This issue of “Progress in Medicine” is devoted to paediatric oncology and haematology, and it includes a selection of papers from Polish centres, which were presented during the 8^th Congress of Polish Society of Paediatric Oncology and Haematology held in June 4, 2016 in Katowice.

The development of diagnostic and therapeutic standards for invasive fungal disease in children is a very important achievement. Invasive fungal disease is currently one of the most important and dangerous complications of immunosuppressive therapy affecting patients treated for cancer, immune disorders or those undergoing stem cell transplantation. Invasive fungal disease can eliminate the effect of previous therapy and contribute to a failure in the treatment of the underlying disease. Therefore, the guidelines for the diagnostic and therapeutic management in paediatric patients developed by experts are of great practical importance.

The article entitled “The role of endothelin as an early marker of acute left ventricular dysfunction in children undergoing haematopoietic stem cell transplantation” addresses a very important issue of identifying children at risk of heart failure after stem cell transplantation. The authors have shown that the symptoms of transient cardiotoxicity were observed only in children with increased ET-1 serum levels. Therefore, children with increased ET-1 serum levels should be included in the group of high risk of post-transplantation heart failure.

Asymptomatic Epstein-Barr Virus (EBV) carriers are relatively common in Polish population. However, HSCT patients infected with the virus can develop a life-threatening complication, i.e. post-transplant lymphoproliferative disorder (PTLD). Therefore, the importance of an effective diagnostic and therapeutic strategy for EBV infections is emphasised. Professor Styczyński et al. attempted an analysis of this diagnostic and therapeutic strategy in Polish paediatric centres for haematopoietic cell transplantation between 2012 and 2015. A total of 650 HSCT procedures, including 499 allogeneic transplantations, were included in the analysis, which demonstrated that EBV reactivation occurred only in post-allo-HSCT patients. The incidence if EBV reactivations was 24.3% (65/267) between 2014 and 2015, and was significantly higher compared to the period 2012-2013, i.e. 15.5% (36/232) (p = 0.014; OR = 1.8; 95%Cl = 1.1-2.8). PTLD-related death occurred in 4/36 (11.1%) patients with EBV reactivation between 2012 and 2013. No fatal cases (0/65) due to EBV-related PTLD were reported between 2014 and 2015 (p = 0.006; OR = 3.0; 95%Cl = 2.3-4.0). The results of this study lead to the conclusion that the diagnostic and therapeutic strategy for EBV infections based on ECIL guidelines, which was used in Polish paediatric centres for haematopoietic cell transplantation between 2012 and 2015, shows high therapeutic efficacy and can be recommended for further clinical practice.

The paper “Posaconazole in prophylaxis of invasive fungal disease in children and adolescents: one-year follow-up of refund program” aims to assess the outcomes of antifungal prevention using posaconazole in 3 paediatric haemato-oncologic centres and 2 paediatric centres for haematopoietic cell transplantation in the first year of the availability of posaconazole refunded by the National Health Fund. The authors presented a thorough statistical analysis and concluded that Posaconazole used for prophylaxis in post-HSCT patients reduced the incidence of invasive fungal disease compared to historical group from 15.5 to 9.5% (OR = 0.6; p = 0.2). The data collected in the first year of treatment with the refunded posaconazole available in pharmacies (post-HSCT patients) is encouraging due to the high safety profile of the drug, including patients aged < 12 years. Only 2 patients receiving prophylactic posaconazole died due to invasive fungal disease.