Small-scale preliminary trials suggested that careful control of blood pressure could possibly delay or even prevent kidney failure in patients with polycystic kidney disease (PKD), which affects more than 600,000 people in the United States.
Now the National Institutes of Health and the PKD Foundation have launched two large-scale national trials, called the HALT-PKD (Halt Progression of PKD), to see if the combination of two blood-pressure drugs will work better than one in slowing the progression of the disease.
The trials are open to volunteers who have autosomal dominant PKD, the most common form.
The Division of Biostatistics at the School of Medicine will serve as the coordinating center for the studies and will be responsible for organizing, documenting and reporting on the trials, according to J. Philip Miller, coordinating center director, professor of biostatistics and director of the Biostatistics Core for the Siteman Cancer Center.
Autosomal dominant PKD is an inherited disorder that can be passed on to a patient’s children if they inherit a single copy of the abnormal gene, giving each child a 50 percent chance of inheriting PKD. The disease causes numerous cysts to form in the kidneys that contribute to development of high blood pressure and aneurysms. About half of autosomal dominant PKD patients eventually experience kidney failure and require dialysis or a kidney transplant.
“Not only does the patients’ high blood pressure have an adverse effect on their kidneys, but it also leads to cardiovascular complications, which cause most deaths in patients with PKD,” Miller said. “These studies aim to find out if we should treat hypertension in PKD patients with standard treatments or if we should be more aggressive in reducing blood pressure.”
The trials will compare therapy with an angiotensin-converting enzyme (ACE) inhibitor, a traditional medication for reducing blood pressure, to more intensive therapy that uses both an ACE inhibitor and an angiotensin receptor blocker (ARB), a newer agent shown to lower blood pressure in many patients. One trial includes patients at an early stage of PKD while the other focuses on patients with more advanced disease.
Researchers will recruit more than 1,000 patients for the trials and treat patients for up to four years. Patients will take home a device for measuring blood pressure, and all medications will be free. Kidney function will be checked with standard blood tests, or in cases where kidney function is not yet affected, cyst development will be measured with magnetic resonance imaging (MRI) scans.
The MRI techniques for monitoring the progression of PKD were developed at the School of Medicine.
PKD patients may volunteer by contacting the School of Medicine’s HALT-PKD coordinating center at 362-1318 or e-mailing project manager Robin Woltman at robinw@wubios.wustl.edu. Patients will be referred to one of the seven participating centers, which are in Atlanta; Boston; Cleveland; Denver; Kansas City, Mo.; and Rochester, Minn.