Using mass spectrometry to overcome the longstanding inaccuracy of a commercially-available clinical testosterone immunoassay.
Level 3 - non-randomized controlled study
Non-randomized diagnostic/analytical method validation and comparison study against a reference standard
PubMed 34628183 · doi:10.1016/j.jchromb.2021.122969
What was done
The authors developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for testosterone in serum and plasma using supported liquid extraction plates following CLSI C62-A guidelines. They conducted a method comparison on 126 clinical samples between the Beckman UniCel DxI immunoassay and the LC-MS/MS method, and evaluated accuracy against the CDC reference measurement procedure using College of American Pathologists Accuracy-Based Survey specimens.
What was found
Results from the Beckman UniCel DxI immunoassay were 20% lower overall compared to LC-MS/MS. Below 100 ng/dL, the immunoassay showed minimal correlation with LC-MS/MS (R² = 0.403). The LC-MS/MS assay agreed well with the CDC reference measurement procedure.
Why it matters
Standard clinical immunoassays demonstrate severe inaccuracy at low testosterone concentrations typical of women, children, and hypogonadal men. Validated LC-MS/MS methods provide accurate quantification across the full clinical range where immunoassays fail.
Limits
Demographic and clinical characteristics of the 126 sample sources are not described in the abstract. Quantitative analytical performance metrics (such as limit of detection, precision coefficients of variation, and numerical bias relative to the CDC reference method) are omitted from the abstract.
Cited by
- supports Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the gold standard assay for measuring total testosterone.