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Antibodies to Chlamydia pneumoniae in young Swedish orienteers
Insights
Swedish elite orienteers showed no increased prevalence of Chlamydia pneumoniae antibodies compared to blood donors, despite a cardiac death cluster. This study investigated C. pneumoniae infection in athletes.
Area of Science:
- Infectious Diseases
- Cardiology
- Sports Medicine
Background:
- A cluster of sudden cardiac deaths occurred in Swedish elite orienteers.
- Chlamydia pneumoniae DNA and IgG antibodies were detected in some deceased athletes, prompting further investigation.
- The study aimed to determine if orienteers have a higher prevalence of C. pneumoniae antibodies.
Purpose of the Study:
- To assess the seroprevalence of Chlamydia pneumoniae antibodies in Swedish elite orienteers.
- To compare antibody prevalence in orienteers with that of healthy blood donors.
- To investigate potential links between C. pneumoniae and cardiac events in athletes.
Main Methods:
- Sera from 1790 Swedish elite orienteers (1992-93) were tested for C. pneumoniae IgG, IgA, and IgM antibodies.
- Prevalence rates were compared between male and female orienteers and a control group of blood donors.
- Statistical analysis was performed to determine significant differences in antibody prevalence.
Main Results:
- IgG antibody prevalence in male and female orienteers was 54% and 50%, respectively, comparable to blood donors (60% and 53%).
- Male orienteers had a significantly lower prevalence of IgA antibodies (19%) than male blood donors (26%).
- IgM antibody prevalence was less than 1% across all groups; performance level and residence did not affect prevalence.
Conclusions:
- Swedish elite orienteers do not exhibit a higher seroprevalence of Chlamydia pneumoniae antibodies compared to healthy blood donors.
- The observed lower IgA prevalence in male orienteers warrants further research into potential specific immune responses.
- The findings do not support a widespread association between C. pneumoniae infection and cardiac events in this athletic population.
Abstract:
During 1992-93 sera from 1790 Swedish elite orienteers were tested for antibodies to Chlamydia pneumoniae. The reason for this was that a cluster of 16 cases of sudden unexpected cardiac death had occurred among Swedish orienteers and DNA from C. pneumoniae had been found in the myocarditic heart and in the lung in 1 of 2 deceased athletes in whom testing was feasible; in addition, C. pneumoniae IgG was found in all 5 cases where serum was available. Among the orienteers, the prevalence rates of IgG antibodies in males and females were 54% (n = 1194) and 50% (n = 596), respectively. The corresponding figures for 319 male and female blood donors were 60% (n = 169) and 53% (n = 150), respectively. These differences are not statistically significant. Male orienteers had a lower prevalence of IgA antibodies than male blood donors (19% and 26%, respectively; p < 0.05), while no such difference was found in females (16% and 18%). The prevalence of IgM antibodies was < 1% in all groups. Neither the performance level of the orienteers nor the place of residence affected the antibody prevalence. In conclusion, Swedish orienteers do not show a higher prevalence of antibodies to C. pneumoniae than healthy blood donors.
