Diagnosing MAS and biomarkers

For patients with MAS, prompt diagnosis is crucial

Currently, there is no single set of criteria that has been validated for diagnosing MAS across all patient populations. However, if you suspect MAS in your patients, there are a range of laboratory assessments and inflammatory biomarkers that may help you narrow down a diagnosis.

Things to consider when seeking a diagnosis

ACR/EULAR classification criteria and the MS score

Explore the American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR) classification criteria for identifying patients with MAS/sJIA and the MS score for evaluating the probability of MAS in a patient.¹

See the classification criteria

The HScore

Learn more about the HScore, a diagnostic tool for identifying hemophagocytic syndromes in patients.

Learn how to calculate the HScore

Inflammatory biomarkers in MAS

Find information about a variety of inflammatory biomarkers to consider in patients with suspected MAS.

Explore inflammatory biomarkers

Patients with undiagnosed rheumatic disease

Patients may present with MAS before receiving a rheumatic disease diagnosis.²

It’s important to remain aware of the hallmark features of hyperinflammation such as persistent fever, hyperferritinemia, and cytopenia in patients who may have an undiagnosed rheumatic disease.³

Diagnostic delays can prove fatal for patients in these instances.⁴

Signs and symptoms

See how MAS can manifest in patients.

Learn the signs

Managing MAS

Learn about the management strategies for MAS.

Explore management

References: 1. 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 2. 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 3. 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 4. Lerkvaleekul B, Vilaiyuk S. Macrophage activation syndrome: early diagnosis is key. Open Access Rheumatol. 2018;10:117-128. doi:10.2147/OARRR.S151013