Phlebotomy is one of the most complex medical procedures in the diagnosis, management and treatment of patients in healthcare. Since laboratory test results are the basis for a large proportion (60–80%) of medical decisions, any error in the phlebotomy process could have serious consequences. In order to minimize the possibility of errors, phlebotomy procedures should be standardised, well-documented and written instructions should be available at every workstation. Croatia is one of the few European countries that have national guidelines for phlebotomy, besides the universally used CLSI (Clinical Laboratory Standards Institute) H3-A6 Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; approved Standard-Sixth Edition (CLSI, 2007) and WHO (World Health Organization) guidelines on drawing blood: best practices in phlebotomy (WHO, 2010). However, the growing body of evidence in importance of preanalytical phase management resulted in a need for evidence based revision and expansion of existing recommendations.The Croatian Society for Medical Biochemistry and Laboratory Medicine, Working Group for the Preanalytical Phase issued this recommendation. This document is based on the CLSI guideline H3-A6, with significant differences and additional information.

Rhegmatogenous retinal detachment (RRD) is an important cause of vision loss and can potentially lead to blindness. The underlying pathogenesis is complex and incompletely understood. We applied a two-stage genetic association discovery phase followed by a replication phase in a combined total of 2833 RRD cases and 7871 controls. The discovery phase involved a genome-wide association scan of 867 affected individuals and 1953 controls from Scotland, followed by genotyping and testing 4347 highest ranking or candidate single nucleotide polymorphisms (SNPs) in independent sets of cases (1000) and controls (2912) of Dutch and British origin. None of the SNPs selected reached a Bonferroni-corrected threshold for significance (P < 1.27 × 10(-7)). The strongest association, for rs12960119 (P = 1.58 × 10(-7)) located within an intron of the SS18 gene. Further testing was carried out in independent case-control series from London (846 cases) and Croatia (120 cases). The combined meta-analysis identified one association reaching genome-wide significance for rs267738 (OR = 1.29, P = 2.11 × 10(-8)), a missense coding SNP and eQTL for CERS2 encoding the protein ceramide synthase 2. Several of the top signals showing suggestive significance in the combined meta-analysis encompassed genes with a documented role in cell adhesion or migration, including SS18, TIAM1, TSTA3 and LDB2, which warrant further investigation. This first genetic association study of RRD supports a polygenic component underlying RRD risk since 27.4% of the underlying RRD liability could be explained by the collective additive effects of the genotyped SNP from the discovery genome-wide scan.

: RDW is an integrative parameter reflecting tumor specific features and shows significant association with overall survival in patients with CRC. This is especially important in patients with stage 2 disease where elevation in preoperative RDW values can contribute to recognition of higher risk patients.

In certain clinical situations, it is necessary to determine whether clinically relevant plasma levels of direct oral anticoagulants (DOACs) are present. We examined whether qualitative testing of DOACs in urine samples can exclude DOAC plasma concentrations of >30 ng/mL. This prospective single centre cohort study included consecutive patients treated with an oral direct factor Xa inhibitor (DXI) (apixaban, n=31, rivaroxaban, n=53) and direct thrombin inhibitor (DTI) (dabigatran, n=44). We aimed to define the negative predictive value (NPV) and other statistical parameters of detecting DXIs and DTIs by DOAC Dipstick at plasma concentrations of >30 ng/mL. We also determined the best-fit threshold plasma levels using chromogenic substrate assays by logistic regression analysis. Between July 2020 and July 2021, 128 eligible patients (mean age 66 years, 55 females) were included into the study. The NPVs and sensitivities for DXI and DTI of DOAC Dipstick were 100% at >30 ng/ml plasma, for specificities 6% and 21% and for positive predictive values 62% and 72%, respectively. All diagnostic statistical tests improved to values between 86% and 100% at best fitting plasma thresholds of >14 ng/mL for DXI and >19 ng/mL for DTI. Visual analysis using the DOAC Dipstick was 100% in agreement with that of the optoeletronic DOASENSE Reader for all three DOACs. DOAC Dipstick testing can reliably exclude the presence of DOACs in urine samples at best fitting thresholds of >14 and >19 ng/mL in plasma. The performance of the DOAC Dipstick at detecting lower DOAC concentrations in plasma requires confirmation.

IntroductionClinical application of rivaroxaban and apixaban does not require therapeutic monitoring. Commercial anti-activated factor X (anti-FXa) inhibition methods for all anti-FXa drugs are based on the same principle, so there are attempts to evaluate potential clinical application of heparin-calibrated anti-FXa assay as an alternative method for direct FXa inhibitors. We aimed to evaluate relationship between anti-FXa methods calibrated with low molecular weight heparin (LMWH) and with drug specific calibrators, and to determine whether commercial LMWH anti-FXa assay can be used to exclude the presence of clinically relevant concentrations of rivaroxaban and apixaban.Materials and methodsLow molecular weight heparin calibrated reagent (Siemens Healthineers, Marburg, Germany) was used for anti-FXa activity measurement. Innovance heparin (Siemens Healthineers, Marburg, Germany) calibrated with rivaroxaban and apixaban calibrators (Hyphen BioMed, Neuville-sur-Oise, France) was used for quantitative determination of FXa inhibitors.ResultsAnalysis showed good agreement between LMWH calibrated and rivaroxaban calibrated activity (κ = 0.76) and very good agreement with apixaban calibrated anti-Xa activity (κ = 0.82), respectively. Low molecular weight heparin anti-FXa activity cut-off values of 0.05 IU/mL and 0.1 IU/mL are suitable for excluding the presence of clinically relevant concentrations (< 30 ng/mL) of rivaroxaban and apixaban, respectively. Concentrations above 300 ng/mL exceeded upper measurement range for LMWH anti-FXa assay and cannot be determined by this method.ConclusionLow molecular weight heparin anti-FXa assay can be used in emergency clinical conditions for ruling out the presence of clinically relevant concentrations of rivaroxaban and apixaban. However, use of LMWH anti-FXa assay is not appropriate for their quantitative determination as an interchangeable method.