Related Experiment Video
Updated: Aug 27, 2025
Whole-cell MALDI-TOF Mass Spectrometry is an Accurate and Rapid Method to Analyze Different Modes of Macrophage Activation
Published on: December 26, 2013
Clinical characteristics of children with MIS-C fulfilling classification criteria for macrophage activation syndrome
Piotr Buda1, Ewa Strauss2, Danuta Januszkiewicz-Lewandowska3
1Department of Pediatrics, Nutrition and Metabolic Diseases, Children's Memorial Health Institute, Warsaw, Poland.
Background:
Macrophage activation syndrome (MAS) is a potentially life-threatening complication of various inflammatory disorders, including multisystem inflammatory syndrome in children (MIS-C). MIS-C refractory to treatment should raise suspicion of MAS, which can be fatal if a definitive diagnosis is delayed. Unfortunately, there is a lack of data on MAS in children with MIS-C.
Objective:
Our study aims to analyze the risk factors for the development of MAS in MIS-C, its clinical course and response to treatment, and identify predictive factors for pediatric intensive care.
Material And Methods:
We analyzed data from the Polish MIS-C registry of the MultiOrgan Inflammatory Syndromes COVID-19 Related Study. Patients were diagnosed according to the WHO MIS-C definition and treated according to national guidelines (Polish Pediatric Society) based on international consensus. MAS definition was based on 2016 Classification Criteria for Macrophage Activation Syndrome Complicating Systemic Juvenile Idiopathic Arthritis.
Results:
Two-hundred and seventy four children met the study inclusion criteria. Fifty-nine patients fulfilled MAS classification criteria, nine of which required admission to the pediatric intensive care unit (PICU). MIS-C patients with MAS were significantly older than patients without MAS (median 11.2 vs. 8.1 years). Multivariable analysis showed that age, symptoms characteristic of atypical Kawasaki disease, and skin erosions were significant factors associated with MAS in MIS-C patients. Analysis of laboratory parameters showed that on admission, MIS-C patients with MAS had significantly lower median lymphocyte and platelet counts, albumin and sodium levels, and higher median levels of C-reactive protein, procalcitonin, ferritin, D-dimers, triglycerides, serum creatinine, urea, and γ-glutamyl transpeptidase, and neutrophil count. Multivariate analysis showed that higher procalcitonin, ferritin, and fibrinogen levels at admission were predictive of MAS. Only elevated troponin level was a factor indicating a requirement of PICU hospitalization for children with MAS. MIS-C patients fulfilling MAS criteria were treated more often with intravenous immunoglobulins and steroids than children without MAS. Children with MAS more often required mechanical ventilation. None of the patients required biological agents.
Conclusions:
The clinical course of MAS in MIS-C seems milder, treatment less aggressive, and the prognosis better than expected based on the current knowledge on MAS complicating other rheumatological diseases.
Insights
Macrophage activation syndrome (MAS) in children with multisystem inflammatory syndrome (MIS-C) is associated with older age and specific symptoms. Early identification of MAS in MIS-C patients may improve outcomes.
Area of Science:
- Pediatric rheumatology
- Infectious diseases
- Critical care medicine
Background:
- Macrophage activation syndrome (MAS) is a severe complication of inflammatory disorders like multisystem inflammatory syndrome in children (MIS-C).
- Delayed diagnosis of MAS in MIS-C can be fatal, yet data on this specific patient group is limited.
- This study addresses the lack of information regarding MAS in pediatric MIS-C cases.
Purpose of the Study:
- To investigate risk factors for MAS development in MIS-C patients.
- To analyze the clinical course, treatment response, and outcomes of MAS in MIS-C.
- To identify predictors for pediatric intensive care unit (PICU) admission in MIS-C patients with MAS.
Main Methods:
- Analysis of data from the Polish MIS-C registry (MultiOrgan Inflammatory Syndromes COVID-19 Related Study).
- Patients diagnosed per WHO MIS-C criteria; MAS diagnosed using 2016 Classification Criteria.
- Retrospective analysis of 274 MIS-C patients, with 59 meeting MAS criteria.
Main Results:
- MAS was diagnosed in 59 of 274 MIS-C patients; 9 required PICU admission.
- Older age, atypical Kawasaki disease symptoms, and skin erosions were associated with MAS.
- Elevated procalcitonin, ferritin, and fibrinogen predicted MAS; elevated troponin predicted PICU need.
- MAS patients had distinct laboratory profiles, including lower lymphocytes/platelets and higher inflammatory markers.
Conclusions:
- MAS in MIS-C appears to have a milder clinical course and better prognosis than in other rheumatological conditions.
- Treatment for MAS in MIS-C was less aggressive, often involving IVIG and steroids, with no need for biological agents.
- Children with MAS more frequently required mechanical ventilation, but overall outcomes were better than anticipated.
