Stability of HE4 and CA125 in blood samples from patients diagnosed with ovarian cancer.
OBJECTIVE
To investigate the influence of handling and storage on HE4 and CA125 serum and EDTA plasma levels to clarify any important consequences for a clinical setting.


METHODS
Blood samples from 13 ovarian cancer (OC) patients were collected and allowed to clot or sediment for up to 72 hours at 4 °C or 20 °C, then processed into serum and EDTA plasma. Furthermore, the effects of up to eight repetitive cycles of freeze/thaw were investigated. HE4 and CA125 were analyzed using a Chemiluminescent Microparticle Immunoassay on the Architect i2000sr System.


RESULTS
No significant effect of processing time for HE4 could be shown. HE4 EDTA plasma levels were insignificantly lower (3%) than serum levels (p = 0.41). Similarly, no significant effect of processing time for CA125 could be demonstrated. CA125 levels at 4 °C were significantly reduced compared to levels at 20 °C (p = 0.024). No significant difference between CA125 serum and plasma levels were found (p = 0.46). Serum and EDTA plasma samples were stable during the eight cycles of freezing and thawing (CA125: all p > 0.2; HE4: all p > 0.5).


CONCLUSIONS
No systematic difference could be demonstrated for HE4. CA125 is not dependent on processing time, EDTA plasma or serum. Levels of CA125 are significantly reduced at 4 °C compared to levels at 20°C, but this difference was less than 6% and is not considered clinically relevant.
Department of Clinical Biochemistry, Immunology & Genetics, Statens Serum Institut , Copenhagen , Denmark.
Noreen
N
Sandhu
Mona A
MA
Karlsen
Claus
C
Høgdall
Inga A
IA
Laursen
Ib J
IJ
Christensen
Estrid V S
EV
Høgdall
D014408:Biomarkers, Tumor / Q000097:blood*; D018394:CA-125 Antigen / Q000097:blood*; D005260:Female; D006801:Humans; D010051:Ovarian Neoplasms / Q000097:blood*; D011506:Proteins / Q000378:metabolism*; D015203:Reproducibility of Results; D000081102:WAP Four-Disulfide Core Domain Protein 2
D014408:Biomarkers, Tumor; D018394:CA-125 Antigen; D011506:Proteins; D000081102:WAP Four-Disulfide Core Domain Protein 2; C569698:WFDC2 protein, human
Biomarker; EDTA plasma; Human epididymis protein 4; cancer antigen 125; chemiluminescent immunoassay; serum; specimen handling