engleski

Clinical significance of the aspartate aminotransferase (AST) to platelet ratio index in assessing the degree of liver fibrosis in chronic hepatitis C

INTRODUCTION: Information on the stage of liver fibrosis is crucial in managing chronic hepatitis C (CHC) patients. Liver histology is considered the gold standard for assessing the degree of liver fibrosis. However, liver biopsy is invasive procedure associated with sampling error, interobserver variability and potential complications. Therefore, there is a need for simple, noninvasive blood test that could serve as a surrogate for biopsy to distinguish mild from significant fibrosis in CHC. Some recent studies have found AST to platelet ratio index (APRI) as an accurate predictor of fibrosis in CHC [1, 2]. AIMS & METHODS: The aim of this study was to evaluate clinical efficacy of APRI as a predictor of the degree of liver fibrosis in CHC patients. We retrospectively analysed 45 consecutive patients (22 male, 23 female, mean age 38.2 years) with CHC and no history of alcohol abuse, who underwent liver biopsy at the Charity Sisters University Hospital, Zagreb. The liver biopsy specimens were staged using the METAVIR scoring system. Significant (moderate/severe) fibrosis was determined as an METAVIR score F2-F4. APRI was calculated as AST value/upper limit of normal ×100/platelets. In previous studies of APRI, thresholds of 0.5 or lower were used to indicate mild fibrosis and 1.0 or higher to indicate significant fibrosis [1, 2]. Results obtained with APRI were compared with biopsy results. RESULTS: Of 45 patients studied, 32 (71.1%) had no/mild fibrosis (METAVIR score F0-F1) and 13 (28.9%) patients had significant fibrosis (METAVIR score F2-F4). For the prediction of mild fibrosis, when using a previously described cut-off of 0.42 (APRI up to 0.42), APRI had a sensitivity of 50.0% with a specificity of 84.6%, negative predictive value (NPV) was 40.7% and positive predictive value (PPV) was 88.9%. In predicting significant fibrosis, when using a cut-off of 1.0 (APRI more then 1.0), APRI showed a sensitivity of 53.9% and a specificity of 87.5%, PPV was 63.6% while NPV was 82.4%. But, when using a cut-off of 0.60 for significant fibrosis, NPV was 91.3%. CONCLUSION: This study confirms that APRI is an accurate index and can be used to differentiate mild from significant fibrosis in patients with CHC. If APRI is less then 0.60 there is a 91.3% chance that significant fibrosis does not exist. Application of this simple index alone, or in combination with other blood tests, can decrease the need for more invasive staging of CHC using liver biopsy.

aspartate aminotransferase to platelet ratio index; hepatitis C; liver fibrosis

nije evidentirano