MOVING POINTS IN NEPHROLOGY

A Framework and Key Research Questions in AKI Diagnosis and Staging in Different Environments

Patrick T. Murray ^*1, Prasad Devarajan , Andrew S. Levey , Kai U. Eckardt ^*, Joseph V. Bonventre ^||, Raul Lombardi ^¶, Stefan Herget-Rosenthal ^**, and Adeera Levin

*Section of Nephrology, University of Chicago, Chicago, Illinois; Division of Nephrology and Hypertension, University of Cincinnati, Cincinnati, Ohio; Division of Nephrology, Tufts University-New England Medical Center, Boston, Massachusetts; Department of Nephrology and Hypertension, University of Erlangen-Nuremberg, Erlangen, Germany; ||Renal Division, Brigham and Women’s Hospital, Harvard University, Boston, Massachusetts; ¶Department of Critical Care Medicine, Instituto Médico de Previsión y Asistencia IMPASA, Montevideo, Uruguay; **Division of Nephrology, University of Duisburg-Essen, Essen, Germany; and Division of Nephrology, University of British Columbia, Vancouver, Canada

¹ To whom correspondence should be addressed. E-mail: pmurray{at}medicine.bsd.uchicago.edu.

	Abstract

Background and Objectives: Acute Kidney Injury (AKI) is common worldwide, and associated with significant morbidity, mortality, and resource utilization. The RIFLE system of staging AKI correlates with survival in AKI in several settings. A similar AKI definition and staging system that also incorporates lesser degrees of serum creatinine elevation was proposed at the inaugural Acute Kidney Injury Network (AKIN) meeting in 2005. At the Second AKIN meeting in Vancouver, Canada in September 2006, our group developed a research agenda that would test the utility of these diagnostic and staging criteria to predict patient outcomes in a variety of clinical settings and patient groups.

Design, Setting, Participants & Measurements: Three-day, international, consensus conference. A multidisciplinary stakeholder committee was divided into work groups. Recommendations for clinical practice and for future research were developed by the committee as an iterative process. This procedure consisted of a literature review phase and focus group interactions with presentations to the entire committee.

Results: We first proposed a conceptual framework of disease that describes a series of AKI stages, antecedents and outcomes, and allows a description of research recommendations based on transition between AKI stages. We further proposed methods for testing of the definition and development of research questions to establish the utility of new biomarkers for the diagnosis and staging of AKI and associated illnesses.

Conclusions: Retrospective studies should be conducted to initiate the process of validating the AKIN definition of AKI, followed by comprehensive prospective studies that incorporate sampling for emerging AKI biomarkers.