AGE AND PLATELET COUNT - A SIMPLE INDEX FOR PREDICTING THE PRESENCE OF HISTOLOGICAL LESIONS IN PATIENTS WITH ANTIBODIES TO HEPATITIS-C VIRUS

The aim of this study was to identify clinical and biological factors associated with histological lesions in patients with chronic hepatiti s C and to construct a simple diagnostic index. A database consisting of 500 patients with untreated biopsy-proven chronic non-A non-B hepat itis was used. Liver biopsies were reviewed, blind, by a panel of path ologists. Patients were classified according to the presence of necroi nflammatory lesions (histological activity) and fibrosis. The diagnost ic value of nine clinical and 10 biological factors was assessed using logistic regression analysis, sensitivity, specificity and predictive values, and a score was constructed combining the most significant fa ctors identified. The validation used an independent population of 120 patients. Serum platelet concentration and age were the two main fact ors significantly and independently correlated with the presence of fi brosis and/or histological activity. A simple score referred to as AP, combining age and platelet count, varied from 0-10. For the presence of significant histological disease (moderate to severe necroinflammat ory lesions and/or septal fibrosis to cirrhosis), an AP score of 6 or more had a specificity of 0.93 and a sensitivity of 0.52%. In the vali dation population, the area under the curve was 0.690 +/- 0.085, not s ignificantly different from that of the first population, 0.763 +/- 0. 043. Hence, a simple score combining age and platelet count enabled th e accurate prediction of the presence of activity and fibrosis in pati ents infected with the hepatitis C virus. When this score reached 6, l iver biopsy could be avoided owing to its high predictive value. Howev er, the negative predictive value was not high enough to prevent a liv er biopsy in patients with a lower score.