Serum α-SMA is a potential noninvasive biomarker of liver fibrosis.

The severity of fibrosis is central to the therapeutic course for patients with chronic liver disease; therefore, early detection of liver fibrosis is critical for timely therapeutic interventions. Liver biopsy is the gold standard for the diagnosis of liver fibrosis; however, it is contraindicated in several pathological conditions. Activated hepatic stellate cells (HSCs) are the main cells for fibrotic tissue synthesis, such as that of alpha-smooth muscle actin (α-SMA). This study aimed to determine whether serum α-SMA levels are a suitable noninvasive, sensitive, and reliable liver fibrosis marker. Fibrosis was induced in male Wistar rats via chronic CCl4 administration. Fibrosis was determined in the liver tissues by quantifying the hydroxyproline content and visualized using Masson's trichrome staining. Rats chronically administered CCl4 exhibited a progressive increment in the hepatic collagen content, as well as both hepatic and serum α-SMA levels in a time-dependent manner. Moreover, serum levels of α-SMA significantly correlated with hepatic α-SMA levels (p ≤ 0.001), as well as with the severity of liver fibrosis (p ≤ 0.001). These findings suggest that increased levels of serum α-SMA can be considered a potential reliable and noninvasive biomarker for early liver fibrosis.