Detection of Trichomonas vaginalis in prostate tissue and serostatus in patients with asymptomatic benign prostatic hyperplasia

BACKGROUND: Despite a worldwide common and progressive nature of benign prostate hyperplasia (BPH) in older men, no association has been observed between a causative pathogen and other etiology so far. METHODS: In this study, we investigated a causative association of Trichomonas vaginalis, a flagellate protozoan parasite, in 171 BPH cases presenting without symptoms of prostatitis at a surgical outpatient clinic in Kuwait. We detected T. vaginalis DNA by polymerase chain reaction (PCR) and T. vaginalis antigen by immunocytochemistry (ICC) in the prostate tissue of these cases. A total of 171 age-matched controls with no urinary tract symptoms were also included in the study. A detailed information regarding the sexual history and sexually transmitted infections (STIs) was enquired from all the enrolled subjects. RESULTS: We detected T. vaginalis DNA and T. vaginalis antigen in 42 (24.6 %) and 37 (21.6 %) of the 171 BPH cases respectively in their prostate tissue. Both these assays showed a very good agreement and statistically no significant difference in their sensitivities and specificities. A relatively higher seropositivity rate for antibodies to T. vaginalis was detected in BPH cases (53 of 171 cases, 31.0 %) than in the control group (26.9 %) [p: 0.19] and both were higher than in earlier reports but no significant association was observed between BPH and T. vaginalis serostatus. However, a greater proportion of seroreactive BPH cases had high IgG2 antibody absorbance score than in the control group (p:0.000). Furthermore, no significant association was observed between T. vaginalis seropositivity and presence of T. vaginalis DNA in the prostate tissue. CONCLUSIONS: Our study documents T. vaginalis DNA and T. vaginalis antigen in 24.6 and 21.6 % respectively in the prostate tissue of the BPH cases. We also detected a relatively higher seropositivity rate for antibodies to T. vaginalis both in the BPH cases and in normal control group, 31 and 26.9 % respectively but no significant association was observed between BPH and T. vaginalis serostatus or presence of T. vaginalis DNA in the prostate tissue. Further epidemiological and case-controlled studies are needed to focus on local response to chronic asymptomatic retention of T. vaginalis in prostate tissue in the development of benign prostate hyperplasia. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-016-1843-1) contains supplementary material, which is available to authorized users.