Influence of apixaban on commonly used coagulation assays: results from the Belgian national External Quality Assessment Scheme.

INTRODUCTION: The Belgian national External Quality Assessment Scheme performed a survey to assess the effect of the direct oral anticoagulant apixaban on the coagulation assays prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen and antithrombin as performed with a large number of reagent/instrument combinations. METHODS: Four lyophilized plasma samples spiked with apixaban (0, 41, 94 and 225 ng/mL) were sent to the 195 Belgian and Luxembourg clinical laboratories performing coagulation testing. RESULTS: PT and aPTT were barely influenced at the concentrations tested. At 225 ng/mL apixaban, PT and aPTT clotting times were only 1.15 times longer than at 0 ng/mL. Among PT reagents, RecombiPlasTin 2G® showed a slightly higher sensitivity with 225 ng/mL apixaban prolonging the PT clotting time 1.3-fold. Among aPTT reagents, there was no appreciable difference in sensitivity. Fibrinogen results were unaffected by the presence of apixaban, but antithrombin activity was considerably overestimated when measured with a FXa-based assay. At 225 ng/mL apixaban, the median percentage increase in antithrombin level was 31% when measured with the Liquid Antithrombin® reagent and 44% with the Innovance Antithrombin® reagent. CONCLUSION: Our data provide clinical laboratories with useful information on the impact of apixaban on their routine coagulation assays.

Fifteen years of Belgian experience with external quality assessment of semen analysis.

Semen analysis is difficult to standardize, quality control and quality assurance are necessary to ensure that results are accurate and precise. This Belgian EQA survey over a 15-year period, involving 121 laboratories, attempted to reduce interlaboratory variability and at the same time, encouraged participating laboratories to implement correct techniques as advised by the WHO. Over the total period, the median coefficient of variation (CV) for sperm count, irrespective of the method used was 19.2%, while using improved Neubauer chamber resulted in a significantly (p < 0.001) lower median CV (14.4%). The overall median CV for rapid progressive motility was high (37.1%), but progressive motility (15.1%) and total motility (13.8%) were acceptable. Sperm morphology revealed a large variability in 79.4% irrespective of the staining procedures or evaluation criteria used. Participation in the Belgian EQA is on voluntary basis. Both, participation and implementation of the correct techniques should be made mandatory for accreditation and benefit of patient treatment. The existing Belgian EQA program should now be harmonized with other existing EQA schemes in Europe.

Low yield by molecular detection of Chlamydophila pneumoniae in respiratory samples in Belgium questioning its etiological role in respiratory tract infections.

The actual burden of respiratory infections due to Chlamydophila pneumoniae is difficult to assess due to the major differences in positivity rates between PCR- and serology-based methods. The aim of the current study was to objectively analyse the yield of PCRs for the detection of C. pneumoniae in respiratory samples and to evaluate the additional value of performing laboratory diagnosis for C. pneumoniae in a setting of respiratory infection. The data based on routine analysis of respiratory samples with request for C. pneumoniae detection were collected from 4 large Belgian hospitals during 2 consecutive years. In total 3560 respiratory samples have been analysed and overall only 7 samples (0.2%) were found positive. Based on these observations, the critical evaluation of the actual role of C. pneumoniae in the etiology of lower respiratory infections and consequently of the extensive use of diagnostic tools for the detection of C. pneumoniae is needed.