APRI With Reflex to NASH FibroSure® Plus

Serum and whole blood

Serum: 4.0 mL divided into two tubes, 0.5 for initial testing and 3.5 for possible reflex

Whole blood: tube filled to capacity

Serum: 3.0 mL divided into two tubes, 0.5 for initial testing and 2.5 for possible reflex

Whole blood: tube filled to capacity

Gel-barrier tube or red-top tube and lavender-top (EDTA) tube

Patient should be fasting for at least eight hours.

AST to Platelet Ratio Index (APRI) is reported to be a simple, noninvasive and readily available laboratory test index that can stratify patients with HCV and nonalcoholic steatohepatitis (NASH), now known as metabolic dysfunction-associated steatohepatitis (MASH), who are at high or low risk for significant fibrosis and cirrhosis with high degree of accuracy.

NASH FibroSure® Plus test is a noninvasive assessment of liver status in patients with nonalcoholic fatty liver disease (NAFLD), now known as metabolic dysfunction-associated steatotic liver disease (MASLD). Quantitative results of 10 biochemicals, in combination with age and gender, are analyzed using a computational algorithm to provide a quantitative surrogate marker (0.0-1.0) of liver fibrosis (Metavir F0-F4), hepatic steatosis (0.0-1.0, S0-S3) and NASH/MASH (0.0-0.75, N0-N2). The absence of steatosis (S<0.41) precludes the diagnosis of NASH/MASH.

Clumping may cause false low platelet count. Platelet satellitism around neutrophils will cause a pseudothrombocytopenia. RBC or WBC fragments including fragmented fragile leukemic cells and neutrophil pseudoplatelets may cause falsely elevated counts. NASH FibroSure® Plus is recommended for patients with suspected non-alcoholic fatty liver disease, now called metabolic dysfunction-associated steatotic liver disease (MASLD). It is not recommended for patients with other liver diseases. It is also not recommended in patients with Gilbert disease, acute hemolysis, acute hepatitis, acute inflammation of the liver, autoimmune hepatitis, extrahepatic cholestasis, transplant patients and/or renal insufficiency patients. Any of these clinical situations may lead to inaccurate quantitative predictions of fibrosis.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

See individual test components.

The cascade starts with AST to Platelet Ratio Index (APRI). APRI is reported to be a simple, non-invasive and readily available laboratory test index that can stratify patients with NAFLD, now called metabolic dysfunction-associated steatotic liver disease (MASLD), who are at high or low risk for significant fibrosis and cirrhosis with high degree of accuracy. If the APRI result stratifies the patient to be at low risk, the testing will stop and the result will be reported with the following comment: "Low risk for liver fibrosis, consider monitoring APRI every 2 years."

If the APRI result stratifies the patient to be at high risk, the testing will stop and the result will be reported with the following comment: "High risk for liver fibrosis."

If the APRI result stratifies the patient to be at intermediate risk, the testing cascade will reflex to NASH FibroSure® Plus. This test is a non-invasive assessment of liver status in patients with NAFLD, now called metabolic dysfunction-associated steatotic liver disease (MASLD). Quantitative results of 10 biochemicals are analyzed using a computational algorithm to provide a quantitative surrogate marker (0.0-1.0) of liver fibrosis, hepatic steatosis and NASH/MASH. The absence of steatosis precludes the diagnosis of NASH/MASH.