Conference Review: Renal Biopsy in Medical Diseases of the Kidneys

I'm not a huge conference goer.   I've been to ASN a few times and have made a brief appearance at the Advanced Nephrology for the Consultant down in San Diego but otherwise haven't seen much of the conference circuit.  But when I got the Columbia flyer for the Renal Biopsy in Medical Diseases of the Kidneys a few years ago I knew it was going to be something I'd have to eventually check out.  It features the core of the GN clinical and pathology brain trust lecturing on what they know best: what GNs look like and how to manage them.  Falk and Jennete on ANCA, Appel and D'Agati on SLE, Rennke on, well, anything.  So this summer I finally got myself organized and funded and took the trip out to Manhattan to see the show.

First, a few general comments.  Staying in Manhattan is expensive.  Like $400 a night expensive.  The conference had a block of rooms reserved at hotel called the Lucerne for $200 a night.  I procrastinated and called the hotel after the deadline listed in the flyer and was politely told that all the rooms were gone and I could now book one for $440 a night if I was interested.  I declined and luckily had a family member take mercy on me and allowed me to stay with them on short notice.  If that hadn't come through I was ready to book a room through Airbnb which, if you haven't used it, is a cool site where you can find locals renting out space in their homes for cheap.

Second, it is hot and humid in Manhattan in the summer. Crazy hot. Bring wardrobe accordingly. I scuttled between air conditioning on the subway, lecture hall and my hosts place the whole week (I know, soft Californian behavior).

Third, take advantage and see Manhattan. I channeled my inner intern and skimped on sleep to hit the conference then experience the city.  Well worth it.

As for the conference it is certainly one of the best I've ever been to.  It's truly education focused, the talks are given in series rather than parallel like some of the big conferences so you're never at risk for missing anything.  The speakers are, for the most part, amazingly clear and avoid the common sin of nerding out on their own particular pet projects but rather focus on big picture relevance.

It's fun watching the older and younger members of the team interact as they clearly like each other and have a great back and forth.  You also get a sense of how some of the younger faculty like Glenn Markowitz, Andrew Bomback and Leal Herlitz are coming into their own and making their marks on the GN world.

The group aren't afraid to give their opinions when it gets to the grey areas.  Who doesn't want to hear how Gerry Appel manages not so clear cut cases of Lupus Nephritis?

Lots of path slides, which for those like myself about to take boards, is great review.  The faculty clearly take pride in their lectures and are up-to-date current in their lectures with recent literature incorporated.  Lots of interested cases discussed.  Very nice syllabus with all slides included.  If they want to kick up their game they could go for online access to high res versions of the path slides - though many of them you can find in the recent NephSap renal path edition.

My inner intern unfortunately caught up with me on the last day and I missed Saturday morning and had to catch a flight out before the path and case workshops in the afternoon.

My only gripe would be the daily supplied lunch - terrible.  I bailed and braved the heat to find something good to eat, which was actually a lot of fun.  All in all a wonderful conference that I highly recommend.  I kept up a pretty good twitter feed of pearls from the first three days of lectures which you can check out here.



A unified view of abnormal sodium regulation in the nephron

Summer has come to the northern hemisphere and it is time to praise our kidneys for all the hard work of preserving the intravascular volume. Although only 30% of Na reabsorption takes place in the distal nephron, this is the place for most common genetic diseases causing abnormal sodium handling:

What are the responsible proteins for these diseases?
1. Bartter syndrome: Na reabsorption decreases via NKCC2 due to defects in NKCC2, ROMK and basolateral Cl channels or from an overactive basolateral CaSR.
2. Gitelman syndrome: Na reabsorption decreases due to a reduced number of NCCs on the luminal membrane.
3. Pseudohypoaldosteronism type 1: Na reabsorption decreases due to the defects in ENaC or mineralocorticoid receptor.
4. Liddle syndrome: Na reabsorption increases due to a higher number of ENaCs on the luminal membrane (they are spared from ubiquitination).
5. Gordon syndrome: Na reabsorption increases due to a higher concentration of NCCs on the luminal membrane (defects in WNK4 or overactive WNK1). More recently, mutations were discovered in the genes encoding KLHL3 and CUL3 proteins.
CUL3 is a component of ubiquitin ligase and KLHL3 is its partner (expressed in the DCT). It is speculated that the defects in these proteins may change the distribution of NCC.
Is this clinically relevant?
In Gordon syndrome, these mutations can occur de novo and are encountered more frequently (47% for KLHL3 and 32% for CUL3) than those involving the WNK kinases (13%). It appears that they are under-diagnosed and some of the cases of RTA type 4 with hypertension could be caused by them!
50 years after Bartter syndrome was described, the work on mechanisms responsible for abnormal Na regulation in the nephron continues…

Posted by Tomoki Tsukahara MD