Friday, April 24, 2015

Hyperkalaemia, ICDs and ECG changes.

I recently admitted a woman overnight with prerenal AKI and serum K+ of 7 mmol/L. A passing ED physician mumbled to me not to worry as their ECG didn’t require calcium gluconate, and besides, they had an ICD inserted recently.
As I looked over the ECG, I realised I had no idea what effect hyperkalaemia would have on a pacemaker. Furthermore I always suspected that ECG changes were not a sensitive method of alerting physicians to danger and just delayed treatment. So firstly, what effect does hyperkalaemia have on those pacing/ICD leads?

A recent review from europace describes 3 key changes:

1. The QRS complex can widen due to intraventricular conduction delay

2. The increased ventricular pacing thresholds can cause failure to capture

3. It can lead to over-sensing of spontaneous T waves and inappropriate shocks if the device is an ICD


An hour later this lady had multiple long runs of ventricular tachycardia and lost consciousness .The overdrive pacing spikes could be seen on the monitor but there was no electrical capture and after 20 seconds the device ultimately defibrillated the patient each time. Could this have been avoided with quicker initial treatment and administration of calcium? 
Given the potentially disastrous consequences of hyperkalaemia in a patient with a pacemaker, just fix it, and don’t rely on the ECG to reassure you!
So what about my suspicion that ECG changes are not particularly sensitive?

It would seem that physicians cannot predict clinical severity based on ECG changes alone. A blinded reading of 200 ECGs gave a best  positive predictive value for the presence of hyperkalaemia of 0.65. In addition to this, another study  in CJASN could find no correlation between T waves changes and serum K+. The problem worsens in dialysis patients who appear even less likely to ever manifest ECG changes. This is associated with having a higher serum calcium. Furthermore there are multiple case reports of profound hyperkalaemia both in patients with and without CKD who do not manifest any ECG changes. It is hypothesised that perhaps it if the rate of change that produces the ECG abnormalities, which makes some sense as to why the RRT cohort do not manifest these
Furthermore it has been shown worsening stages of CKD tolerate any given level of hyperkalaemia better, again perhaps due to the rate of change. I could find no good study showing that ECG changes, except for sinusoidal waves, predicted death or morbidity. The long described progression of t wave changes through to QRS widening and then sinusoidal waves is a physiologically pleasing one, it feels right and is very logical. The ECG itself however, would seem not to be particularly useful in treating real patients, and I am going to force myself to ignore normal ECGs. I think my assessment of the urgency will centre around how the patient looks and the rate of flux, background CKD, serum K+, likelihood of rapid improvement, medications and cardiac history.
A final point I stumbled across which I found interesting was the interaction between verapamil and hyperkalaemia. Both dogs and humans on verapamil have profoundly lower cardiac indexes when hyperkalaemic. I’m not sure is it the Ca2+ blocking effect worsening the hyperkalaemic effect on myocardium or the cumulative negative inotropy, but I can see a logical argument for empirical calcium therapy in those on verapamil and perhaps other calcium channel blockers.
Any thoughts?




Thursday, April 23, 2015

Biosimilars: does a rose by any other name smell as sweet?

A biopharmaceutical, or biologic, is any medicinal product manufactured in or extracted from a living system, such as a microorganism or plant or animal cells. Several biologic agents are produced using recombinant DNA technology, while others may be manipulated or humanized after their production. Most of these agents are very large and complex molecules compared to traditional small-molecule drugs. Given this fact, the manufacturing process of biologics is more challenging than traditional drugs, as even minor changes in the manufacturing process can impact efficacy or immunogenicity. 
 Use of biologic agents is now commonplace in many disease states, including oncology, rheumatology, renal transplant and nephrology. One of the major limitations of use of these agents is their associated costs. A small molecule drug costs, on average, $1/day, with generic drugs often costing just cents. In comparison, a biological drug costs, on average, $22/day. It is estimated that global biological sales are projected to reach $221 billion by 2017. One way to limit the healthcare expenditure on biologic agents is to allow for competition within the marketplace. However, given the complex manufacturing processes involved in making biologics, the Food and Drug Administration (FDA) has traditionally not allowed generic competition for these products, even after their patents have expired. This all changed on March 23, 2010 when the Patient Protection and Affordable Care Act was signed into law. This created an abbreviated licensure pathway for biological products that are demonstrated to be “biosimilar” to or “interchangeable” with approved, reference biological agents. 
 A biosimilar is simply defined as a biopharmaceutical protein designed to have active properties similar to an innovator biologic and approved through an abbreviated regulatory process. Due to the complexity of the manufacturing process, biosimilars should not be considered generic versions of biologics. The FDA requires animal studies to assess toxicities, as well as human pharmacokinetic (PK) and clinical studies prior to approval of a biosimilar product. The objective of the PK study is to demonstrate comparability of relevant parameters in a sufficiently sensitive and homogeneous population. This analysis is often done in concert with the clinical study. For the clinical study, the primary objective is to establish biosimilarity, not clinical benefit, as its efficacy is already known from the registration studies of the innovator product. Biosimilarity is often established through a randomized, parallel group, comparative clinical trial. 
 The FDA has published “The Purple Book” that contains a list of licensed biologic products to help clinicians see whether a particular product has been determined by the FDA to be biosimilar to, or interchangeable with, a reference biologic product. Despite the approval pathway for biosimilars being signed into law over five years ago, it was not until March 2015 that the FDA approved the first biosimilar product, Zarxio® (filgrastim-sndz). Biosimilars are a relatively new in the US; however, the European Medicines Agency (EMA) has had a regulatory process for approval of biosimilars for nearly 10 years. Their approvals for biosimilars cover five classes: recombinant erythropoietins (i.e., epoetin alfa, epoetin zeta); recombinant granulocyte-colony stimulating factors (i.e., filgrastim); recombinant human growth hormone (i.e., somatropin); recombinant follicle stimulating hormone (i.e., follitropin alfa) and monoclonal antibodies (i.e., infliximab). To date, the EMA has approved 19 biosimilars. 
 Biosimilars in Nephrology 
After 6 years of successful use in Europe, data has demonstrated that biosimilar erythropoiesis-stimulating agents (ESAs) are safe and effective alternatives to brand-name epoetin alfa for treating anemia in patients with kidney disease. In United States, the patent for Procrit® (epotein alfa) expired in August 2013; however, the patent for Epogen® (epoetin alfa) remains active until May 2015. On the other hand, the patency for Aranesp® (darbapoetin alfa) will expire in 2024. Since the U.S. key patents on epoetin alfa have begun to expire, Hospira has submitted Biologics License Application to U.S FDA to get Retacrit® (epoetin zeta) approved as a proposed biosimilar for epoetin alfa.
  Biosimilars in Transplantation 
Monoclonal antibodies are very complex biologics that have shown to be effective for different indications. In renal transplantation, a series of monoclonal antibodies have been used as induction therapy or to treat steroid-resistant acute rejections, such as Simulect® (basiliximab) or Campath® (alemtuzumab). It appears that alemtuzumab will lose patent protection at the end of 2015, while basiliximab patent protection will expire in 2018. These could be among the first transplant-related immunosuppressive biosimilars approved in the US within the next five years.

-      Razan M. Alsheikh, PharmD, BCPS, PGY-2 Organ Transplant Pharmacology Resident, Brigham and Women’s Hospital, Boston, MA

-      Steven Gabardi, PharmD, FCCP, BCPS, Department of Transplant Surgery and Renal Division, Brigham and Women’s Hospital, Boston, MA

Last Call: Apply to the Origins of Renal Physiology Course by May 15th

The National Course for Renal Fellows: Origins of Renal Physiology course will run from August 30 to September 5, 2015 at the Mount Desert Island Biological Laboratories. Each year renal fellows come to the Acadia coastline to explore the fundamentals of renal physiology with a distinguished faculty drawn from top institutions around the world. Funded by the National Institutes of Health (NIDDK), the course covers the costs of instruction, food and housing for the week.

The application link is here. Applications will close May 15th.




This is a wonderful opportunity that you don't want to miss.

Sunday, April 12, 2015

Update from Hepatology: AKI and HRS in patients with cirrhosis

In the recent edition of Hepatology, the International Club of Ascites (ICA) have published their revised recommendations on the diagnosis and management of AKI in patients with cirrhosis. They first proposed diagnostic criteria for Hepatorenal syndrome (HRS) in 1996 and last updated them in 2007 (covered by RFN). Since their first publication, there has been much work done in defining AKI with RIFLE, AKIN and KDIGO and this is reflected in the ICA’s latest guidance. This time, they have gone beyond defining HRS to include staging of AKI in patients with cirrhosis and proposed how this could be used to inform management.
Here are the definitions they propose (the ICA-AKI classification):



















The first thing to note is that they’ve removed the fixed threshold of sCr of ≥ 1.5 mg/dl (133 mmol/l) from the old criteria and brought in an absolute increase in sCr.  Indeed, the eagle eyed amongst you will have noticed that their definitions and staging of AKI are based on the KDIGO criteria but with the use of urine output removed. The rationale for this being that patients with cirrhosis can often be oliguric with avid sodium retention but still have preserved renal function. Conversely, they can have an increased urine output as a result of diuretic therapy.
Whilst a sCr less than 7 days before admission would be the ideal result to use as baseline, they have pragmatically suggested that the most recent value available in the last 3 months can be used. When this is not available, the admission sCr should be used as baseline. They do not recommend using the reverse application of the MDRD formula to calculate an estimate of baseline sCr as MDRD is known to be inaccurate in patients in cirrhosis (covered in a previous RFN post ). If no previous sCr is available and the admission value is ≥ 1.5 mg/dl (133 mmol/l), decisions should be based on clinical judgement.
Moving onto management, the ICA has suggested the following algorithm:





















Treatment for those with AKI stage 1 is outlined in the table. Note that the plasma volume expansion can be with crystalloid or albumin (or blood in the case of GI bleeding) at this stage. Those who present with AKI stage 1 who progress are then treated in the same way as patients who present with AKI stage 2 and 3 i.e. stopping the diuretics and 48 hours of albumin 1g/kg (max dose 100g per day). Further management then varies on the aetiology and whether or not this is HRS, which the algorithm helpfully informs. The new criteria for HRS:



Again, they have removed the cut off value in sCr from the diagnosis in favour of a dynamic change in sCr as per the ICA-AKI criteria. Importantly, they have suggested revising the diagnostic criteria for type 1 HRS and with it the indications for treatment with vasoconstrictors. Type 1 HRS is currently defined as a doubling of the initial sCr to level ≥ 2.5mg/dl (226 mmol/l) in < 2 weeks. Evidence however suggests that a higher sCr at the beginning of treatment leads to a lower chance of response to vasoconstrictors and albumin. With the new algorithm, patients at AKI stage 2 or 3 or who have progression from stage 1 that meet all the other criteria for HRS, should receive treatment with vasopressors irrespective of the final value of sCr. This will allow treatment earlier and hopefully lead to better outcomes though at present there is no data to confirm this.

No consensus was reached on the optimal management of those patients who present with AKI stage 1 but then have stable renal function (i.e. do not regress or progress). Whilst all agreed that if the patient has a final sCr ≥ 1.5 mg/dl (133 mmol/l), they should be treated according to the right side of the algorithm, most of them had concerns about the use of vasoconstrictors for those with HRS if the sCr was < 1.5 mg/dl (133 mmol/l). Hence, they advise to treat these patients on a case-by-case basis.




Authored by David Baird,
Royal Infirmary of Edinburgh

Thursday, April 2, 2015

Uremic Pruritis - Algorithm for Management

Uremic pruritus affects more than 40% of dialysis patients. Even though is not considered a major complication of ESRD, it is significantly debilitating to patients.

Prior blog discussed the potential causes of uremic pruritus, though the clear pathogenesis remains obscure. Clearly, the whole skin seems to be affected and evidence of inflammation has been documented.

Recent article on KI by Mettang and Kremer nicely reviewed the available data. The management of uremic pruritus is limited though I have summarized in the figure a potential approach.

Sunday, March 29, 2015

Metformin Guidelines

Metformin is one of the most useful drugs in patients with type 2 diabetes and yet its use in patients with CKD is limited by the perceived association with lactic acidosis. These concerns are due to the association of a prior biguanide, phenformin, with a marked increase in the rate of lactic acidosis. The mechanism for this appears to be reduced peripheral glucose oxidation and increased lactic acid which occurs with even small increases in phenformin levels. The drug was eventually removed from the market because of a number of fatal cases.

Metformin, in contrast, does not appear to be as closely associated with lactic acidosis. Most of the reported cases are in patients who would appear to have other reasons for lactic acidosis (although this case series including patients on dialysis that appears to be reasonably convincing and there are multiple smaller case series in patients on HD). A large meta-analysis of clinical trials if metformin showed no increase in the rate of lactic acidosis in patients on the drug. However, it should be pointed out that these trials did not include patients with advanced CKD.  Metformin is not protein-bound and is largely cleared by the kidneys so there is clearly accumulation of the drug in patients with CKD. However, it is unknown what the real "safe" level is and no studies can ethically be performed to establish this.

As a result, in general, guidelines regarding the use of metformin have been conservative. The insert for the drug suggests that it is contraindicated in individuals with a serum creatinine >1.4mg/dl (women) or 1.5mg/dl (men). Personally, I find these guidelines to be insufficient and frustrating because of course, a creatinine of 1.5mg/dl can mean entirely different things depending on the context (age, weight, race etc.) So it is gratifying to see that the diabetes associations have moved forward with newer guidelines.

The ADA published a paper with new guidelines for the use of metformin in 2011 incorporating eGFR. This paper also summarizes very nicely all of the evidence for and against the use of metformin in CKD. In summary, they suggest that for individuals with eGFR>45, metformin can be safely initiated. For those with an eGFR between 30-45, it can be continued with caution if it is already in use. Finally, it is contraindicated in patients with eGFR<
30. These guidelines make more physiologic sense and although they may still be too conservative, in this era of automatic reporting of eGFR, to me, it is the better approach to take.

Saturday, March 28, 2015

Precision Nephrology


One of our attendings, Dr. Sylvia Betcher, PhD, MD gave an excellent presentation at our renal conference about genetic testing in renal diseases that she learned about at #KidneyWeek2015. There were so many good things I liked about her talk, that I want to share what I learned. On January 30th 2015, President Obama announced in his State of the Union address a Precision Medicine initiative. This will provide researchers in the biomedical field with the necessary tools to define preventive measures and treatment of disease by examining variability in genes, environment, and lifestyle of each patient. Precision Medicine relies on specific molecular and genetic information to classify a certain disease into subsets that allow consideration of focused therapies, which is currently being accomplished through GWAS (Check the #NephMadness genetic nephrology region bracket on GWAS here), whole gene sequence analysis via next generation sequencing (NGS) and VAAST (Variant Annotation, Analysis and Search Tool) which is used to identify damaged genes and their disease-causing variants in genome sequences. The president’s 2016 budget will provide $215 million to the various agencies including the NIH and FDA to accomplish his goals. The objectives of such initiative can be found here.

Most of the budget will go to cancer research and there is no mention of rare diseases or any particular hereditary or genetic disease. In the Nephrology world, are there any diseases in particular that need to be addressed? Yes, for instance Steroid Resistance Nephrotic Syndrome (SRNS), among many others. In this paper, a single-gene cause of SRNS was detected in 526 out of 1,783 families (29.5%), by examining 21 genes. The authors mentioned that screening of these genes is cost-effective and may avoid the undesirable side effects of steroids when a mutation is detected and potentially offer targeted therapy (for example with Coenzyme Q10 in cases of COQ2 nephropathy)

According to the NCBI Genetic Testing Registry as of August 2014, there were approximately 4,500 conditions for which genetic testing is available, many of which will have renal manifestations. Advantages to testing include providing specific therapies, allowing family counseling and to evaluate kidney donors in family members. Diseases that are being considered in Nephrology for genetic testing include: rare autosomal dominant interstitial nephropathies (UMOD, MUC1, REN), Syndromic and Polycystic Kidney Disease, Alport Syndrome and Congenital Anomalities of the Kidney and Urinary Tract (CAKUT). Additionally, I want to emphasize the fact that Genomics England (a company owned by the UK Department of Health) and Illumina (an American biotechnology company based in San Diego, California) have launched a $524M project to create a large genome database. Their plan is to sequence 100,000 whole genomes by 2017 focusing on rare diseases, cancer and infectious diseases. A nephrology consortium has been set up to provide renal patients for this ambitious project.

Let’s say we have screened our patients for congenital kidney diseases. Now what? We have to consider whether the results will influence any change in management, or perhaps we need to screen for extra-renal manifestations. I think that providing family counseling will definitively be helpful. It will also influence the decision on safety of kidney donation. Urine could be an excellent source of genetic information through DNA fragmentation which is a normal process in apoptotic cells to eliminate mutated, damaged or infected cells and is usually highly fragmented whereas in cancer cells the DNA maintains its integrity. So in conclusion, these are exciting times in Nephrology with precise genetic testing now a diagnostic option. Do you see yourself practicing Precision Nephrology in 10-20 years? Let us know what you think!

Saturday, March 21, 2015

#NephMadness Increased MAP in Sepsis Haiku Deck


Increased MAP in Sepsis - Created with Haiku Deck, presentation software that inspires

Post by Hector Madariaga. Go to the AJKD blog NephMadness critical care in nephrology region to read more. Make your picks before March 22nd

Monday, March 16, 2015

#NephMadness Norepinephrine in Sepsis Haiku Deck


Norepinephrine in Sepsis - Created with Haiku Deck, presentation software that inspires


Post by Hector Madariaga. Go to the AJKD blog NephMadness critical care in nephrology region to read more. Make your picks before March 22nd

Friday, March 13, 2015

Is there a benefit in pre-transplant weight loss? #NephMadness

To complement the NephMadness Nutrition in Nephrology obesity match-ups, we thought a post on pre-transplant weight loss was timely. According to a recent report published in JAMA, more than one third of the US population are obese (BMI>30) with an estimated medical annual cost of $147million in 2008. Obesity causes heart disease, stroke, type 2 diabetes mellitus and certain types of cancer. According to a recent policy statement of ASCO, obesity is predicted to overtake tobacco as the leading modifiable cause of cancer in the United States in the near future.
In the Nephrology world, we are all aware of the survival advantage of obesity in dialysis patients with the so-called “reverse epidemiology” or “obesity paradox” (While obesity, hypertension and hyperlipidemia are indicators of high cardiovascular risk in the general population, in dialysis patients these conditions are associated with a survival advantage). This was demonstrated in several well-conducted studies (ref, ref, ref) in the United States and Europe.

But is there any survival advantage for obese patients while they are waiting for a kidney transplant? Obesity is not an absolute contraindication for transplant listing although some transplant centers do not evaluate patients with BMI >30-35 kg/m2. At our center, we recommend patients should aim for a BMI < 35kg/m2; however we have performed kidney transplants in patients with higher BMIs. Approximately 60% of kidney transplant recipients are overweight, which represents a 116% increase from 1987. But is BMI an accurate reflection of obesity in adults? The answer is no. The accuracy is limited and although a BMI cutoff of >30 kg/m2 has good specificity, it misses more than half of people with excess fat. Newer techniques to evaluate obesity include abdominal circumference, waist to hip ratio, hydrostatic weighing and body fat measuring.

There are concerns about allograft survival, weight gain after kidney transplantation and wound healing. Two retrospective analyses in obese patients undergoing kidney transplantation reported higher rates of delayed graft function, acute rejection, peri-operative complications and worse renal function with higher BMIs.
On the other hand, there is evidence that higher BMIs do not influence outcomes. A study of >164,000 patients demonstrated that low pre-transplant BMI, low pre-transplant serum creatinine (which could be due to sarcopenia), were associated with worse post-transplant outcomes. Bariatric surgery is becoming more popular prior to kidney transplantation and according to this study of USRDS data that evaluated the safety of the procedure, bariatric surgery provides substantial weight loss to kidney recipients. However, it also reported more peri-operative complications and increased mortality in comparison to patients undergoing the same procedure without kidney disease. Significant pre-transplant weight loss (>10kgs) may be a risk factor for peri-operative complications, particularly wound problems. Another study reported that weight loss during transplant listing had no effect on long term outcomes after transplantation and rapid weight loss was associated with subsequent post-transplant rapid weight gain. According to this analysis, the rate of mortality before and after transplantation is unchanged despite weight loss.

In conclusion, there is no evidence that weight loss before transplantation improves long-term outcomes following transplantation although much of the evidence is retrospective and observational in nature. The absence of significant central obesity certainly helps with wound healing and it is intuitive that a ‘healthy weight’ augers well for long term morbidity. How we measure this ‘healthy weight’ however is debatable including where BMI fits into this assessment, if at all.

Hector M. Madariaga,
SUNY Upstate Medical University

Wednesday, March 11, 2015

Scleritis and Kidney Disease - More than meets the eye...

Scleritis is a severe inflammation involving the deep episclera and sclera. Symptoms include moderate to marked pain, hyperemia of the globe, lacrimation, and photophobia.

Scleritis tends to recur and is frequently associated with an underlying systemic illness, such as rheumatoid arthritis, lupus, IgA vasculitis, polyarteritis nodosa and granulomatosis with polyangiitis.   A few cases are infectious in origin and about half of the cases of scleritis have no known cause.

 In Renal Grand Rounds on Tuesday, Patrick McGlynn presented a case of 30 year-old healthy female who came to clinic complaining of pain and redness on her right eye. Blood pressure was elevated at 155/90 mmHg. On exam, right eye had redness on sclera. No involvement of left eye. No papilledema on fundoycopic exam. Ophthalmology was consulted and thought the exam was consistent with sectoral scleritis inferotemporally on right eye (representative figure above). Labs showed a creatinine of 1.79mg/dL and urine sediment analysis revealed few WBC casts. Based on acute presentation with renal failure and active urine sediment, a kidney biopsy was performed, revealing IgA nephropathy.

 Ocular involvement in patients with IgA nephropathy is infrequent, but may lead to uveitis, episcleritis, scleritis or retinal vasculitis. For sure worth keeping an eye…

Accepting Applications to the Origins of Renal Physiology Course

Nate Hellman, in front of the "Kidney Shed" at Mount Desert Island
The National Course for Renal Fellows: Origins of Renal Physiology course will run from August 30 to September 5, 2015 at the Mount Desert Island Biological Laboratories. Each year renal fellows come to the Acadia coastline to explore the fundamentals of renal physiology with a distinguished faculty drawn from top institutions around the world. Funded by the National Institutes of Health (NIDDK), the course covers the costs of instruction, food and housing for the week.

The application link is here. Applications will close at the end of April.

"The MDIBL Renal Fellows course gave me the opportunity to learn renal physiology from the experts in their fields, in a place where so many important discoveries were made by the giants of nephrology. Collaborating with my peers from programs all over the country, we re-created the experiments that helped characterize ENaC structure and function, osmoregulation, and the complex proximal tubular in a supportive yet intellectually stimulating environment. And when our lab presentations were finished, we enjoyed Acadia National Park and the coast of Maine, by foot and by bike, making great new friends along the way." - Jeffrey William, Fellow, Beth Israel Deaconess Medical Center

This course is a fantastic offering and was life changing for myself and I know many others. Where else can you go to learn about the kidney with fantastic faculty and fellows from all around. This was where I met the late Nate Hellman back in 2008, founder of RFN. You can read some nice blog posts from Nate from the actual course here and if you scroll down here. I would not only highly recommend this course but I would urge you to go. Now that it is supported by the NIH you really have no excuse not to go.

Matt Sparks

Saturday, March 7, 2015

#NephMadness Furosemide Stress Test Haiku Deck #CCRegion


Furosemide Stress Test - Created with Haiku Deck, presentation software that inspires

Post by Hector Madariaga. Go to the AJKD blog NephMadness critical care in nephrology region to read more.

Wednesday, March 4, 2015

Is Matching at the HLA Epitope Level the Holy Grail of Longer Graft Survival?

All HLA antigens are composed of strings of several polymorphic sites, which may serve as targets, or epitopes, for antibody binding. An important consideration is that HLA antigens have multiple epitopes that can be recognized by specific antibodies. The current nomenclature of the HLA system does not take into account the nature or identity of these epitopes. Elucidation of three-dimensional molecular structures and amino acid sequence differences between HLA antigens has made it possible to define the structural basis of HLA epitopes (reviewed by Tambur, Claas AJT 2015).

Why could this be important?
For certain HLA phenotypes a given mismatch has no or few mismatched epitopes and for other phenotypes, the same HLA antigen has many mismatched epitopes and is therefore, structurally highly incompatible. Altogether, the degree of structural compatibility of a donor HLA mismatch is largely determined by the HLA type of the recipient. Therefore, the level of epitope match may help identifying the best compatible donor. Furthermore, it may identify epitopes that are most immunogenic and lead to a greater risk of antibody generation post-transplant (Wiebe et al. AJT 2013).

How can you do this?
HLA Matchmaker, a computer algorithm available for free at www.hlamatchmaker.net, determines histocompatibility at the epitope rather than antigen level. Therefore, it can provide an estimate of the degree of epitope matching or mismatching.

Who would benefit the most?
Highly sensitized patients with difficult matches and younger patients to minimize risk of de novo DSA development post-transplant.

Monday, March 2, 2015

#NephMadness Early Goal Directed Therapy Haiku Deck #CCRegion



Early Goal Directed Therapy - Created with Haiku Deck, presentation software that inspires

Check out the NephMadness Critical Care Nephrology region.

Post by Hector Madariaga

Thursday, February 26, 2015

#NephMadness 2015: It’s almost here

It’s almost March, time to fill out your bracket. No not college hoops, it’s time for the annual Nephrology SoMed educational phenomenon that is NephMadness. The brainchild of Matt Sparks and Joel Topf has grown legs in its 3 years of existence and now represents a highlight of the Nephrology #FOAM calendar.

NephMadness is a homage to the NCAA Basketball Tournament, March Madness, but instead of matching up college basketball teams, NephMadness throws some of the most important concepts in nephrology together to battle it out. This years theme is Nephrologys interaction and cross-over with other specialties. See the current editorial in AJKD by the NephMadness team for the complete low-down. The overall regions/specialties, each with 8 Nephrology topics, for 2015 are:

1.         Obstetric Nephrology
2.         Infectious Disease and Nephrology
3.         The Heart and Kidney Connection
4.         Nephrology and Nutrition
5.         Genetic Nephrology
6.         Critical Care Nephrology
7.         Nephrology and Vascular Surgery
8.         Onconephrology

The game will progress throughout March with winners and losers announced along the way via ongoing blog posts. My own (extremely biased) view is that the winner will come from the strong Genetic Nephrology region! Let us know what you think when the brackets are published on March 1 on the AKJD blog. Also follow along on Twitter using the hashtag #NephMadness.


Wednesday, February 25, 2015

Blood pressure target in diabetes mellitus

Hypertension in diabetic patients increases the risk of microvascular and macrovascular complications. It is quantitatively and qualitatively different from the non-diabetic population and characterized by disturbed circadian rhythm of blood pressure (BP) with increased variability. It also features frequent nocturnal hypertension with high 24 hour BP load and impaired auto-regulation of blood flow leading to microvascular injury.

A large meta-analysis of 1 million individuals followed for 14 years showed a continuous decrease in cardiovascular risk with reduction in BP to as low as 115/75 mmHg. In the absence of RCT data, presuming “lower is better”, BP targets of < 130/80 mm Hg were traditionally recommended in diabetic patients. However the hypothesis of a J-shaped relationship with risk challenges the lower BP targets suggesting that benefits of extreme BP reductions are smaller than moderate reductions. This seems logical as physiologically there is a low (as well as high) BP threshold for organ blood flow auto-regulation. Two diabetic statin trials (TNT and PROVE IT-TIMI) reported a J-shaped relationship between BP and adverse cardiovascular events, although there were no BP lowering interventions.  Recently, JNC 8 (based on the ACCORD trial, where the SBP target of < 120 mm Hg could have produced J shaped curve) and ESH/ESC 2013 (diastolic target based on HOT trial) recommended a relaxed BP target of < 140/90 mmHg in diabetic patients. These conflicting recommendations on hypertension targets, from various professional bodies have created confusion in the minds of physicians.

Comparison of BP targets (in mm Hg) by different guidelines

 

Age 

Diabetes

Chronic Kidney disease

JNC 8 (2013)

<60 y: <140/90
≥60 y: <150/90

<140/90

<140/90

ESH/ESC (2013)

Elderly < 80y:
SBP 140-150SBP < 140 in fit patientsDBP < 90
 Elderly > 80 y:
SBP 140-150DBP < 90

<140/85

<140/90

ASH/ISH (2014)

< 80 y: <140/90
≥ 80 y: <150/90

<140/90

<140/90

AHA/ACC/CDC (2013)

<140/90
Lower targets may be appropriate in some patients including the elderly

<140/90
Lower targets may be considered

<140/90
Lower targets may be considered

KDIGO BP guidelines in CKD (2012)

No recommendation for general population. For Elderly with CKD ND
Tailor BP target based on age and co-morbidities

CKD ND with or without diabetes

Albuminuria < 30 mg /24 hr
≤ 140/90
Albuminuria > 30 mg /24 hr
≤ 130/80 

CKD ND = non-dialysis-dependent CKD
A recent meta-analysis in JAMA has reignited the debate of BP targets in patients with diabetes. Emdin et al analyzed 45 RCT`s (100,354 participants), conducted between Jan 1966 and October 2014, of BP lowering treatment in patients with diabetes (regardless of presence or absence of defined hypertension). Trials with predominantly type 1 diabetes patients were excluded. The researchers examined the associations between BP-lowering treatment and vascular disease in type 2 diabetes. They found that:
  •  Each 10-mmHg lower systolic BP was associated with a lower risk of mortality, cardiovascular disease events, coronary heart disease events, stroke, albuminuria and retinopathy.
  • All outcomes, including mortality, were reduced when SBP was lowered from elevated baseline of >140 mm Hg and higher to a range of 130-140 mmHg. 
  •  Further reduction of SBP below 130 mm Hg yielded lower risk of stroke, retinopathy and progression of albuminuria.
  •  Irrespective of drug class, the associations between BP-lowering treatments and outcomes were not significantly different except for stroke and heart failure.

The authors recommended that for patients at high risk of stroke, retinopathy or progression of albuminuria, BP treatment should be commenced at initial SBP level of 140 mmHg and target SBP below 130 mmHg.
The lower risk of stroke with reduction of SBP below 130 mmHg has been previously reported in the TNT trial, this meta-analysis and a subgroup analyses from the ONTARGET trial. However, the bigger question is if such lower SBP target can be achieved without any adverse events in the elderly diabetic population. The rate of serious adverse events reported in ACCORD trial in intensive treatment group (achieved BP 119 mmHg) was 2.5 times that of the control group (achieved BP 133 mmHg). While there is clear benefit in BP sensitive outcomes like stroke, it is unclear why lower SBP target below 130 mmHg does not benefit other outcomes like heart failure and renal failure. This could be due to the fact that hypertension trials have a short follow up and these outcomes occur too late in the disease process to see early benefits. Or could this be due to J-shaped relationship?
As summed up in a recent commentary titled “Hypertension Guidelines in need of Guidance”: We should be more worried about hypertension, not hypotension. Surely, one would avoid excessive or unwanted degree of BP lowering in patients with hypertension; it needs only common sense, not guideline committees.
Which hypertension guidelines do you follow? And what BP target do you set for your diabetes patients? Will you try to target these lower SBP if your patient tolerated them? Leave your comments below.

Amit Langote
Nephrology Fellow, Ottawa



Friday, February 6, 2015

#MyNephroStory: A Rewarding Journey

There is a lot of discussion about the recent nephrology Match in the US and everyone is discussing what’s wrong with nephrology? Why is the interest in Nephrology waning? Like most people I took a unique journey to nephrology and maybe by sharing my tale it will inspire others to take up nephrology. I went from a small town, Jalgaon, in India to nephrology fellowship in Canada.

Screen Shot 2015-02-05 at 7.27.54 PM.png
My journey to renal enlightenment began on a wet monsoon night in Pune, India where I was on call in the ICU during residency. We had a patient dying of multi-organ dysfunction and he desperately needed dialysis. The only dialysis machine available was a vintage Drake Willock beast that had sprung a leak. We called the on-call nephrologist, a new recruit at the time, for help. After a we saw this dripping wet, unassuming guy carrying not a stethoscope but a screwdriver. This nephrologist gets down on his hands and knees, pulls out the section of the Drake Willock, identifies the leak and fixes it, all in about 15 minutes. The patient survived and I knew right then, I wanted to be a nephrologist. From that moment on I was wide eyed boy in the candy shop for anything nephrology.

The rain soaked nephrologist was Dr Valentine Lobo, and he took me under his wing, and guided me through residency and then through nephrology fellowship. He was the mentor that was always there, teaching me to place lines, do biopsies, place PD catheters. We covered the widest swath of nephrology, we did pediatrics, electrolytes, transplant, pathology. We went to the lab to measure creatinine and do HPLC drug levels. I remember placing a dialysis line in a man receiving chest compressions for a hyperkalemic arrest. I remember doing plasmapheresis for aHUS and staring at the foley tube waiting for the first trickle of urine after a transplant. I sprinted from the clinic to the lab with containers of warm urine to search for dysmorphic RBC and RBC casts. He was the best mentor, knowledgeable, excited and encouraging. He made nephrology not just my vocation but my destiny.


In 2009, I was a final year nephrology fellow and was looking for some information on the net and stumbled across UKidney, Initially I thought it was some renal-inspired spoof of YouTube, but as I explored the site I saw the structure and vision of it’s creator, Dr Jordan Weinstein. and I wrote him about who I was and what I was doing. Specifically, I asked him about nephrology training in Canada and what were the possibilities. I never really expected a reply, but once again a senior nephrologist noticed my enthusiasm and took the time to write back with encouraging words to give Canada a try. 
So, that is what I did, and three years later I landed in Edmonton at the University of Alberta with my pediatrician wife and 3 -year old daughter, to start another renal roller coaster ride. We arrived in November and until that moment, my experience with snow was limited to defrosting the freezer. I had never seen so much white stuff in my entire life. But when you are excited about nephrology what’s a couple of feet of snow? 
The fellowship was in renal transplant and was wonderful. I continued at U of A as a nephrology Fellow after my Transplant Fellowship. Every moment is a new learning experience, every staff is loaded with #NephPearls, and everyone is eager to teach. I bet it is a two way street, probably my “kid in a candy store” attitude helped. Recently, with the help and urging of my program director, Dr Mark Courtney, I began exploring social media. He sent me a #NephJC link saying this is something I would be interested in, and once again I launched myself into another facet of nephrology education with the same wide eyed zeal that made me choose this beautiful specialty. 
Looking back, honestly, I would change nothing. I would still go to medical school and still select nephrology. It has everything that a branch can offer and enough unknowns that I remain that “wide eyed boy in the candy store”. I remember the excitement with which I opened my brand new copy of Schrier’s text in 2008 and it is with the same tingling excitement I open my twitter account every day. New research, new people, new thoughts, new ideas, all geared to improve the life of the kidney patient – why wouldn't I choose nephrology, It ROCKS!

Authored by Nikhil Shah 
NMSC Intern & Nephrology Fellow at University of Alberta Hospital