Liudmila V. Bregel

Background: Macrophage activation syndrome (MAS) can be regarded as a key factor determining the severity of multisystem inflammatory syndrome associated with COVID-19 in children (MIS-C), and often requires treatment in the intensive care unit (ICU) to avoid life-threatening complications. No reputable specific criteria for the diagnosis of MAS in MIS-C patients have yet been identified, and criteria currently used for the diagnosis of hemophagocytic syndromes, such as HLH-2004, MAS-2005, and MAS-2016, are not sufficient for MAS in MIS-C. Our goal in this study was to work out the criteria for the early diagnosis of MAS in MIS-C. Methods: One hundred and sixty-six (166) patients with MIS-C were assessed retrospectively. The two most experienced experts independently identified patients with MAS. The patients were divided into three cohorts: MAS (n = 19), without MAS (n = 78), and probable MAS (n = 67). The latter included patients diagnosed with MAS by only one expert, and it was excluded from the analysis. Results: The age of patients with MAS was much higher, and they more frequently had edematous syndrome, hypotension and/or shock, splenomegaly, and CNS involvement. In their blood tests, thrombocytopenia, hypoalbuminemia, and hypertriglyceridemia occurred more often. The level of biomarkers of inflammation, such as ferritin, CRP, troponin, AST, and ALT, was also higher in this group. Increased fibrinogen and D-dimer were also found, demonstrating hypercoagulation in the MAS-MIS-C group. We chose 21 continuous and categorical variables with statistical significance, out of which 2—ferritin > 469 μg/L or platelets < 114 × 10⁹/L—allowed us to discriminate MAS patients. Conclusions: Ferritin > 469 μg/L or platelets < 114 × 10⁹/L can be regarded as key signs to differentiate MAS in MIS-C patients with a sensitivity of 100% and specificity of 94.9%, and they can be used along with other diagnostic methods.

Introduction. A review of the current literature on the features of the diagnosis of myocarditis in children is presented. Myocarditis is an acute or chronic inflammatory myocardial disease characterized by a variety of clinical manifestations, nonspecific symptoms and physical data. With insufficient number of informative diagnostic tests, there is a challenge for practitioners at all stages of medical care. Aim of the review is to comprehensively present the features of the clinical diagnosis of myocarditis in children. The presence of myocarditis should be assumed in situations where children, regardless of the age, first developed symptoms of heart failure (HF), as well as in the presence of a clinic of viral infections accompanied by respiratory or abdominal symptoms, combined with the development of tachycardia, hypotension or cardiac arrhythmias, even in the absence of cardiomegaly. Myocarditis should be clinically suspected at the stage when the necessary decisions should be made about the patient’s routing, the formation of a complex of diagnostic examinations and the start of therapy. Magnetic resonance imaging (MRI) of the heart is today the non-invasive gold standard for the diagnosis of myocarditis that allows detecting myocarditis within 2–3 weeks after the first symptoms appear. Endomyocardial biopsy can be used for accurate morphological diagnosis of myocarditis in children. Molecular biological and genetic studies that determine the severity and outcome of the disease are important for the diagnosis of myocarditis in children. Conclusion. Based on the literature data and own experience in diagnosing myocarditis, the authors have developed an original diagnostic algorithm to make the right medical decision in case of suspected acute myocarditis in children.

Readers will be presented with a series of articles on myocarditis in children, which are based on clinical guidelines developed by a group of authors on this topic. Myocarditis is an inflammatory myocardial disease characterized by a wide range of clinical manifestations — from minor to sudden cardiac death. Given the absence of pathognomonic symptoms, as well as the similarity of manifestations in the onset with common childhood diseases such as respiratory distress, gastrointestinal diseases, infectious pathology, specialists often overlook the likelihood of a diagnosis of “myocarditis”, which causes a late start of therapy and an adverse outcome. Considering that myocarditis accounts for 12% of cases of sudden cardiac death in adolescents and young adults, suspicion of this disease in differential diagnosis in children with nonspecific symptoms and disease progression may be the key to the formation of a proper treatment strategy. Despite significant advances in the study of myocarditis in both adults and children, there are still many unresolved issues. The purpose of this article is to highlight the current view of the etiology, pathogenesis, epidemiology and clinical features in children with various types of myocarditis in order to increase the knowledge of practitioners for better clinical management of patients with myocarditis.

Hemophagocytic syndrome is a key point in the pathogenesis of severe forms of multisystem inflammatory syndrome associated with COVID-19 in children (MIS-C). The factors associated with hemophagocytosis in patients with MIS-C were assessed in the present study of 94 boys and 64 girls ranging in age from 4 months to 17 years, each of whose HScore was calculated. In accordance with a previous analysis, patients with HScore ≤ 91 (n = 79) and HScore > 91 (n = 79) were compared. Patients with HScore > 91 had a higher frequency of symptoms such as cervical lymphadenopathy, dry cracked lips, bright mucous, erythema/swelling of hands and feet, peeling of fingers, edematous syndrome, hepatomegaly, splenomegaly, and hypotension/shock. They also had a higher erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and D-dimer levels, and a tendency to anemia, thrombocytopenia, and hypofibrinogenemia. They more often needed acetylsalicylic acid and biological treatment and were admitted to ICU in 70.9% of cases. Conclusion: The following signs of severe MIS-C were associated with HScore > 91: myocardial involvement, pericarditis, hypotension/shock, and ICU admission.

The problem of myocarditis treatment in children remains a difficult task, often causing controversy among practicing physicians, and this is primarily due to the lack of consensus on a number of fundamental issues, such as the impossibility of establishing the etiology of the disease due to the extremely rare use of the gold standard of diagnosis - endomyocardial biopsy, the feasibility, timing and duration of the use of intravenous immunoglobulins and immunosuppressive therapy, due to the insufficient evidence base. The objective of this publication is to highlight the approaches to the therapy of myocarditis from the point of view of experts. We would like to emphasise that this article presents expert opinion based on the knowledge and experience available to date. In paediatric practice, there are still no randomised multicentre studies on the choice and use of certain treatment methods.

Multisystem inflammatory syndrome associated with COVID-19 in children (MIS-C) is a life-threatening condition that often requires intensive care unit (ICU) admission. The aim of this study was to determine risk factors for severe/life-threatening course of MIS-C. The study included 166 patients (99 boys, 67 girls) aged 4 months–17 years (median 8.2 years). The criterion of severity was the fact of ICU admission. To conduct a comparative analysis, MIS-C patients were divided into two groups: patients hospitalized in the ICU (n = 84, 50.6%) and those who did not need ICU admission (n = 82, 49.4%). Patients with a more severe course of MIS-C were significantly older. They had a higher frequency of signs such as rash, swelling, hepatomegaly, splenomegaly, and neurological and respiratory symptoms. Hypotension/shock and myocardial involvement were much more common in patients with severe MIS-C. These patients had a more significant increase in CRP, creatinine, troponin, and D-dimer levels. Additionally, the presence of macrophage activation syndrome was higher in patients admitted to the ICU. Conclusion: Nineteen predictors of severe course of MIS-C were found, out of which hepatomegaly, splenomegaly, D-dimer > 2568 ng/mL, troponin > 10 pg/mL were mainly associated with the probability of being classified as early predictors of severe MIS-C requiring ICU admission.

Background: The causative agent of the new coronavirus infection SARS-CoV-2 has unique properties causing hyperinflammatory syndrome and cytokine storm, as well as widespread endotheliitis and thrombotic microangiopathy, initially detected in the lungs of adult patients who died from a severe form of the disease. Venous and arterial thrombosis in adults were identified as common causes of severe complications and deaths in new coronavirus infections. There are very few reports of thrombotic events in children with COVID-19 in the literature. Methods: We conducted a retrospective analysis of the histories of 60 patients in the Irkutsk Regional Children’s Clinical Hospital from November 2020 to November 2022 with a MIS-C diagnosis established according to WHO criteria, of which 8 (13.3%) were diagnosed with venous and/or arterial thrombosis, confirmed by laboratory and ultrasound and/or X-ray methods. Results: The average age of children with thrombosis (Me) was 7.5 years (min 4 months, max 17 years), with a M:F ratio of 3.0. Venous thrombosis was detected in six of the eight patients, including in the deep veins of the lower extremities in four. Pulmonary embolism occurred in two (one of them was fatal), and cerebral venous sinus thrombosis and thrombosis of the branches of the upper and lower vena cava were found in one patient. Extensive bilateral stroke due to thrombosis of the large cerebral arteries occurred in two patients, including one in combination with distal gangrene. Secondary thrombotic renal microangiopathy took place in three of the eight patients. Among these three, atypical HUS was diagnosed in one case. Multiple thrombosis involving the venous and arterial bed was detected in four of the eight patients. High levels of D-dimer, thrombocytopenia, increased NT-proBNP, cerebral coma, and aseptic meningitis were the events most often associated with thrombosis. All patients received immunomodulatory therapy (immunoglobulin, dexamethasone/methylprednisolone), pathogenetic therapy for multiorgan failure, anticoagulant therapy with heparin/LMWH, and acetylsalicylic acid. Biologics were used in two patients. Conclusions: The main predictors of thrombosis in children with MIS-C were increased D-dimer, thrombocytopenia, hospitalization in the ICU, and noncardiogenic pulmonary edema. Thrombosis of the deep veins of the lower extremities, large cerebral arteries, and secondary thrombotic microangiopathy was common. There was a single death (12.5% of the eight patients), associated with PE.

Objective. The aim of this study was to present the laparoscopic end-to-side ureteroureteroanastomosis technique in a young child a treatment option of duplex kidney. Material and methods. In the present study, a retrospective study of the medical history of a patient who underwent laparoscopic ureteroureteroanastomosis for duplication of the left kidney was performed. The indication for surgery was obstruction of a well-functioning upper segment. Results. The duration of the operation was 80 minutes. The drainage tube was removed after the control ultrasound on the 2nd day. The patient was then discharged for outpatient follow-up. The follow-up period was 12 months. The patient was asymptomatic throughout the control period. A repeat ultrasound examination performed 3, 6, and 12 months after surgery demonstrated a decrease in the anteroposterior diameter of the pelvis to 5 mm. There was no dilatation of the ureters. Conclusion. Laparoscopic ureteroureteroanastomosis is a safe and reproducible treatment for children with kidney duplication and can be used as an alternative to other methods. The case report demonstrated the possibility of laparoscopic end-to-side ureteroureteranastomosis in young children without signs of stenotic disorder of the recipient ureter.