Abstract
Numerous studies of putative biomarkers in patients with acute lung injury (ALI) have been conducted to date, but none has proved worthy of entering routine clinical practice, largely because they have shown no clear advantage over clinical predictors (1, 2). Furthermore, the exemplar biomarker for ALI would be biologically plausible, sensitive, and highly specific, adding prognostic information independent of existing systems. The marker should also vary in proportion to the severity of injury and reflect the effects of therapeutic intervention. Conceivably, it would identify subgroups of patients who would benefit from specific therapies targeted at relevant pathogenetic pathways. Ideally, it would be inexpensive and rapidly quantified in a highly reproducible fashion. In this context, a prospective study published in this issue of Critical Care Medicine by Jabaudon et al (3) investigates whether the soluble form of the receptor for advanced glycation end products (sRAGE), is a valuable biomarker in patients with ALI regardless of whether it was associated with severe sepsis or septic shock.