Moderate physical activity possesses positive effects on the immune system function. Numerous studies investigated such effects also in cancer patients. As most studies were conducted on adults, much less is known in children and adolescents. Moreover, most studies were conducted under laboratory conditions in order to control the duration and intensity of the activity. However, daily life also includes outdoor activities.

The aim of the present study was to investigate immunological parameters in a pediatric cancer survivor (8 years) suffering Acute Myeloid Leukemia (AML) who underwent bone marrow transplantation. The values were compared to those of a healthy control group (CG; N = 10). Blood samples were taken at the first (pre-test) and at the last day (post-test) of a winter sports camp by using a portable flow cytometry BD Accuri C6 device.

No significant changes were observed between the pre- and post-test in the CG. The patient showed an increase in the total lymphocyte population, and in the CD3+ and CD4+ cells, all of them being within the range of variation of the CG. NK-cells increased slightly in the patient, however, both values were below the range of variation of the CG. B-Lymphocytes decreased from a value above the range of variation of the CG to a level close to their median value.

Although the intensity of the skiing activities was difficult to assess, the patient showed changes in immunological parameters which might be interpreted as an improvement of the immune system in the course of a one-week skiing intervention.