آلبومین، بیماری کبد و نگرش جدید در مورد آن
Abstract
Introduction
Structure and Function of Albumin
Forms of Albumin in Liver Cirrhosis
Indications for Treatment with Albumin in Liver Cirrhosis
Conclusion
References
Abstract
Decompensated liver cirrhosis has a dismal prognosis, with an overall survival of 2-4 years, which is worse than for many oncological diseases. Albumin is an important tool in the management of patients with cirrhosis, since it decreases for less than half the risk for post-paracentesis cardiocirculatory dysfunction and mortality associated with spontaneous bacterial infection, as well as, it triplicates the response to terlipressin in patients with hepatorenal syndrome. Recently, research on albumin has been a hot topic, with important new insights such as the characterization of the pleiotropic effects of albumin (which surpass its oncotic properties) and the concept of effective albumin concentration. In fact, patients with liver cirrhosis present posttranslational modifications on albumin that compromises its function. Those modified albumin forms were proved to have prognostic value and its knowledge may change the paradigm of albumin treatment. In this review, we critically summarize the latest evidence on the potential benefits of albumin in patients with end-stage liver disease.
INTRODUCTION
Liver cirrhosis is the 14th most common cause of death, being responsible for over a million deaths per year worldwide.1,2 Survival significantly decreases when the disease progresses to a decompensated phase.1 In fact, survival of patients with decompensated cirrhosis is 2 to 4 years, which is worse than survival associated with many oncologic diseases.3 Ascites is the most frequent decompensation, and once it develops, about one half of the patients will be dead in 5 years.4 The development of renal failure associates with further increase in mortality, with more than 60% of the patients being dead in one year.5 Advanced cirrhosis is associated with a decrease in plasmatic albumin.6 Patients with cirrhosis have impaired hepatocellular function and reduced albumin synthesis, which can reach a 60-80% reduction in advanced cirrhosis.7 Protein levels further decrease due to the dilution effect from water and salt retention, and to the sequestration of circulating albumin in extracellular space and ascitic fluid.8.9 Importantly, albumin is a major prognostic factor, being a significant predictor of death in over a hundred studies in patients with cirrhosis.6 Albumin is a component of the most important and widely used prognostic score in cirrhosis, the Child-Pugh-Turcotte score.10 Recently, a new concept of effective albumin concentration indicates that not only serum albumin decreases in liver cirrhosis, but the quality of albumin also changes. In fact, in patients with liver cirrhosis, albumin undergoes several reversible and irreversible posttranscriptional changes (for example oxidation) that change its properties.11-14 Treatment with albumin has been widely used in liver cirrhosis due to its oncotic properties, in order to expand plasma volume and to increase effective circulatory volume, and hence to abrogate the cardiocirculatory changes associated with portal hypertension.7 However, recently, other potentially beneficial albumin functions have been reported, such as its binding capacity, anti-oxidant and anti-inflammatory properties, modulation of hemostasis, vasodilatation and acid base homeostasis.