As more data is collected, hematologists will be able to gain more insight into the impact of coronavirus disease 2019 (COVID-19) on pediatric patients with hematological malignancies. Material and methods: We analysed 21 cases of COVID-19 in pediatric patients with onco-hematological diseases treated in the Western Ukrainian Pediatric Medical Center from March 2020 through May 2021. The majority of patients (71.4%) were diagnosed with acute lymphoblastic leukemia. All patients from the analyzed cohort had an asymptomatic, mild or moderate course of coronavirus-19 infection. The most common symptoms of COVID-19 were fever, cough, gastrointestinal symptoms, and dermatitis. Severe severe acute respiratory syndrome coronavirus 2 increased the risk of liver toxicity and venous thrombosis. Results and conclusion: Our analysis showed that pediatric patients with hematological malignancies need the same treatment approach for COVID-19 as for other infective complications.

On Feb 24, 2022, Russian military forces began a coordinated invasion of Ukraine. Russian assaults resulted in widespread damage to densely populated residential areas and critical civilian infrastructure, including power stations, transportation hubs, schools, and health care facilities. As a result, more than 10 million refugees have fled Ukraine, approximately 50% fleeing to Poland. Attacks on Ukraine's health system and pharmaceutical supply chains created challenges for the provision of critical services for people with injuries and chronic illnesses. Among the most vulnerable patients are children with cancer and blood disorders, who require timely access to diagnostic, therapeutic, and supportive care for survival. The war has resulted in acute interruption of medical care, threatening the lives of thousands of Ukrainian children.

The work describes a case of rare neonatal systemic juvenile xanthogranuloma with an initial damage of the scalp, limbs, back and abdomen, multiple damages of the parenchyma of both lungs, spleen and liver with the development of a severe form of congenital cholestatic hepatitis. The diagnosis was established on the basis of histopathological and immunohistochemical examination of the skin nodules. The child on the background of therapy under the Langerhans cell histiocytosis III program achieved a partial response, which was manifested by a reduction of granulomatous formations on the skin, elimination of liver failure, but retained hepatosplenomegaly, specific lesions of the lung parenchyma, liver, and left kidney. Against the background of cytostatic therapy, the patient developed secondary pancytopenia, perianal ulcerative-necrotic dermatitis with lesions on buttocks, stomatitis, protein-energy deficiency, acute liver failure. coagulopathy, disseminated intravascular coagulation syndrome, acute renal failure, respiratory failure of III degree, cardiovascular insufficiency of III degree, pulmonary edema, cerebral edema, cerebral coma of II-III degree, enterocolitis, intestinal paresis. Despite multicomponent intensive care, the child's condition progressively deteriorated, and the patient died. The aspects of differential diagnosis of neonatal systemic juvenile xanthogranuloma are discussed.

Rett syndrome is one of the most common causes of mental retardation in girls. The aim of our work was to study a spectrum of genetic heterogeneity and various clinical manifestations of Rett syndrome in girls Western Ukraine. There were used clinical, molecular and genetic methods. We observed seven girls with Rett syndrome aged from 6 months to 15 years who were diagnosed and followed-up at the Institute of Hereditary Pathology, National Academy of Medical Sciences of Ukraine, Lviv for three years (2019–2021) and underwent molecular genetic analyses confirmed by next-generation sequencing. In this study, patients with Rett syndrome had individual clinical heterogeneity and age variability due to different mutations. Mental retardation was not observed among siblings in families with Rett syndrome. We identified seven different pathogenic mutations among seven girls, including two deletions and one duplication of the MECP2 gene. Microcephaly was observed in two girls with MECP2 c.880C>T (p.Arg294*) and MECP2 Gain (Entire coding sequence) at birth. The following developmental disabilities were found in five girls: lack of independent sitting, lack of independent gait (regression of development). Among musculoskeletal disorders, there were diagnosed scoliosis, X-shaped deformation of the lower extremities and muscular hypotonia. A two-year-old girl with Rett syndrome, along with other clinical symptoms, had breathing problems - hyperventilation (rapid shallow breathing). In cases with unknown cause of delayed developmental disability and mental retardation the patients should be referred for medical genetic counselling

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) caused a new coronavirus disease (COVID-19), which is highly contagious and its pathogenesis has not been fully elucidated. In COVID-19, the inflammation and blood coagulation systems are excessively activated. SARS-CoV- 2 damages endothelial cells and pneumocytes, which leads to disruption of hemostasis in SARS. Thromboembolism is the main cause of mortality in patients with COVID-19. Clots, including pulmonary embolism (PE) and deep vein thrombosis (DVT), ranging from minor to fatal complications of the SARS-CoV-2 infection are known. Individuals with pre-existing diseases are more susceptible to the development of blood clots and poor outcomes. High levels of circulating cytokines and D-dimer (DD) are influential biomarkers of poor outcomes in COVID-19. The latter occurs as a result of hyperfibrinolysis and hypercoagulation. Plasmin is a key player in fibrinolysis and is involved in the cleavage of many viral envelope proteins, including SARS-CoV. Due to this function penetration of viruses into the host cell occurs. In addition, plasmin is involved in the pathophysiology of acute respiratory distress syndrome (ARDS) in SARS and promotes the secretion of cytokines, such as IL-6 and TNF, from activated macrophages. The focus of existing treatment to alleviate fibrinolysis in patients with COVID-19 is the use of systemic fibrinolytic therapy given thrombotic pathology in severe forms of COVID-19 which may lead to death. However, fibrinolytic therapy may be harmful in the advanced stages of COVID-19, when the status of disseminated intravascular coagulation (DIC) changes from suppressed fibrinolysis to its enhancement during the progression of the disease. This narrative review aims to elucidate the pathogenesis of COVID-19, which will further help in precise diagnosis and treatment.