About Our Lab

Laboratory Services

Acetaminophen Toxicity Diagnostics (ATD) has developed an HPLC-EC assay that detects a unique bio-marker of Acetaminophen (Tylenol™, Paracetamol, APAP) exposure and toxicity in peripheral blood. (References) This test method is performed in a laboratory that is certified by CLIA and that has been awarded accreditation by the College of American Pathologists (CAP). Client samples are tested and reported back after quality review and approval by a licensed Pathologist. The expected turn-around-time for routine test results are 5 to 10 business days, but stat testing is available.

Our Method

Acute exposure to >10 grams Acetaminophen, excessive chronic exposure to Acetaminophen, or unintended exposure to multiple combination drugs containing Acetaminophen can result in liver toxicity. Alanine aminotransferase elevations above 1000 IU/L are highly correlated with Acetaminophen Protein Adduct levels of > 1.0 nmol APAP-Cys/mL. Our Laboratory test method detects and quantifies the presence of Acetaminophen Protein Adducts in human serum using a validated high pressure liquid chromatography assay with coulometric electrochemical detection (HPLC-EC). The sample requirement is 0.5 mL of serum and results are reported in nmol/mL APAP-CYS (derived from serum protein)/mL. The ATD, LLC Laboratory test method analytical measurement range is from 0.16 nmol/mL to 10.0 nmol/mL The reportable range is 0.16 to 20.0 nmol/mL.

Reference Levels

The reference interval for APAP Cysteine is <0.16 nmol/mL. Test values in the range between 0.16 – 0.5 nmol/mL are indicative of values that would been observed in healthy individuals that have taken acetaminophen but have no indication of liver injury. The “toxicity” threshold level for this assay is considered to be >/= 1.00 nmol/mL. The results of this test method should be evaluated in conjunction with other clinical factors. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. The APAP Cysteine assay was developed by and the performance characteristics were determined by Acetaminophen Toxicity Diagnostics, LLC. It has not been cleared or approved by FDA. The laboratory is regulated under CLIA as qualified to perform high-complexity testing. Acetaminophen-cysteine adducts (APAP-CYS) are a specific biomarker of acetaminophen exposure that has been defined in animal and clinical research.