Biology of Sport, Vol. 29 No2, 2012 101 White blood cells in Polish athletes of various sports disciplines Reprint request to: Joanna Orysiak Department of Nutrition Physiology Institute of Sport Str. Trylogii 2/16 01-982 Warsaw, Poland E-mail: joanna.orysiak@insp.waw.pl Accepted for publication 15.01.2012 INTRODUCTION White blood cells (WBC) are one of the most important cells in the immune system, playing a role in defence against foreign sub- stances. Neutrophils are irst line defenders against bacterial infection, macrophages phagocyte foreign substances and enable antigen pre- sentation, while lymphocytes activate other lymphocyte subsets and produce immunoglobulins. It was proved that physical exercise in- duces changes in the number of leucocytes and their subsets in the circulating blood [18]. These changes can be inluenced by many factors such as catecholamines, increase in cardiac output or de- creased adherence of leucocytes to endothelial tissues [9]. It is sug- gested that suppression of the immune system could increase sus- ceptibility to upper respiratory tract infections (URTI) in athletes [13]. For many years researchers have examined a lot of aspects of the immune system. There are some papers concerning the inluence of the selected exercise programme on immunology indicator changes [16,21]. To the author’s knowledge there are only a few articles concerning WBC counts and their subsets in athletes at rest. In the WHITE BLOOD CELLS IN POLISH ATHLETES OF VARIOUS SPORTS DISCIPLINES AUTHORS: Orysiak J. 1 , Witek K. 2 , Żmijewski P. 3 , Gajewski J. 4 1 Department of Nutrition Physiology, Institute of Sport, Warsaw, Poland 2 Department of Biochemistry, Institute of Sport, Warsaw, Poland 3 Department of Physiology, Institute of Sport, Warsaw, Poland 4 Department of Biomechanics, Institute of Sport, Warsaw, Poland ABSTRACT: The purpose of this study was to examine the diversity of white blood cell (WBC) counts and their subsets (neutrophils, lymphocytes and monocytes) among competitive athletes of different sports disciplines. The blood samples were collected from 608 healthy, medically examined athletes (181 females and 427 males) aged 20.1 ± 5.1 years, who represented ive sport disciplines: canoeing, judo, rowing, swimming and volleyball. All blood samples were taken from the antecubital vein in the morning, after overnight fasting, in a seated position. Haematological analyses were conducted using a haematology analyser (ADVIA 120, Siemens). Neutropenia (deined as neutrophil count <2.0 · 10 9 ·L -1 ) was found in athletes of both sexes in each discipline. There was no incident of lymphopenia (deined as a lymphocyte count <1.0 · 10 9 ·L -1 ). Monocytopenia (deined as a monocyte count <0.2 · 10 9 ·L -1 ) was seen only in male athletes, except judo athletes. Differences in WBC and their subset counts were related to sport disciplines: in volleyball players WBC counts were signiicantly higher than in athletes of canoeing and rowing (in females); neutrophil counts were the lowest in swimming athletes; lymphocyte counts were lower in athletes of canoeing than in volleyball and swimming, but only in females; monocyte counts were lower in athletes of canoeing than swimming (in females) and judo (in males). In women, counts of neutrophils were greater and counts of monocytes were smaller than in men. It seems that prevalence of neutropenia and monocytopenia and differences in WBC counts and their subsets among disciplines could be related to the adaptive response to physical exercise. KEY WORDS: white blood cells, sports, neutropenia, monocytopenia, lymphopenia, reference values majority of these studies, WBCs are considered in only one kind of sport discipline [1,10,22]. The purpose of this study was to examine the diversity of white blood cell counts and their subsets (neutrophils, lymphocytes and monocytes) among competitive athletes of different sports disciplines. MATERIALS AND METHODS The blood samples were collected from 608 athletes (181 females and 427 males) of mean age 20.1 ± 5.1 years who represented ive different sport disciplines: canoeing, judo, rowing, swimming and volleyball (Table 1). The majority of subjects were well-trained or elite athletes. Some samples were taken from the same athletes from two consecutive years; the data were not aggregated for those samples. The minimum break time between successive blood collecting was 6 months. Moreover, blood sample taking was done in different an- nual training cycles. The programme of the study was approved by the Ethical Research Committee at the Institute of Sport in Warsaw. Original Paper Biol. Sport 2012;29:101-105 DOI: 10.5604/20831862.988883