Albumin is a negatively charged, relatively small
protein synthesized by liver cells. Is the most abundant
protein in extracellular fluid and accounts for about 70% of the plasma
colloid osmotic pressure. Therefore it plays a crucial role in regulating fluid distribution in the body. In addition,
albumin possesses functional domains with important non-oncotic properties, such as potent anti-oxydant and scavenging activities, binding of highly toxic reactive
metal species and a great amount of endogenous and exogenous substances. We have recently learned that
albumin in
cirrhosis undergoes a number of post-transcriptional changes that greatly impair its non-oncotic properties. The overall assessment of these changes clearly shows that the relative abundance of the native form of
albumin is significantly reduced in hospitalized patients with
cirrhosis and that these abnormalities worsen in parallel with the increasing severity of the disease. Thus, it is time to abandon the concept of
serum albumin concentration and refer to the effective
albumin concentration, that is the native intact
albumin. Given the pathophysiological context in which we use
human albumin in patients with
cirrhosis, who are characterized by peripheral vasodilation and a low-grade but sustained inflammatory state, the use of
albumin in patients with
cirrhosis should aim at enhancing effective
hypovolemia and exploiting its
antioxidant and scavenging activities. The indications for the use of
albumin in
cirrhosis that clearly emerge from evidence-based medicine are represented by conditions characterized by an acute aggravation of effective
hypovolemia and
inflammation, such as such post-paracentesis circulatory dysfunction, spontaneous bacterial
peritonitis, and
hepatorenal syndrome. Other indications to the use of
albumin that still require further studies are represented by
bacterial infections other than spontaneous bacterial
peritonitis,
hepatic encephalopathy and long-term treatment of
ascites, which has been debated for the last half-century.