Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1230 page)

   As a bronchodilator to prevent and treat asthma

   Interpretation

   
Potentially toxic:
20–25 μg/mL

   Limitations

   Serum: Quantitative immunoassay limitations

   FPIA, chemiluminescence, EMIT, particle-enhanced turbidimetric inhibition immunoassay.

   Do not use serum separator tubes or gels. Separate serum from cells as soon as possible.

   The incidence of patients having antibodies to
Escherichia coli
β-galactosidase is extremely low. However, some samples containing such antibodies may result in artificially high results that do not fit the clinical profile.

   Due to cross-reactivity with 1,3-dimethyluric acid (metabolite), the assay should not be used to quantitate samples from uremic patients.

   If mouse antibodies are utilized, the possibility exists for interference by human antimouse antibodies (HAMA) in the sample, which could cause falsely elevated results.

THROMBIN TIME (TT)
*

   Definition

   TT measures the time of conversion of fibrinogen into fibrin once thrombin (used as a reagent) is added.

   
Normal range:
14–21 seconds (may vary depending on reagent and equipment used).