title: Septic acute kidney injury: molecular mechanisms and the importance of stratification and targeting therapy.
abstract: The most common cause of acute kidney injury (AKI) in hospitalized patients is sepsis. However, the molecular pathways and mechanisms that mediate septic AKI are not well defined. Experiments performed over the past 20 years suggest that there are profound differences in the pathogenesis between septic and ischemic AKI. Septic AKI often occurs independently of hypoperfusion, and is mediated by a concomitant pro- and anti-inflammatory state that is activated in response to various pathogen-associated molecular patterns, such as endotoxin, as well as damage-associated molecular patterns. These molecular patterns are recognized by Toll-like receptors (TLRs) found in the kidney, and effectuate downstream inflammatory pathways. Additionally, apoptosis has been proposed to play a role in the pathogenesis of septic AKI. However, targeted therapies designed to mitigate the above aspects of the inflammatory state, TLR-related pathways, and apoptosis have failed to show significant clinical benefit. This failure is likely due to the protean nature of septic AKI, whereby different patients present at different points along the immunologic spectrum. While one patient may benefit from targeted therapy at one end of the spectrum, another patient at the other end may be harmed by the same therapy. We propose that a next important step in septic AKI research will be to identify where patients lie on the immunologic spectrum in order to appropriately target therapies at the inflammatory cascade, TLRs, and possibly apoptosis.
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. morrelled@upmc.edu.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Morrell
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. kellumja@ccm.upmc.edu.|The Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. kellumja@ccm.upmc.edu.|CRISMA (Clinical Research Systems Modeling of Acute Illness) Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. kellumja@ccm.upmc.edu.|Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. kellumja@ccm.upmc.edu.
authors.forename: John A
authors.initials: JA
authors.lastname: Kellum
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. pastorn@pitt.edu.|The Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. pastorn@pitt.edu.|Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. pastorn@pitt.edu.
authors.forename: Núria M
authors.initials: NM
authors.lastname: Pastor-Soler
authors.affiliation: Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. hallows@pitt.edu.|The Center for Critical Care Nephrology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. hallows@pitt.edu.|Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15261, USA. hallows@pitt.edu.
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Hallows
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology* / Q000503:physiopathology; D017209:Apoptosis; D004731:Endotoxins / Q000502:physiology; D006801:Humans; D007249:Inflammation; D018805:Sepsis / Q000150:complications* / Q000628:therapy; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
chemical_list: D004731:Endotoxins; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4