Blood Test Distinguishes Between Severe and Mild BPH

February 6, 2007

BALTIMORE -- Men with an aggressive form of benign prostatic hyperplasia, which requires early intervention to stave off bladder complications, can be found with an investigational blood test, reported a multicenter team.

BALTIMORE, Feb. 6 -- A simple blood test may help to identify men with not-so-benign benign prostatic hyperplasia (BPH), a multicenter trial found.

The serum-based assay for JM-27, a molecular marker for BPH, distinguished between those with mild BPH and the small percentage with the more aggressive form, which requires early intervention to stave off serious bladder complications, reported Robert Getzenberg, Ph.D., of Johns Hopkins, and colleagues.

The marker did not appear to be affected by the presence of prostate cancer, the authors noted in the February issue of the Journal of Urology.

"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," Dr. Getzenberg added, "and BPH that is highly symptomatic with increased potential to do damage to the bladder."

JM-27 is an androgen-regulated gene expressed in the prostate, testes, and uterus. It is expressed at significantly higher rates in men with symptomatic BPH than in men with either asymptomatic prostatic enlargement or no BPH.

The serum-based assay uses monoclonal antibodies raised against JM-27 to quantify the levels of the marker in serum. To see whether it could help clinicians to distinguish between different forms of BPH, the authors first analyzed the assay for sensitivity, and found that it could detect JM-27 at normal physiological quantities down to the ng/mL level.

They then tested it in 68 men with either asymptomatic BPH (defined as an American Urological Association symptom score

However, in men with severe BPH, JM-27 levels in tissue were higher than in men with milder disease, while serum levels of the marker were actually lower in men with severe BPH.

It's possible that in men with severe disease more of the JM-27 is bound to tissues, leaving less to circulate freely. Alternatively, the protein may be secreted at higher levels in patients with low AUA symptom scores, or might be degraded in the serum of men with high AUA scores, the authors speculated.

They also found high levels of JM-27 in the serum of men with confirmed prostate cancer, and are currently investigating how cancer might affect the pattern of expression.

The next step, Dr. Getezenberg said, is to see whether specific drugs for BPH have different action against the forms of the disease as differentiated by the JM-27 assay

"This is a provocative report detailing a potential new means of identifying patients with symptomatic BPH, and a significant addition to the urological literature with much scientific promise," wrote urologist Kevin T. McVary, M.D., of Northwestern in Chicago, in an accompanying editorial comment.

"The potential of JM-27 to screen patients at risk for symptomatic lower urinary tract symptoms is an immediate and reasonable justification for pursuing this line of study," he continued.

Dr. McVary cautioned however, that the study is preliminary and "thus a heavy dose of skepticism is warranted." He pointed out that the authors did not demonstrate whether the assay will be able to distinguish between symptomatic BPH and inflammation. He concluded that "simply put, additional studies with adequate controls are needed and likely under way."