Table 1. Candidate approaches to endotype individual patients with sepsis.

Approach	Examples
Current phenotyping
Demographic	Gender/sex-related differences; racial/ethnic group differences
Clinical/laboratory
Source/type of infection	Pneumonia vs. urinary; Gram positive vs. Gram negative bacteria
Critical care scoring systems	APACHE
Organ dysfunction	Type, number, severity, SOFA, MODS
Individual physiologic parameters	Oxygenation: “mild” vs. “severe” ARDS
Complex physiologic signatures	Vitals, hemodynamics, gas-exchange, metabolomics
Future endotyping
Genetic predisposition/risk
Genomics	Single-nucleotide polymorphisms (SNPs); haplotypes; short tandem repeats/microsatellites; copy number variations (CNVs); mitochondrial DNA (mtDNA)
Epigenomics	DNA methylation, Histone modification, microRNAs
Pathobiology
Genome-wide expression	Expression quantitative trait loci (eQTLs); transcriptomics (microarrays, RNA-Seq); proteomics
Metabolomics	Complete set of metabolites in a biofluid, cell, or tissue
Biomarkers	Procalcitonin; presepsin (soluble CD14); CD64; soluble urokinase-type plasminogen activator receptor (suPAR); soluble triggering receptor expressed on myeloid cells (sTREM-1)
Bioassays	Effects of patient-specific plasma on isolated human target organ tissues/cells [e.g., microvascular endothelial cells (MVEC)] in vitro
Microbiome	Skin, oropharyngeal, lung lavage, stool
Imaging	Microscopic microvascular perfusion; cellular injury, metabolism, or tracking; biomolecule expression or tracking

APACHE, Acute Physiology and Chronic Health Evaluation; SOFA, Sequential Organ Failure Assessment; MODS, Multiple Organ Dysfunction Score; ARDS, acute respiratory distress syndrome.