UKidney Nephrology News and Insights

I have never been a fan of vitamins. They fall in to a category of interventions with presumed safety and benefit. An important study in the Journal of the American Medical Association shows the opposite; that vitamins can cause harm in patients with chronic kidney disease.

The following appears on the BC Renal Agency Website:

In April, the Journal of the American Medical Association (JAMA) published a study that looked at whether high doses of B vitamins (folic acid, B12, B6) helped people with kidney disease due to diabetes. The study found that high doses of these vitamins were actually harmful. Study participants who took the vitamins had an increased risk of heart attack and stroke. They also had reduced kidney function.

As we continue to process data from the EMPA-REG renal outcomes presentation - which most importantly showed a 46% reduction in the composite of creatinine doubling, end-stage renal disease or renal death - speculation is well underway to explain the mechanism for renal protection. And the emerging story appears to be quite fascinating indeed. 

Poster: Racial/Ethnic Disparities in Atrial Fibrillation Treatment and Outcomes in US Dialysis Patients

Presenter: Adan Z. Becerra PhD, Social & Scientific Systems

Authors: Paul L. Kimmel, MD, FASN, National Institute of Diabetes and Digestive Kidney Diseases (NIDDK), Salina Paulette Waddy, MD, Atlanta Veterans Administration, Allen J. Solomon, MD, The George Washington University, Adan Z. Becerra PhD, Social & Scientific Systems, Julia B. Ward, PhD, MPH, Social & Scientific Systems, Inc., Kevin Chan, MD, MS, MGH, Chyng-Wen Fwu PhD, Social & Scientific Systems, Inc., Jenna M. Norton MPH, NIH/NIDDK, Paul Eggers PhD, Kevin C. Abbott, MD, MPH, The National Institutes of Health, NIDDK,

Increased racial/ethnic disparities in stroke rates among end-stage renal disease (ESRD) dialysis patients with atrial fibrillation (AF) are partially explained by lower use of oral anticoagulants among Blacks, Hispanics, and Asians. The reasons for these racial disparities in practice are unknown, although the results support an identified need to develop strategies that will maximize stroke prevention in minority populations and resolve system barriers between patient/physician that may block optimal treatment.

Imagining the Dream RCT in nephrology is an important exercise, but not for the reasons you might think. For many, there might be the temptation to devise trials that will pave the way for future enhancements to patient care or to some other exciting, forward thinking outcome. For me however, the Dream RCT in nephrology is about shattering or affirming nephrology dogma - and in nephrology we seem to have more dogma influencing core tenets of our specialty than in other medical disciplines. There is a popular saying among those in the clinical epidemiology world - that you don’t need to conduct an RCT to prove that parachutes are required when jumping out of a plane. Unfortunately in nephrology, thought leaders have bestowed parachute status on too many interventions. I can think of no better example for this analogy than treating hyperphosphatemia in CKD/ESRD. And it is this topic that would underlie my Dream RCT.

At the end of 2011, Novartis suspended the ALTITUDE Study, effectively ending the possibility that the direct renin inhibitor (DRI) Aliskiren will play a significant role in the management of patients with CKD already on an ACE or ARB. This development was disappointing but actually represents only part of a growing body of evidence that now casts major doubt on the use of microalbuminuria (MAU) as a treatment surrogate in patients with cardiovascular disease.

The use of MAU as a predictor of cardiovascular risk is sound and supported by a sizable evidence base. There is little doubt that patients with risks for cardiovascular disease who also have MAU are at far greater risk for adverse outcomes including death. In numerous studies, including the Heart Outcomes Prevention Evaluation (HOPE) Trial [7], MAU was the single most potent risk factor for adverse outcomes, with greater predictive power than diabetes, male gender, smoking and hypertension. The fascinating part of this observation is that even seemingly modest elevation in MAU was highly predictive of adverse events. It was very tempting then to anticipate a concomitant reduction in risk among patients whose MAU was targeted for therapeutic reduction with any of: (1) high dose ACE or ARB, (2) combination ACE and ARB, and most recently, (3) combination ACE or ARB with DRI. Unfortunately, recent prospective studies have essentially decimated this hypothesis and in all, proteinuria improved whereas patients did not or actually fared worse.

ScienceDaily (May 6, 2010) — Two-year results from phase III clinical trials show the experimental immunosuppressive drug belatacept can better preserve kidney function in kidney transplant recipients while preventing graft rejection when compared with the standard immunosuppressive drug cyclosporine.

The KDIGO guideline group has released its bone and mineral guidelines.

• These can be seen online at this link.
• Alternatively, you may download the .PDF of these guidelines using this link

Dr. Jeff Berns, editor in chief of Medscape Nephrology, had this to say on this development:

Over the past 2 years, considerable excitement has been building over the results of the ACCOMPLISH study. This trial suggested that the combination of benazapril plus amlodipine is superior to benazapril plus hydrochlorothiazide for the prevention of a composite cardiovascular outcome. While there are methodological concerns regarding this trial that make me question its generalizability, it is thought-provoking to consider that one medication combination is superior to another even if blood-pressure between the 2 groups is negligible.

In the latest issue of Lancet, a follow-up paper suggests that benzapril-amlodipine prevented renal outcomes more-so than in the benazapril-hydrochlorothiazide arm. However, as the excellent accompanying editorial points out, all is not as it appears. (continued...)

The TREAT Trial was presented at the ASN in San Diego. This much publicized trial examined the role of Aranesp in the management of diabetic patients with CKD. One group was randomized to receive Aranesp with a hemoglobin target of 130 g/l while the control group was given placebo and treated with Aranesp only if their hemoglobin fell below 90 g/l.

There was no advantage to the group given Aranesp and a statistically significant increase in strokes observed in the the treatment group. Below is a link to the article from NEJM and the accompanying editorial written by renowned nephrologist, Dr. Phil Marsden of the University of Toronto.

It is worth noting, that the treatment group was targeted to a higher hemoglobin than we now conventionally use. Furthermore, the dose of Aranesp was more than double the typical dosages used by the majority of my predialysis patients. As has been observed in other studies where high hemoglobin seems harmful, the dose of Aranesp required might explain the observation of harm. Perhaps those patients who respond to lower dosages and those whose hemoglobins remain with target would be perfectly safe to continue.

More study is needed to clarify this and perhaps might be forthcoming from further analysis of the TREAT Study.

Click for:

A Trial of Darbepoetin Alfa in Type 2 Diabetes and Chronic Kidney Disease

Treatment of Anemia in Chronic Kidney Disease — Strategies Based on Evidence

Hyperphosphatemia has been been linked to poor patient outcomes, including a link to higher mortality. This relationship has been inferred by several retrospective and observational studies. In fact, the relationship between hyperphosphatemia and death is one of the most consistently espoused theories in all of nephrology. There is just problem however; there has never been a randomized trial to confirm this association.

In the latest issue of Nephrology Dialysis and Transplantation, Smith et al cast doubt on this long-held belief. In their retrospective CKD-inception cohort study, there was no association between hyperphosphatemia and death, though there was less risk of renal replacement therapy in patients with better phosphorus control.

This finding is by no means conclusive. I continue to aggressively treat hyperphosphatemia. However, it does lend further support for a large-scale randomized trial to study this seemingly unimpeachable belief.

In a fascinating article from November's Journal of the American Society of Nephrology, researchers present data suggesting that patients returning to dialysis after a transplant fails experience improved survival if the kidney is removed. In this study, despite correction for comorbidities and socioeconomic factors, graft nephrectomy prolonged survival. One explanation of the results might be that nephrectomy removes an inflammatory stimulant and would allow complete withdrawal of immunosuppression and its risks. This finding is somewhat contradictory to current dogma which suggests that immunosuppression should be continued once returning to dialysis in order to preserve residual renal function. This study's finding would need to be reproduced with a prospective randomized trial to reduce bias but in the meantime, is quite compelling.

Genome-wide association studies have previously shown a strong signal between a region residing on chromosome 22 centered on MYH9 and African Americans with FSGS and hypertension attributed end-stage kidney disease (H-ESKD). On July 15, 2010, Science released online a publication revealing a strong association between the same but expanded interval containing a nearby gene encoding for apolipoprotein L-1 (APOL1) in a similar group of patients.

The investigators, led by Dr. Martin Pollak, the chief of the Division of Nephrology at Boston's Beth Israel Deaconess Medical Center, reasoned that because no causal mutations have been identified in MYH9, other alleles ought to be considered. Furthermore, recent selection pressures in Africans could lead to longer patterns of linkage disequilibrium (LD). More, but previously unavailable, data from African individuals whose DNA were sequenced in the 1000 Genomes Project (www.1000genomes.org) was used to identify polymorphisms that showed large frequency differences between Africans and Europeans.

The SHARP study was reported at the American Society of Nephrology Meeting in Denver on November 20th, 2010. The results are positive. This is excellent news indeed when previous lipid trials in patients with renal failure were a disappointment.

Here is a summary of the key findings:

• The patients allocated to take ezetimibe plus simvastatin had one-sixth fewer heart attacks, strokes or operations to unblock arteries ("major atherosclerotic events"), with similar reductions observed in all types of patient studied.
• During this long trial, the proportion of patients who stopped taking their allocated treatment was about one third, but this was not generally due to side-effects and was the same for both real and dummy treatments. If taken without interruption, however, ezetimibe plus simvastatin could have even larger effects than were seen in SHARP, potentially reducing risk by about one quarter.
• Adding 10mg daily of ezetimibe to 20mg daily of simvastatin produced a large reduction in LDL cholesterol safely. This combination treatment may be particularly good for kidney patients, as it avoids the possibility of side-effects with high statin doses.
• There was no support for previous concerns with ezetimibe about possible adverse effects on cancer, and no evidence of an increased risk of muscle or liver problems.

(Source: http://ukid.cc/atgiPN)

As with any study, a complete critical appraisal should be done on the published article once available. One key question is whether the observed benefit was the result of ezetimibe or simply the result of lower LDL in the treatment group, regardles how obtained (i.e. with higher statin dosing).

Any news on promising treatments for Lupus is always welcome. Indeed, it has been years since any new therapies have provided much new hope for a disease which has very significant renal implications.

Benlysta is an investigational human monoclonal antibody drug and the first in a new class of drugs called BLyS-specific inhibitors. These drugs prevent b-cell proliferation and development in to mature plasma cells with a resuling drop in antibody production. This mechanism of action is very well-suited to Lupus whose pathophysiology is widely thought to involve autoantibody formation.

Results of phase-3 clinical trials have been previously reported showing positive results, a first in many years for the management of lupus. As a result,  the drug has been granted a priority review designation by the FDA (Food and Drug Administration, USA), an indication that this drug has an important role in managing lupus as other medications have left much to be desired.

What is not clear however, is the role that this medication will have in the management of lupus nephritis as it seems that these patients were excluded from the initial trials.

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As nephrologists with a significant interest in mineral metabolism practicing in Ontario, we are writing to inform you about a class review of all phosphate binders in end-stage renal disease that has been initiated by the Ontario Public Drug Program to evaluate and review their funding, as well as associated reimbursement criteria.

Controlling serum phosphorus, serum calcium and secondary hyperparathyroidism is a day-to-day challenge in the management of patients with end-stage renal disease on dialysis. Strategies to limit dietary phosphate intake and/or increasing the frequency or duration of dialysis when possible do not succeed in maintaining serum phosphate levels below 1.8 mmol/L and the majority of our patients require the use of oral phosphate binders in addition.

Calcium salts are the mainstay of pharmacological treatment, but many of our patients develop hypercalcemia and vascular calcification. The limitations associated with calcium salts have led to the development of newer non-calcium based agents, such as sevelamer and lanthanum, which have been widely adopted and funded worldwide. Other major Canadian provinces, including Quebec and British Columbia, also reimburse them. In Ontario, we have limited or no access to these drugs and we are concerned that this class review could result in further restrictions.

The recently published comprehensive evidence-based clinical practice guidelines^1,2 stress the importance of maintaining serum phosphorus and calcium levels within an acceptable range. The Ontario Renal Network's (ORN) Clinical Advisory Committee has also established the percentage of dialysis patients who achieve a phosphate level of less than 1.8mmol/L as one of three patient outcome quality indicators for dialysis patients. http://www.renalnetwork.on.ca/quality/ Although the recent guidelines acknowledge the fact that there is limited evidence from randomized controlled clinical trials on the longer-term clinical outcomes, they support the need for a non-calcium based strategy in patients with high serum calcium levels.

While we acknowledge that the evidence from clinical trials to date does not entirely support the use of non-calcium based phosphate binders, we also believe that the federal and provincial committees responsible for recommending exclusion of these agents in the formularies have simultaneously ignored the evidence for harms arising from the use of calcium-based binders in the control subjects. Thus the need for access to non-calcium based phosphate binders should focus around issues of patient safety, and not simply those related to cost.

We would like to hear your opinions on this subject. We are also interested to learn whether terms of references have been established for this phosphate class review and whether the Ministry has involved the Ontario nephrology community, the Ontario Renal Network or the Ontario Association of Nephrologists

The Planet 1 and 2 studies are not widely publicized. However, they do provide some eye-opening information.

According to these studies, in patients with diabetes and intact renal function, there was a significant decline in renal function and failure to reduce urinary protein in patients randomized to rosuvastatin but not atorvastatin. Furthermore, there were more renal events in the rosuvastatin group (doubling of serum creatinine and episodes of acute renal failure).

These results are very surprising and difficult to rationalize at face value. Nevertheless, the design of the trials appears sound and the number of patients adequate.

Dr. Marecllo Tonelli from the University of Alberta walks us through this data in his outstanding presentation seen here on UKidney

This is a great post on chloroquine in lupus. It appears as below on Skin and Allergy News. A great and promising read:

SNOWMASS, Colo. – The past 12 months have brought a slew of studies making a persuasive case for hydroxychloroquine as a far more important drug in lupus than previously thought. Indeed, the drug could now even be considered essential.

"In 2011, all lupus patients should receive hydroxychloroquine," Dr. David Wofsy flatly declared at a symposium sponsored by the American College of Rheumatology.

"The indication for hydroxychloroquine in lupus is lupus," added Dr. Wofsy, professor of medicine and microbiology/immunology at the University of California, San Francisco.

There is now solid evidence that hydroxychloroquine (Plaquenil) prevents lupus flares, treats the skin manifestations of the disease, protects against thromboembolic events, prevents cardiac neonatal lupus, and prolongs life.

"It will be a very long time before we've proven that any biologic therapy can do all those things," Dr. Wofsy, who is also chief of rheumatology at the San Francisco Veterans Affairs Medical Center.

This fascinating video discusses the concept of organ generation as a method of bridging the enormous gap between supply and demand that exists among patients who experience organ failure.

This may well move from science fiction to the mainstream in the not-too-distant future.

Click 'Read more' below to see the video

This week in the New England Journal of Medicine, 2 studies reported on the use of mTor inhibitors in Autosomal Dominant Polycystic Kidney Disease (ADPKD). The results were mixed but overall, disappointing.

In the first study, investigators used open label sirolimus versus standard care in 100 patients with ADPKD and mean GFR of 70 ml / min, (stage 2 chronic kidney disease). After 18 months, there was no difference in kidney volume nor kidney function between the 2 groups while the sirolimus group had higher urinary albumin excretion.

In the second study, a 2-year, double-blind trial, 433 patients were randomly assigned to receive placebo versus everolimus. After 24 months there was less kidney volume but the mean decrement in the estimated glomerular filtration rate after 24 months was the same: 8.9 ml per minute per 1.73 m² of body-surface area in the everolimus group versus 7.7 ml per minute in the placebo group (P=0.15). There were more side effects in the treatment group.

I had been awaiting these studies with great anticipation but the results over-all are disappointing, namely because renal function was no better in the treatment groups. It is not clear how to explain the disconnect between reduction in cyst growth in the everolimus group yet no change in kidney function. There is little doubt that cyst volume is a less important outcome than renal function, however, it is hoped that with longer term studies, possibly earlier in the course of the disease, that the sustained control of cyst growth by everolimus could lead to preservation of renal function. I hope to see such longer term studies done in this fashion.

Drs. Anish Kirpalani and Darren Yuen, both of St. Michael's Hospital in Toronto, appear to be on the verge of a major practice-changing advance in the assessment of chronic kidney disease. Their study, appearing in cJASN, describes the new methodology which assesses kidney fibrosis in a novel way using MRI. We caught up with the authors of this exciting study and they shared some further perspective on their exciting findings.