Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (728 page)

   Clotted specimen, incomplete filling of test tubes, severe lipemia, icteric samples, and hemolysis produce unreliable results.

   Heparin therapy interferes with the coagulant assay but not with the chromogenic one.

   AT results are affected by the use of thrombin inhibitors such as hirudin (or its congeners) or argatroban and the newer antithrombin drugs.

APOLIPOPROTEINS (APO) A-1 AND B

   Definition

   An apolipoprotein is a protein component of lipoprotein, whose main function is to transport lipids. Apolipoproteins play an important role in maintaining structural integrity and solubility of lipoproteins and play an important role in lipoprotein receptor recognition and regulation of certain enzymes in lipoprotein metabolism. Apolipoprotein A (apo-A; also known as Apo A-1) is the major protein (90%) of HDL. Apolipoprotein B (apo B) is major protein component of low-density lipoprotein and is important in regulating cholesterol synthesis and metabolism.

   
Normal range:

   Apo A-1

   Male: 94–178 mg/dL

   Female: 101–199 mg/dL

   Apo B

   Male: 55–140 mg/dL

   Female: 55–125 mg/dL

   Apo B/A-1 ratio