Sandhu, Noreen3; Karlsen, Mona A3; Høgdall, Claus5; Laursen, Inga A3; Christensen, Ib J6; Høgdall, Estrid V S5
1 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet2 Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, Københavns Universitet3 unknown4 Undervisning - SB, Department of Public Health, Faculty of Health and Medical Sciences, Københavns Universitet5 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet6 Undervisning - SB, Department of Public Health, Faculty of Health and Medical Sciences, Københavns Universitet
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). CONCLUSION: 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.
Scandinavian Journal of Clinical and Laboratory Investigation, 2014, Vol 74, Issue 6, p. 477-484