Measurements of eftrenonacog alfa by 19 different combinations reagents/instrument: A single‐centre study

International audienceIntroduction Recombinant factor IX Fc fusion protein (rFIXFc) is an extended half-life concentrate for the treatment of haemophilia B (HB). rFIXFc activity monitoring is crucial in several clinical situations. However, differences were observed between one-stage clotting (OSC) and chromogenic assays, but not for all factor IX (FIX) concentrations.Aims To compare rFIXFc measurements obtained using different instruments and common OSC and chromogenic asssays.Methods FIX:C measurements were performed in rFIXFc-spiked plasma aliquots (targeted FIX levels of 1.5, 1, 0.5, 0.2, 0.05, 0.02 and 0.01 IU/mL) and plasma samples collected from two patients with HB at various time points after rFIXFc infusion, using three instruments (STA-R MAX, ACLTOP700 and CS2100i) and common clotting and chromogenic FIX:C assays.Results The same reagent could give different FIX:C measurements when adapted to different instruments. Moreover, the same reagent/instrument combination could give different results depending of the FIX concentration. For OSC assays, only STA-Cephascreen on STA-R MAX and CS2100i, SynthAFax on ACLTOP 700 and Actin on CS2100i provided acceptable recoveries for all rFIXFc concentrations. The chromogenic assays ROX-FIX and Biophen FIX:C underestimated rFIXFc for concentrations lower than 0.05 and 0.2 IU/mL, respectively.Conclusions Our study demonstrates that the same reagent adapted to different instruments could lead to different rFIXFc values. As rFIXFc under/overestimation could be associated with inappropriate treatment or biased calculation of pharmacokinetic parameters, the reagent/instrument combination used by haemostasis laboratories should be considered and regularly evaluated by external quality assessment programmes

Prevalência de anticorpos antifosfolípides em diabéticas gestacionais e pré-gestacionais Antiphospholipid antibodies in gestational and pregestational diabetic women

OBJETIVO: identificar e descrever a prevalência de anticorpos antifosfolípides (anticorpo anticardiolipina e anticoagulante lúpico) em gestantes diabéticas. MÉTODOS: estudo prospectivo de prevalência, realizado no período de julho de 2003 a março de 2004. Foram estudadas 56 gestantes diabéticas gestacionais e pré-gestacionais que ingressaram ao pré-natal e aceitaram participar do estudo. Nenhuma gestante foi excluída. Se um ou outro anticorpo estivesse presente, a gestante seria tratada com heparina e ácido acetilsalicílico. Foram caracterizados os perfis da gestante, a evolução da gestação e o recém-nascido. RESULTADOS: foram diagnosticados anticorpos antifosfolípides em apenas quatro gestantes das 56 estudadas, o que representou prevalência de 7% (IC 95% - 0,1-13,9). Nas gestantes diabéticas com anticorpos antifosfolípides a duração do diabetes foi de cinco anos ou mais. A idade variou de 27 a 38 anos, sendo uma primigesta, outra secundigesta e as outras duas multíparas. As gestantes com anticorpos antifosfolípides, que foram tratadas, tiveram recém-nascidos vivos, de termo, cujos pesos variaram entre 2.650 g e 4.000 g. CONCLUSÃO: a prevalência de anticorpos antifosfolípides em gestantes diabéticas gestacionais é baixa, e similar à população geral de grávidas. Está prevalência aumenta quando a gestante é diabética pré-gestacional.<br>PURPOSE: to diagnose and treat diabetic pregnant women with antiphospholipid antibodies and to describe the gestational and perinatal results. METHODS: we evaluated 56 gestational and pregestational diabetic women who were attended at one specialized prenatal care unit, between July 2003 and March 2004. All of them had a blood test to quantify antiphospholipid antibodies. If positive, they were treated with heparin and aspirin at low doses and the usual treatment for diabetes. We calculated the prevalence and 95% confidence interval for all and also those for the pregestational ones. The characteristics of the pregnancies and the newborns are described. RESULTS: antiphospholipid antibodies prevalence among the diabetic pregnant women was 7% (95% CI - 0.1 to 13.9). Among pregestational diabetic women it was 12% (95% CI - 0.2 to 23.3). Among the diabetic women with antiphospholipid antibodies the duration of disease was five years or more. Maternal age in positive antiphospholipid antibodies diabetics ranged from 27 to 38 years; one was primiparous, another was secundiparous and two were multiparous. CONCLUSION: antiphospholipid antibodies prevalence in diabetic pregnant women was similar to that in the general population and lower than that of the pregestational diabetic women