Purpose: The Meares-Stamey 4-glass test is the standard method of assessing inflammation and the presence of bacteria in the lower urinary tract in men presenting with the chronic prostatitis syndrome. However, most urologists do not use it in daily practice because of the time and difficulty in performing it, as well as the additional expense. We evaluated a simpler test, the 2-glass pre-massage and post-massage test, and compared it with the Meares-Stamey 4-glass test to detect inflammation and bacteria in men with chronic prostatitis/chronic pelvic pain syndrome.
Materials and methods: The study population included 353 men enrolled in the National Institutes of Health Chronic Prostatitis Cohort study with baseline leukocyte counts and 2-day bacterial cultures on specimens obtained from a standard 4-glass test (VB1, VB2, expressed prostatic secretions, VB3). The chi-square test was performed to assess associations of white blood cell counts in expressed prostatic secretions and VB3. A receiver operating characteristic curve was constructed to determine the optimal cut point of white blood cells in VB3 in predicting white blood cells in expressed prostatic secretions. Sensitivity and specificity of VB3 cultures predicting expressed prostatic secretions and positive Meares-Stamey results were calculated from 2 x 2 contingency tables.
Results: Analysis of binary leukocyte outcomes (no white blood cells vs any white blood cells) suggests that white blood cells tend to be present in expressed prostatic secretions when there are any white blood cells in VB3, p <0.0001, the optimal cut point being white blood cell counts of 3 in VB3 (best predictive ability with area under ROC 0.771) to predict 5+ in expressed prostatic secretions with a sensitivity of 76% and specificity of 70%. The optimal cut point of white blood cells in VB3 to predict 10 white blood cells in expressed prostatic secretions was 4 (62% sensitivity and 75% specificity). Uropathogens localizing to expressed prostatic secretions or VB3 confirms a positive 4-glass Meares-Stamey localization test. The sensitivity and specificity of a VB3 localizing culture only in predicting a positive Meares-Stamey 4-glass test result for any uropathogen were 44% to 54% (depending on definition) and 100%, respectively. The pre-massage and post-massage test predicted a correct diagnosis in more than 96% of subjects.
Conclusions: The value of localizing leukocytes and uropathogens to prostate specific specimens remains controversial in chronic heavily pretreated patients, but these data may help direct therapy (anti-inflammatory or antimicrobial) when obtained at first presentation. The pre-massage and post-massage test has strong concordance with the 4-glass test and is a reasonable alternative when expressed prostatic secretions are not obtained.