Detective Nephron: Next venture

The detective returns with the next adventure in ASN Kidney News 2020 August issue

Topic Discussion: Pyelonephritis but no Urinary Tract Infection?

Pyelonephritis is defined as neutrophilic infiltration within the interstitium suggestive of a bacterial cause of urinary tract infection that might have migrated to the kidney. It rarely evolves into an abscess.

Can this exist without any signs of an urinary track infection? 
A study published in NDT looked prospectively of over 200 cases of acute pyelonephritis. 
What did they find?

Urinary culture was only positive in 31% of patients and blood cultures in 21%

92% did have CT findings of pyelonephritis. 
No differences were noted in patients with positive or negative CT findings in terms of fevers, and wbc counts, pyuria, urine cultures and symptoms. 

Why the negative urinalysis and urine culture? 

The low frequency of positive urine culture may be explained by previous antibiotic treatment, either self-prescribed or prescribed by the general practitioner, and by the possibility that infection was confined to the renal parenchyma. Could reflux disease explain some findings?While the association between acute pyelonephritis  and reflux has been extensively studied in children, the literature does not indicate when reflux must be searched in adults. The authors performed retrograde urethrocystography in the case of recurrent acute pyelonephritis or in the presence of urinary cavities dilation or urinary tract abnormalities: they found reflux in 20.9% of patients. 

In other words, the absence of infected urine does not rule out the diagnosis of acute pyelonephritis in common clinical practice. Renal abscesses are frequent and need to be looked for. Hence, it seems advisable to systematically perform CT or MRI, which have greater sensitivity than ultrasound in detecting them.

Topic Discussion: COVID and Kidneys- the biopsy experience

As we expand our understanding of COVID-19 related AKI, in the last few weeks, more studies are emerging on what might be the main kidney biopsy findings with COVID related AKI.
We have now established the incidence being around 30-40% in the US.

What is exactly going on in the kidney? Is the virus attacking the kidney or is the renal disease a consequence of "being sick" and or  "inflammatory state".

This figure from an article in JASN summarizes the potential way the SARS-Cov2 might be effecting the kidney



Two recent biopsy series from Columbia and Northwell Nephrology showed the variety of pathology reported in COVID-19



In addition, an autopsy series (specific) to the kidneys showed ATN only.  Finally, in KI, a series of anti GBM were reported in UK related to COVID-19

All recent papers added interesting few things to the ongoing literature.

1. ATN is by far the most common presentation for AKI( if not pre renal)- even in transplanted kidney. Pigment nephropathy from myoglobin or hemoglobin is rare. Vitamin C overdose induced oxalate nephropathy is rare.
2. Podocytopathies( MCD and cGN) are the most common glomerular findings
3. Other glomerular diseases are a varied amount( TMA, ANCA, Membranous GN, anti GBM)
4. The virus was not found in the kidney with immunohistochemistry in all 3 studies.

Does the kidney get infected?- time will tell.. data is mixed

10 Years of Nephrology Social Media

10 years and a few months ago, I wrote the first nephronpower post. It was simple and about a historical event in nephrology. My inspiration was the Late Nate Hellman from Renal Fellow Network. What has transpired since then is truly amazing for the field of Nephrology.

Few of us started blogging at National conferences, some of us tweeting like a storm. Finally, the academic community noticed this and soon ASN, NKF and all wanted tweets and blogs of their events. The first landmark paper summarizing some of this was in AJKD in 2011.

Following that, was the birth of AJKDblog or then called eAJKD. This allowed for more collaboration and more social media to flourish in nephrology and leading to the ultimate- Nephmadness ( mastermind game by the Topf Sparks team) in 2013.

After 2013, nothing was stopping nephrology to take the lead in social media.
From NephJC to tweetorials to whatsApp to creation of NSMC-- happening so fast and furious!

Nephrologists quickly stormed the social media world to lead and show how it's done!
In NDT is a brief tutorial for how to be social media savvy.

Academic journals- AJKDBlog
Journal club- NephJC
Well ironed blogs- Renal Fellow Network
Online Successfully run interactive game for over 7 years- Nephmadness
Online academy of educators for future social media wannabees- NSMC
Every fellowship program trying to have a twitter account and social media presence.

What else can you ask for?
All this is summarized in recent issue in Seminars in Nephrology by guest editor Joel Topf and includes all various aspects of the social media
Here is a nice tweetorial by Chan on the entire issue

Seminars in Nephrology has an entire issue devoted to social media in the discipline of nephrology.

The mastermind @kidney_boy highlights the contents here:https://t.co/1XhYQLpEyS pic.twitter.com/OQs757SxmI

— Teresa Chan (@TChanMD) June 20, 2020

Introduction to social media
Tweet or not to tweet
Twitter based journal clubs
Tweetorials
Podcasting
Newsletters
Visual abstracts
Slack
Semi-private Apps ( WhatsApp)
FOAM quality 
NSMC

Congratulation to the nephrology community to being leaders in education via social media in medicine!

Topic Discussion: Use of immunotherapy in ESRD patients

Two recent studies from US now describe the use of immunotherapy in ESRD patients. Though both are case studies and series, this is encouraging data.

One study comes from Boston published in AJKD, with a database search leading to 18 patients: overall, six patients (32%) experienced irAEs and two (11%) experienced an irAE of grade 3/4 toxicity (pneumonitis, myocarditis).

Another study from New York published in Kidney 360, with a database search lead to 8 patients: only 2 patients (25%) experienced irAEs overall. A literature review done in that paper also found another 26 patients have previously been described in the literature, with the majority of them from  Italy and China.  Interestingly, 27% of these patients were on dialysis as a result of a rejected kidney transplant due to ICI therapy, and then continued to receive ICI. Over 80% of the patients had either partial or complete response to treatment. Aside from the kidney transplant rejection preceding dialysis, a minimal number of patients had a grade 2, 3, or 4 adverse immunotherapy related event (15%).  In the general population, between 40-60% of patients receiving ICIs experience irAEs at some point during therapy.

Again, due to smaller numbers, we cannot be sure the effects of ICI in ESRD patients but it appears that the rate of irAEs appears similar to general population. 

In the News: AKI in COVID-19 patients, a study and a story ( pics and words)

(Our fearless fellows during COVID-19)

As we tackle the world of COVID-19, at Northwell, we faced a lot of AKI related to COVID-19.
We were able to gather this data and publish a large 13 hospital dataset from US looking at AKI related to COVID-19. The data was just released in Kidney International today. This study is dedicated to all the patients and families we helped treat and our fearless warriors in this fight- our faculty, fellows, nurses, and all nephrology division staff at the two main campuses of North Shore University Hospital and LIJ at Northwell. Without their hard work, this study wouldn't be possible. We wanted to share some of our data here ( as a summary) with some personal faculty/fellows pics from the last 2 months of hard work.

1. When NY became the epicenter of COVID-19, nephrologist across NY noticed an alarming number of patients who developed AKI, at rates higher than reported in China. Our study reports the AKI rate and describes the presentation and risk factors of AKI in this population. We reviewed health records of patients hospitalized with COVID-19 between March1- April 5th, 2020, and followed up through April 12th. The data was from 13 hospitals. Our final cohort had 5449 patients.

2. Out of 5449 patients, 1993 (37%) developed AKI (stage 1-47%, stage 2- 22% and stage 3- 31%).
Up to 14% of all AKI patients required renal replacement therapy. At the time of this writing, among patients with AKI, 694 died (35%), 519 (26%) were discharged and 780 (39%) were still hospitalized.

3. AKI occurred early in the course of hospitalization, with 37% either arriving with AKI or developing within 24 hours of admission.

4. AKI was primarily seen in Covid-19 patients with respiratory failure, with 89.7% of patients on mechanical ventilation developing AKI compared to 21.7% of non-ventilated patients.
276/285 (96.8%) of patients requiring RRT were on ventilators.

                                           (Our LIJ renal team with Dept of Medicine Chair)


5. We found that independent risk factors for AKI included older age, diabetes mellitus, cardiovascular disease, Black race, hypertension, vasopressor medications and need for ventilation. In our study, baseline ACE-inhib use and BMI were not risk factors for AKI.

6. Around 66% of the patients had a urine Na of <35, suggestive of a prerenal state. In urinalysis, 46% had +ve blood and 42% had +ve protein. Unfortunately, we do not have accurate data on urethral catheters and baseline proteinuria.

                                            ( Our North Shore Inpatient rounding teams)

7.Why was our AKI rate higher (37%) than the study reported (5%) by Cheng et al?
We cannot completely explain this difference, but their patients had lower rates of comorbidities and ventilation needs than our patients. Our rates seem consistent with reports from US hospitals that are going to be published soon. In a recent preprint from Mt Sinai in NY- AKI rate was also 40%. Another US study also published at the same time from New Orleans found a rate of 28%.

8. We found a close temporal relationship between AKI and timing of intubation. It is possible that these patients developed ATN during systemic collapse. Since the 66% of AKI patients had urine Na of <35, they could have prerenal AKI.

9. Although not a primary purpose of this study, among the 285 on dialysis, 55% died, 42% still in the hospital and 3% were discharged.

                                            (Our North Shore Inpatient rounding teams)

10. It is important to note that because of early censoring and incomplete hospital disposition data, we cannot make definitive inferences about outcomes. We will do an update on full outcomes in 30 days. This study to define the rate of AKI, timing and risk factors.

11 The goal of this study was a broad description of AKI in COVID-19 patients. We believe that it is very important this information becomes available rapidly for clinicians. A full assessment of all patients’ outcomes will require a longer period of time to allow for disease processes to fully play out.

                                               (Our chief and associate chief in action)

12 What limitations do we have? 1. The cause of AKI were not fully elucidated. 2. Since this is an observational study, we will not be able to make causal inferences between exposures and AKI. 3. CKD could not be assessed given EHR data mining.

13 What are the strengths of the study? This is the largest cohort to date of hospitalized patients with COVID-19 with a focus on AKI. Our identification of AKI is consistent with guidelines, well-validated and automatically calculated in real-time for almost 1 year.

Cause of AKI- likely ischemic ATN( but AKI can come in various variants as noted on my prior post but a recent NEJM article also highlights potential involvement of ACE2 and renal tropism in AKI seen with COVID-19. In addition, there is an excellent CPC this week in NEJM on AKI with COVID-19.

Check out the above updates and tweetorial by first author Jia Ng, MD

I want to share our new paper “Acute kidney injury in patients hospitalized with COVID-19”. @kidney_int @hofstrakidney @hofstramed @jam_hirsch @danielwross4 @purvasharma821 @hiteshhshah Richard Barnett @gracezra1 @sfishbane @kdjhaveri https://t.co/XzvPa1vKtk

[THREAD] pic.twitter.com/Rq24N6XrLR

— Jia Hwei Ng, MD, MSCE (@jiahweing) May 14, 2020

The real heroes of our renal fight against COVID-19- our dialysis nurses and technicians!

Concept Map: AKI with COVID-19

Here is a concept map of early causes of AKI- what others and we have seen in NY. As you can see, tubular cause most likely but other compartments can be involved as well.