Distribution characteristics of leukocytes in EPS and correlation with serum PSA levels: results from a Chinese male population survey.

OBJECTIVE

To explore the distribution characteristics of leukocytes in expressed prostatic secretions (EPS) in a large Chinese male population and the correlation with leukocytes and prostate-specific antigen (PSA) levels.

MATERIALS AND

METHODS

From September to December 2009, EPS specimens were collected from 2504 men (age 20-69 years) who had undergone prostatic massage and were recruited from a large-scale community-based population survey in Southern China. The EPS specimens were divided into 5 categories according to the leukocyte count. The lifestyle and demographic characteristics were obtained by questionnaire. Asymptomatic and symptomatic men were defined according to the findings from the National Institutes of Health-Chronic Prostatitis Symptom Index questionnaire.

RESULT: EPS specimens were successfully collected from 1779 of the 2504 participants (71%). The degree of inflammation in the EPS specimens progressively increased with age, education, and body mass index (P <.001 for trend for all). A similar result was observed for men living with a partner compared with those living alone (P <.001) but not for men who smoked (P = .084) or consumed alcohol (P = .461). Moreover, a trend for PSA levels increasing progressively across leukocyte categories was observed (P <.001). The PSA levels were greater in all participants with inflammation than in those without (P <.001 for all) when inflammation was defined at 5+, 10+, and 20+ but not for 20+ in asymptomatic men and or not for 5+ and 10+ in symptomatic men.

CONCLUSION

The results of the present study have shown that the degree of inflammation in EPS progressively increases with increasing age, body mass index, and education. Moreover, an increase of leukocytes in the EPS specimen correlated with increasing PSA levels. Prospective studies are needed to determine whether the minor elevations have clinical significance for prostatitis assessment.