Biomarker Detects Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BHP) is a common disease in men that until recently was considered a single disease with varying symptoms. A recent analysis revealed that a molecular marker, JM-27, is able to distinguish at the tissue level between highly symptomatic individuals and those with histologic disease.

Millions of middle-aged and older men experience the symptoms of an enlarged prostate multiple times during the day and night. What they may not know is that the disease known as BPH, marked by urgency and frequent urination, is not one but at least a pair of disorders.

A serum based enzyme-linked immunosorbent assay (ELISA) was developed using a novel anti-JM-27 monoclonal antibody. The assay was sensitive, detecting JM-27 at the low ng/ml level within the serum. A quantitative measurement of serum JM-27 levels was performed in 68 patients. The patients consisted of three groups of 29 patients with asymptomatic benign prostatic hyperplasia (American Urological Association symptom score of 15 or less), 39 with symptomatic benign prostatic hyperplasia (American Urological Association symptom score 16 to 32) and 17 with confirmed prostate cancer. The assay cutoff was determined after a pilot run of samples and applied prospectively.

The study was carried out by scientists at Johns Hopkins University (Baltimore, MD, USA) who found substantially higher levels of a protein made by a gene known as JM-27 in men whose BPH is more severe and more likely to lead to bladder-related complications if left untreated. The study was published in the February 2007 issue of the Journal of Urology.

Although BPH affects the prostate, the resulting symptoms are often called lower urinary tract symptoms, or LUTS. These symptoms reflect not only the direct effects of the prostate on urinary flow and urgency, but functional changes in the bladder that result from the increased pressure.

The Johns Hopkins team, lead by Robert Getzenberg, Ph.D., also developed a blood test that detects the JM-27 protein in men with severe symptoms. The JM-27 diagnostic test, if eventually approved by the FDA, could be used to identify men with this highly symptomatic form of the disease early, before there is any damage to the bladder or urinary tract.

Our experiments show that the expression of this marker is related to the presence of the severe form of BPH and not to the size of the prostate or to the presence or risk of prostate cancer, said Dr. Getzenberg. What we're looking at is two diseases: BPH that produces more mild symptoms and is less likely to lead to bladder and other urinary tract damage, and BPH that is highly symptomatic with increased potential to do damage to the bladder.

Current medical therapy for men who suffer from BPH is with two classes of drugs: alpha blockers, which relax the prostate and 5-alpha reductase inhibitors, which help to shrink it. Forms of BPH that do not respond to medical therapies frequently require surgical intervention. The next step is to figure out which drugs work best on which form of the disease as differentiated by JM-27, Dr. Getzenberg said.




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