Association of serum Clara cell protein CC16 with respiratory infections and immune response to respiratory pathogens in elite athletes

Abstract

BackgroundRespiratory epithelium integrity impairment caused by intensive exercise may lead to exercise-induced bronchoconstriction. Clara cell protein (CC16) has anti-inflammatory properties and its serum level reflects changes in epithelium integrity and airway inflammation. This study aimed to investigate serum CC16 in elite athletes and to seek associations of CC16 with asthma or allergy, respiratory tract infections (RTIs) and immune response to respiratory pathogens.MethodsThe study was performed in 203 Olympic athletes. Control groups comprised 53 healthy subjects and 49 mild allergic asthmatics. Serum levels of CC16 and IgG against respiratory viruses and Mycoplasma pneumoniae were assessed. Allergy questionnaire for athletes was used to determine symptoms and exercise pattern. Current versions of ARIA and GINA guidelines were used when diagnosing allergic rhinitis and asthma, respectively.ResultsAsthma was diagnosed in 13.3% athletes, of whom 55.6% had concomitant allergic rhinitis. Allergic rhinitis without asthma was diagnosed in 14.8% of athletes. Mean CC16 concentration was significantly lower in athletes versus healthy controls and mild asthmatics. Athletes reporting frequent RTIs had significantly lower serum CC16 and the risk of frequent RTIs was more than 2-fold higher in athletes with low serum CC16 (defined as equal to or less than 4.99 ng/ml). Athletes had significantly higher anti-adenovirus IgG than healthy controls while only non-atopic athletes had anti-parainfluenza virus IgG significantly lower than controls. In all athletes weak correlation of serum CC16 and anti-parainfluenza virus IgG was present (R = 0.20, p < 0.01). In atopic athletes a weak positive correlations of CC16 with IgG specific for respiratory syncytial virus (R = 0.29, p = 0.009), parainfluenza virus (R = 0.31, p = 0.01) and adenovirus (R = 0.27, p = 0.02) were seen as well.ConclusionsRegular high-load exercise is associated with decrease in serum CC16 levels. Athletes with decreased CC16 are more susceptible to respiratory infections. Atopy may be an additional factor modifying susceptibility to infections in subjects performing regular high-load exercise.

Pneumoproteins and markers of inflammation and platelet activation in the blood of grain dust exposed workers

“…However, exposed workers are physically more active during the day, and we cannot exclude that this may be the reason for the increased CC-16 in exposed workers compared with controls that were office workers. CC-16 has indeed been shown to be higher after exercise and heavy work (Nanson et al 2001), but lower in elite athletes (Kurowski et al 2014). Helleday and colleagues showed that serum CC-16 concentrations in healthy nonsmoking subjects drops from 7 am to 1 pm, stabilizes somewhat, and then starts to increase again at 7 pm, following a U-shaped curve (Helleday et al 2006).…”

Urine Club Cell 16-kDa Secretory Protein and Childhood Wheezing Illnesses After Lower Respiratory Tract Infections in Infancy

“…In a recent cross-sectional study of 203 adult elite athletes, low serum levels of CC16 were also associated with a history of frequent upper respiratory tract infections. 52 To date, only a few pediatric studies have been conducted in this topic, all of which used serum levels of CC16 and had a crosssectional design. In a study of 100 Australian children aged 0-18 years, asthmatics had lower serum levels of CC16 when compared with nonasthmatics.…”

The role of sports and exercise in allergic disease: drawbacks and benefits

“…It has been suggested that the relation between exercise and respiratory infections follows a 'J' curve, with moderate and regular exercise improving the ability to resist infections and heavy acute or chronic exercise decreasing the infections [43]. Several studies have demonstrated that prolonged periods of intense training may lead to high numbers of neutrophil and low numbers of lymphocytes in blood counts, impaired phagocytosis and neutrophilic function, decreased oxidative burst activity, natural killer cell cytolytic activity, mucosal immunoglobulin levels and decreased serum clara cell protein [38][39][40]44]. Intense training may also induce enhanced secretion of proinflammatory cytokines, such as TNF-a, IL-1b, and IL-6, followed closely by anti-inflammatory cytokines, such as IL-10 and IL-1 receptor antagonist [40,45].…”