Blood, Sweat and Smears: 5 Questions with Dr. Ashley Geffen
Podcast: Blood, Sweat and Smears – A Machaon Diagnostics Podcast
Air Date: August 5, 2024
Host: Bjorn (standing in for Dr. Brad Lewis)
Guest: Dr. Ashley Geffen, Pediatric Nephrologist, Phoenix Children’s
Episode Overview
This episode features pediatric nephrologist Dr. Ashley Geffen, who responds to "Five Questions" about diseases at the intersection of nephrology and hematology, especially those involving complement dysregulation and rare kidney disorders. The conversation covers disease differentiation, the challenges of diagnosing and treating pediatric cases, the future of genetic testing, and advice for aspiring pediatric nephrologists.
Key Discussion Points and Insights
1. Comparing C3G and HUS
- Bjorn’s Question: “I once heard C3G described as a HUS, confined to the kidneys. To what extent is that description correct or off the mark?”
- Dr. Geffen’s Insight [01:43]:
- The analogy is “mostly... off the mark.”
- Commonality: Both involve complement dysregulation.
- Key Distinction:
- On biopsy, they look “totally different.”
- C3GN is marked by C3 deposition in the kidneys.
- HUS presents as a thrombotic microangiopathy.
- Quote:
“Even though they're both closely related to complement, they look totally different. … The kidney presentation is totally different.” — Dr. Geffen [01:59]
- Genetics may overlap due to complement dysregulation, but the clinical manifestations and pathology differ greatly.
2. Acquired TTP in Pediatrics
- Bjorn’s Question: “Is it ever acquired TTP in pediatrics?”
- Dr. Geffen’s Insight [02:59]:
- “Never say never, but... extremely rare.”
- First consideration in children is almost always HUS.
- Rare pediatric TTP cases seen are usually genetic/inherited, not acquired.
- Plasma exchange is considered if presentation is unusual.
- Quote:
“Never say never, but highly unlikely from my experience.” — Dr. Geffen [03:28]
3. Making the Case for Pediatric Nephrology
- Bjorn’s Question: “How would you market pediatric nephrology to medical students?”
- Dr. Geffen’s Insight [03:48]:
- If you like kids, pediatrics is fulfilling—“always brings a smile to my face.”
- Offers tremendous variety: ICU, outpatient, chronic care, and genetics.
- “The physiology of the kidneys is so complicated and involves so many transporters. And math, if you like math, probably right for you.”
- Exposure to rare diseases is common—“I see rare disorders pretty much every day.”
- Emphasizes intrinsic interest, variety, intellectual challenge, and patient connections.
- Quote:
“If you like variety, I think that's a great specialty.” — Dr. Geffen [04:49]
“If you're someone who likes rare conditions… get bored doing the same thing every day, pediatric nephrology would be like a perfect thing for you and highly recommend it.” — Dr. Geffen [05:48]
4. Biggest Question Facing Pediatric Nephrology
- Bjorn’s Question: “What is the single biggest question facing pediatric nephrology?”
- Dr. Geffen’s Insight [06:14]:
- Integration of genetic testing into daily practice.
- Genetic testing has become more accessible in the last five years.
- Pediatric nephrologists now have wider access and support for genetic counseling.
- The ongoing question: How will genetic insights change care and therapy?
- Potential for developing novel therapies targeting rare genetic kidney diseases.
- Quote:
“I really think that's going to make a huge difference over the next five to 10 years as to how we practice, and not only that, but potentially novel therapies for all these rare diseases that we see all the time.” — Dr. Geffen [07:23]
5. Most Important Tool When AHUS is on the Differential
- Bjorn’s Question: “When AHUS is on your differential, what is the most important tool in your toolbox?”
- Dr. Geffen’s Insight [07:52]:
- Genetic testing is invaluable for long-term management and care planning.
- Treatment decisions (e.g., eculizumab) are not delayed for genetic results.
- A positive genetic finding informs prognosis: may justify lifelong complement inhibitor therapy.
- Up to 50% of cases may not have a known variant—patients should be counseled accordingly.
- Quote:
“If a patient has genetic testing that clearly shows they have a variant [that] would predispose them to genetic HUS, that's super useful because then I know, okay, these patients are going to need complement inhibitors, likely lifelong.” — Dr. Geffen [08:23]
Bonus Question: Recommendation for Listeners
- Travel Recommendation:
- Dr. Geffen recommends visiting Japan—recently spent a month there, traveling widely including Okinawa and Hokkaido.
- “Japan is so interesting and such a great place to visit… the food is amazing. The culture is so different… but similar in a lot of ways too.”
- Quote:
“If you like to travel, take the opportunity to visit Japan. That would be my one recommendation.” — Dr. Geffen [09:43]
Notable Quotes & Memorable Moments
-
On the difference between C3GN and HUS:
“The pathology being so different, you can't really say they're like the same thing confined to the kidney because the kidney presentation is totally different.” — Dr. Geffen [02:16]
-
On the appeal of pediatric nephrology:
“You get a taste of the ICU… you're also sort of a primary care doctor for a lot of these kids, especially with chronic kidney disease… If you like variety, I think that's a great specialty.” — Dr. Geffen [04:20, 04:49]
-
On genetic advances:
“About five years ago, [there was] this sort of boom in genetics in nephrology... how is this going to affect what we do?” — Dr. Geffen [06:35]
Timestamps for Key Segments
- C3G vs HUS: 01:43 – 02:52
- Acquired TTP in Pediatrics: 02:52 – 03:34
- Marketing Pediatric Nephrology: 03:48 – 06:05
- Biggest Question Facing the Field: 06:14 – 07:44
- AHUS: Most Important Tool: 07:52 – 09:12
- Bonus Recommendation (Japan): 09:22 – 10:11
Summary
Dr. Ashley Geffen articulates both the scientific complexity and personal fulfillment she finds in pediatric nephrology, emphasizing the specialty’s diversity, intellectual excitement, and the dramatic impact emerging genetic tools will have on the diagnosis and management of rare kidney diseases. Her clinical approach is pragmatic and patient-centered—empowering families with information, leveraging genetic testing for long-term planning, and advocating for early and aggressive therapy when needed. Her enthusiasm for her field and life (with a plug for travel in Japan) makes this interview informative and inspiring for both clinicians and students considering this unique subspecialty.