Multisystem inflammatory syndrome in children: clinical presentation, management, and short- and long-term outcomes.

OBJECTIVE: In this study, it was aimed to evaluate the demographic, clinical and laboratory characteristics of MIS-C patients in our hospital, to share our treatment approach, and to assess the outcomes of short- and long-term follow-up. METHODS: MIS-C patients who were admitted and treated in our hospital between July 2020 and July 2021 were evaluated. Demographic, clinical, laboratory, and follow-up data were collected from patient records retrospectively. RESULTS: A total of 123 patients with MIS-C (median age, 9.6 years) were included the study. Nineteen (15.4%) were mild, 56 (45.6%) were moderate, and 48 (39%) were severe MIS-C. High CRP, ferritin, pro-BNP, troponin, IL-6, and D-dimer values were found in proportion to the severity of the disease (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.005, p < 0.001), respectively. Two (1.6%) patients died. The mean follow-up period was 7.8 months. Valve failure, left ventricular dysfunction/hypertrophy, coronary involvement, and pericardial effusion were the most common cardiac pathologies in the short- and long-term follow-up of the patients. In the long-term follow-up, the most common reasons for admission to the hospital were recurrent abdominal pain (14.2%), cardiac findings (14.2%), pulmonary symptoms (8%), fever (7.1%), neuropsychiatric findings (6.2%) and hypertension (3.5%). Neuropsychiatric abnormalities were observed significantly more common in severe MIS-C patients at follow-up (p = 0.016). In the follow-up, 6.2% of the patients required recurrent hospitalization. CONCLUSION: MIS-C is a serious and life-threatening disease, according to short-term outcomes. In addition to the cardiac findings of patients with MIS-C, long-term outcomes such as neuropsychiatric findings, persistent gastrointestinal symptoms, fever and pulmonary symptoms should be monitored. Key Points • In MIS-C patients, attention should be paid not only to cardiac findings, but also to symptoms related to other systems. • Patients should be followed up in terms of neuropsychiatric findings, persistent gastrointestinal symptoms, fever and pulmonary symptoms that may occur during follow-up.

Delta neutrophil index and C-reactive protein: a potential diagnostic marker of multisystem inflammatory syndrome in children (MIS-C) with COVID-19.

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening hyperinflammation syndrome emerging after COVID-19. The serum delta neutrophil index (DNI) reflects the fraction of circulating immature granulocytes and is evaluated in infection and inflammation. The aim of this study is to evaluate the usefulness of DNI as a diagnostic marker in patients with MIS-C and to assess its role in determining the severity of MIS-C. This retrospective, observational study included 83 patients with MIS-C and 113 patients with COVID-19, and 102 healthy controls. C-reactive protein (CRP), the absolute neutrophil count (ANC), absolute lymphocyte count (ALC), DNI, and the platelet count were recorded. The DNI levels were 4.60 ± 5.70% in the MIS C group, 0.30 ± 0.99% in the COVID group, and 0.20 ± 0.56% in the control group (p < 0.001). According to the severity of MIS-C, the DNI level was found to be 1.22% in mild MIS-C, 4.3% in moderate MIS-C, and 5.7% in severe MIS-C. There was a statistically significant correlation between DNI levels and the severity of MIS-C. The cutoff value of DNI for predicting MIS-C was 0.45%. In the analysis of the diagnostic performance of DNI compared with CRP, ANC, ALC and platelet counts, sensitivity, specificity, positive predictive value, and negative predictive value were found to be 79.5%, 97.1%, 95.7%, and 85.3%, respectively.Conclusions: The delta neutrophil index was identified as a diagnostic marker for MIS-C such as ANC, ALC, platelet count, and CRP. DNI levels in hemogram analysis may guide clinicians in determining the diagnosis and severity of MIS-C. What is Known: • Although CRP, sedimentation, ALC, ANC, platelet count, sodium, and albumin are used as first step tests, there is no specific laboratory marker used in the diagnosis of MIS C. • The serum delta neutrophil index (DNI) reflects the fraction of circulating immature granulocytes and is elevated in infection and inflammation. What is New: • DNI is a promising and easily accessible marker that can be used with other markers in the diagnosis and determines the severity of MIS C. • DNI is an easily accessible, inexpensive, and dynamic marker and its levels in simple hemogram analysis will guide pediatricians in determining the diagnosis and severity in MIS C.

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

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.