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The European Urinalysis Guideline (EUG) 2023, published in the Clinical Chemistry & Laboratory Medicine journal, is an update to the previous European Urinalysis Guideline from 2000. The updated guideline focuses on new diagnostic markers, infectious agents, automated particle counting, specimen collection, quality control processes, and analytical performance specifications. It is a collaboration between clinical chemistry and clinical microbiology laboratories, providing recommendations for laboratory tests, preanalytical procedures, and interpretation of analytical results. The EUG 2023 contains 65 graded recommendations and discusses urinary tract infections, kidney disease, and other diseases at a screening level. The guideline was developed by a multidisciplinary expert group and received input from various stakeholders. It is considered an approved guideline by the European Federation of Clinical Chemistry and Laboratory Medicine and has been endorsed by the European Society of Clinical Microbiology and Infectious Diseases. The guideline aims to assist laboratory professionals in maintaining the quality of clinical laboratory tests in urine. [Extracted from the article]

Accordingly, efforts by IFCC to develop a new Primary Reference Measurement System with a mass spectroscopy-based primary reference method and serum-based reference materials are well underway and will allow true SI-traceable standardization of apolipoproteins [[3]]. To declare a particular method as standardized, a clinical laboratory or IVD manufacturer must demonstrate adequate agreement between their measurement and a consensus reference method and/or consensus reference material to establish metrological traceability of results. In this issue of I Clin Chem Lab Med i , the study by Smit et al. [[1]] from Leiden University Medical Center (LUMC, The Netherlands) highlights the importance of a standardized preanalytical phase for accurate mass spectrometry applications in clinical chemistry. [Extracted from the article]

Introduction: Two new formulas, the Martin-Hopkins and the Sampson formula, were recently developed to overcome shortcomings of the Friedewald formula for calculating LDL-cholesterol. We aimed to compare the concordance of the two formulas with apolipoprotein B (apoB), a surrogate marker of the number of LDL particles. Materials and methods: In a study of serum lipid data of 1179 patients who consulted the AZ St-Jan Hospital Bruges for cardiovascular risk assessment, the correlation and concordance of the Friedewald, Martin-Hopkins and Sampson formulas with apoB concentration, measured by immunonephelometry, were determined and compared. Results: The Martin-Hopkins formula showed significantly higher correlation coefficient than the Friedewald formula with apoB in the entire dataset and in patients with low LDL-cholesterol < 1.8 mmol/L. Both Martin-Hopkins and Sampson formulas yielded > 70% concordance of LDL-cholesterol with regard to treatment group classification based on population-equivalent thresholds of apoB in hypertriglyceridemic patients (2-4.5 mmol/L), with the highest concordance (75.6%) obtained using Martin-Hopkins formula vs. 60.5% with Friedewald formula. Conclusion: The Martin-Hopkins (and, to a lesser extent, Sampson) formula is more closely associated with the number of LDL particles than Friedewald formula. This, in combination with literature evidence of lesser accuracy of the Friedewald formula, is an argument to switch from Friedewald to a modified, improved formula. [ABSTRACT FROM AUTHOR]

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently addressed present and future challenges in the laboratory diagnostics of atherogenic lipoproteins. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), LDL cholesterol (LDLC), and calculated non-HDLC (=total – HDLC) constitute the primary lipid panel for estimating risk of atherosclerotic cardiovascular disease (ASCVD) and can be measured in the nonfasting state. LDLC is the primary target of lipid-lowering therapies. For on-treatment follow-up, LDLC shall be measured or calculated by the same method to attenuate errors in treatment decisions due to marked between-method variations. Lipoprotein(a) [Lp(a)]-cholesterol is part of measured or calculated LDLC and should be estimated at least once in all patients at risk of ASCVD, especially in those whose LDLC declines poorly upon statin treatment. Residual risk of ASCVD even under optimal LDL-lowering treatment should be also assessed by non-HDLC or apolipoprotein B (apoB), especially in patients with mild-to-moderate hypertriglyceridemia (2–10 mmol/L). Non-HDLC includes the assessment of remnant lipoprotein cholesterol and shall be reported in all standard lipid panels. Additional apoB measurement can detect elevated LDL particle (LDLP) numbers often unidentified on the basis of LDLC alone. Reference intervals of lipids, lipoproteins, and apolipoproteins are reported for European men and women aged 20–100 years. However, laboratories shall flag abnormal lipid values with reference to therapeutic decision thresholds. [ABSTRACT FROM AUTHOR]