Topic Discussion: Collapsing GN and high interferon states

Collapsing GN is an interesting entity that is now thought to be related to proliferative epithelial cells in the kidney rather than a form of FSGS. ApolipoproteinL1(APOL1) gene mutation has been linked with this entity as well.

Individuals with genetic variants in the ApolipoproteinL1  gene have greatly increased risk of kidney disease. The high-risk genotypes are associated with elevated risk (7–29 fold) of hypertension-associated end-stage renal disease (H-ESRD), focal segmental glomerulosclerosis (FSGS), and HIV-associated nephropathy.

Nichols et al did an interesting study that sheds light on what might be upregulating these certain genetic foci.  We are aware of interferon associated collapsing GN . This finding raised the possibility that interferons and the molecular pattern recognition receptors that stimulate interferon production may contribute to APOL1-associated kidney disease. In cell culture, interferons and toll-like receptor agonists increased APOL1 expression by up to 200-fold, in some cases with the appearance of transcripts not detected under basal conditions. PolyI:C, a double-stranded RNA TLR3 agonist, increased APOL1 expression by upregulating interferons directly or through an interferon-independent, IRF-3 dependent pathway.

The authors showed that inflammatory factors can induce APOL1 expression, and extended them to include interferon subclasses, multiple cell types, and the appearance of new APOL1 transcript variants. What produces interferons?—viruses such as HIV, HTLV, CMV, H pylori infection and cancers and autoimmune diseases such as SLE( their presence in the kidney is marked by TRI- as I had proposed is a TRI associated nephropathy)

So an APOL1 gene variant patient is doing fine till this second hit happens that increases inflammatory factors and lead to FSGS.  In SLE patients as well, APOL1 G1/G2 alleles strongly impacted the risk of LN-ESRD in African Americans, as well as the time to progression to ESRD. How many of these had the FSGS lesions, few of the patients did but there was proliferative GN as well in many of the cases. 

It basically supports the notion that “ high interferon state” + APOL1 Gene mutation == bad renal outcomes!”

In the NEWS: LVADs and ESRD

Should patients on dialysis or kidney transplant be offered LVADS for severe CHF?
A new study just published in JAMA internal Medicine showed that patients with ESRD at the time of LVAD placement had an extremely poor prognosis, with most surviving for less than 3 weeks.

This was a observational analysis of the USRDS data of all patients on ESRD that received an LVAD.  155 Medicare beneficiaries with ESRD (median and interquartile range [IQR] days from ESRD onset to LVAD placement were 1655 days [453-3050 days]) and 261 beneficiaries without ESRD in the Medicare 5% sample received an LVAD. During a median follow-up of 762 days, 127 patients (81.9%) with and 95 (36.4%) without ESRD died. More than half of patients with ESRD (80 [51.6%]) compared with 11 (4%) of those without ESRD died during the index hospitalization. The median time to death was 16 days for patients with ESRD compared with 2125 days for those without ESRD. Most of these patients were hemodialysis with a small minority being PD and transplantation. So, unclear what the data is for PD vs transplantation.

In addition, what would have happened if the patients continued conservative management and not offered LVAD- would their outcomes have been similar or better? This really brings the question on whether LVADS should be offered to ESRD patients on dialysis.

Two recent reviews in AJKD and CJASN discuss the role of the Nephrologist and the Kidney in patients with LVADs.

Clinical Case and Discussion 90

Which has a better prognosis?

C3GN, idiopathic	1 (16%)
C3GN secondary to paraproteinemias	5 (83%)

Which has a better prognosis?

— Kenar Jhaveri (@kdjhaveri) November 29, 2017

One study from the Mayo Clinic found 31% of patients with C3GN had a paraprotenemia. Bone marrow biopsy revealed a diagnosis of monoclonal gammopathy of undetermined significance (MGUS) in 90% of these patients, whereas 10% were diagnosed with low-grade chronic lymphocytic leukemia (CLL). No outcome data was reported. Another study of patients with DDD from the same institution found 71.4% of the patients. All had MGUS at the time of diagnosis, but one patient progressed to MM at 120 months of follow-up. These results are similar to those from the University of Utah, which found 83% of the patients with C3G over the age of 49, had an monoclonal gammopathy. In this cohort, 40% had multiple myeloma (MM) or smoldering MM, 40% had monoclonal gammopathy of renal significance (MGRS), and 10% had polyclonal plasmacytosis. The data was mixed regarding outcomes in that small study.

Chavet et al recently in Blood 2017 reported the outcomes of 50 patients with C3G and monoclonal gammopathy treated after treatment. The patients were divided into groups based on the treatment received: clone-directed therapy (alkylator or bortezomib [or rituximab for CLL]), immunosuppressive therapy (corticosteroids, cyclophosphamide, rituximab, mycophenolate, and azathioprine), or RAS inhibition. In this study clone-directed therapy produced superior renal survival than immunosuppressive and RAS inhibition therapy. No differences in patient survival were noted.  The differences in hematological response helped explain why renal response was superior in patients treated with clone-directed therapy. Only 5% of patients treated with immunosuppressive or RAS inhibition therapy achieved a very good partial response (VGPR) or better vs 31% of patients treated with clone-directed therapy. In fact, 95% of the patients treated with immunosuppressive or RAS inhibition therapy had no hematological response. The authors were also able to show renal function was only preserved in patients who achieved a VGPR or better, similar to other MGRS-associated kidney diseases.

While idiopathic C3GN and C3GN associated with MGUS have not been directly compared, based on the large study by Chavet et al, we can expect the outcomes to be better when there was an MGUS associated with the C3GN and the clone was treated. If you have a secondary cause, fix it and the kidney improves!

Nephro-Cards 2018 symposium

The Heart-Kidney Connection: An Update in Nephro-Cardiology 2018

Northwell health in Long Island New York will host a one-day symposium aimed at providing updates on the Nephro-Cardiology on Saturday March 10th( #nephrocards2018)

Go to this link for more information and to register. Fellow, Students and Residents registration is free

ASN, ISN, NKF and Cardio-renal society of America endorsed

Below is the itinerary


7:30am Registration, Breakfast and Exhibits

8am Contrast Nephropathy? Does it Exist-The Latest Update and Prevention
Paul M. Palevsky, MD

9am Cardio-Renal Syndrome
Jai Radhakrishnan, MD, MS, MRCP

9:30am TAVR and the Kidney
a. Basics of Transcatheter Aortic Valve Replacement: A Primer
Barry Kaplan, MD

b. The Renal Effects of Transcatheter Aortic Valve Replacemen
Kenar D. Jhaveri, MD

10:30am Break

10:45am Left Ventricular Assist Devices
a. Basics of Left Ventricular Assist Devices
David Majure, MD

b. Left Ventricular Assist Devices and the Kidney
Daniel W. Ross, MD

11:30am Novel Agents Used in Hyperkalemia - What Cardiologists and Nephrologists Need to Know
Steven Fishbane, MD

12:15pm Interventional Therapies for Refractive Hypertension
Avneet Singh, MD

12:40pm Lunch 1:30pm Novel Anticoagulants and the Kidney
Nupur N. Uppal, MD

2pm Cardiac Workup of the Kidney Transplant Patient
Alexander Lee, MD

2:30pm Cardiac Surgery and the Kidney
Mitchell H. Rosner, MD

3:30pm Panel Discussion

4pm Program Conclusion

Detective Nephron; Next Venture

Check out the next venture of Detective Nephron
This time the case of AKI

In the News: DNAJB9- a novel autoantigen staining for Fibrillary GN

A new paradigm shift in diagnosis of Fibrillary GN(FGN) has occurred. This rare form of organized deposit related GN might have a pathology staining marker in the making.

Through the use of laser microdissection assisted liquid chromatography tandem mass spectrometry , The Mayo pathologist  recently discovered a novel proteomic biomarker for FGN: DnaJ homolog subfamily B member 9 (DNAJB9), a member of the molecular chaperone gene family. When looking at specific biopsy samples of FGN vs non FGN cases, strong, homogeneous, smudgy DNAJB9 staining of glomerular deposits was seen in all but 2 cases of FGN in one report published in KI-R.

This test had a 98% sensitivity and > 99% specificity. Immunoelectron microscopy showed localization of DNAJB9 to FGN fibrils but not to amyloid fibrils or immunotactoid glomerulopathy microtubules. (http://www.kireports.org/article/S2468-0249(17)30341-8/pdf)

Another similar manuscript in JASN showed the same finding. 

http://jasn.asnjournals.org/content/early/2017/11/02/ASN.2017050566.abstract( below is the visual abstract)

Looks like we may have a diagnostic test and catch more cases of FGN 

TOPIC DISCUSSION: Diuresis in CHF

An amazing article this month in NEJM discusses Diuretic use in CHF- a must read for Cardiologist and Nephrologists.

Some interesting take home points:

1. Diuretic resistance causes: Non adherence, gut edema, impaired diuretic secretion due to CKD or aging, hypoproteinemia, hypotension, nephrotic syndrome, use of NSAIDS, low renal blood flow, nephron remodeling and neurohormonal activation.

2. Bumetanide and torsemide have higher and more consistent oral bioavailability over furosemide and make oral and IV doses kinetics similar( often under utilized by many)

3. Torsemide has the longest half life of all loop diuretics-- 6 hours.

4. Two forms of adaptations: a) A dose of loop diuretic increases urinary Na loss for few hours but then is followed by a period of very low sodium excretion often called " post diuretic Na retention". When dietary Na intake is high, the post diuretic Na retention effect will offset the initial natriuresis. 
The second is braking phenomenon.  When diuresis happens and fluid volume declines, this activates the SNS and RAS leading to nephron remodeling( distal nephron hypertrophy). This is a helpful thing to put brakes on the severe contraction of the ECF. But when this occurs in a patient that is volume overloaded, it's causing harm.

5. Treatment should aim for daily urine volume of 3-5L till euvolemia.  A stepped wise approach is suggested in bolus of furosemide followed by drip if needed. Metolazone or HCTZ( high dose) can be used as additional agents.

6. Tolvaptan: Data is mixed and can be used in some especially if Na issues are also a concern
7. Dopamine and Nesirtide - no data to support use
8. Aldactone didn't improve outcomes in acute CHF patients that require aggressive diuresis
9. Diuretic Resistance: Failure of diuretics to achieve decongestion, so with max doses you still get a a urine Na<10.
10. Use of amiloride and carbonic anhydrase inhibitors may be beneficial in diuretic resistant patients.
11. UF in CHF appears to be indicated primarily when dialytic therapy is also indicated for worsening cardiorenal syndrome.
12. Hypertonic saline with diuresis might be an interesting option -- robust trials still pending.
13. Skillful use of diuretics is the bottom line on how to succeed in treating CHF with renal dysfunction.

I had hoped the authors had commented on use of lung US in this disease. Diuretic use guided by Lung US findings might be more useful in many cases than later exam findings of edema( personal observation). 

TOPIC Discussion: LVAD and the Kidney

Left ventricular assist devices (LVADs) are common and implantation carries risk of AKI. LVADs are used as a bridge to heart transplantation or as destination therapy. Patients with refractory heart failure that develop chronic cardiorenal syndrome and CKD often improve after LVAD placement. Nevertheless, reversibility of CKD is hard to predict. After LVAD placement, significant GFR increases may be followed by a late return to near baseline GFR levels, and in some patients, a decline in GFR.

In a recent review in CJASN, we discuss changes in GFR after LVAD placement, the incidence of AKI and associated mortality after LVAD placement, the management of AKI requiring RRT, and lastly, we review salient features about cardiorenal syndrome learned from the LVAD experience.

Salient points   

Most of the AKI and CKD post LVAD is related to right ventricular failure. Identifying that and providing aggressive diuresis and or UF might be important.
Long term CKD related to LVAD might be related to hemolysis and R-CHF.
Hemodialysis and PD – both can be successfully be done in outpatient setting with LVADs
AVF should be still the first choice for LVAD patients in the outpatient settings that require dialysis e
The most important of all, interdisciplinary teams including cardiologist, surgeons, and nephrologists are critical in the success of an LVAD program.

Nephrology on the rise, Positive trials, Positive job market!!

Nephrology really took an amazing turn this Kidney week in 2017. Positive trials, positive news and amazing things are happening for everyone involved in renal care.

First and foremost, the high impact clinical trials in 2017 ASN Kidney week revealed several positive trials.

The REPRISE study showed the impressive promise of use of tolvaptan in late stage ADPKD.  The liver related side effects were minimal. Hope to see this in clinical practice soon

The MENTOR trial that compared cyclosporine to rituximab for PLA2R membranous GN showed rituximab to be non inferior with lower rate of adverse effects. Looks like rituximab will be changing the treatment paradigm in membranous GN treatment.

Is contrast nephropathy dead? No not really. A randomized controlled trial showed that intra arterial contrast studies are more likely to cause contrast nephropathy compared to intra-venous, but both did have a incidence of contrast nephropathy.

A novel agent called QPI-1002 showed significant promise in decreasing AKI post CABG in high risk population.

Bardoxolone Methyl Improved GFR Measured by Standard Inulin Clearance: The TSUBAKI Study in Japan. The return of Bard!!

Another positive note: The GW-ASN fellows survey showed an upswing in job opportunities for our fellows in training. https://www.asn-online.org/education/training/workforce/

Finally, social media nephrology Guru Joel Topf wins Robert Narins award with an amazing video presentation done by ASN.

Check out the plenary sessions, award ceremonies and high impact trials at ASN video casts

Consult Rounds: Podocytic infolding glomerulopathy( PIG)

Podocytic infolding glomerulopathy( PIG)

What is PIG? – This is a pathology based finding seen rarely in the EM section of the report. It is a form of  glomerulopathy, in which microspheres or microtubular structure or both are associated with infolding of cytoplasmic processes of podocytes into the glomerular basement membrane.  This type of glomerulopathy is not included in the World Health Organization’s classification of glomerular diseases but has been noticed in few cases reports and large case series from Japan.

Associations: In the largest series from Japan,  most patients might have a subtype of lupus, nephritis  class V, or membranous glomerulonephritis.  MCTD, Sjogren's syndrome and tumor lysis syndrome was also found. Interestingly, hydronephrosis was associated with most patients seen with this entity. There have been cases associated with Myeloma as well. 

( Courtesy: https://link.springer.com/article/10.1007/s10157-008-0104-z)

Electron micrograph shows cytoplasmic  processes of podocytes infolded into the GBM. At the end of an infolded cytoplasmic process of podocyte, microspheres or microtubular structures or both were found. b The infolded cytoplasmic process of a podocyte went through the middle layer of the GBM, which was accompanied by thickening of the lamina densa.

The pathogenic mechanism of PIG is unknown. Hydronephrosis was found in three of 25 patients.  However, no study has shown that experimental hydronephrosis can induce podocytic infolding.In the large series from Japan, all had GBM thickening, and IF was negative in many, followed by some that had only C1q,c3 and some with a full house pattern.  Membranous GN is the most common light microscopy finding followed by FSGS and MPGN.  In an earlier report, some might have called this entity  Membranous glomerulopathy with spherules.

Some researchers performed an immunohistochemical study of complement C5b-9 complexes in several human kidney diseases and have shown positive reactions on round extracellular particles and on striated membranous structures in the GBM. Therefore, the mechanism of podocytic infolding might be related to the role of special types of complement activation in situ on the microstructure.  We don’t know if infolding of the podocyte cytoplasm may be a pattern of GBM/podocyte disruption rather than a true disease entity. However, the diffuse extent and severity of PIG raise the suspicion of defects in the repair mechanism.

Worth a read as we learn about this new entity!

Here are some interesting references

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3926855/

http://www.tandfonline.com/doi/full/10.1080/01913123.2016.1229703

https://link.springer.com/article/10.1007/s10157-008-0104-z

https://www.ncbi.nlm.nih.gov/pubmed/16731293

In the NEWS: Point of Care ultrasound of the Lungs and the Nephrologists

Point of care US is increasingly being used in many medical specialties. Nephrology is catching along swiftly as well.  A recent review by our team led by Ross et al discuss the role of Lung US in the ESRD population.  After a systematic review,  we concluded that lung US can be used to determine volume status in chronic ESRD patients by using the B-line score model( see figure above from paper) as discussed in the paper.

As nephrologists, we should be using this in practice and help diagnose and prognosticate high risk patients and perhaps prevent re-admissions.

The role of lung ultrasonography in nephrology practice requires further research regarding its clinical applications. We stated in our paper the following amazing ways it can be used in clinical practice..

i.            What is the role of lung ultrasonography in the management of AKI in the intensive care unit? Could it be used as an endpoint for continuous renal replacement therapy?

ii.            Given the association of mortality with the presence of B-lines in the chronic dialysis population, what is the role of lung ultrasonography in the management of the patient on chronic HD? Could B-lines be used to guide need for increased ultrafiltration and would this change long-term outcome?

iii.            Could lung ultrasonography be used to guide diuretic therapy in patients with chronic cardiorenal syndrome?

iv.            As B-lines detect subclinical volume expansion, could lung ultrasonography be useful in differentiating hypervolemic from euvolemic hyponatremia?

Where can one learn to get point of care US training?

The Emory US course is the mecca of US training: check out the details here

http://medicine.emory.edu/renal-medicine/education/ultrasonography-nephrologists.html

NKF Spring Clinical Meetings 2017 had a course run by us as a pre-course specifically on point of care US. Similar course will be prepared for 2018

https://www.kidney.org/spring-clinical/program/physician-highlights

KidneyCon 2018 will also be having a hands on workshop for Point of care US training

http://kidneycon.org/workshop/

Consult Rounds: Cryoglobulins and the Kidney

Cryoglobulins and the Kidney

Cryoglobulins are Igs that reversibilly precipitate at temperatures <37C.  This results in symptoms that can lead to rashes, vasculitis, ulcers, ischemia, joint pains, and eventually in 25% cases – renal injury.

Two mechanisms: immune complex GN vs high viscosity related.  All have nephritic/nephrotic syndrome with various levels of kidney function.

1/3 with purpura and arthralgia
¾ with low C4 and ½ with low C3

All 3 types of cryoglobulins reported with renal disease

Most commonly it occurs in settings of type II (“mixed”) cryo secondary to hepatitis C virus.  Most patients with type II or III cryoglobulins have a positive rheumatoid factor.  The pathology pattern of injury is either membranoproliferative or diffuse proliferative GN.

•          Type 1 Cryo( monoclonal IgM or IgG) – MM, MGUS, WM, lymphomas and CLL

•          Type 2 Cryo(monoclonal IgM + polyclonal IgG)- CLL, lymphoma, SLE, Hep C

•          Type 3 Cryo(polyclonal)- lymphoproliferative diseases, SLE

Treatment

Treatment of underlying cause- Hep, SLE, Myeloma

Steroids

Alkylating Agents

Anti CD-20 agents( good response in some cases)

Plasmapheresis ( adjunct) if skin involved and early renal
involvement

Topic Discussion: Baclofen and ESRD

Baclofen is often used as a muscle relaxant in many patients. It has a half life of 3-7 hours and 80% excreted by the kidneys.  It is extremely important to dose adjust in CKD and avoid use in ESRD patients. Dialysis is a good mechanism to remove the agent as well in-case of ingestions and overdoses.

A recent case published in AJKD highlights this important drug related interaction in CKD and ESRD patients. 

The authors describe two excellent clinical algorithms.

The first algorithm discusses dose adjustments.
If GFR>90, no dose adjustment necessary
If GFR 60-90, decrease initial dose by 1/3
If GFR 30-60, decrease dose by ½ and watch for mental status changes
If on RRT or GFR<30, avoid use

The second algorithm discusses if there is a known baclofen toxicity( seizures, hypotenia, encephalopathy, etc.)

If severe AKI, CKD or ESRD- start daily HD or CRRT
If normal renal function or mild AKI but with respiratory depression or seizures- start daily HD or CRRT
If normal renal function or mild AKI and no severe symptoms- no dialysis

Consult Rounds: Tamoxifen induced hypercalcemia

A forgotten cause of hypercalcemia we need to remember is the drug- tamoxifen

This chemotherapy agent used in breast cancer has had a track record of causing hypercalcemia.
It was first described in 1980s.  In that large study, 470 patients with metastatic breast cancer treated with tamoxifen, ten patients (2.3%) developed hypercalcemia. All patients with hypercalcemia had osteolytic or mixed lytic and blastic bone metastases. Hypercalcemia developed after a median period of seven days (range 4-11 days) of tamoxifen administration. Hypercalcemia was treated with conventional measures and serum calcium levels normalized in nine patients, either with a brief interruption of tamoxifen therapy or in spite of continued treatment. Four patients experienced partial remissions with continued tamoxifen therapy. These results indicate that hypercalcemia is a potentially serious complication of tamoxifen therapy but is generally short-lived, and can be controlled with supportive measures, thus allowing continued tamoxifen administration.

Other published reports are

https://www.ncbi.nlm.nih.gov/pubmed/8241000

http://annals.org/aim/article/692303/tamoxifen-hypercalcemia

http://www.sciencedirect.com/science/article/pii/0002961081901744

One recent study looked at a large series of breast cancer patients who were hypercalcemic post tamoxifen- happened within 9 days of start and peaked at a level of 13. All patients also had bone lesions as well.  Gallium nitrate was used to reverse the abnormality while keeping tamoxifen on.

https://link.springer.com/article/10.1007%2Fs00774-005-0678-4

No mention of this in any renal literature. Unclear mechanism of this entity. 

Topic discussion: Downsizing in Nephrology

A timely editorial just got published in CJASN. 

http://cjasn.asnjournals.org/content/early/2017/08/23/CJN.04740517.full

Three large NYC related programs give their thoughts on downsizing in nephrology fellowship spots. A comparison is made with anesthesiology that helped revert their trend of decrease supply in the 1990s.  The authors bring up few major concerns

1.       The debt burden of recent graduates and the compensation that nephrologists receive is not attractive. But the authors make a good point that while the starting salaries are low, there is room for growth and potential that other fields might not have. This is speculative and might depend on coast to coast in the US. While certain parts of the country, nephrologist make a lucrative salary, there are others where hospitalists make much more than nephrologists.

2.       The authors make an interesting suggestion of broadening our certification. This is an excellent thought. I urge the nephrology community to try to do this in the 2-3 year time frame of a fellowship. There are a minority of candidates who would do an extra year given their debt burden but incorporating something extra in your fellowship might help that candidate get that certificate along with Nephrology- be it glomerular disease, onconephrology or critical care.

3.       Chronic disease models have done well with PA and NP based teams in certain parts of the country. Examples are oncology, BMT, renal transplant, CT surgery. Nephrology should learn from these models. As the authors suggest, perhaps cautious downsizing might help reverse trend of supply/demand and help get outstanding candidates back in Nephrology.  A formula was suggested back few years ago by Desai and perhaps can be considered if need be.

4.       Overnight call is part of being a nephrologist. While authors suggest that the fellows might be called in a lot- one cannot ignore a K of 8 and wait till the 8AM fellow/attending comes in. Remote management might be possible but we have to be cautious in those methods.  Transplant overnight call should be reduced and can be the most helpful. A DDRT call should really not involve the nephrology fellow unless dialysis is required pre transplant. 

5.       Regardless of number of applicants a program is getting- the dependence on fellows for day to day work should be abolished.  This makes the applicant feel that the program is “fellow” centric and not “fellow” dependent. Attending directed services, NP, and PA based practice can help foster this environment. The flip side is loss of intensive education.  Given the rounding in the dialysis unit to only an NP or PA and relieving the fellow might lead to long term loss of education that we may regret. If planning this, would careful involve fellow in some of the rounding as well.  In addition, taking care of certain volume of patients and putting a cap on consults can also lead to “inefficient” graduates and unable to handle the volume when in private practice.  Fellows also have to learn how to manage and prioritize sick vs not that sick patients and how to manage a long and busy list. Nephrologists are smart physicians. We also want our fellows to be effective communicators, and efficient doctors.

I commend the authors on this very provocative essay and hoping this dialogue continues in making nephrology more attractive as it was many years ago.  

Glomerular Diseases Video: Crescentic GN

By Dr Vanesa Bijol, Nephropathologist at Northwell health

Glomerular Diseases Videos: Secondary FSGS

By Dr. Vanesa Bijol, Nephropathologist at Northwell Health

Glomerular disease Videos: The big picture

By Dr Vanesa Bijol, Nephropathologist at Northwell Health

Consult Rounds: Parvovirus b19 and Glomerular disease

Parvovirus b19 has been associated with the following glomerular findings

1.  Collapsing GN
2. Proliferative GN
3. FSGS
4. Thrombotic Microangiopathy

https://www.ncbi.nlm.nih.gov/pubmed/17699510 in an amazing review article that summarizes all renal associated findings with parvovirus b19 especially in the transplanted kidney.

Topic Discussion: CAR-T therapy and the Kidney

A new dawn is breaking in the field of hematologic malignancies, as the first product based on chimeric antigen receptor (CAR) T cells was scrutinized today by a panel of experts and unanimously recommended for approval at the FDA for pediatric and young adult patients (age 3-25 years) with relapsed or refractory acute lymphoblastic leukemia (ALL).

Blood is collected from the patient, and then autologous T cells are separated out and genetically engineered. The process involves inserting a CAR that targets CD19, an antigen expressed on B cells and tumors derived from B cells.  These CAR T cells are then infused back into the patient, who has undergone chemotherapy, and in the body the product homes in on B-cell leukemic cells and destroys them.  The main action happens mostly about 2 weeks after those CAR-T cells have been re-infused.  Some have termed this form of therapy as the “ living drug”

Autologous CAR-T cell therapy first shot into headlines about 4-5 years ago when it was thought about in CLL patients.   Then several other studies were done essentially confirming that the concept is correct but there are serious toxicities.

https://www.ncbi.nlm.nih.gov/pubmed/25317870 (leukemias)

https://www.ncbi.nlm.nih.gov/pubmed/26760100 (myelomas)

https://www.ncbi.nlm.nih.gov/pubmed/28029927 ( gliobastoma)

The technology is complicated and initially when tried in CLL led to multiple toxicities of various organs including CNS, cardiac, renal and mostly requiring ICU admissions from acute cytokine release syndrome. This happens due to high levels of IL-6, a cytokine that is secreted by T cells and macrophages in response to inflammation.  Etanercept and tocilizumab have been used to block the IL-6 activity to treat such side effects.

Acute renal injury following CAR T-cell infusion is multifactorial and almost always reversible. Reduced renal perfusion is often the most important cause of renal injury. Reduced renal perfusion can be caused by cytokine-mediated vasodilation, decreased cardiac output, or intravascular dehydration due to insensible losses from high fevers. Tumor lysis syndrome and drug effect from medications such as antibiotics are other possible causes of renal injury. Electrolyte disturbances, such as hyponatremia, hypokalemia, and hypophosphatemia are not uncommon but have been reported. A recent article in Blood summarizes all toxicities.

Now the therapy has returned and we may see this in many centers. We must be aware of the cytokine release storm that it can cause leading to AKI in that setting.  There might be more in the pipeline of similar products such as the one that just got approved for ALL.

Figure source: http://www.lymphomation.org/programing-t-cells.htm

Consult Rounds: Cholemic nephrosis or Bile cast nephrpathy or should we say Jaundice associated nephropathy

Bile cast nephropathy or also called cholemic nephrosis represents a spectrum of renal injury from proximal tubulopathy to intrarenal bile cast formation found in patients with severe liver dysfunction. Bile can be toxic directly to the tubule or can form casts and have similar damage as myeloma cast nephropathy.

Recently this entity has gained some interest in the literature.

1.      Classically seen with patients with acute or chronic liver disease

2.      Usually, the total bilirubins are over 20 and conjugated over 16 is the cases that had bilirubin casts on kidney biopsies

3.      The LFTS were also higher in these patients

4.      The cause of liver disease doesn’t matter

The mechanisms responsible for tubular dysfunction include uncoupling of mitochondrial phosphorylation (thereby decreasing ATPase activity) by bilirubin  and oxidative damage of tubular cell membranes as well as inhibition of Na-H and Na-K pumps in the tubular cell membranes by bile acids. Cholemic nephrosis is reversible provided bilirubin levels are reduced early. This recovery is however delayed if there is extensive bile cast formation.

Some have suggested jaundice-related nephropathy as a replacement for cholemic nephrosis. Based on their definition, jaundice-related nephropathy would encompass the spectrum of injury that ranges from proximal tubulopathy to extensive tubular injury and tubular pigment. 

As bile passes via tubules, there is pigment nephropathy.

Pathology findings include: extensive acute tubular injury with bile stained tubular casts.
Macroscopic findings will include bile stained yellowish discoloration of the kidneys in jaundiced patients which become dark green after formalin fixation.
The Hall's stain confirms bilirubin presence.

Other interesting articles on this topic

http://www.kidney-international.org/article/S0085-2538(15)56212-1/fulltext

http://onlinelibrary.wiley.com/doi/10.1111/hdi.12169/pdf

http://www.ajkd.org/article/S0272-6386(16)30488-7/abstract

https://www.karger.com/Article/Pdf/371689

Consult Rounds: Acyclovir and dialysis

An often unforgotten drug that we must be aware of in ESRD patients is acyclovir.

Acyclovir can accumulate in ESRD if not dosed appropriately and can lead to neurotoxicities- leading to confusion, tremors and coma.

Initial study of 7 patients with end stage kidney disease receiving hemodialysis looked at levels following hemodialysis with each patient received a single 800-mg tablet of acyclovir. Plasma acyclovir levels were monitored over the next 48 h as well as before and after the next routine dialysis. Peak plasma levels were achieved at 3 h (12.54 +/- 1.76 microM, range 8.5-17.5 microM) with the half-life calculated to be 20.2 +/- 4.6 h. Mean plasma level of 6.29 +/- 0.94 microM were within the quoted range to inhibit herpes zoster virus (4-8 microM) at 18 h. Hemodialysis (4-5 h) eliminated 51 +/- 11.5% of the acyclovir which remained at 48 h. Computer modelling of various dose modifications suggests that a loading dose of 400 mg and a maintenance dose of 200 mg twice daily is sufficient to maintain a mean plasma acyclovir level of 6.4 +/- 0.8 microM. A further loading dose (400 mg) after dialysis would raise the residual acyclovir concentration by 6.1 +/- 1.0 microM.

Acute acyclovir neurotoxicity can be treated in CKD and ESRD patients with dialysis. The drug is water soluble, not albumin bound and small- hence an ideal dialysis candidate for removal.  It is important to keep this toxicity in mind as many might come in to your office with non renal dosing of this agent on ESRD and CKD patients and can lead to neurotoxicity. PD is not an option; HD is preferred mode for removal of acyclovir. 

  Some references

http://www.ajkd.org/article/S0272-6386(12)70234-2/abstract

http://onlinelibrary.wiley.com/doi/10.1111/1346-8138.13196/pdf

http://www.revistanefrologia.com/en-publicacion-nefrologia-articulo-acyclovir-valacyclovir-neurotoxicity-in-patients-with-renal-failure-X2013251412000456

http://www.shmabstracts.com/abstract/the-monster-in-my-room-acyclovir-neurotoxicity-in-a-hemodialysis-patient

Topic Discussion: New Glomerular diseases cases with targeted therapies

Targeted therapies can lead to a glomerular disease. Previously, two reviews didn’t find any glomerular diseases associated with BRAF inhibitors and PD-1 inhibitors.  In the last 6 months, 3 recent papers have highlighted interesting cases of both BRAF-MEK combination and PD-1 inhibitors leading to glomerular diseases.

Encorafenib, a new BRAF inhibitor, and binimetinib, MEK inhibitor—Proliferative GN
Pembrolizumab ( PD-1 inhibitor)- Minimal Change Disease
Dabrafenib, BRAF inhibitor and tramitinib( MEK inhibitor)- Podocytopathy- like MCD

  

While the PD-1 inhibitor case is the first of it’s kind, we must be mindful of GN in these patients as well. In terms of the BRAF+MEK combo, both authors of the above listed papers. Showed that it was the BRAF inhibition that decreased PLCε1 expression in podocytes, accompanied by a reduction in nephrin expression and an increase in permeability to albumin. Additionally, these drugs inhibited the podocyte–vascular endothelial growth factor (VEGF) system leading to perhaps a component of TMA as well.

ASN Robert G Narins Award for 2017 goes to Blogger, educator Joel Topf

The Robert G. Narins Award by ASN honors individuals who have made substantial and meritorious contributions in education and teaching. This award is named for Robert G. Narins, who is also the first recipient of the award.

Dr. Narins' contributions to education and teaching started in 1967 from chairing for eight years the ABIM's Nephrology Board and working on the ACP's Annual Program Committee. His contributions to education in the fields of fluid-electrolyte and acid-base physiology are prodigious and well-recognized.  Dr. Narins was also involved in the creation and planning of many ASN educational programs during Renal Week and throughout the year, including: Board Review Course and Update, one and two day programs at Renal Week, Renal WeekEnds, and NephSAP.

Prior Award winners of this award are( from ASN website)

·    2015 Mark L. Zeidel, MD, FASN
·    2014 Stuart L. Linas, MD, FASN
·    2013 Mark E. Rosenberg, MD, FASN
·    2012 Donald E. Kohan, MD, PhD, FASN
·    2011 Agnes B. Fogo, MD
·    2010 Barry M. Brenner, MD
·    2009 Burton D. Rose, MD
·    2008 Mitchell L. Halperin, MD
·    2007 Richard J. Glassock, MD
·    2006 Robert G. Narins, MD

This year marks a landmark in this award as it’s being presented to Joel Topf, MD.



While all other educators followed a conventional track for teaching and educating, Joel’s contribution to nephrology education has been very unique and different.  Here is what Joel has accomplished in the last 10 years!
1.       Creation and maintaining the Precious Body Fluids Blog with educational material that spans from electrolyte disorders to AKI
2.       The best acid base book written in Nephrology as a “resident”. This is by far the easiest book to understand acid base disorders.
3.       Co creation of the first ever academic journal blog- AJKD blog
4.       Creation of Nephmadness since 2013 ( first ever online game in Nephrology) with educational material that spans all parts of renal medicine
5.       Creation of NephJC( the first and most successful online journal club that meets every 2 weeks)
6.       Co creation of DreamRCT( how to propose and create a dream RCT that we need in nephrology competiton)
7.       Creation of Nephrology Social Media Collective Internship to train trainees, and faculty on become social media experts to improve medical education
8.       Teaching and promoting social media education in nephrology
9.       Showcasing how twitter can be used in nephrology education at it’s best! (https://twitter.com/kidney_boy)
10.   Several teaching awards at his local institution

Most important of all: He has inspired and trained many young and old teachers/and educators due to his passion for nephrology!
Way to go Joel and congrats!