Clinical and prognostic value of serum procollagen levels in chronic alcoholic liver disease

Serum laminin and type IV collagen are accurate markers of histologically severe alcoholic hepatitis in patients with cirrhosis

BACKGROUND/AIMS

Severe alcoholic hepatitis occurs mainly in patients with cirrhosis, and has a high death rate. Corticosteroid therapy has been particularly advocated as reducing mortality in patients with severe histologic lesions. However, identification of these patients is difficult, requiring transvenous liver biopsy. Extracellular matrix serum markers have been proposed as non-invasive diagnostic tools in alcoholic liver disease. The aim of this study was to determine the accuracy of 5 extracellular matrix serum markers, i.e. laminin (Lam), N-terminal peptide of type III procollagen (PIIINP), type I (CI), type III (CIII) and type IV (CIV) collagens in identifying patients with severe histologic alcoholic hepatitis from among those with cirrhosis and suspected alcoholic hepatitis.

METHODS

We studied 80 consecutive patients with alcoholic cirrhosis and clinical suspicion of alcoholic hepatitis referred for transvenous liver biopsy. Clinical severity of alcoholic hepatitis was assessed according to Maddrey's score. Histological severity was scored using the sum of the 3 following items: polynuclear infiltration (0-3); hepatocytes alterations (0-3); Mallory bodies (0-2). According to this score, patients were divided into 3 groups: mild (1-3), moderate (4-6), and severe (7-8) alcoholic hepatitis. Serum levels of the 5 extracellular matrix serum markers were measured at the time of biopsy using radioimmunoassays. Diagnostic value for histologically severe alcoholic hepatitis of the 5 extracellular matrix serum markers was assessed using receiver operating characteristic curves.

RESULTS

Histological alcoholic hepatitis was present in 67 patients (mean alcoholic hepatitis score: 3.4+/-2.3). Maddrey's score was 66% sensitive and 69% specific for the diagnosis of severe histologic alcoholic hepatitis. The serum Lam and CIV concentrations were the most accurate in identifying correctly patients with severe histologic alcoholic hepatitis. At a cut-off of 4.1 UI/ml, Lam was 90% sensitive and 77% specific, whereas at a cut-off of 150 ng/ml, CIV was 89% sensitive and 77% specific. Combination of markers did not result in improved diagnostic value.

CONCLUSION

In patients with cirrhosis, determination of serum Lam or CIV could represent a simple and accurate non-invasive method for identification of patients with histologically severe alcoholic hepatitis eligible for corticosteroid treatment.

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.