocytosis/macrophage activation syndrome (HLH/MAS). Arthritis Rheumatol. 2023;75(10):1714-1732. doi:10.1002/art.42636 3. He L, Yao S, Zhang R, et al. Macrophage activation syndrome in adults: characteristics, outcomes, and therapeutic effectiveness of etoposide-based regimen. Front Immunol. 2022;13:955523. doi:10.3389/fimmu.2022.955523 4. Carter SJ, Tattersall RS, Ramanan AV. Macrophage activation syndrome in adults: recent advances in pathophysiology, diagnosis and treatment. Rheumatology (Oxford). 2019;58(1):5-17. doi:10.1093/rheumatology/key006 5. Cron RQ, Goyal G, Chatham WW. Cytokine Storm Syndrome. Annu Rev Med. 2023;74:321-337. doi:10.1146/annurev-med-042921-112837
