Serum Type I Collagen Propeptide and Severity of Alcoholic Liver Disease

We assessed the relationship of serum type I collagen propeptide concentrations with various severity indices of alcoholic liver disease, including clinical and morphological severity, the amount of alcohol consumption, and the serum levels of other components of connective tissue. The serum concentration of the carboxyterminal propeptide of type I procollagen (PICP) was measured with a new radioimmunoassay that is devoid of a crossreaction caused by type III procollagen-derived fragments. A significant correlation was found between serum PICP and the Combined Clinical and Laboratory Index (CCLI) (rs = 0.58, p < 0.001) and the Combined Morphological Index (CMI) (rs = 0.57, p < 0.01). However, PICP was elevated less frequently than serum type III collagen propeptide (PIIINP), type IV collagen or laminin, and the correlations with the latter three parameter with both the CCLI (PIIINP: rs = 0.80, type IV collagen: rs = 0.80; and laminin: rs = 0.81) or CMI (PIIINP: rs = 0.75, type IV collagen: rs = 0.72; and laminin rs = 0.61) were all stronger than that of PICP. Furthermore, although during a follow-up period of 6 months, the mild or moderately drinking patients had a significant decrease in PIIINP and the heavily drinking patients had no improvement. PICP was, however, found to improve in both the mild and heavy drinkers. These results point to differences in handling of type I and type III collagen propeptides in alcoholic liver disease. The latter appears to be a more sensitive indicator of disease severity, presence of alcoholic hepatitis, and the amount of alcohol intake.