Biomarkers are of great importance for prediction, diagnosis and monitoring the progression and therapeutic success of a disease. Whole body fluids, such as blood or urine, constitute the main desired biological source to identify these markers, mostly due to the minimally invasive procedures used to collect them. An additional benefit of studying these biological fluids that has been demonstrated by many different groups is that they contain cell-released extracellular vesicles, carrying a cargo of lipids, proteins and nucleic acids that reflects cell/tissue origin and, remarkably, cellular status. In this review, the information obtained from the characterization of this body fluid compartment in human samples is discussed in the context of its usefulness as diagnostic resource for several pathologies, including cancer, inflammatory, vascular and metabolic diseases. The review shows the great variety of methods used for this purpose as well as the different types of molecules that could serve as specific or common disease markers.
Keywords: biomarker; body fluids; circulating vesicles; diagnosis; exosomes; extracellular vesicles; human samples; microparticles; microvesicles.