Browsing by Author "Vukomanovic, Vladislav (55881072000)"

[No abstract available]

Background: Angiotensin-converting enzyme inhibitors, such as enalapril, are foundational in treating pediatric heart failure. However, they are often administered off-label to young children using extemporaneous formulations. This study, conducted as part of the EU-funded Labeling of Enalapril from Neonates up to Adolescents (LENA) project, aimed to evaluate the acceptability and palatability of an age-appropriate enalapril orodispersible minitablet (ODMT). These factors are critical for ensuring adherence, efficacy, and safety in pediatric patients. Methods: An 8-week trial was conducted in children with heart failure caused by dilated cardiomyopathy or congenital heart disease. Enalapril ODMTs (0.25 mg or 1.0 mg) were dose-titrated and administered to 38 children aged 0–6 months and 22 children aged 6 months to 6 years. This study aimed to assess its acceptability and palatability, key factors contributing to adherence, and therefore, efficacy and safety. Results: Across all 169 assessments in 38 children aged 0–6 months and 22 aged 6 months to 6 years, complete or partial swallowability was observed, and the acceptability rate was 100%. There were no cases of choking, inhalation/coughing, or spitting out. A favorable or neutral rating was observed in 96% of palatability assessments based on observations of facial expressions. Acceptability and palatability were higher in subjects aged 6 months–6 years than 0–6 months, with no significant influence from repeated administration. Conclusions: Enalapril ODMTs are widely accepted and well-tolerated among young children, including neonates, with heart failure. These findings suggest that ODMTs are a suitable and effective method for administering pediatric medicinal products. © 2025 by the authors.

Cardiovascular (CV) manifestations are common (35%–100%) in the multisystem inflammatory syndrome in children. Our study aimed to analyze treatment impact and CV involvement in patients with multisystem inflammatory syndrome in children. The retrospective cohort included 81 patients treated between April 2020 and December 2021 (9.3 ± 4.6 years). Elevated cardiac troponin I and pro-B-type natriuretic peptide were observed in 34.2% and 88.5% of patients, respectively. Myocardial dysfunction was observed in 50.6%. Children older than 10 years had a 4-fold increased risk of myocardial dysfunction (odds ratio [OR] 3.6, 95% confidence interval [CI] 1.4–8.9; p = 0.006). A moderate negative correlation was proved between left ventricular ejection fraction and C-reactive protein (rr = −0.48; p < 0.001). More than one-fifth of the patients presented with shock. Coronary artery dilatation was observed in 6.2% of patients. Mild pericardial effusion was detected in 27.1% of children. On standard electrocardiogram, 52.6% of children had negative T waves in the inferior and/or precordial leads; transient QTc prolongation was registered in 43% of patients. Treatment failure was observed in 19 patients. Patients initially treated with intravenous immunoglobulins had 10-fold higher chances for treatment failure than patients treated with corticosteroids (OR 10.6, 95% CI 3.18–35.35; p < 0.001). CV manifestations were observed in more than half of the patients, with acute myocardial dysfunction being the most common, especially in children older than 10 years. We established a negative association between the degree of elevation of inflammatory markers and left ventricular ejection fraction. Patients treated with intravenous immunoglobulins who had CV manifestations had treatment failures more frequently than patients treated with corticosteroids. © 2022 Krasic et al.

Cardiovascular (CV) manifestations are common (35%–100%) in the multisystem inflammatory syndrome in children. Our study aimed to analyze treatment impact and CV involvement in patients with multisystem inflammatory syndrome in children. The retrospective cohort included 81 patients treated between April 2020 and December 2021 (9.3 ± 4.6 years). Elevated cardiac troponin I and pro-B-type natriuretic peptide were observed in 34.2% and 88.5% of patients, respectively. Myocardial dysfunction was observed in 50.6%. Children older than 10 years had a 4-fold increased risk of myocardial dysfunction (odds ratio [OR] 3.6, 95% confidence interval [CI] 1.4–8.9; p = 0.006). A moderate negative correlation was proved between left ventricular ejection fraction and C-reactive protein (rr = −0.48; p < 0.001). More than one-fifth of the patients presented with shock. Coronary artery dilatation was observed in 6.2% of patients. Mild pericardial effusion was detected in 27.1% of children. On standard electrocardiogram, 52.6% of children had negative T waves in the inferior and/or precordial leads; transient QTc prolongation was registered in 43% of patients. Treatment failure was observed in 19 patients. Patients initially treated with intravenous immunoglobulins had 10-fold higher chances for treatment failure than patients treated with corticosteroids (OR 10.6, 95% CI 3.18–35.35; p < 0.001). CV manifestations were observed in more than half of the patients, with acute myocardial dysfunction being the most common, especially in children older than 10 years. We established a negative association between the degree of elevation of inflammatory markers and left ventricular ejection fraction. Patients treated with intravenous immunoglobulins who had CV manifestations had treatment failures more frequently than patients treated with corticosteroids. © 2022 Krasic et al.

[No abstract available]

Clinical implications of blood pressure variability (BPV) on subclinical organ damage in children are unknown. The authors sought to explore the potential utility of two newly derived BPV indices: weighted standard deviation (wBPSD) and real average variability (ARV), as well as two standard ambulatory blood pressure indices: average 24-hour systolic blood pressure (SBP) and 24-hour SBP load, to identify children at high risk for left ventricular (LV) hypertrophy (LVH). The study group consisted of 67 consecutive children who were referred to our institution for evaluation of suspected hypertension. LV mass was estimated by M-mode echocardiography using Devereux's formula according to the Penn convention and indexed for height2.7. We found a statistically significant, positive correlation between 24-hour wBPSD and LV mass index (LVMI) (ρ=0.389; P=.002) and no correlation between 24-hour ARV and LVMI (P>.05). However, partial correlation analysis of 24-hour wBPSD adjusted for body mass index (BMI) and LVMI showed only a weak correlation (ρ=0.3; P=.022). By using multiple linear regression analysis in a model with LVMI as a dependent variable and 24-hour wBPSD, 24-hour ARV, and BMI as independent variables, only BMI showed statistically significant independent positive associations with LVMI (P=.028). Results of our study showed that currently used BPV indices (24-hour wBPSD and 24-hour ARV) are not clinically reliable parameters to identify children at risk for LVH. Apparent contribution of the 24-hour wBPSD parameter to LVMI is negligible and is secondary to its close correlation with BMI (ρ=0.335 P=.009). © 2013 Wiley Periodicals, Inc.

Background: The angiotensin-converting enzyme inhibitor (ACEI) enalapril is often administered to infants and young children with heart failure (HF) in various dosing regimens and formulations not adapted for their age. Methods: This prospective, two-center, open-label 8-week study evaluated an age-appropriate formulation of orodispersible minitablets (ODMTs) of enalapril (0.25 mg and 1 mg) in children aged 0 to 6 years with HF due to congenital heart disease. An age/weight-based dosing schedule was followed. Measures of echocardiographic parameters, blood pressure, heart rate, modified Ross score, and biochemistry were obtained over the 8-week period. The following two groups were assessed: ACEI-naïve and ACEI-pretreated patients. Results: In total, 53 children (age range of 0.05 to 4.8 years) were enrolled and 29 were ACEI-naïve. The average enalapril dose was 0.098 mg/kg (0.06–0.17 mg/kg) in the naïve group and 0.15 mg/kg (0.07–0.3 mg/kg) in pretreated patients. After 8 weeks, the modified Ross score and left ventricular diastolic dimension (LVD) z-score showed a significant decrease in both groups (p < 0.005). During 8 weeks follow-up, there were no difference in the z-scores for the systolic blood pressure (p = 0.071) or heart rate (p = 0.146). Conclusions: Pediatric patients treated with ODMTs of enalapril for 8 weeks had favorable improvements in LVD and HF symptoms. © 2024 by the authors.

Objective: Myocarditis has spontaneous resolution in 50% of patients. Our study aimed to define risk factors for developing dilated cardiomyopathy (DCM) and death in pediatric patients with acute myocarditis (AM). Methods: The retrospective cohort study included all patients with treated AM. The Mother and Child Health Institute from January 2011 to March 2019. Results: In the study, 62 patients were included, 40 boys and 22 girls (11.15±5.86 years) with AM. Twelve out of sixty-two children had acute fulminant myocarditis. Four patients died in the acute phase of AM, and 11 developed DCM. Follow up was 27.14±36.52 months. Patients with poor outcome (DCM development) were under the age of seven (odds ratio [OR] 10.1; p=0.003), more likely to be girls (OR 4.6; p=0.03), and had fulminant myocarditis (OR 27.0; <0.001). An ejection fraction (EF) <55% and fractional shortening (FS) <30% increased risk of DCM 13- and 5-fold, respectively, but patients with EF between 40 and 55% remain at highest risk of developing DCM. There was a 12-fold increased risk for DCM in patients with left ventricular end-diastolic diameter Z score >2+. The receiver operator curve showed that the lactate dehydrogenase (LDH) cut-off value for developing DCM was 1780 mmol/l (sensitivity 80%, specificity 100%). Conclusion: Acute fulminant myocarditis was an independent risk factor for DCM. Children with EF between 40 and 50% at admission were at highest risk of developing DCM. Lactate dehydrogenase value could be a significant prognostic value for the outcome of pediatric myocarditis. © 2021 Sociedade Portuguesa de Cardiologia

A National Immunization Technical Advisory Group (NITAG) is a multi-disciplinary body of national experts that provide evidence-based recommendations to policy-makers to assist them in making informed immunization policy and programme decisions. During the COVID-19 pandemic, NITAGs faced many challenges in making evidence-based recommendations for COVID-19 vaccines due to the rapidly evolving situation with new vaccine products available in a short time period and limited data on vaccine effectiveness. The authors reviewed the process used by Serbia's NITAG, which is called the Serbian Expert Committee on Immunization, to develop COVID-19 vaccine recommendations during the pandemic. The article examines the challenges and successes faced by the committee. Serbia's expert committee used the best available evidence to develop over forty recommendations on all aspects of COVID-19 vaccination. These expert committee recommendations facilitated the early procurement and successful roll-out of COVID-19 vaccines, guidance for vaccination of individuals at the highest risk, and high COVID-19 vaccination coverage in the country. The availability of five COVID-19 vaccines in Serbia was an advantage for the successful roll-out but posed challenges for the expert committee. Serbia's expert committee plans to use the experience and best practices developed during the pandemic to improve and expand its work moving forward. Copyright © 2022 Markovic-Denic, Popadic, Jovanovic, Bonaci-Nikolic, Samardzic, Tomic Spiric, Rancic, Sankar Datta, Mosina, Jancic, Vukomanovic, Jovanovic, Vukomanovic, Antic, Veljkovic, Saponjic and Jacques-Carroll.

Objectives: The bicuspid aortic valve (BAV) is the most common congenital heart defect. Patients with BAV frequently develop aortopathy, which depends on the dysfunction and morphotype of the BAV. Aim: The aim of our study was to compare the echocardiography and cardiac magnetic resonance (CMR) findings in BAV patients, and to define the risks of BAV dysfunction and aortopathy. Methods: The retrospective study included 50 patients (68% male) with BAV, with an average age of 13.6 ± 3.9 years, who underwent a transthoracic echocardiographic examination and CMR at our institute from 2012 to 2020. Results: The BAV types were evaluated significantly differently by echocardiography and CMR (p = 0.013). 54% of patients had BAV insufficiency on echo and 70% on echo CMR. It was more prevalent in males, older patients, and patients with a higher body surface area. By comparing the degree of insufficiency measured by echo (1+, IQR 0–1), and CMR (0, IQR 0–1), a significant difference was observed (p = 0.04), while a moderate positive correlation was proved (rr = 0.4; p = 0.004). Stenosis was registered in 44% of patients by echo, while 58% had stenosis on CMR. The peak pressure gradient measured by echo was significantly higher than the velocity on CMR (41, IQR 22.7–52.5 mmHg vs. 23, IQR 15.5–35.0 mmHg; p = 0.002). Aortopathy was registered in 76% of patients on echo and 78% on CMR; 38% of patients had severe aortic dilatation on echo and 54% on CMR (p = 0.003). Patients with BAV stenosis on echo had more frequent dilatation of the tubular ascending aorta (15/24 pts; p = 0.02). All patients with BAV insufficiency on CMR had aortopathy (p = 0.04) and had enlargement of the sinus of Valsalva and sinotubular junction. In patients with associated coarctation, the development of aortopathy occurred less frequently than those without coarctation (7/39 vs. 32/39; p = 0.003). The Bland-Altman method, a specific type of scatterplot that is used to visualize the results of comparing two measures, demonstrated the existence of agreement between the two methods, and a level of agreement between the methods of 95% was demonstrated. Conclusion: Our study indicated significant differences in the measured BAV morphotype and dysfunction when comparing the two diagnostic methods. On the other hand, moderate to strong correlations were found in the evaluated parameters, which indicates the importance of performing noninvasive diagnostic procedures in the follow-up of these patients. 2024 Krasic, Zec, Topic, Popovic, Nesic, Zdravkovic and Vukomanovic.

Background and Objectives: Recurrence of pericarditis (ROP) is an important complication of the acute pericarditis. The aim of this study was to analyse the influence of aetiology, clinical findings and treatment on the outcome of acute pericarditis. Methods: Data were retrospectively collected from medical records of patients treated from 2011 to 2019 at a tertiary referent heart paediatric center. Results: Our investigation included 56 children with idiopathic and viral pericarditis. Relapse was registered in 8/56 patients, 2/29 (7.41%) treated with nonsteroidal anti-inflammatory drugs (NSAID) and 6/27 (28.57%) treated with corticosteroids (CS) and NSAID. Independent risk factors for ROP were viral pericarditis (p = 0.01, OR 31.46), lack of myocardial affection (p = 0.03, OR 29.15), CS use (p = 0.02, OR 29.02) and ESR = 50 mm/h (p = 0.03, OR 25.23). In 4/8 patients the first recurrence was treated with NSAID and colchicine, while treatment of 4/8 patients included CS. Children with ROP treated with CS had higher median number of recurrence (5, IQR: 2-15) than those treated with colchicine (0, IQR: 0-0.75). Conclusions: Independent risk factors for recurrence are CS treatment, viral aetiology, pericarditis only and ESR = 50 mm/h. Acute pericarditis should be treated with NSAID. Colchicine and NSAID might be recommended in children with the first ROP. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

[No abstract available]

Double-outlet left ventricle is a very rare congenital cardiac anomaly with various anatomic types. This report describes an infant with the aorta anterior and to the left of the pulmonary trunk, a subpulmonary ventricular septal defect, and pulmonary artery stenosis. This variation has not been described to date in patients with a double-outlet left ventricle. © 2012 Springer Science+Business Media, LLC.

Objectives: Coronary artery fistulas (CAFs) are rare congenital anomalies with an occurrence rate of 0.002–0.3%. The right coronary artery (RCA) is reportedly the most common site of origin of CAFs, but fistulas draining to the left atrium (LA) are rare. We presented a three-year-old boy with a symptomatic congenital RCA-to-LA fistula, which was successfully percutaneously occluded with an Amplatzer vascular plug 4 (AVP4). Case report: The diagnosis was made by echocardiography when he was two months old. During the follow-up period of 2 years, a progressive dilatation of the RCA and enlargement of the left ventricle was detected, so treatment for congestive heart failure was initiated. At the age of three, the patient presented with a history of occasional mild central chest pain and discomfort and mild dyspnea on exertion. On a 24 h ECG Holter monitor, the depression of ST segments was registered. CT angiography highlighted a large type B RCA fistula to the LA, which extended along the atrioventricular sulcus. The proximal RCA diameter was 7 mm. The fistula was tortuous, with segmental narrowing and three curves. Cardiac catheterization was performed across the right femoral artery on the three-year-old boy (body weight: 13 kg). Across the 4F Judkins right guiding catheter, an AVP4 of 5 mm was placed in the distal part of the CAF connected with the delivery cable. After 15 min, ECG changes were not registered, so the device was released. Immediate post-deployment angiography demonstrated complete CAF occlusion, with satisfying flow in the distal coronary artery. The patient was discharged after four days. In the short-term follow-up period, the boy was symptom-free. Conclusions: In our experience, given the existence of the left-to-left shunt and the more pronounced exercise-induced coronary steal phenomenon that occurs in medium-sized and large CAFs, occlusion is necessary to prevent the further progression of clinical signs and symptoms. © 2024 by the authors.

Objectives: Coronary artery fistulas (CAFs) are rare congenital anomalies with an occurrence rate of 0.002–0.3%. The right coronary artery (RCA) is reportedly the most common site of origin of CAFs, but fistulas draining to the left atrium (LA) are rare. We presented a three-year-old boy with a symptomatic congenital RCA-to-LA fistula, which was successfully percutaneously occluded with an Amplatzer vascular plug 4 (AVP4). Case report: The diagnosis was made by echocardiography when he was two months old. During the follow-up period of 2 years, a progressive dilatation of the RCA and enlargement of the left ventricle was detected, so treatment for congestive heart failure was initiated. At the age of three, the patient presented with a history of occasional mild central chest pain and discomfort and mild dyspnea on exertion. On a 24 h ECG Holter monitor, the depression of ST segments was registered. CT angiography highlighted a large type B RCA fistula to the LA, which extended along the atrioventricular sulcus. The proximal RCA diameter was 7 mm. The fistula was tortuous, with segmental narrowing and three curves. Cardiac catheterization was performed across the right femoral artery on the three-year-old boy (body weight: 13 kg). Across the 4F Judkins right guiding catheter, an AVP4 of 5 mm was placed in the distal part of the CAF connected with the delivery cable. After 15 min, ECG changes were not registered, so the device was released. Immediate post-deployment angiography demonstrated complete CAF occlusion, with satisfying flow in the distal coronary artery. The patient was discharged after four days. In the short-term follow-up period, the boy was symptom-free. Conclusions: In our experience, given the existence of the left-to-left shunt and the more pronounced exercise-induced coronary steal phenomenon that occurs in medium-sized and large CAFs, occlusion is necessary to prevent the further progression of clinical signs and symptoms. © 2024 by the authors.

The novel coronavirus disease (COVID-19) may induce multisystem inflammatory syndrome (MIS) in children, which may be associated with Kawasaki-like disease and cardiac injury. In this study, we presented three male adolescents with MIS and myocardial injury admitted to the hospital during the peak of COVID-19 pandemic. All of the three patients had a history of fever, gastrointestinal symptoms, polymorph rash, non-exudative conjunctivitis, and signs of acute myocarditis (AM). One of them had renal failure. Previously, they did not have an acute infection. Upon admission, they were hypotensive and tachycardic. A nasopharyngeal swab for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on reverse transcription-polymerase chain reaction (PCR) assay was negative, but neutralizing viral antibodies were positive. In combination with blood tests, electrocardiogram, echocardiography, and computerized tomography, a MIS associated with acute myocarditis with mild to moderate systolic dysfunction and dilated coronary arteries were diagnosed. Two of three patients had shock syndrome and required inotropic support. All patients were treated with intravenous immunoglobulins (Ig). The second patient had a fever up to 102.2°F (39°C) 3 days after intravenous Ig. Further, he was treated according to protocols for refractory Kawasaki disease, with an intravenous methylprednisolone pulse therapy and aspirin. After a few hours, he became afebrile and the clinical signs disappeared. The favorable short-term outcome may reflect early recognition and adequate therapy; however, the long-term outcomes are currently unknown. © The Author(s) (2021).

Purpose: The purpose of this study was to evaluate long-term outcome and assess predictors of prognosis in children with neonatal seizures (NS). Method: This retrospective study includes children with NS treated at our Institute from January the 1st 2005 until December the 31st 2015. The data were collected from medical charts and the electroencephalogram (EEG) database at the Institute. The predictive value was evaluated for following parameters: (1) characteristics of the patients, such as gender, gestational age, birth body weight, Apgar score, artificial ventilation; (2) etiology; (3) characteristics of seizures such as type, time of onset, resistance to treatment; and (4) EEG background activity and paroxysmal discharges. The outcome of NS was assessed at the end of the follow-up period and was categorized as one of the following: (1) lethal outcome, (2) neurological abnormalities, (3) intellectual disability, and (4) epilepsy. Univariate and multivariate logistic regression analyses were used to assess predictors of NS outcome. Results: The study included 168 children with NS (of which 109 are males, and 59 are females), mean aged 5.6 (SD 3.5) years at the end of the follow-up (with a range of 1 to 12 years). There was normal neurological development without epilepsy in 131 patients (78%), neurological abnormality in 31 (19.0%), intellectual disability in 28 (17.2%), epilepsy in 12 (7.4%), and lethal outcome in 7 patients (4.17%). Conclusions: Long-term outcome in children with NS could be favorable in most patients, and it appears to be related to specific early clinical and paraclinical variables. Newborns with an abnormal background EEG activity, with seizures resistant to antiepileptic drugs and/or low Apgar score are at a higher risk of a poor outcome. Females are at a much higher risk of lethal outcome than males. © 2018 Elsevier Inc.

Purpose: The purpose of this study was to evaluate long-term outcome and assess predictors of prognosis in children with neonatal seizures (NS). Method: This retrospective study includes children with NS treated at our Institute from January the 1st 2005 until December the 31st 2015. The data were collected from medical charts and the electroencephalogram (EEG) database at the Institute. The predictive value was evaluated for following parameters: (1) characteristics of the patients, such as gender, gestational age, birth body weight, Apgar score, artificial ventilation; (2) etiology; (3) characteristics of seizures such as type, time of onset, resistance to treatment; and (4) EEG background activity and paroxysmal discharges. The outcome of NS was assessed at the end of the follow-up period and was categorized as one of the following: (1) lethal outcome, (2) neurological abnormalities, (3) intellectual disability, and (4) epilepsy. Univariate and multivariate logistic regression analyses were used to assess predictors of NS outcome. Results: The study included 168 children with NS (of which 109 are males, and 59 are females), mean aged 5.6 (SD 3.5) years at the end of the follow-up (with a range of 1 to 12 years). There was normal neurological development without epilepsy in 131 patients (78%), neurological abnormality in 31 (19.0%), intellectual disability in 28 (17.2%), epilepsy in 12 (7.4%), and lethal outcome in 7 patients (4.17%). Conclusions: Long-term outcome in children with NS could be favorable in most patients, and it appears to be related to specific early clinical and paraclinical variables. Newborns with an abnormal background EEG activity, with seizures resistant to antiepileptic drugs and/or low Apgar score are at a higher risk of a poor outcome. Females are at a much higher risk of lethal outcome than males. © 2018 Elsevier Inc.

Background: Multisystem inflammatory syndrome in children (MIS-C) associated with being infected with coronavirus-19 (COVID-19) is a life-threatening condition resulting from cytokine storm, increased synthesis of reactive oxygen species (ROSs), and hyperinflammation occurring in genetically predisposed children following an infection with SARS-CoV-2. Aim: The primary aims of our study were to identify changes in the activity of antioxidant enzymes in erythrocytes and total oxidative status in plasma after being treated with methylprednisolone (MP). Methods: A prospective cohort study of 67 children (56.7% male) under 18 with MIS-C being treated with MP was conducted at the Mother and Child Health Institute from January 2021 to April 2022. The impact of the therapy was assessed on the basis of the clinical condition, haematological and biochemical blood parameters, and echocardiographic findings. Results: 59.7% of patients presented cardiovascular (CV) manifestations, while myocardial dysfunction was observed in half of all patients (50.7%). A severe clinical course was observed in 22/67 patients. Children with CV involvement had a significantly higher relative concentration of B lymphocytes and lower relative concentration of NK cells than patients without CV issues (p < 0.001 and p = 0.004, respectively). Patients with severe MIS-C had a lower relative count of NK cells than those with moderate MIS-C (p = 0.015). Patients with myocardial dysfunction had a higher total oxidative plasma status (TOPS) than children without (p = 0.05), which implicates pronounced oxidative stress in the former cohort. In patients with shock, lower erythrocytes superoxide dismutase (SOD) activity was observed on admission compared to patients without shock (p = 0.04). After MP was administered, TOPS was significantly reduced, while catalase (CAT) and SOD activity increased significantly. Treatment failure (TF) was observed in 6 patients, only females (p=0.005). These patients were younger (p=0.05) and had lower CAT activity on admission (p=0.04) than patients with favorable treatment responses. In the group of patients with TF, TOPS increased after treatment (before 176.2 ± 10.3 mV, after 199.0 ± 36.7 mV). Conclusion: MP leads to rapid modulation of TOPS and increases the activity of antioxidant enzymes in erythrocytes resulting in clinical and echocardiographic improvement. Based on the observed changes in the activity of the antioxidant enzymes, we can conclude that s hydrogen peroxide is the dominant ROS in patients with MIS-C. Patients with TF showed reduced CAT activity, whereas the treatment with MP led to pronounced oxidation. This implies that low CAT activity may be a contraindication for using MP. Copyright © 2023 Krasic, Vukomanovic, Ninic, Pasic, Samardzija, Mitrovic, Cehic, Nesic and Bajcetic.

Background: Multisystem inflammatory syndrome in children (MIS-C) associated with being infected with coronavirus-19 (COVID-19) is a life-threatening condition resulting from cytokine storm, increased synthesis of reactive oxygen species (ROSs), and hyperinflammation occurring in genetically predisposed children following an infection with SARS-CoV-2. Aim: The primary aims of our study were to identify changes in the activity of antioxidant enzymes in erythrocytes and total oxidative status in plasma after being treated with methylprednisolone (MP). Methods: A prospective cohort study of 67 children (56.7% male) under 18 with MIS-C being treated with MP was conducted at the Mother and Child Health Institute from January 2021 to April 2022. The impact of the therapy was assessed on the basis of the clinical condition, haematological and biochemical blood parameters, and echocardiographic findings. Results: 59.7% of patients presented cardiovascular (CV) manifestations, while myocardial dysfunction was observed in half of all patients (50.7%). A severe clinical course was observed in 22/67 patients. Children with CV involvement had a significantly higher relative concentration of B lymphocytes and lower relative concentration of NK cells than patients without CV issues (p < 0.001 and p = 0.004, respectively). Patients with severe MIS-C had a lower relative count of NK cells than those with moderate MIS-C (p = 0.015). Patients with myocardial dysfunction had a higher total oxidative plasma status (TOPS) than children without (p = 0.05), which implicates pronounced oxidative stress in the former cohort. In patients with shock, lower erythrocytes superoxide dismutase (SOD) activity was observed on admission compared to patients without shock (p = 0.04). After MP was administered, TOPS was significantly reduced, while catalase (CAT) and SOD activity increased significantly. Treatment failure (TF) was observed in 6 patients, only females (p=0.005). These patients were younger (p=0.05) and had lower CAT activity on admission (p=0.04) than patients with favorable treatment responses. In the group of patients with TF, TOPS increased after treatment (before 176.2 ± 10.3 mV, after 199.0 ± 36.7 mV). Conclusion: MP leads to rapid modulation of TOPS and increases the activity of antioxidant enzymes in erythrocytes resulting in clinical and echocardiographic improvement. Based on the observed changes in the activity of the antioxidant enzymes, we can conclude that s hydrogen peroxide is the dominant ROS in patients with MIS-C. Patients with TF showed reduced CAT activity, whereas the treatment with MP led to pronounced oxidation. This implies that low CAT activity may be a contraindication for using MP. Copyright © 2023 Krasic, Vukomanovic, Ninic, Pasic, Samardzija, Mitrovic, Cehic, Nesic and Bajcetic.