November 2023: Test Update – Chromogranin A, New Assay

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

Chromogranin A (CHROMA)

Update?

Details

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%.

Test Code

No

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).