Immediate Test Change
Test Update – Chromogranin A (CHROMA), New Assay
Effective November 9, 2023.
Chromogranin A (CHROMA) will be updated to a new assay effective November 9, 2023.
The results of the current and new tests are not interchangeable. Due to a reagent shortage, the laboratory will not be able to undergo a rebaseline/parallel testing process.
Please contact Client Services for laboratory assistance with interpreting results in patients undergoing serial monitoring.
Test Change Overview
Methodology
Yes
New Assay:
Immunoassay, BRAHMS CGA II Kryptor Kit
Discontinued:
Cisbio CGA II, ELISA
The results in the new assay are, on average, 20% lower than the previous assay. The bias is more pronounced at concentrations below 200 ng/mL, where the observed bias is 30%.
Specimen
No
Type
Serum
Container
Gold Serum Separator Tube, or
Red Plain (No Additive) Tube
Stability
Yes
Ambient:
48 hours
Refrigerated:
48 hours
Frozen:
3 months
Transport samples frozen.
Days Performed
Yes
Days Performed
Tuesday, Friday
Reported
1-4 days
Reporting
Yes
Reference Interval
<187 ng/mL
The results of the new and old assays will not trend together in the laboratory information system (e.g., Beaker/EPIC).