Serum Autofluorescence, a Potential Serum Marker for the Diagnosis of Liver Fibrosis in Rats

Fluctuations in serum autofluorescence (AF) intensity have recently been widely used as markers of certain diseases such as cancer. To determine the diagnostic value of serum AF intensity for liver fibrosis in rats, we induced liver fibrosis by subcutaneous injection of carbon tetrachloride into rats. The rat serum AF intensities were detected at the excitation wavelength of 337 nm and the emission wavelength of 512 nm. The degree of liver fibrosis was evaluated by Van Gieson’s staining. The relationship between serum AF intensity and the degree of liver fibrosis was analyzed by Spearman and Pearson Correlation. The diagnostic sensitivity and specificity of the serum AF was determined by analyzing the receiver operating characteristic (ROC) curves. Our results show that the serum AF intensity in the rat liver fibrosis model increased when compared with control rats eight weeks and twelve weeks post induction of liver fibrosis. However, there was no significant difference in serum AF intensity between fibrotic and control rats at four week post induction. Furthermore, serum AF intensity correlated positively with the severity of the degree of hepatic fibrosis. ROC analysis further suggested that serum AF intensity is a valid marker for staging fibrosis. Therefore, it may potentially be developed as a novel diagnostic tool for hepatic fibrosis.