Andrew Bomback, MD, Columbia University Medical Center, gives an IC-MPGN and C3G overview, two rare inflammatory kidney diseases.
Transcription:
My name is Andrew Bomback. I am a nephrologist at Columbia University Irving Medical Center, where I am co-Director of the Center for Glomerular Diseases.
Immune complex MPGN, or what we call IC-MPGN, and C3 glomerulopathy are two diseases along a spectrum of inflammatory kidney diseases, where we believe that the alternative complement pathway is involved in the pathogenesis of the kidney injury.
In C3 glomerulopathy, we believe that the alternative complement pathway and its overactivity is responsible solely for the kidney injury and immune complex MPTN. We know that there’s a significant contribution in most of these patients from alternative pathway hyperactivity, but there may also be some contributions from the more traditional immune complex-mediated pathways.
They’re really two disease states along a spectrum, but they clearly are related. One of the ways we know that is that there are some patients who do multiple biopsies, and their first biopsy might be called immune complex MPGN, and their second biopsy is called C3 glomerulopathy. I tend to think of them as two diseases along the spectrum.
The diagnosis of these conditions has to be made by a kidney biopsy. There’s no other way to diagnose either immune complex MPGN or C3 glomerulopathy without a kidney biopsy. But even with the biopsy, that really is just describing a pattern of inflammation and suggesting a pathogenesis. In the case of these conditions, the biopsy really suggests that there is overactivity of the complement pathway that’s driving the kidney injury.
That still requires work on the pathologist and the nephrologists who are caring for this patient to figure out why the complement pathway is overactive, where the complement pathway might have lost control of its regulation. Ideally in the future, as we start to see the availability of complement targeting therapies, which complement targeting therapies may actually be beneficial for these patients.
There really is no standard of care for either of these conditions. Most patients with immune complex MPGN or C3 glomerulopathy, who have the more aggressive forms of the disease, are treated with nonspecific immunosuppression. I think the most common regimens for both combine the use of corticosteroids, typically with mycophenolate mofetil.
But that’s not disease-specific treatment, that’s essentially borrowing treatment regimens from other types of glomerular diseases that are more common, like lupus nephritis. But in terms of a standard of care that’s really specific to these diseases, those don’t exist.
To learn more: https://checkrare.com/diseases/kidney-and-urinary-diseases/