Albumin is the most abundant
plasma protein and
albumin infusion is commonly used. Conventionally, the biologic and
therapeutic effects of
albumin have been thought to be due to its oncotic properties. However,
albumin has a variety of biologic functions, including molecular transport, anti-oxidation, anti-
inflammation, endothelial stabilisation, anti-thrombotic effects, and the adjustment of capillary permeability. Despite this, the functions of
albumin have not been thoroughly investigated. Recent studies have shown
non-alcoholic fatty liver disease (
NAFLD), viral
hepatitis,
cirrhosis, and
liver failure to be associated with impairments in
albumin function, which are associated with impairments in liver function and disease prognosis. Post-translational modifications of
albumin cause structural modifications that affect
protein function. Recently, the concentration of
albumin associated with normal function, the 'efficient
albumin concentration', has been attracting more interest. In addition, although many
biologic markers, including
albumin concentration, are widely used for the assessment of early
liver dysfunction in patients with
liver diseases, the predictive values are unsatisfactory. However, clinical evidence has suggested that
albumin function may represent a novel
biomarker of early impairment in liver function. In this review, we summarise the factors affecting
albumin function and discuss the clinical significance of impairments in
albumin function in various
liver diseases.Key messagesThe importance of
albumin depends not only on its concentration, but also on its various physiological functions.Impaired
albumin function has been reported in a variety of
liver diseases, and is associated with disease severity and prognosis, thereby proposing the concept of 'effective
albumin concentration'.
Albumin dysfunction occurs earlier than other conventional indicators, and
albumin dysfunction may be a new
biomarker of early impairment in liver function.Many exogenous and endogenous factors lead to post-translational modifications of
albumin, which alters the three-dimensional structure of
albumin, resulting in a decrease in its biological activity.