With over 10% of the global population affected by kidney disease, the need for evidence-based clinical guidelines has never been more critical. In response to this urgent need, the U.S.-based National Kidney Foundation established Kidney Disease: Improving Global Outcomes (KDIGO) in 2003.
KDIGO now operates as an independent non-profit and is a leading global authority that develops evidence-based clinical practice guidelines on kidney disease and offers recommendations on their implementation.
KDIGO publishes these guidelines, hosts conferences for thought leaders who are working to advance the field of nephrology, and provides education on kidney disease in a variety of formats. In this article, we’ll examine some of these foundational guidelines commonly used by clinicians to inform their practice.
The KDIGO Organization
KDIGO is made up of volunteers from around the world who develop guidelines for managing kidney disease based on the latest scientific advances in nephrology. Their goal is to improve global outcomes of kidney disease. Their Methods Committee has developed the KDIGO Methods Manual, which serves as a playbook for evaluating new evidence-based practice and incorporating that evidence into new clinical practice guidelines. KDIGO also convenes Controversies Conferences around the world, providing an opportunity for experts in the field to come together to work toward resolving unsolved challenges in kidney disease management. Additionally, KDIGO offers educational sessions, webinars, podcasts, videos, and other resources to support new knowledge and learning for providers as the kidney management landscape continues to evolve.
The clinical guidelines developed and published by KDIGO are designed to be the standard used by healthcare organizations in treating kidney disease, with a goal of promoting uniform care while improving outcomes and lowering treatment costs. There are currently 17 guidelines published by KDIGO, including guidelines on acute kidney injury (AKI), chronic kidney disease (CKD), kidney transplantation, and more.
Furthermore, the KDIGO stages of kidney disease inform proactive identification and treatment of developing kidney dysfunction using the latest methodology available to clinicians. Here, we examine a few of the prominent guidelines and these stages.
Chronic Kidney Disease (CKD) Guidelines
The KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (CKD) is the most recent update to KDIGO’s 2012 CKD guidelines. The document covers the optimal approach to CKD evaluation and classification, risk assessment for CKD, management of complications, and appropriate medication management. It also helps clinicians provide patient-centered care that considers patients’ unique needs and preferences.
At a baseline, CKD is defined by KDIGO as “abnormalities of kidney structure or function, present for >3 months, with implications for health,” and includes documentation of the following criteria for >3 months: either GFR <60 ml/min/1.73 m2 or markers of kidney damage, including albuminuria.
The new guidelines also revise the previous KDIGO classification structure for CKD, refining the classification as based on the following elements: cause, glomerular filtration rate (GFR) category, and albuminuria category (CGA).
These criteria help to differentiate patients with acute kidney injury from those with CKD, and KDIGO further describes treatment approaches based on evaluation and staging of these patients.
Acute Kidney Injury (AKI) Guidelines
KDIGO’s AKI Guidelines were most recently published in 2012, with new AKI Guidelines currently under development. New updates are informed by the KDIGO 2019 Controversies Conference on Acute Kidney Injury and the 2020 Consensus Conference on Harmonizing Acute and Chronic Kidney Disease Definitions and Classification.
Current AKI Guidelines define AKI as the presence of any of the following: increase in serum creatinine by 0.3 mg/dL or more within 48 hours, OR increase in serum creatinine to 1.5 times or more than the baseline of the prior 7 days, OR urine volume less than 0.5 mL/kg/h for at least 6 hours.
Early identification of AKI using these criteria facilitates prompt intervention to improve outcomes, which is crucial to preventing long-term health consequences from AKI, including development of CKD. This also emphasizes the importance of intensive urine output monitoring in the timely identification of AKI, an area in which advances in technology are allowing interventions earlier than ever before, including clinical alerts triggered by persistent downward trends in urine production.
Proteinuria Evaluation Guidelines
Proteinuria is significant in identifying and staging kidney disease. KDIGO includes it alongside GFR in the classification of CKD, as it serves both as an early marker of kidney disease and as an indicator of disease progression based on its severity.
To accurately evaluate proteinuria, KDIGO guidelines recommend the use of albumin-to-creatinine ratio (ACR). ACR is calculated by dividing the albumin concentration in the urine by the creatinine concentration. Normally, urine albumin (measured as mg/d) would be less than 30 in healthy patients; microalbuminuria is a level of 30-300 and macroalbuminuria is a level greater than 300.
KDIGO guidelines recommend that patients with albuminuria ≥30 mg/d be treated with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. A decrease in ACR represents decreased risk of kidney damage, highlighting the importance of this marker in identifying and managing kidney disease. In recognition of this, KDIGO classification of albuminuria by category (CGA) breaks down albuminuria into levels A1-A3 (mild, moderate, severe) that correlate with degree of CKD.
Kidney Transplantation Guidelines
KDIGO has also developed robust guidelines for both transplant candidates and recipients to help inform the management and care of these patients. There are currently more than 90,000 patients on kidney transplant waiting lists, with 28,492 having received a transplant in 2024.
KDIGO examines two core challenges in kidney transplantation: the evaluation of eligible candidates and the management of patients who have received transplantation. Transplant candidate guidelines consider the risk of poor transplantation outcomes and offer advice on maximizing favorable outcomes.
For transplant recipients, KDIGO guidelines offer recommendations on immunosuppressant drug adjustments, assessing the risk of CKD recurrence, and managing common complications post-transplant. These include rejection, nonadherence, infection, new onset diabetes, and the impact of other chronic health conditions such as hypertension.
KDIGO notes that while the transplantation guidelines are evidence-based, their recommendations also highlight areas where evidence is lacking, and further research is needed to improve transplant programs worldwide. The scope of the guidelines is limited to transplantation management up to the point of secondary failure or patient demise only and does not provide recommendations for failure after transplantation or re-transplantation.
KDIGO Stages of Kidney Failure
The KDIGO metrics for staging kidney failure are a significant contribution to the management of acute kidney injury and chronic kidney disease. For AKI, other developed criteria include RIFLE and AKIN; KDIGO stages have been shown in some contexts to be a superior predictive tool for AKI, such as for patients with comorbid acute heart failure.
KDIGO criteria for AKI divide diagnosis into three stages of AKI:
• Stage 1 AKI: Serum creatinine 1.5-1.9 times baseline or ≥ 0.3 mg/dl increase and/OR a decrease in urine output of 0.5 ml/k/h for 6-12 hours
• Stage 2 AKI: Serum creatinine 2.0-2.9 times baseline and/or decrease in urine output of 0.5 ml/k/h ≥ 12 hours
• Stage 3 AKI: Serum creatinine 3 times baseline or ≥ 4 mg/dl increase OR initiation of renal replacement therapy (RRT), OR in patients <18 years of age, a decrease in eGFR to <35 ml/min per 1.73 m2 and/or urine output < 0.3 ml/k/h for ≥ 24 hours OR anuria for ≥ 12 hours
For CKD, KDIGO classification of severity is based on cause and two other distinct factors: GFR and the aforementioned albuminuria classifications (CGAs). These levels, cross-referenced with each other, make up the basis for the most recent KDIGO CKD classifications.
In this method, along with CGAs of A1-A3, GFR is broken into categories of G1, G2, G3a, G3b, G4, and G5 based on GFR level. By leveraging this classification system, physicians can evaluate kidney function impairment and create a personalized treatment plan for better CKD outcomes.
The Future of KDIGO
As described here, the scope of KDIGO’s impact in the treatment of kidney disease is clearly evident. Continuous development, updating, and publication of guidelines is underway, with the 2025 ADPKD Guideline being a recent example.
In 2025, Controversies Conferences are slated to include Green Dialysis: Environmentally Sustainable Care, Growth and Innovation, and Therapies Targeting B Cells in Immune-Mediated Kidney Disease. Ongoing events will include in-person sessions as well as webinars for educating providers.
KDIGO also invites input from providers and stakeholders as they continue to refine existing guidelines. For example, they have published a Scope of Work for their AKI Update as they work to revise AKI Guidelines, which asks valuable questions to be investigated.
Going forward, together with their partners and the support of the healthcare community, KDIGO will continue to improve the care and outcomes of people with kidney disease worldwide.
References
1. https://www.kidney.org/what-s-new-about-new-ckd-guideline#
2. https://kdigo.org/wp-content/uploads/2024/03/KDIGO-2024-CKD-Guideline.pdf
3. https://kdigo.org/guidelines/acute-kidney-injury/
4. https://www.ncbi.nlm.nih.gov/books/NBK441896/#
5. https://www.ncbi.nlm.nih.gov/books/NBK564390/
6. https://www.ncbi.nlm.nih.gov/books/NBK564390/
7. https://www.kidney-international.org/article/S0085-2538(15)55762-1/fulltext#
8. https://www.sciencedirect.com/science/article/pii/S0085253820302337
9. https://www.kidneyfund.org/all-about-kidneys/quick-kidney-disease-facts-and-stats
10. https://kdigo.org/guidelines/transplant-recipient/
11. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0114369
12. https://kdigo.org/wp-content/uploads/2016/10/KDIGO-2012-AKI-Guideline-English.pdf
13. https://www.kidney-international.org/article/S0085-2538(23)00766-4/fulltext
