A passion that started early

For a lot of physicians, a subspecialty is something they grow into over years of training. For Dr. Arun Rajasekaran, it was closer to love at first sight.

Dr. Rajasekaran found glomerular disease before he found a residency program. In his final year of medical school in India, he came to the United States as a visiting medical student and spent about four months rotating through nephrology, including a three-month research rotation in glomerular disease at Johns Hopkins.

That was all it took.

"I realized that I should be doing glomerular disease as a career," he said. "I was very interested in it way before even joining residency. My research focus was glomerular diseases."

He carried that focus through his internal medicine residency at the University of Central Florida in Orlando, then a nephrology fellowship and an advanced glomerular disease and clinical research fellowship at the University of Alabama at Birmingham, where he later spent several years on the faculty. In 2025, he moved into private practice at Renal Medicine Associates in Albuquerque, New Mexico, where he now co-directs the Glomerular Disease Center and Clinical Trials Unit.

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Why glomerular disease

First, a bit of background. Your kidneys are filled with tiny filters called glomeruli that clean waste and extra fluid out of your blood while keeping the things your body needs, like protein, where they belong. Glomerular diseases are a group of conditions, many of them rare, in which those filters become damaged, often because the immune system attacks them. When the filters stop working the way they should, protein and/or blood can leak into the urine, leading to symptoms like swelling, foamy urine, and fatigue. Over time, some of these diseases can quietly threaten the kidney's ability to do its job. Primary membranous nephropathy and IgAN are some of them.

Ask Dr. Rajasekaran what keeps him fascinated in glomerular diseases after all these years, and he lights up talking about the biology.

"The kidneys are a very, very complicated and interesting organ, and glomerular diseases are extremely fascinating," he said. "There's a lot to do with immunology. It's one area of nephrology that involves critical thinking, along with immunosuppression and a strong foundation in immunology. That's what attracts me."

It is that interdisciplinary quality, where kidney physiology, pathology, and immunology all meet, that he keeps coming back to. Treating these conditions, he says, increasingly means thinking like an immunologist as much as a nephrologist.

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A field transformed

For much of Dr. Rajasekaran's early career, nephrology was a quiet corner of medicine when it came to new treatments. Clinical trials were hard to run because they depended on long-term outcomes like kidney failure or dialysis, which can take many years to measure.

That has changed dramatically.

"The last decade in nephrology has been transformative," he said. "The future is very fascinating for this niche area within nephrology."

The turning point, he explains, was the acceptance of earlier surrogate markers of kidney health, like the amount of protein leaking into the urine and slopes/trajectories of kidney function, as meaningful signs that a treatment is working. Instead of waiting a decade to see results, researchers can now learn a great deal in a year or two. That shift opened the door to a wave of new trials and newly approved medications.

He describes clinical trials not as a last resort, but as one of several options he can offer, and he works hard to clear up a common fear about them.

"Placebo in today's world does not mean a sugar pill," he said. In many current glomerular disease trials, everyone eventually receives the active treatment through what is called an open label extension. "You're not going to be left without treatment. You will get treatment at some point, or you may receive it from the beginning." For him, trials are also simply how the field moves forward. "Clinical trials are the only way to advance science."

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The patience membranous nephropathy demands

When it comes to primary membranous nephropathy, Dr. Rajasekaran starts by making the disease understandable. He reaches plain language and patient education booklets from groups like NephCure and the GlomCon Foundation, and he walks each person through what their biopsy found and what it means for them.

He is honest about what makes membranous nephropathy hard. It is one of the most common causes of nephrotic syndrome, and while a few patients do well without immunosuppression, majority of patients will need tailored immunosuppressive treatments.

"You have to be very patient with this disease," he said. "You shouldn't act on sudden bursts of protein in the urine. You have to look at the entire history." Getting a patient into lasting remission, he explains, can take a long time, and that is exactly where he sees an unmet need worth chasing. The treatment landscape is shifting quickly, with newer targeted therapies now being studied, and he wants better, safer, and tolerable options for the patients who wait the longest.

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"We are in this together"

What gives him the most hope is the science itself: new immune pathways being uncovered, treatments tailored to the individual patient rather than a one-size-fits-all approach, and real world data from large community based private practices like his own feeding back into what the whole field knows.

But when asked what he would most want a newly diagnosed patient to hear, he did not reach for any of that. His answer was five words.

"We are in this together."

It is a fitting line from a physician who has spent his entire career choosing, again and again, to stay close to these diseases and the people living with them.

Interested in learning about rare kidney studies? Visit patientwing.com to learn more about clinical studies for primary membranous nephropathy.