The THROMB-HEM study: first results and future prospects

   THROMB-HEM is an observational research study discovering the prevalence, risk factors and features of the course and therapy of deep venous thrombosis (DVT) in children with hemoblastosis and bone marrow aplasia which was conducted on from 2012 to 2017 on the basis of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology.

   Aim: assessment of the DVT prevalence in children with hemoblastosis and and bone marrow aplasia based on the results of the THROMB-HEM study. The cumulative incidence rate (CIR) of objectively confirmed DVT, symptomatic (sDVT) and asymptomatic (aDVT) DVT in was assessed in children hospitalized in the center from 01.01.2013 to 12.31.2017 in order to verify and treat various hemoblastosis and bone marrow aplasia. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. Data from 1623 patients were included for CIR DVT analysis. Among the patients included in the event analysis, DVT was detected in 361 children (285 aDVT and 73 sDVT, in 3 cases there were no data on the clinical picture of DVT). The maximum patient observation time was 5 years. The median follow-up time for patients was 332.15 days (95 % confidence interval (CI) 295.65–379.60). At the third year of follow-up, CVR DVT was 34.8 % (95 % CI 31.3–38.7), CVR aDVT was 28.9 % (95 % CI 25.7–32.5), while sDVT was 8.2 % (95 % CI 5.8–11.5). Unlike aDVT, most sDVT occurred within the first 6 months of therapy. DVT, mostly aDVT, is a common finding in children receiving inpatient treatment for hemoblastosis and bone marrow aplasia, which dictates the need for further research to assess risk factors and the effectiveness of therapy and prevention of these complications.