Find Locations
For hours, walk-ins and appointments.Expected Turnaround Time
Within 1 day
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Documents
For more information, please review the literature below.
Specimen Requirements
Specimen
Serum and whole blood
Volume
0.5 mL (serum); fill tube to capacity (whole blood)
Minimum Volume
0.5 mL (serum), 0.5 mL (whole blood)
Container
Gel-barrier tube or red-top tube and lavender-top (EDTA) tube
Collection
Separate serum from cells within 45 minutes of collection; invert EDTA tube immediately 8 to 10 times once tube is filled at the time of collection.
Storage Instructions
Room temperature
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 1 day |
Refrigerated | 3 days |
Frozen | Unstable |
Freeze/thaw cycles | Unstable |
Causes for Rejection
Serum: gross hemolysis; improper labeling
Whole blood: hemolysis; clotted specimen; tube not filled with minimum volume; improper labeling; transfer tubes with whole blood; specimen diluted or contaminated with IV fluid; specimen received with plasma removed; specimen collected in any anticoagulant other than EDTA
Test Details
Use
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 Non-Alcoholic Fatty Liver Disease (NAFLD) who are at high or low risk for significant fibrosis and cirrhosis with high degree of accuracy.
Limitations
Clumping may cause false low count. Platelet satellitism around neutrophils will cause a pseudothrombocytopenia. RBC or WBC fragments including fragmented fragile leucemic cells and neutrophil pseudoplatelets may cause falsely elevated counts.
Methodology
AST: kinetic; Platelet Count: automated cell counter
References
Angulo P, Bugianesi E, Bjornsson ES, et al. Simple noninvasive systems predict long-term outcomes of patients with nonalcoholic fatty liver disease. Gastroenterology. 2013 Oct;145(4):782-789.23860502
Boursier J, Vergniol J, Guillet A, et al. Diagnostic accuracy and prognostic significance of blood fibrosis tests and liver stiffness measurement by FibroScan in nonalcoholic fatty liver disease. J Hepatol. 2016 Sep;65(3):570-578.27151181
Chou R, Wasson N. Blood tests to diagnose fibrosis or cirrhosis in patients with chronic hepatitis C virus infection: a systematic review. Ann Intern Med. 2013 Jun 4;158(11):807-820.23732714
Lin ZH, Xin YN, Dong QJ, et al. Performance of the aspartate aminotransferase-to-platelet ratio index for the staging of hepatitis C-related fibrosis: an updated meta-analysis. Hepatology. 2011 Mar;53(3):726-736.21319189
Rinella ME, Sanyal AJ. Management of NAFLD: a stage-based approach. Nat Rev Gastroenterol and Hepatol. 2016 Apr;13(4):196-205.26907882
Sanyal A, Ratziu V, Goodman Z, et al. 507 APRI and FIB-4 index scores can enrich for subjects with fibrotic nonalcoholic steatohepatitis (NASH) in Clinical Trials - The CENTAUR trial data. Gastroenterol. 2016 Apr;150(4)Supp1:S1037-S1038.10.1016/S0016-5085(16)33508-9
Shaheen AA, Myers RP. Diagnostic accuracy of the aspartate aminotransferase-to-platelet ratio index for the prediction of hepatitis C-related fibrosis: a systematic review. Hepatology. 2007 Sep;46(3):912-921.17705266
Tapper EB, Krajewski K, Lai M, et al. Simple non-invasive biomarkers of advanced fibrosis in the evaluation of nonalcoholic fatty liver disease. Gastroenterol Rep (Oxf). 2014 Nov;2(4):276-280.25002154
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 385375 | AST and Platelets with APRI | 001123 | AST (SGOT) | IU/L | 1920-8 | |
| 385375 | AST and Platelets with APRI | 015172 | Platelets | x10E3/uL | 777-3 | |
| 385375 | AST and Platelets with APRI | 011579 | APRI Index | 86465-2 |
© 2021 Laboratory Corporation of America® Holdings and Lexi-Comp Inc. All Rights Reserved.
CPT Statement/Profile Statement
The LOINC® codes are copyright © 1994-2021, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at https://loinc.org/license/. Additional information regarding LOINC® codes can be found at LOINC.org, including the LOINC Manual, which can be downloaded at LOINC.org/downloads/files/LOINCManual.pdf