The chronic pelvic pain syndrome (CPPS) is characterized by pelvic pain, voiding symptoms and varying degrees of inflammation within expressed prostatic secretions (EPS). We evaluated the chemokines MCP-1 (CCL2) and MIP-1α (CCL3) in EPS to identify marker elevations associated with both inflammatory (IIIA) and non-inflammatory (IIIB) CPPS. In addition, chemokine levels were correlated with clinical pain as determined by the NIH chronic prostatitis symptom index (CPSI).
MATERIALS AND METHODS
EPS were collected by digital rectal examination and evaluated by ELISA for MCP-1 and MIP-1α in 154 patients; controls (n = 13), BPH (n = 54), CPPS IIIA (n = 37), CPPS IIIB (n = 50). MCP-1 and MIP-1α levels were compared between IIIA, IIIB, and the control subgroups and correlated against the CPSI and pain sub-score using a Spearman test.
Mean levels of MCP-1 in the control, inflammatory BPH, non-inflammatory BPH, inflammatory CPPS, and non-inflammatory CPPS were 599.4, 886.0, 1636.5, 3261.2, and 2272.7 pg/ml, respectively. Mean levels of MIP-1α in the control, inflammatory BPH, non-inflammatory BPH, IIIA CPPS, and IIIB CPPS were 140.1, 299.4, 238.7, 1057.8, and 978.4 pg/ml, respectively. For each cytokine, both CPPS subtypes had statistically higher levels than the control group and BPH patients (p=0.0002). Receiver operating curves utilizing MCP-1 levels greater than 704 pg/ml and MIP-1α greater than 146 pg/ml identified patients with CPPS with an accuracy of 90% from control patients. MIP-1α levels (p=0.0007) correlated with the pain sub-score of the CPSI while MCP-1 (p=0.71) did not.
MCP-1 and MIP-1α within the prostatic fluid in both CPPS subtypes provide candidate future biomarkers for CPPS. In addition, MIP-1α elevation in EPS provides a new marker for clinical pain in CPPS patients. Given these findings, prostatic dysfunction likely plays a role in the pathophysiology of some patients with this syndrome. These chemokines may serve as effective diagnostic markers and modulators against the chemokines could provide an attractive treatment strategy in individuals with CPPS.