#NephMadness 2021: Mining Liquid Gold — Now is the Time to “Shine a Light” on Urine Microscopy

Submit your picks! | NephMadness 2021 | #NephMadness#LiquidBiopsy

Ruth Schulman @RuthSchulman
Ruth Schulman is a second year Nephrology Fellow at Beth Israel Deaconess Medical Center in Boston, MA. She is completing the clinical tract with a focus on medical education. She is particularly interested in how to best inspire more trainees to enter the field of Nephrology.

Competitors for the Liquid Biopsy Region

Microscopy Techniques vs Staining Techniques

Urine Microscopy for GN vs Urine Microscopy for ATN

There is something so elegant in the simplicity of urine microscopy. Physicians have recognized the importance of urine in elucidating kidney pathology since the time of the ancient Babylonians 6000 years ago. The fact that we can take the waste product from the great maintainers of homeostasis and use it to hone in on a likely etiology, determine which tests to order, guide empiric therapy, and inform a broad sense of prognosis remains a core and essential skill in our work as nephrologists.

I still remember the first time I performed urine microscopy. As I slowly turned the polarizer, beautiful acyclovir crystals came into view and voila, I knew the etiology of the acute kidney injury (AKI). I was amazed that using a noninvasive test allowed my team to solve the mystery of the patient’s AKI. It was in that moment during my 3rd year of medical school, that my already budding interest in nephrology was affirmed. As a 1st year fellow, when there was a tremendous amount of new information to process, I valued the quick answers that urine microscopy provided and enjoyed taking the time to look at beautiful images.

© Ruth Schulman, used with permission.

The “liquid biopsy” can be used to help us differentiate between hepatorenal syndrome and acute tubular necrosis, decide which patient should be biopsied versus which one can be monitored without a biopsy, and aid us in predicting severity of AKI. Performing urine microscopy is like a referee reviewing the instant replay – it helps us know what call to make. Yes, of course there are limitations to this test. A sediment can be unrevealing despite the presence of intrinsic kidney disease and parenchymal damage. There is also a degree of interobserver variability in the interpretation of sediment findings. However, when evaluated under the lens of clinical context, it helps a clinician narrow their differential diagnosis.

With the advent of automated laboratory urine testing, some may wonder “why bother performing it ourselves”? There is revitalized excitement around point of care testing, with point of care ultrasound (POCUS) being the most talked about in the world of nephrology. Can urine microscopy give POCUS a run for its money? It has been around for almost 200 years and is still used daily around the world. In fact, it may be one of the oldest point of care tests. Multiple studies have found that automated systems don’t have the same sensitivity for identifying certain elements, such as casts, as compared to a Nephrologist. A small single center study showed that even when blinded to the clinical history, a Nephrologist conducting urine microscopy correctly diagnosed the patient >90% of the time as compared to <20% of the time for another Nephrologist using an automated report. 90%! That’s as good as the best players’ successful free throw percentages.

How can we best use these time-honored skills as a way to inspire #PisseProphets of the future? All four teams bring their own special perspective to the table. My vote, though, is for the colorful and vibrant images that come from Team Staining Technique. As an already diehard fan of the entire Urine Microscopy region, my own recent discovery of a world in color reignited my love for life under the lens. It’s like watching a game with players in their home team colors. In a field of things to view, it’s helpful to have those colors to identify who the players are! The crowd lights up, the player and coaches can be seen. This makes reviewing the play fun and exciting. It might even enhance the accuracy of the replay.

Social media has catapulted to the forefront of medical education with its ability to capture attention in a way that the classroom hasn’t done before. With the advent of microscope camera technology, these platforms bring beautiful images of urine sediment to our fingertips. Not only does social media shine a light on the world of nephrology, it is also a useful tool for those learning how to interpret urine microscopy findings. Now, more than ever, trainees can learn more about urine microscopy and understand how to use these images in clinical decision making. All that glitters is not gold…it’s glitter cells (white blood cells in the urine).

© Ruth Schulman, used with permission.

In ancient times, they used uroscopy. In modern times, we use microscopy. Urine evaluation has been and should remain an important part of our diagnostic arsenal- thankfully we don’t have to taste test it anymore.

– Guest Post written by Ruth Schulman @RuthSchulman

As with all content on the AJKD Blog, the opinions expressed are those of the author of each post, and are not necessarily shared or endorsed by the AJKD Blog, AJKD, the National Kidney Foundation, Elsevier, or any other entity unless explicitly stated.  

Submit your picks! | #NephMadness | @NephMadness | #LiquidBiopsy

Leave a Reply