Comparison of polymerase chain reaction and immunologic methods for the detection of nanobacterial infection in type-III prostatitis.

OBJECTIVE

To compare the results of polymerase chain reaction (PCR) and immunologic methods for the detection of nanobacteria (NB) in the expressed prostatic secretions (EPSs) of patients with type-III prostatitis.

METHODS

In total, 150 patients with type-III prostatitis for whom conventional clinical treatment had failed were selected from September 2009 to April 2010. The EPS of each patient was divided into 3 parts, which were used for PCR analysis, indirect immunofluorescence staining (IIFS), and culture and subsequent indirect immunofluorescence staining (CIIFS).

RESULTS

PCR analysis has a higher sensitivity than IIFS for the detection of NB in EPSs. Of 83 CIIFS-positive EPS samples, 79 (95.2%) were positive by PCR. Of 67 EPS samples that were negative by CIIFS, 60 (89.6%) were negative by PCR. The sensitivity of PCR for the detection of NB compared with the CIIFS method was 95.2%, with a specificity of 89.6%. The positive predictive value was 91.9%, and the negative predictive value was 93.8%. A comparative evaluation showed no statistically significant difference between PCR and CIIFS in the detection of NB in EPSs. A strong agreement in the positive and the negative results obtained by PCR and CIIFS for NB detection was found for all EPS samples.

CONCLUSION

PCR analysis has a higher sensitivity than IIFS for NB detection in type-III prostatitis. PCR can detect nanobacterial infection in type-III prostatitis equally well as CIIFS and offers significant advantages for the rapid, simple, and economical detection of nanobacterial infection in type-III prostatitis.