About IRIS
The IRIS Board made three significant changes to CKD Guidelines during 2014 and 2015. A summary of these new recommendations is presented here. The full version of 2015 Guidelines will be uploaded during our website relaunch by the end of 2015.
Substaging by Arterial Blood Pressure
We recommend replacement of the existing abbreviations for blood pressure substages (AP0-AP1) with descriptive terms as follows:
| Systolic blood pressure (mm Hg) | Diastolic blood pressure (mm Hg) | Risk of future target organ damage | BP substage | |
|---|---|---|---|---|
| Original | New | |||
| <150 | <95 | Minimal | AP0 | Normotension |
| 150 - 159 | 95 - 99 | Mild | AP1 | Borderline hypertension |
| 160 - 179 | 100 - 119 | Moderate | AP2 | Hypertension |
| >180 | >120 | Severe | AP3 | Severe hypertension |
Treatment of Proteinuria
We recommend that IRIS CKD Stage 1 patients with persistent proteinuria (UPC ≥ 0.5 for dogs or 0.4 for cats) are not only monitored and thoroughly investigated but also receive standard treatment for proteinuria as currently recommended for IRIS CKD Stages 2 to 4. This parallels the IRIS consensus statement on standard treatment for glomerulonephritis (J Vet Intern Med 2013;27:S27–S43).
Interpreting Blood Concentrations of Symmetric Dimethylarginine (SDMA) in CKD
SDMA concentrations in blood (plasma or serum) may be a more sensitive biomarker of renal function than blood creatinine concentrations. A persistent increase in SDMA above 14 µg/dl suggests reduced renal function and may be a reason to consider a dog or cat with creatinine values <1.4 or <1.6 mg/dl, respectively, as IRIS CKD Stage 1.
In IRIS CKD Stage 2 patients with low body condition scores, SDMA ≥25 µg/dl may indicate the degree of renal dysfunction has been underestimated. Consider treatment recommendations listed under IRIS CKD Stage 3 for this patient.
In IRIS CKD Stage 3 patients with low body condition scores, SDMA ≥45 µg/dl may indicate the degree of renal dysfunction has been underestimated. Consider treatment recommendations listed under IRIS CKD Stage 4 for this patient.
These comments are preliminary and based on early data from the use of SDMA in veterinary patients. We expect them to be updated as the veterinary profession gains further experience using SDMA alongside creatinine, the long-established marker in diagnosis and monitoring of canine and feline CKD.
IRIS Newsletter
September 2013
The IRIS Board's annual meeting for 2013 was held on June 10 and 11 in Seattle, WA, USA. In attendance both days were Claudio Brovida, Larry Cowgill, Jonathan Elliott, Greg Grauer, Reidun Heiene, Alexander Hüttig, Hervé Lefebvre, David Polzin, Jean-Louis Pouchelon, Xavier Roura, Astrid van Dongen (Acting President) and David Watson; joining on the second day were Pepa Fernandez del Palacio and Toshifumi Watanabe. Apologies were received from Scott Brown.
Also present in a supporting role were Nichola Archer Thompson, Flavien Bai, Philippe Gruet and Silvia Rossetto, of Novartis Animal Health.
As usual, the meeting provided the opportunity for the Board to review and discuss work undertaken since the last meeting (Maastricht, 2012), and to revise current guidelines and plan future actions. Some important outcomes of this year's activities are summarized here.
From left to right: David Watson, Astrid van Dongen, Nicky Archer-Thompson, Flavien Bai, Hervé Lefebvre, David Polzin, Larry Cowgill, Reidun Heiene, Jean-Louis Pouchelon, Toshifumi Watanabe
IRIS Website
The IRIS website (www.iris-kidney.com) was completely upgraded during 2013: the format was improved, existing guidelines and educational articles were reviewed and updated as necessary, and some new features were added. This process was greatly assisted by input from Margot Vaessen.
For 2013, there are no major changes in guidelines for IRIS CKD Staging guidelines but the CKD Treatment guidelines have been fully revised and guidelines for grading Acute Kidney Injury (AKI) have now been added. The current versions of all guidelines are now available on line at www.iris-kidney.com.
The new IRIS AKI Grading guidelines were devised initially by IRIS Board member Dr Larry Cowgill, subsequently reviewed and revised by the IRIS Board, and finally adopted by the Board at the meeting in Seattle. It proposes five grades of AKI based on blood creatinine concentration, then subgrading according to urine production and requirement for renal replacement therapy. The IRIS AKI Grading system is a work in progress and, like the IRIS CKD Staging and Treatment guidelines, will be amended and updated as further information becomes available. It is anticipated that consistent use of the IRIS AKI Grading guidelines will improve patient management and reporting, and facilitate development of AKI treatment guidelines.
There are now 10 Educational Topics on the website – all previous articles have been reviewed and updated where necessary, and several new items have been added recently.
Those new to IRIS CKD staging may find the Overview of the IRIS Staging System for CKD a useful starting point, while the extensively revised and expanded articles on Measurement and Interpretation of Proteinuria and Albuminuria and on Systemic Hypertension should be of interest to everyone.
IRIS Projects
It is widely accepted that proteinuric kidney disease is important in dogs, but little was known until recently about prevalence and therapy of immunologic glomerular disease. Data from the WSAVA Renal Standardization group showed that approximately 50% of proteinuric kidney diseases in dogs were due to immune-mediated processes and that prognosis was positively affected by identification of an underlying pathogenesis. However, the data also demonstrated wide variations and no general consensus as to appropriate treatment protocols.
On considering these findings, the IRIS Board decided in 2011 to develop a consensus report entitled "The IRIS Best Clinical Practice Guidelines for Proteinuric Kidney Disease in Dogs: A Consensus Evaluation." The goal was to use currently available evidence and group consensus to develop clinically applicable recommendations for diagnosis and management of these patients. Two Board members, David Polzin and Larry Cowgill, were nominated to co-Chair the study group.
To cover the wide array of patient presentations and management approaches, the following five working topics were established:
- Diagnostic Investigation of Dogs with Suspected Glomerular Disease,
- Standard Therapy of Dogs with Suspected Glomerular Disease,
- Immunosuppressive Treatment of Dogs with Glomerular Disease Based on Established Pathology,
- Immunosuppressive Treatment of Dogs with Proteinuric Kidney Diseases Absent Histopathologic Diagnosis,
- Immunosuppressive Treatment of Dogs with Suspected Glomerular Disease and Serologic Evidence of A Possible Causative Agent.
Additional experts were invited to join IRIS Board members to enhance the process. These were Luca Aresu, Cathy Brown, Rachel Cianciolo, Fred Clubb, Sylvie Daminet, Thierry Francey, Bernhard Gerber, Richard Goldstein, Clare James, Johan Jansen, F. Charles Mohr, Mary Labato, Cathy Langston, George Lees Meryl Littman, Mary Nabity, Barrak Pressler, Sarah Schneider, Gilad Segev, Shelly Vaden, Jaco van der Lugt and Andrea Zatelli.
The recommendations made were to be supported by various levels of evidence, published and unpublished, and by expert opinion. Because published evidence is often limited and inconclusive, recommendations were formulated by a sub-group and submitted to a formal consensus process, which included review and voting on all recommendations by the entire group of external panel members and all IRIS Board members.
The recommendations have been published online as a November/December 2013 supplement to the Journal of Veterinary Internal Medicine. The supplement includes the five topics above, together with reports from the WSAVA Renal Standardization Project, the WSAVA Pathology Group and the IRIS Board.
The IRIS Board hopes this project will serve as a model for developing future recommendations in nephrology and other fields in veterinary medicine. The development of the report and its inclusion as a journal supplement have been graciously supported by Novartis Animal Health, since acquired by Eli Lilly and Company through its Elanco Animal Health division.
The IRIS Award for 2013
The IRIS Award is granted once every two years to an individual early in his or her research career for outstanding contributions to the field of veterinary nephrology. It consists of a monetary prize (10 000 euro) and an invitation to present a lecture during the ECVIM Congress and the ACVIM Forum, all supported by Elanco.
The decision to award the prize is based on the quality of the candidates' applications, the relevance of their publications to nephrology, and letters of support. After due consideration of a strong field of five applicants, the Board selected Natalie Finch BVSc PhD MRCVS (photo) as the winner of the 2013 IRIS Award.
Natalie completed the majority of the work for which she received the award during a clinical research scholarship at the Royal Veterinary College, London, where she worked in collaboration with Professor Elliott's group. She is currently a senior clinical training fellow in Feline Medicine at the School of Veterinary Sciences, Bristol University.
Dr Finch was evidently someone who had thought deeply about the clinical problems she had encountered during her two years in primary care practice and who wanted to discover new solutions to problems that would advance veterinary medicine. Her research goals, which are ongoing, are to better understand those factors initiating feline chronic kidney disease (CKD) and to facilitate its diagnosis at an earlier stage.
Amongst her important findings to date are the identification of frequent vaccination and dental disease as significant risk factors for development of azotaemic CKD. She has also validated simpler clearance methods for measuring and predicting glomerular filtration rate, recognized renal secondary hyperparathyroidism in early non-azotaemic CKD, and shown that fibroblast growth factor - 23 has an important role in the development of renal secondary hyperparathyroidism.
The use of epidemiological approaches to identify cats most at risk of developing CKD and the development of practical methods for measuring kidney function have taken us closer to the goal of determining which cats should undergo kidney biopsy to determine the underlying causes of renal damage at a time when specific treatment might usefully be instigated.
Dr Finch will present a lecture on "Predicting the development of azotaemia in cats" at the 2013 ECVIM Congress in Liverpool, UK, and at the 2014 ACVIM Forum in Nashville, TN, USA.
IRIS Board President
Scott Brown, VMD, PhD, DACVIM, the current President is a professor in the Department of Physiology and Pharmacology of the University of Georgia's College of Veterinary Medicine. His wife, Cathy, is a veterinary nephropathologist who is involved in the WSAVA Renal Standardization Project. They have a daughter, Jessica and a son, Alex. If Scott and Cathy are not at the College, they can usually be found either at home on their farm or in some remote wilderness area of North America. Scott is shown here on their family farm, where they enjoy producing lamb, beef, chicken, pork, eggs, honey, and vegetables for their family and for others in the Athens, GA area who similarly value local, sustainable, free-range farming methods.
Next IRIS Board Meeting
The next IRIS Board Meeting will be held prior to the ECVIM meeting in Mainz, Germany, on September 1 and 2, 2014.
Acknowledgment
The IRIS Board would like to express our gratitude to Novartis Animal Health who have shared our vision of the importance of nephrology in the health of dogs and cats. Their generous support over the past two decades has facilitated development of the IRIS Guidelines for Staging and Treatment of CKD and, more recently, IRIS Guidelines for Grading of AKI. Their funding has enabled the IRIS Board to recognize the pioneers of veterinary nephrology with the Osborne Award, and to recognize and assist the career development of promising new veterinary nephrologists through the IRIS Award. The Board's goals to advance knowledge and education, the field of veterinary nephrology, and our patients' welfare are all better off because of the support of Novartis Animal Health. –Scott A. Brown, IRIS President-