Comparison of baseline laboratory findings of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis and multisystem inflammatory syndrome in children

Abstract

Aims Recently, multisystem inflammatory syndrome in children (MIS‐C) has been recognized in association with coronavirus disease 2019 as a cytokine storm syndrome. MIS‐C presents with symptoms similar to Kawasaki disease and macrophage activation syndrome (MAS). We aimed to better understand this cytokine storm syndrome by comparing the initial laboratory findings of MIS‐C and MAS. Methods Patients who were diagnosed with MAS due to systemic juvenile idiopathic arthritis in our clinic between March 2002 and November 2020 and with MIS‐C between 20 September and 20 October 2020 were enrolled into the study. The medical files of all patients were reviewed retrospectively. Results A total of 13 MAS (9 boys, 4 girls) and 26 MIS‐C (16 boys,10 girls) patients were included in the study. Hemoglobin, absolute neutrophil and lymphocyte counts, C‐reactive protein (CRP), ferritin, fibrinogen and lactate dehydrogenase (LDH) levels showed significant differences between the two groups (P < 0.05). Patients with MAS had lower hemoglobin (10.10 g/dL) and fibrinogen (2.72 g/dL), but higher ferritin (17 863 mg/dL) and LDH (890.61 U/L) at the time of diagnosis. Patients with MIS‐C had higher absolute neutrophil count (12 180/mm3) and CRP (194.23 mg/dL) values, but lower absolute lymphocyte count (1140/mm3) at the time of diagnosis. Left ventricle ejection fraction was significantly lower in the MIS‐C group in echocardiographic evaluation (P < 0.001). Conclusion Ferritin, hemoglobin, LDH, and fibrinogen levels were significantly changed in MAS compared with MIS‐C. However, patients with MIS‐C have more severe signs than MAS, such as cardiac involvement.

Differences and similarities of multisystem inflammatory syndrome in children, Kawasaki disease and macrophage activating syndrome due to systemic juvenile idiopathic arthritis: a comparative study

“…It is characterized by unremitting fever, hepatosplenomegaly, hyperferritinemia, pancytopenia, hepatic dysfunction, coagulopathy, and encephalopathy [ 34 ]. Even though most of the laboratory findings in MIS-C suggest a MAS-like cytokine storm, ferritin levels are higher and fibrinogen levels are lower in patients with MAS [ 20 , 21 ]. During the diagnosis of sJIA, presence of higher levels of ferritin and lower levels of fibrinogen were regarded as early warning signs of an impending MAS [ 35 ].…”

“…Therefore, displaying the major clinical and laboratory differences of MIS-C is critical for making a proper differential diagnosis. The studies comparing MIS-C with classical KD [ 5 , 6 , 16 – 20 ] or MAS [ 20 , 21 ] are restricted with small sample sizes.…”

Algorithm for the diagnosis and management of the multisystem inflammatory syndrome in children associated with COVID‐19

“…The patients with MIS‐C had higher absolute neutrophil counts and C‐reactive protein (CRP) values but lower absolute lymphocyte counts at the time of diagnosis. Left ventricle ejection fraction (LVEF) was significantly lower in the patients with MIS‐C 10 …”

A Novel and Severe Clinical Picture Related to COVID-19: Multi-Inflammatory Syndrome in Children

“…A male dominance among the patients was shown in several studies. [10][11][12] A systematic review evaluating 917 MIS-C patients showed that the median age of the patients was 9.3 years, and 56.8% of the cases were males. 13 Similarly, male/female ratio was 1.37:1, and the median age was 7.5 years in another systematic review including 992 MIS-C patients.…”