Clinical evaluation of lentil lectin-reactive alpha-fetoprotein-L3 in histology-proven hepatocellular carcinoma

Serum alpha-fetoprotein (AFP) is a useful marker of hepatocellular carcinoma (HCC), although the serum AFP concentration is also increased in patients with chronic liver diseases (CLD). The analysis of AFP glycoforms has been known to be of diagnostic value. We applied the lectin-affinity electrophoresis and antibody-affinity blotting techniques to HCC patients in Vietnam in order to better understand the role of lentil lectin-affinity AFP-L3 in the diagnosis and differential diagnosis of HCC, and its relationship with the biological characteristics of HCC.

Lens culinaris agglutinin-reactive AFP (AFP-L3) was measured in 65 patients with histologically proven HCC and 25 patients with CLD. All patients had serum AFP levels above 54 ng/mL. AFP-L3 levels were determined by lectin affinity electrophoresis coupled with antibody-affinity blotting. The diagnosis of HCC was confirmed histologically by ultrasound-guided biopsy.

The mean value of AFP-L3 in the HCC patients was 49.6 +/- 21.6%, which was significantly higher (p<0.001) than that in the 25 CLD patients (10.7 +/- 4.3%). When the cutoff level for AFP-L3 was set at 15% (mean +/- SD), the sensitivity was 96.9%, the specificity 92.0% and the accuracy 95.5% in the 65 HCC patients. There was no clear correlation between serum AFP level and AFP-L3 percentage (r=0.16). There was no correlation between AFP-L3 and the maximum diameter of HCC nodules (r=0.05). However, the mean AFP-L3 value was higher in moderately or poorly differentiated HCC than in well differentiated tumors (p<0.001).

AFP-L3 is potentially a clinically useful marker for the differentiation of increased AFP levels in hepatocellular carcinoma and chronic liver diseases. The AFP-L3 percentage is closely related to HCC differentiation. We consider the analysis of AFP-L3 a useful adjunct in the diagnosis of HCC.