Researchers are finding better ways to predict chronic kidney disease in an effort to treat it before dialysis becomes necessary. Photo by Mishu57/Wikimedia Commong
Chronic kidney disease is common, but complicated to treat because most people have no symptoms in its early stages. So detection as soon as possible is key to finding treatment that prevents kidney failure and reduces the need for a transplant or dialysis, experts say.
And, ultimately, finding better ways to predict whether a person will become ill could help introduce lifestyle changes to prevent chronic kidney disease — which affects roughly 38 million adults in the United States — in some individuals.
The numbers are startling: Fully one-third of the U.S. population is at increased risk of chronic kidney disease because of conditions including diabetes, hypertension, heart disease, obesity, a family history of the illness or because they are elderly, experts said.
Each year about 120,000 Americans begin kidney dialysis.
Against this daunting backdrop, clinicians in the field worry that making headway likely will be challenging despite advances in creating sophisticated tools to predict what Dr. Steven Coca, a nephrologist and professor of medicine at Icahn School of Medicine at Mount Sinai New York calls “an ignored disease.”
“It’s always been such an ignored disease … and it affects so many people,” Coca said in a phone interview with UPI. “There’s been inertia around kidney disease in physicians recognizing it, patients being aware … and there’s late referral to nephrologists even in late-stage kidney disease.”
Even simple, inexpensive screening tools for chronic kidney disease are vastly underutilized, Dr. Paul M. Palevsky, a nephrologist and president of the National Kidney Foundation, told UPI in a phone interview.
“While all of these screening tools are fascinating, where they fit in clinically must be determined,” said Palevsky, professor of medicine in the renal-electrolyte division at the University of Pittsburgh School of Medicine.
“With simple blood tests and urine tests [already available], we can identify early kidney disease and rapidly intervene.”
“Unfortunately, at this point, the vast majority of people with kidney disease are not being adequately identified and diagnosed,” he said.
“Ideally, as with most disease, if we identify who’s going to develop them, we could be screening more appropriately for it or somehow intervening to prevent it from developing,” Palevsky said.
In May, the National Kidney Foundation said it was encouraged by a news report that the influential U.S. Preventive Services Task Force may consider new guidelines for kidney disease screening.
Palevsky said that finding elevated protein levels in the urine is one of the first signs of kidney disease,
“So we can diagnose kidney disease very readily, but data show only approximately 15% to 20% of individuals known to be at risk, like people with diabetes, are tested with a simple blood and urine [screening] annually,” as recommended.
“What we find is despite the fact there is this tremendous burden of kidney disease in the population, screening for kidney disease does not occur even in high-risk populations, and as a result, there’s a missed opportunity for intervening,” he said.
He said this is particularly disconcerting because of the increased availability of simple, but effective, treatments over the past several years.
Using “screening tools already available to us, which are underutilized, is the step we need to be taking in 2022,” Palevsky said.
Recently, researchers at Columbia University published a study in Nature Medicine about their new algorithm designed to analyze thousands of variants across the genome and estimate a person’s genetic risk of developing chronic kidney disease.
Unlike previous demographically limited studies, the researchers broadly tested their method on 15 different groups of people, including those of African, Asian, European and LatinX descent.
The algorithm developed by the researchers at Columbia analyzes variants of a gene called APOL1, known to be a common cause of kidney disease in people of African descent, plus thousands of other kidney disease variants found in people of all ancestries.
The researchers found that, across all ancestries, individuals with the highest scores — in the top 2% — had triple the risk of kidney disease as compared to the general population. This is equivalent to having a family history of the disease, they noted.
Palevsky decribed the work out of Columbia as “groundbreaking in many ways.” But, he added, “There’s a lot that we can do right now to improve our diagnosis of kidney disease and provide treatment to slow the progression so that kidney disease does not go on to kidney failure.”
Palevsky described the Columbia University study as important because the researchers analyzed a broad population and used “robust” genetic information. “It explores new territory in terms of general risk because one of the big questions is how much of the risk is genetic versus … environmental,” he said.
However, Palevsky said, the reality is that such testing isn’t likely to be immediately useful to doctors and their patients until the cost of genetic testing decreases.
“This [research] has, I think, much more important, biological implications in our understanding of kidney disease than actual clinical applications,” he said, “because the average patient isn’t going out and having whole genomic sequencing done. That’s not the state of medicine in 2022.”
Coca agreed on the study’s significance. “We do have to evaluate polygenic risk scores rigorously, which they did,” he said. “But it’s a first step.”
Coca added it is important to consider that the Columbia University study is looking at relative risk, not absolute risk.
“It sounds impressive — a threefold risk [of developing kidney disease], but it’s only 2% of the population” compared to the remaining 98%, he explained. “For the top 20%, the risk was 2.23 — above a twofold risk,” compared to the remaining 80%.
Coca said his research group has worked on protein-based risk scores and absolute risk for high-risk populations. But he acknowledged that the next step, introducing sophisticated tools into broad clinical practice, will be a challenge.
“How do we leverage the genetic risk scores and biomarker protein-based risk scores to highlight the people who need that change in an efficient manner without causing anxiety or overloading the health system?” he asked.
Dr. Krzysztof Kiryluk, the Columbia University study’s co-author, told UPI that the researchers came up with “a simple DNA test” that looks at blood or saliva test and “can identify individuals at high inherited risk of kidney disease.” He said an individual likely won’t balk at using the advanced test method they devised.
“The testing is sophisticated on the back end, but from the patient’s perspective the test is actually extremely simple,” said Kiryluk, associate professor of medicine and a physician-scientist in the division of nephrology at Columbia University Vagelos College of Physicians and Surgeons.
It involves a one time blood draw or saliva collection for DNA.
“These individuals may require frequent screening for kidney disease [by blood and urine tests], and may benefit from lifestyle changes that could protect their kidneys, such as. weight loss, exercise, smoking cessation, blood pressure control, low salt diet, and avoidance of certain medications, and early initiation of protective medications if kidney disease is detected,” he said.
Asked to comment on the medical community’s inertia in treating kidney disease, Kiryluk said the Columbia University research “aims at prevention and early detection of kidney disease, to enable timely treatment.”
“We still need more effective therapies to prevent progression of kidney disease. The inertia is to some degree related to the limited effectiveness of current treatments, but this has been changing lately,” he said.
He added: “I think further studies are still needed to evaluate clinical utility of this test, and to determine precisely how this test fits with the current screening strategies for kidney disease.”