Primary hypocholesterolemia is associated with an increased risk of hepatic complications in the general population.

Background & Aims: Beyond cardiovascular disease protection, the health consequences of very low concentrations of low-density lipoprotein-cholesterol (LDL-C) remain a matter of debate. In primary hypobetalipoproteinemia (HBL), liver steatosis and cirrhosis have occasionally been reported. Here, we aimed to investigate the association between HBL and the risk of hepatic complications (cirrhosis complications and/or primary liver cancer) in the general population.

Blood inflammatory phenotypes were associated with distinct clinical expressions of asthma in adults from a large population-based cohort.

Background: Asthma is an inflammatory heterogeneous disease. Asthma inflammatory phenotypes based on blood eosinophil and neutrophil counts have never been identified and characterized in population-based studies.

Methods: Adults with current asthma and available blood eosinophil and neutrophil counts from the French population-based CONSTANCES cohort were included.

Recommendation for the review of biological reference intervals in medical laboratories.

This document is based on the original recommendation of the Expert Panel on the Theory of Reference Values of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), updated guidelines were recently published under the auspices of the IFCC and the Clinical and Laboratory Standards Institute (CLSI). This document summarizes proposals for recommendations on: (i) The terminology, which is often confusing, noticeably concerning the terms of reference limits and decision limits. (ii) The method for the determination of reference limits according to the original procedure and the conditions, which should be used.

Prevalence of spondyloarthritis in reference to HLA-B27 in the French population: results of the GAZEL cohort.

Objective: To estimate the prevalence of spondyloarthritis (SpA) in reference to HLA-B27 in the French population.

Methods: In 1989, 20 625 employees of the French national gas and electricity company aged 35-50 years were enrolled in the GAZEL cohort. In 2010, 18 757 still active participants were screened by a questionnaire validated for the detection of SpA.

The theory of reference values: an unfinished symphony.

The history of the theory of reference values can be written as an unfinished symphony. The first movement, allegro con fuoco, played from 1960 to 1980: a mix of themes devoted to the study of biological variability (intra-, inter-individual, short- and long-term), preanalytical conditions, standardization of analytical methods, quality control, statistical tools for deriving reference limits, all of them complex variations developed on a central melody: the new concept of reference values that would replace the notion of normality whose definition was unclear. Additional contributions (multivariate reference values, use of reference limits from broad sets of patient data, drug interferences) conclude the movement on the variability of laboratory tests.

Relationship between the achievement of successive periodic health examinations and the risk of dying. Appraisal of a prevention scheme.

Background: In the field of Periodic Health Examination (PHE), few studies brought information on their efficiency, both on morbidity and mortality.

Objective: The association between the reduction of mortality and a regular participation in PHE has been estimated.

Methods: This study concerned 50,116 persons 40-59 years old, of European origin, examined at the Centre of Preventive Medicine, Nancy, France, between 1 January 1980 and 31 December 1985 with a maximum duration of follow-up reaching 25 years.

[Determining and verifying reference intervals in clinical laboratories].

Based on the original recommendation of the Expert Panel on the Theory of Reference Values of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC-LM), updated guidelines were recently published under the auspices of the IFCC-LM and the Clinical and Laboratory Standards Institute (CLSI). This article summarises these new proposals: (1) defining more precisely the terminology, which is often confusing, noticeably concerning the terms of reference limits and decision limits; (2) showing the different steps for determining reference limits according to the original procedure and the conditions which should be respected and (3) proposing a simple methodology allowing to the Clinical Laboratories to satisfy the needs of the Regulation and Standards. The updated document proposes to verify if published reference limits are applicable to the Laboratory involved.

Common reference intervals for aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transferase (GGT) in serum: results from an IFCC multicenter study.

Background: Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transferase (GGT) measurements are important for the assessment of liver damage. The aim of this study was to define the reference intervals (RIs) for these enzymes in adults, paying attention to standardization of the methods used and careful selection of the reference population.

Methods: AST, ALT and GGT were measured with commercial analytical systems standardized to the IFCC-recommended reference measurement systems.

The CONSTANCES cohort: an open epidemiological laboratory.

Background: Prospective cohorts represent an essential design for epidemiological studies and allow for the study of the combined effects of lifestyle, environment, genetic predisposition, and other risk factors on a large variety of disease endpoints. The CONSTANCES cohort is intended to provide public health information and to serve as an "open epidemiologic laboratory" accessible to the epidemiologic research community. Although designed as a "general-purpose" cohort with very broad coverage, it will particularly focus on occupational and social determinants of health, and on aging.

Traceability of values for catalytic activity concentration of enzymes: a Certified Reference Material for aspartate transaminase.

Background: A new reference material for the liver enzyme aspartate transaminase (AST) (L-aspartate: 2-oxoglutarate-aminotransferase, EC 2.6.1.

"Are my Laboratory Results Normal?" Considerations to be Made Concerning Reference Intervals and Decision Limits.

This paper looks at the topic of reference intervals from the point of view of the patient or the clinician. The differences between the concepts of reference intervals (biological characteristic of a well defined population) and the various types of decision limits are illustrated and discussed. Decision limits can be defined in different ways: based on a Bayesian approach, on epidemiological studies or on clinical experience, but differ from reference intervals because, while the latter deals with physiology, decision limits are related to some kind of disease or risk of developing it.

Reference intervals for serum creatinine concentrations: assessment of available data for global application.

Background: Reference intervals for serum creatinine remain relevant despite the current emphasis on the use of the estimated glomerular filtration rate for assessing renal function. Many studies on creatinine reference values have been published in the last 20 years. Using criteria derived from published IFCC documents, we sought to identify universally applicable reference intervals for creatinine via a systematic review of the literature.

Standardization of gamma-glutamyltransferase assays by intermethod calibration. Effect on determining common reference limits.

Background: The improvement of the consistency of gamma-glutamyltransferase (GGT) activity results among different assays after calibration with a common material was estimated. We evaluated if this harmonization could lead to reference limits common to different routine methods.

Methods: Seven laboratories measured GGT activity using their own routine analytical system both according to the manufacturer's recommendation and after calibration with a multi-enzyme calibrator [value assigned by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference procedure].

Stepwise strategies in analysing haematuria and leukocyturia in screening.

The aim of the present work was to compare in a supposed healthy population of 680 subjects several algorithms for positive selection of urine samples requiring microscopic examination for erythrocytes and leukocytes after screening by automated test-strip measurement and particle counting on a Sysmex UF-50 flow cytometer. Four strategies have been formulated and the sensitivity, specificity, positive predictive value, negative predictive value, false positive rate, false negative rate, and microscopic review rate were measured. The strategy combining test strip analysis and automated counting on all samples, followed by microscopic examination of only discordant samples gave the best results.

Bacteroides fragilis and Escherichia coli bacteriophages in human faeces.

Some bacteriophages found in human faeces are being evaluated as possible indicators of viral contamination of water. These bacteriophages include somatic coliphages and Bacteroides fragilis phages. The aims of this study were to determine the occurrence and concentrations of somatic coliphages and Bacteroides fragilis phages in the stools of a human population residing in eastern France (n = 193).