The lecture is devoted to the basic principles for laboratory diagnosis of blood coagulation as one including: 1) trained doctors; 2) demand equipment and methods appropriate to the profile and capacity of health facilities; 3) constructive solutions to issues of organizational and economic nature; 4) «Noli nocere» («do not harm») from the hospital management.

In the lecture new perspectives are given on thrombophilia, thrombogenic risk factors and the state of thrombotic readiness preceding and accompanying critical vascular ischemia. The role of these concepts is defined by explaining the occurrence of arterial and venous thrombosis. Modern laboratory methods for the assessment of thrombogenic risk factors and thrombotic state of readiness, which help to determine the need to start thromboprophylaxis, are canceled.

Haemophilia is a hereditary X-linked desease manifested in coagulatory hemostasis disorder. Haemophilia A is a recessive mutation in X-chromosome which results in the absence or malfunction of blood clotting factor VIII. Its frequency from 1:5000 to 1:10,000 of born boys. Haemophilia B is caused by the factor IX deficiency (recessive mutation in X-chromosome), with an incidence from 1:25,000 to 1:30,000 of born boys. Frequency of occurrence hemorrhagic stroke in children is 0.7–5.1 (average – 2.9) per 100,000. Reported intracranial hemorrhages (ICH) boys with haemophilia are rare, however, according to foreign authors encountered in 1.7–11.7 % of patients that with appropriate recalculation was 290–2142:100,000 per year. Thus, the risk of ICH patients with hemophilia in 56–420 times higher than the general population. The median age of children with ICH ranges from 5.9 months to 8 years. Operational tactics not developed.

The article is devoted to general issues of classification and differential diagnosis of thrombocytopathy. Features of pathogenesis, clinical course and diagnosis of certain rare inherited thrombocytopathies are highlighted. Particular attention is paid to the formation of the molecular basis of these diseases. The basic genetic mutations associated with a number of thrombocytopathies are given.

The analysis of the results of dalteparin sodium (Fragmin®) application for the prevention and treatment of thrombosis of various biodisposition in 62 children has been given. The average relative dose depending on the age of the patient, the effectiveness of application and the drug, s safety; the need to select individually controlled doses has been evaluated.

Venous thromboembolism (VTE) is a frequent complication in children receiving treatment of cancer. VTE in a child with cancer increases duration of treatment and its cost, may reduce survival rates and affects the quality of life. Better understanding of pathologic processes, causing VTE in children with cancer, will raise an effectiveness of prophylactic approach.

In the practice of pediatric hematologist, patients with isolated neutropenia occupy a certain place and account for about 15–20 % of all requests for a consultation with a hematologist or a pediatrician. “Reactive lymphocytosis” is the most common interpretation of this state by experts of “hematological” type, which leads to a certain confusion. The article presents a review of the literature with an emphasis on the problem of acquired isolated neutropenia in children, which is not associated with congenital and acquired myelosuppression, congenital neutropenia syndromes, and hyperspelenism.

The article is devoted to early anemia in premature newborns, which occupies the 1st place among the indications for blood transfusion in children with very low and extremely low birth weight. Ways of optimization of anemia treatment in premature newborns are shown based on the analysis of international experience and the results of in-house researches. The most important of these include limiting the number of blood transfusions, justified early application of recombinant human erythropoietin and reduction in the volume of blood samples for laboratory tests.

The article presents current data on prevention of fungal infection in children in the context of hematopoietic stem cell transplantation (HSCT) and the place of voriconazole in it. Own experience shows the results of treatment of patients with malignant and non-malignant diseases in the Department of bone marrow transplantation of the Russian Children's Clinical Hospital. A total of 161 patients aged 4 to 18 years who received allogeneic or autologic HSCT for the period from 2012 to 2014 was examined. It has been shown that the application of voriconazole prophylaxis reduces the incidence of fungal infection development, particularly in conditions of not always favorable epidemiological situation. The characteristics of preventive treatment of this group of diseases in children were analyzed.

This paper presents a clinical case of portal vein thrombosis in a child with a malignant rhabdoid tumor of the liver with the description of tactics of antithrombotic therapy application in thrombocytopenia. Literature data on the epidemiology of venous thrombosis among pediatric patients with cancer, the pathogenesis of venous thrombosis, diagnostic methods and principles of antithrombotic therapy choice in children with thromboembolic sequela are presented. The role of interdisciplinary interaction in determining the treatment tactics of patients with cancer and concomitant thrombohemorrhagic pathology is emphasized.

This paper presents a protocol of dispensary observation of patients with neuroblastoma of low-risk group. Development of the observation protocol is based on the experience of German group on treatment of neurogenic tumors (protocol NB-2004) and published data on the prognosis and incidence of recurrence in this cohort of patients.

Aspects of distant organ toxicity for patients receiving chemotherapy due to availability of life-threatening symptoms at diagnosis and further observation are covered. In this article we do not touch upon the subject of observation of patients with stage 4S disease, as this group of patients requires a more detailed discussion.