Filling the Gap: Testing to Identify Early-Stage CKD
Experts discuss key challenges in testing and diagnosing a patient with chronic kidney disease, especially for those who are asymptomatic. In addition, they highlight new screening approaches to accurately identify these patients.
Transcript
Dhiren Patel, PharmD: Do you think those guidelines, specifically the KDIGO [Kidney Disease: Improving Global Outcomes] guidelines on staging, and the heat map accurately capture the patient’s overall health status and potential prognostic outcomes?
Robert Busch, MD: They’re helpful, and a lot of our colleagues don’t even use those, but now there is some better testing that could give a prognosis of how likely you are to [have] your kidney disease advance versus someone you don’t have to worry about as much based on these inflammatory markers. [There is a] new test that is currently being done, but a lot of our colleagues don’t know about the test, and some of them just do a GFR and don’t even do a urine microalbumin.
Dhiren Patel, PharmD: Sure.
Robert Busch, MD: So if you can do the urine microalbumin and a GFR, that’s good, but now there are even better [options] to be able to do the prognosis, how likely you are to rapidly worsen in your kidney disease, and then what you could do about it. It’s an actionable test [to lead you to] do something to prevent kidney disease worsening.
Dhiren Patel, PharmD: OK, I would love to learn more about that test…. So what you’re saying is this test is now helpful in addressing some of these key challenges that you have in early CKD, because you might not be picking that up, especially if you only have 1 of the 2 tests. Talk to us a little bit about that gap that it’s filling and a little bit more about the test.
Robert Busch, MD: OK, so first of all, you’re doing a GFR and a urine microalbumin to see how likely you are to progress, but that’s just 1 point in time. You know, there are a lot of things that can affect GFR; your volume status can, and also when you’re adding an ACE [angiotensin-converting enzyme inhibitor] or an ARB [angiotensin receptor blocker] or an SGLT2 inhibitor, sometimes the GFR worsens. [This could lead you to falsely believe] thinking the person’s kidneys are getting worse, even though that will stabilize things. This other test, it’s KidneyIntelX test from Renalytix. It is a proprietary test where they looked at many factors that would give the prognosis [of] who’s likely to go on to worsening kidney disease and who isn’t. And they found factors beyond GFR and urine microalbumin. These factors are inflammatory markers made in the kidneys based on tubular damage. Interestingly, GFR and urine microalbumin look at glomerular damage, but don’t really look at the tubules, You could have inflammation in the tubules as demonstrated by these tests and you wouldn’t know it by GFR and urine microalbumin. So it’s a point score that you get by looking at several factors called tumor necrosis factor receptor 1, tumor necrosis factor receptor 2, and kidney injury molecule, or KIM. And those are the 3 key things that they look at plus some other clinical factors to give you a prognosis: How likely is your patient to go on to advance kidney disease versus?
Dhiren Patel, PharmD: OK, that’s really helpful. And as you were talking about it, it seemed like there’s underutilization of the urine albumin-creatinine ratio, or uACR. Why do you think that is?
Robert Busch, MD: Well, during the [COVID-19] pandemic, patients didn’t want to give a urine specimen. [For example,] women didn’t want to sit on a toilet seat…. You’ll miss a lot of patients who are urine microalbumin positive, even though their GFR is OK, you’ll miss the [patients with] stage 1 and 2 [disease who] are urine microalbumin….
Dhiren Patel, PharmD: So having that, you’re not going to basically be able to get an accurate CKD diagnosis; that is what I’m hearing.
Robert Busch, MD: No, and some labs just give you GFR above 60, so you think all is fine. You really have to modify that by doing the urine microalbumin because if that’s positive, you do have to worry about that patient and do something to prevent the kidneys from worsening.
Transcript was AI-generated and edited for clarity.
