Does in vitro hemolysis affect measurements of plasma apixaban concentration by UPLC-MS and anti-Xa assay?

INTRODUCTION: Hemolytic interference may impact various laboratory tests, including coagulation analyses. Apixaban is the most commonly used direct oral anticoagulant in Norway, and there is lacking knowledge on how apixaban concentration measurements might be influenced by hemolysis. Moreover, hemolysis-induced alterations in apixaban levels could potentially impact the risk of bleeding in specific clinical scenarios. We wanted to study whether hemolysis would increase apixaban concentration and investigate the impact of hemolytic interference on apixaban concentration measurements. METHODS: Blood samples from 20 apixaban-treated patients and 8 healthy controls were hemolyzed in vitro by a freeze method. The degree of hemolysis was measured with plasma free hemoglobin (PfHb) at baseline and two levels of hemolysis. Apixaban concentration was measured in plasma using both the chromogenic anti-Xa method and the ultraperformance liquid chromatography mass spectrometry (UPLC-MS). Thrombin generation assay was performed to assess coagulability. RESULTS: UPLC-MS measurements showed a mean concentration change of -1.66% (±3.2%, p = 0.005) and anti-Xa assay showed a mean concentration change of 3.37% (±6.5%, p = 0.09) with increasing hemolysis. Thrombin generation lagtime decreased, and endogenous thrombin potential and peak thrombin increased with increasing hemolysis in both the control group and the apixaban group. CONCLUSION: Apixaban concentration measurements by anti-Xa assay and UPLC-MS were not affected by hemolysis to a clinically relevant extent. Furthermore, hemolysis did not lead to hypocoagulability when assessed by thrombin generation.

Trends in the prevalence of breastfeeding up to 6 months of age using structured data from routine child healthcare visits.

AIM: The Norwegian Action Plan for a Healthier Diet (2017-2021) set the target that 25% of infants should be exclusively breastfed for 6 months by 2022. Our aim was to determine trends in the prevalence and duration of breastfeeding in the municipality of Bergen. METHODS: Data on breastfeeding status in 2010-2018 were extracted from a standardised electronic medical record kept by public child health centres and recorded as exclusive, partial or none, at 6 weeks and 6 months of age. RESULTS: We found that 28,503 and 26,735 infants attended the 6-week and 6-month consultations, respectively. The prevalence of any breastfeeding was 92.0% at 6 weeks and 78.0% at 6 months with no trend over time between 2010 and 2018. The prevalence of exclusive breastfeeding at 6 weeks was 73.9% and stable over time, but it declined at 6 months, from 28.1% in 2010 to 11.1% in 2014 and remained stable thereafter. CONCLUSION: During 2010-2018, the prevalence of any and exclusive breastfeeding at 6 weeks and any breastfeeding at 6 months was stable. Exclusive breastfeeding at 6 months declined halfway through the study period, to a stable, but low, prevalence of 11.1% by 2014.