National Network of Renal Function Laboratories

Full Title: National Network of Renal Function Laboratories

Funded by: Instituto de Salud Carlos III (PMP22/00119)

Grant Awarded: €1,337,976.20

Duration: 3 years (2023-2025)

Principal Investigator: Esteban Porrini

Associated Researchers: Renata Linertová, Cristina Valcárcel Nazco

Summary:

The National Network of Renal Function Laboratories project aims to address a significant issue in clinical medicine in 2022: the inaccuracies in renal function estimation formulas and their consequences. Various studies have demonstrated that formulas using creatinine, cystatin-C, or both often have substantial, frequent, and random errors when estimating renal function in patients. The magnitude of these errors is considerable: the average variability of any equation is +/- 30% of the actual renal function as measured by reference patterns. While this variability might be acceptable in the general population or in those without renal disease, errors in estimation for patients with chronic kidney disease (CKD) or those needing reliable measurements for clinical decisions can have serious implications. Alternative methods using reference patterns (e.g., inulin, DTPA, iohexol, iotalamato) are complex and labor-intensive, presenting a dilemma for clinical practice: measure renal function with these complex methods or estimate with inherent errors.

The project proposes using iohexol clearance with dry chemistry (iohexol-DBS) as a simple, reliable, cost-effective, and realistic alternative for measuring renal function in specific clinical conditions where accurate renal function evaluation is crucial. The iohexol-DBS method, developed and validated by the Renal Function Laboratory at ULL (LFR-ULL), is used for CKD patients, including adults and children, living kidney donors, kidney transplant recipients, and those requiring dose adjustments for potentially toxic medications.

Our goal is to establish 9 Spanish centers with a Renal Function Laboratory (LFR) to offer this technique to patients needing accurate renal function values. LFR-ULL will train the centers, provide necessary training and software for implementing the method, and establish a regular validation system among the centers.

Objectives:

  1. Primary Objective:
    • Assess the technical and economic feasibility of implementing the simplified iohexol-DBS method in daily clinical practice to provide more accurate and precise renal function assessments, adhering to principles of personalized medicine.
  2. Secondary Objectives:
    • Validate and fine-tune the iohexol-DBS method in all participating centers, including conducting a training course in Tenerife and providing ongoing technical support.
    • Establish a validation network with semi-annual external validation of the method.
    • Implement a computer system for GFR calculation using a project-specific software: GFR-Manager, with initial portable computers provided and a web version developed within the first year.
    • Use iohexol-DBS in real patient groups at participating centers.
    • Confirm the error rate of current renal function estimation formulas in various clinical circumstances, with a focus on pediatric populations.
    • Evaluate the impact of estimation errors on clinical decision-making.
    • Simplify the iohexol-DBS method further by eliminating pre-analytical steps and reducing the long procedure time from 8 to 6 hours.
    • Analyze the cost-effectiveness of iohexol-DBS to ensure sustainability within the National Health System.
    • Establish technical and economic foundations for continued use of the method post-project.
    • Execute a communication and dissemination plan for project results.

Impact:

Given the significant and unpredictable errors in current renal function estimation methods, the project anticipates a high and relevant impact from implementing a more reliable method within the National Health System (SNS). Key expected impacts include:

  1. In Population Health:
    • More precise and practical renal function measurement will benefit at-risk populations by improving CKD diagnosis, enabling early intervention, and providing more accurate risk assessments and management.
    • Increased safety for special populations, such as living kidney donors and patients on potentially toxic medications.
    • Improved precision in diagnosing CKD in children, where formula variability is particularly significant.
  2. In the SNS:
    • CKD is among the most costly diseases for health systems, with an estimated annual cost of €1108 million in Spain and €140 billion in Europe. Implementing a more accurate and cost-effective method like iohexol-DBS could reduce direct and indirect costs associated with CKD and other clinical conditions.
  3. Social Impact:
    • CKD affects an estimated 75 million people in Europe and 700-800 million globally, with projections showing it may become the fifth leading cause of death by 2040. The COVID-19 pandemic has exacerbated CKD rates and mortality. Improving CKD management with a reliable method like iohexol-DBS will address this growing global health challenge.

Contact Person: Renata Linertová (renata.linertova@sescs.es)