Thrombotic Microangiopathy Associated with Macrophage Activation Syndrome: A Multinational Study of 23 Patients.

Objective: To describe the clinical characteristics, treatment, and outcomes of a multinational cohort of patients with macrophage activation syndrome (MAS) and thrombotic microangiopathy (TMA).

Study Design: International pediatric rheumatologists were asked to collect retrospectively the data of patients with the co-occurrence of MAS and TMA. Clinical and laboratory features of patients with systemic juvenile idiopathic arthritis (sJIA)-associated MAS and TMA were compared with those of an historical cohort of patients with sJIA and MAS.

Monocytes From Patients With Macrophage Activation Syndrome and Secondary Hemophagocytic Lymphohistiocytosis Are Hyperresponsive to Interferon Gamma.

Objective: To investigate the activation of the IFNγ signaling pathway in monocytes of patients with secondary hemophagocytic lymphohistiocytosis (sHLH)/macrophage activation syndrome (MAS) and to evaluate whether levels of phosphorylated STAT1 represent a biomarker for the identification of patients at early stages of the disease.

Methods: Fresh whole blood samples from pediatric patients with active sHLH/MAS, not receiving (n=10) and receiving glucocorticoids (n=14) at time of sampling, were prospectively collected. As disease control groups, patients with active systemic juvenile idiopathic arthritis (sJIA) without MAS, patients with sHLH/MAS in remission and patients with other rheumatic diseases were also sampled.

An unusual presentation of purine nucleoside phosphorylase deficiency mimicking systemic juvenile idiopathic arthritis complicated by macrophage activation syndrome.

Background: Systemic juvenile idiopathic arthritis (sJIA) is an inflammatory condition that presents with fever, rash and arthritis. At onset systemic features are predominant and the diagnosis may be a challenge. Secondary hemophagocytic lymphohistiocytosis (sHLH) forms may be associated with different disorders, including rheumatic diseases, and this form is called macrophage activation syndrome (MAS).