Endocrine Abstracts

While evidence of concordance between reproductive hormone measurements in venipuncture and capillary serum exists, variation between blood collection tubes has not been investigated. We compared the performance of two capillary and venipuncture blood collection tubes (red and gold top) and assessed variation between two leading tube manufacturers. To compare tube types, venipuncture and finger prick capillary samples were concurrently collected from 11 premenopausal women in red and gold top tubes. In all four sample types, serum concentrations of Anti-Müllerian Hormone (AMH), Estradiol (E2), Follicle-Stimulating Hormone (FSH) and Luteinising Hormone (LH) were measured via chemiluminescence immunoassay. To compare capillary tube manufacturers, the same hormones were measured in a second cohort of 8 premenopausal women using Greiner and Becton Dickinson (BD) red top tubes. Data was log-transformed prior to statistical analysis via paired t test and subsequent Cohen’s d (d) to calculate effect size; P values=<0.05 were considered significant. Gold top capillary tubes produced higher AMH (P<0.001, d=0.12), FSH (P<0.001, d=0.30) and LH (P<0.001, d=0.29) measurements compared to gold top venipuncture tubes. Measurements of AMH (P<0.001, d=0.22), FSH (P<0.001, d=0.29) and LH (P=0.008, d=0.13) were higher and E2 measurements were lower (P=0.012, d=0.34) in gold top compared to red top capillary tubes. No significant differences were found between red top capillary tubes and venipuncture tubes. Greiner red top tubes produced moderately lower E2 measurements than BD (P=0.046, d=0.04), however no other significant differences were found. This suggests that gold top, but not red top, capillary blood collection tubes yield significantly different measurements than venipuncture tubes and measurements are not manufacturer-dependent. Further investigation into gold top tubes is required.