APRI or FIB-4 index can be performed where resources are limited and there is no access to other noninvasive tests like FibroScan.
The formulas for calculating APRI and FIB-4 are shown below. ALT is alanine aminotransferase, AST is aspartate aminotransferase, IU is international unit, and ULN is the upper limit of normal:
APRI = [(AST (IU/L)/AST_ULN (IU/L))×100]/platelet count (10 9 /L)
FIB-4 = age (years) × AST (IU/L)/platelet count (10 9)/L × [ALT (IU/L)1/2]
EASL guidelines recommend that the stage of liver fibrosis should initially be assessed noninvasively by methods that include liver stiffness measurement or serum biomarkers (eg, APRI and FIB-4) that are inexpensive and reliable biomarker panels. Using a combination of tests and combination of blood biomarkers, liver stiffness measurement and blood tests improve assessment accuracy. Liver disease stage must be determined before starting treatment, and if cirrhosis is present, some treatment regimens must be adjusted and post-treatment surveillance for hepatocellular carcinoma (HCC) becomes mandatory.
Total bilirubin measurement can be useful during the acute phase of hepatitis where sequential testing can help in assessing the severity and progression of disease. In acute hepatitis, hyperbilirubinemia is usually caused by the direct (conjugated) fraction more than the indirect (unconjugated) fraction, but both can be elevated. Total and direct bilirubin are measured at baseline and during the treatment of HCV infection but do not provide comprehensive information on hepatic disease progression if used alone.
Prior to starting therapy for HCV infection, EASL, AASLD, and WHO recommend a comprehensive laboratory workup that includes: full complete blood count; a liver function panel including ALT, AST, and alkaline phosphatase; and an evaluation of gamma-glutamyl transpeptidase and PT/INR, and serum creatinine and eGFR. It is recommended to evaluate comorbidities, the patient's alcohol and drug consumption, and extrahepatic manifestations before commencing therapy. Testing ALT alone does not provide complete information about liver disease progression.
Ultrasound can demonstrate the patency of the portal vein, the intra and extrahepatic biliary tree, gallstones, and masses, if present. Better noninvasive modalities of assessing hepatic disease progression are vibration controlled transient elastography (VCTE), and magnetic resonance elastography (MRE).
The patient is diagnosed with chronic HCV genotype 1a. His liver disease severity was further assessed by real-time shear wave elastography (SWE) and FibroScan which indicated an F2 fibrosis stage.
Medscape © 2021 WebMD, LLC
Cite this: Alastair O'Brien. Skill Checkup: A Man With Itching and Abdominal Pain - Medscape - Mar 18, 2021.