Evaluation of the cytokines interleukin 8 and epithelial neutrophil activating peptide 78 as indicators of inflammation in prostatic secretions

Abstract

Objectives: Chronic prostatitis/chronic pelvic pain syndrome (CPPS) is a disorder characterized by pelvic pain and varying degrees of inflammation exhibited in expressed prostatic secretions (EPS). To provide objective parameters of inflammation, we measured the cytokines interleukin 8 (IL-8) and epithelial neutrophil activating peptide 78 (ENA-78) in EPS of healthy men, men with benign prostatic hyperplasia (BPH), men with bacterial prostatitis (BP), and men with chronic prostatitis/CPPS.

Methods: Enzyme-linked immunosorbent assays of the EPS for IL-8 and ENA-78 were done in 63 men: control (n = 9), BPH (n = 6), BP (n = 3), inflammatory CPPS (National Institutes of Health [NIH] category IIIa) (n = 17), noninflammatory CPPS (NIH category IIIb) (n = 17), and asymptomatic inflammatory prostatitis (NIH category IV) (n = 11).

Results: IL-8 was detectable in all patients, and ENA-78 was detectable in all except 2 patients (threshold of detection 10 pg/mL for IL-8, 15 pg/mL for ENA-78). Mean levels of IL-8 [ENA-78] were similar in control (3010 pg/mL [423 pg/mL]), BPH (3341 pg/mL [98 pg/mL]), and IIIb (2751 pg/mL [335 pg/mL]) groups. Both cytokine levels were higher in BP (11,175 pg/mL [13,761 pg/mL]), IIIa (10,418 pg/mL [2240 pg/mL]), and IV (8571 pg/mL [1865 pg/mL]) groups. A statistically significant difference between the control group versus BP, IIIa, and IV (P <0.05) groups was found for IL-8 but not for ENA-78.

Conclusions: IL-8 and ENA-78 are frequently elevated in the EPS of men with BP, CPPS IIIa, and asymptomatic inflammatory prostatitis category IV. These cytokines are direct mediators of leukocyte accumulation and activation at inflammatory sites and may be responsible, in part, for the presence of inflammatory reaction in the prostate.