Annales de biologie clinique最新文献

The existence of alpha-1 antitrypsin variants with apparently unremarkable phenotypes and serum concentrations, contrasting with a clinical picture suggestive of a severe deficiency, led us to investigate whether in these cases there was a reduction or even suppression of the capacity of alpha-1 antitrypsin to inhibit elastase. To this end, in two different laboratories, we adapted and validated a method for measuring the functional activity of alpha-1 antitrypsin, based on spectrophotometric kinetic analysis of the inhibition by serum alpha-1 antitrypsin of the hydrolytic activity of porcine pancreatic elastase on a chromogenic substrate. This method has proved to be robust, reproducible and transferable and made possible to define, on the basis of an analysis of a hospital population, a functionality index with a confidence interval comprised between 0.87 and 1.2, allowing to identify subjects likely to have a functional deficiency of alpha-1 antitrypsin, whether this deficiency being of a genetic origin without any quantitative or phenotypic translation, or whether being acquired under the effect of external agents (cigarette smoke or viruses).

A 24 years-old woman was admitted to hospital for an epistaxis that had not resolved. Biological results show bi-cytopenias (anemia and thrombopenia). Clinically she presents a fourth grade splenomegaly. To explore these cytopenias, a myelogram is performed.

Present in quantities ranging from hundreds of milligrams to several grams in various environmental compartments, trace metal elements (TMEs), formerly known as "heavy metals," have been the subject of much discussion in recent years due to their major toxicological impact on human health. They are divided into essential elements such as iron, zinc, copper, selenium, manganese, and toxic elements such as mercury, cadmium, lead, lithium, and arsenic. Essential trace elements play a vital role in the body, and their deficiency can alter important physiological functions, while toxic elements have no physiological role and can lead to serious illnesses. However, essential elements can also cause intoxication depending on their concentrations and chemical forms. The industrialization of the modern world exposes the global population to high concentrations of trace elements that can be toxic in the short or long term. These TMEs enter the human body through various pathways (inhalation, ingestion, or dermal contact). The clinical manifestations of TME intoxications are highly varied and nonspecific, making their diagnosis and management difficult. Inductively coupled plasma mass spectrometry (ICP-MS) allows the detection of TME intoxications. Indeed, it enables the simultaneous quantification of around thirty trace metal elements in biological media. Thus, it has led to the establishment of a new approach: the metal profile, which has many applications in clinical biology and clinical, forensic, occupational, or environmental toxicology.

Although two clusters have been identified in France, constitutional factor XI deficiency is a rare disorder. Acquired factor XI deficiency is extremely rare. The management of factor XI deficiency is not staightforward because of the unpredictable bleeding tendency that does not clearly relate to the factor XI level. Other haemostastis parameters have to be taken into account to evaluate the bleeding tendency. We report the cases of a congenital factor XI deficiency, an acquired factor XI deficiency and a von Willebrand disease associated to a factor XI deficiency. On the other hand, some interferences can lead to underestimation of factor XI and we report the case of an interference by lupus anticoagulant. The objective of this review is to better understand how to manage a reduced factor XI level.

The Westgard quality control (QC) rules are often applied in infectious diseases serology to validate the quality of results, but this requires a reasonable tradeoff between maximum sensitivity to errors and minimum false rejections. This article, in addition to illustrate the six sigma methodology in the QC management of the (anti-HCV Architect®) test, it discusses the main influencing factors on sigma value. Data from low positive and in-kit control materials spreading over 6 months and using four reagent kits, were used to calculate the precision of the test. The difference between the control material reactivity and the cut-off defined the error budget. Sigma values were > 6, which indicates that the method produces four erroneous results per million tests. The application of the six sigma concept made it possible to argue the choice of the new QC strategy (use of 13S rule with one positive control) and to relax the existing QC rules. This work provides a framework for infectious diseases serology laboratories to evaluate tests performances against a quality requirement and design an optimal QC strategy.

Dyslipidemia plays a key role in metabolic syndrome (MS), intricately linked to type 2 diabetes mellitus (T2DM). This study aimed to investigate the differences in low-density lipoprotein cholesterol (LDL-C) subfraction levels between T2DM and T2DM with MS, and identify the risk factors associated with the disease. A total of 246 individuals diagnosed with T2DM, including 144 T2DM patients with MS, and 147 healthy subjects were recruited. All participants underwent a comprehensive clinical evaluation. Lipoprotein subfraction analysis was performed using the Lipoprint LDL system. Multivariate logistic regression analysis revealed that several lipid markers, including triglyceride (TG), LDL-C, large buoyant LDL-C (lbLDL-C), small dense LDL-C (sdLDL-C), LDLC2-5, and sdLDL-C/lbLDL-C ratio, were identified as independent risk factors for T2DM. Additionally, TG, sdLDL-C, LDLC-4, LDLC-5, and sdLDL-C/lbLDL-C ratio were found to be independent risk factors for T2DM with MS. Furthermore, the results of the receiver operating characteristic (ROC) curves demonstrated that sdLDL-C, LDLC-4, LDLC-3, and sdLDL-C/lbLDL-C ratio exhibited excellent predictive performance for the risk of T2DM (AUC > 0.9). The sdLDL-C/lbLDL-C ratio emerges as a shared independent risk factor for T2DM and MS complications. Furthermore, sdLDL-C/lbLDL-C ratio, along with LDL-4 and LDL-3, exhibits noteworthy predictive capabilities for T2DM.

Contrary to direct oral anticoagulants (DOAC), unfractionated heparin (UFH) requires daily monitoring when administered at therapeutic dose. At present, UFH monitoring is preferably carried out by measuring plasma anti-Xa activity, however, in patients previously treated with an anti-Xa DOAC and switched to UFH, there is a high risk of DOAC interfering with the measurement of UFH anti-Xa activity. Residual anti-Xa DOAC in the sample can lead to an overestimation of the anticoagulant activity attributed to heparin and thus to incorrect anticoagulation. This risk of interference should not be overlooked because interference may occur even at concentration of DOAC below the hemostatic safety threshold and can last several days. To overcome this issue, several alternatives are being studied. This note provides an update on anti-Xa DOAC interference and different strategies available in current practice. It also underlines the importance of communication between biologists and clinicians on anticoagulant treatments received by patients.