Diagnosing IgAN: The Importance of Early and Accurate Identification

Announcer:
You’re listening to Clinician’s Roundtable on ReachMD. On this episode, Dr. James Chevalier will discuss challenges in diagnosing IgA nephropathy, or IgAN. Dr. Chevalier is an Assistant Attending Physician at New York-Presbyterian Hospital and an Assistant Professor of Clinical Medicine at Cornell University’s Weill Cornell Medical College. Let’s hear from Dr. Chevalier now.

Dr. Chevalier:
It actually can be fairly challenging to diagnose IgA nephropathy, especially when it’s in its early stages. A lot of times, a person will have a little bit of blood or a little bit of protein in the urine, and when a doctor or an urgent care is seeing somebody like that, they may think, “Oh, it’s just an infection. We’ll give you some antibiotics,” which is another common cause for those things in the urine.

In a lot of countries, especially in Asia, they actually do screening of school-aged children looking for blood and protein in the urine and will then have the child seek medical attention. In other countries of the world where they have mandatory military service, again, they’ll do blood and urine testing before the person joins the military, and abnormal urine samples with blood and protein will get referred to a doctor for further screening for IgA nephropathy.

In the United States, people have often wondered whether or not a college physical, for example, might be a chance to screen for blood and protein in the urine and have somebody get checked more closely for IgA nephropathy. But I do think that if and when any medical personnel or even a patient sees blood and protein in their urine, they shouldn’t just let it go unchecked but, at the minimum, repeat it and follow up on abnormal results.

A biopsy is the only way that we can tell that a person has IgA nephropathy. There are a lot of different diseases that might have some blood and protein in the urine. Some of them are benign, and some of them are more serious. Usually, if the amount of protein in the urine is very, very low, a person might not get a biopsy at all because the abnormalities are so mild. A biopsy takes a sample of the kidneys and looks at the microscopic filters of the kidneys to see why they’re damaged and how they’re damaged, meaning why they’re leaking this blood and protein in the urine.

Once we have confirmation that the biopsy shows this is IgA nephropathy, our pathologist will give it a score. It’s called the MEST-C score. An example of a MEST score would be M1, E1, S1, T0, or C0. Every number in the MEST score that’s not a 0 increases the person’s risk of having kidney failure later on in their life, so in general, a MEST-C score of 0 is the least aggressive and a MEST-C score of 7 is the most aggressive. If there’s a 1 or a 2 next to the E or the C, that usually means that the immune system is actively attacking the kidneys and that a person is more likely to respond well to medicines that suppress the immune system. A person who has a 1 or a 2 next to the M, the S, or the T is usually described as having old damage or chronic scarring, which is less likely to be fixed. In the end, anyone who’s newly diagnosed with IgA nephropathy should use this MEST score as part of the overall evaluation of how aggressive the IgA is and how to treat them.

Right now, the current diagnostic tools for IgA nephropathy are limited because we really need the kidney biopsy to tell us that this is definitely IgA nephropathy. I think that everyone in the world of nephrology and in medicine in general is hoping that in the future we’ll have ways of diagnosing people with IgA nephropathy and other kidney diseases just by doing urine and blood tests. And then eventually, we’ll even be able to personalize the treatment plan based on the blood and urine tests with more information about levels of other chemicals in the blood or urine, which could help us say which medicines might be better and how aggressive the IgA is for each individual person.

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That was Dr. James Chevalier talking about challenges in IgA nephropathy diagnosis. To access this and other episodes in our series, visit Clinician’s Roundtable on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!