CD4+ and CD8+ T-lymphocyte scores cannot reliably predict progression in patients with benign prostatic hyperplasia

To determine whether the density of CD4(+) and CD8(+) T-lymphocytes in a transrectal ultrasonography (TRUS) biopsy of the prostate can be used to predict the progression of lower urinary tract symptoms (LUTS) in benign prostatic hyperplasia (BPH).

In total, 100 patients were randomly selected from a pool of patients with histologically proven, benign TRUS biopsy specimens. There were seven full years of follow-up available. Clinical data were recorded, including prostate volume, International Prostate Symptom Score (IPSS), prostate-specific antigen, urine flow rate, postvoid residual urine volume and previous prostate surgery. Markers of disease progression included the subsequent development of acute urinary retention (AUR), ≥4 point rise in IPSS, prescription of medical therapy (α-blocker or 5-α-reductase inhibitor) and bladder outlet surgery. Four patients' specimens were unsuitable for analysis. Biopsy sections from 96 patients were immunohistochemically stained for the presence of CD4(+) and CD8(+) T-lymphocytes and the density of infiltrate was assessed using random field sampling and point counting.

Some 29% of patients (28/96) did not have BPH at the time of biopsy. Of all patients, 41% (39/96) progressed, 10% of whom (4/39) did not have BPH at the time of biopsy. A further 10% (10/96) developed AUR, 7% (7/96) had a ≥4 point rise in IPSS, 33% (32/96) required medical therapy for BPH and 11% (11/96) required bladder outlet surgery. There was low correlation between CD4(+) and CD8(+) densities in paired sections. CD4(+) and CD8(+) densities did not provide any significant predictive function in the progression of BPH, nor was their any predictive association noted between CD4(+) and CD8(+) scores and the development of prostate cancer. Sub-analysis did show that a threshold mean of ≥1.35 CD8(+) cells per field predicted progression to AUR with a sensitivity of 60% (95% confidence interval, CI, 26.2-87.8), specificity of 73.3% (95% CI 62.6-82.2) but a positive predictive value of 20.6% (95% CI 8.0-39.7). CD4(+) infiltrate density suggested a trend to general progression but without statistical significance.

The present study, despite certain trends, shows no evidence for an association between CD4(+) and CD8(+) T-lymphocytes and the progression of LUTS in BPH.