NON INVASIVE EVALUATION OF LIVER FIBROSIS IN PATIENTS WITH CHRONIC HEPATITIS B AND C

ABSTRACT

Aim: 

To compare with liver biopsy the predictive value of biochemical and haematological markers for the assessment of fibrosis in patients with chronic liver disease from hepatitis B and C. 

Setting:  

Baqai Medical University, Karachi.

Methods: 

Twenty five laboratory parameters were measured in 100 chronic viral hepatitis patients to assess the stages of fibrosis; stage 0 to stage 4, who also had liver biopsy performed. Multivariate analysis identified a set of 5 most useful markers. Statistical analysis was by descriptive statistics, area under the receiver operating characteristic curve, and logistic regression. 

Results: 

The fibrosis index, FibroScore, consisted of: bilirubin, gamma glutamyl transferase, hyaluronic acid, alpha 2 macroglobulin, and platelets. The index showed strong correlation with stages of fibrosis. A score of > 0.5 predicted combined stages 2, 3 and 4, with a sensitivity of 82%, specificity of 92%, positive predictive value (PPV) of 79 %. A score of > 0.65 for stages 3 and 4, had sensitivity of 80%, specificity of 95% and PPV of 84%. At a score of > 0.80, the PPV for stages 3 and 4 was 87% (there was >85% strong possibility of presence of stage 3 or 4). A score of < 0.20 predicted the absence of stages 2, 3, and 4 with a negative predictive value (NPV) of 96%, sensitivity of 91% and specificity of 86%. Scores from 0.00 to 0.08 almost certainly ruled out the presence of stages 2-4 (actual NPV 98%). The areas under the receiver operating characteristic curve were 0.808 for stage 2, (p = 0.07); 0.938 for stage 3, (p <0.0001); and 0.959 for stage 4, (p = 0.02). The Platelet Distribution Width Index showed good correlation with advanced fibrosis of; stages 3 & 4. The area under the receiver operating characteristic curve for stages 3 and 4 for Platelet Distribution Width Index was 0.840, which compares with the AST (aspartate aminotransferase) to Platelet Ratio Index with area under the receiver operating characteristic curve of 0.888, (p for both ,<0.0001). 

Conclusion: 

FibroScore has a high diagnostic accuracy for fibrosis of stages 2-4, and Platelet Distribution Width Index reliably predicts advanced fibrosis of; stages 3 and 4. The noninvasive markers can be helpful in the screening and management of fibrosis in liver disease, and has the potential to replace liver biopsy in patients with chronic liver disease from viral related causes. 

Key Words: Liver fibrosis, non invasive markers, hepatitis B and C