Annales de biologie clinique最新文献

The Sysmex XN-1000 cellular hematology analyzers, widely used in Burkina Faso, can provide information on Plasmodium infection with the "iRBC?" flag triggered during a blood count. This study aims to evaluate the contribution of this alarm to the diagnostic orientation of malaria in an endemic area. The samples were collected between August and September 2023. The blood was sampled on EDTA tubes and the blood count was performed on the Sysmex XN-1000. The Sysmex XN-31 was used as a reference diagnostic method for malaria and identification of the Plasmodium falciparum species. Identification of the non-falciparum species and non-plasmodial inclusions was made on blood smears stained with the RAL MCDh kit. 148 samples were analyzed. Children under 5 years of age represent 63.5%, and females 52.7%. The "iRBC?" flag shows a PPV and an overall specificity to malaria of 100%. Depending on the species, the sensitivity was 12.3% (13/106) for P. falciparum and 83.3% (5/6) for P. malariae. Non-plasmodial inclusions were not associated with triggering this flag. This alarm triggered by the XN series automatons can help to anticipate the diagnosis of malaria. Particular attention from the biologist is necessary during biological validation: the presence of this alarm should lead to specific malaria research, but its absence should not lead to exclude malaria, especially with P. falciparum.

It is important that a clinical laboratory has implemented appropriate procedures for quality control, which includes both internal quality control (IQC) and external quality assessment (EQA) with the common goal to detect systematic errors and random errors. It is the case for both the Hemohub® Bayesian tools for IQC results interpretation and the ECAT EQA optimised bivariate z-scores analysis. On a concrete case study, we demonstrate both the higher sensitivity and specificity of optimised bivariate z-scores analysis than the univariate approach. The Bayesian IQC results interpretation like the ECAT analysis confirmed the explicit conclusion i.e. an increase of the random error corresponding to the increase of the inter assay coefficient of variation (CV) at the date of EQA samples runs. Improvement of repaired dysfunction could be then daily observed on IQC results and then confirmed on EQA results thanks to the complementarity of the two approaches.

Urine drug screening is carried out on numerous automated analysis platforms using enzyme-linked immunosorbent assays. While these methods are rapid, they often lack specificity. We report the case of a 5-year-old child treated for Dravet disease and hospitalized for clonic seizures. During her hospitalization, 3 urine samples were sent to the Toxicology laboratory to rule out any toxic origin to these seizures. The first two were positive for ecstasy, and negative for other drugs. For the last sample, all tests were negative. The presence of ecstasy in the first 2 samples was not confirmed by gas chromatography-mass spectrometry, which identified stiripentol in all 3 urines. Stiripentol is an antiepileptic drug that shares a 3,4-methylenedioxy group with MDMA. We determined that the antibody in the kit crossed 20% with stiripentol, and were able to define a stiripentol cut-off concentration of 2,500 ng/mL. We checked this cut-off by measuring stiripentol in the 3 urine samples, finding concentrations of 47,600 and 5,800 ng/mL for the first and second samples respectively, and 1,900 ng/mL for the last. These concentrations explain the false positives in the first two urine samples, and the negative result in the last. This work underlines the need to remain critical of the results of immuno-screening methods, and to confirm them with a reference method.

The preservation of blood capital is essential in many clinical situations. The laboratory, by optimizing the tubes to be sampled, provides valuable assistance in this context. The aim of this work is to study the possibility of analyzing an expanded panel of usual biochemistry and automated hormonal parameters on a single tube: heparin lithium with separator gel. Thirty-two blood samples were analyzed for a usual biochemistry panel (ALT, uric acid, albumin, AST, bicarbonates, total bilirubin, calcium, chloride, creatine kinase, creatinine, iron, GGT, glucose, haptoglobin, LDH, magnesium, PAL, inorganic phosphorus, potassium, total protein, sodium, triglycerides, urea) and a hormonal automated panel (cortisol, hGH, insulin, prolactin, free T3, free T4, TSH, B12 vitamin). For each panel, the sample was taken from the laboratory's classically recommended tube (lithium heparin without separator gel for usual biochemistry and plain without separator gel for automated hormonology) and from the single tube to be tested (heparin lithium with separator gel). The results of the recommended tubes were compared to those of the single tube, statistically and then with regard to the clinical impact. Significant differences were observed between the recommended tube and the single tube for: AST, calcium, chloride, GGT, LDH and phosphorus. Apart from LDH, no parameter revealed a clinically significant difference. Plasma collected on lithium heparin with separator gel is suitable for the determination of a wide range of biochemistry parameters, except for LDH, which should need an adaptation of its usual values with regard to the considered tube.

While the latest WHO classification of hematological neoplasms helps refine the diagnostic criteria for anaplastic large cell lymphomas (ALCL), their diagnosis can still be challenging. This retrospective series of 10 ALCL cases illustrates the cytological appearance and immunological profile obtained through flow cytometry (FCM) from various sample types, including lymph node biopsies (LN), peripheral blood (PB), cerebrospinal fluid (CSF), and pleural fluid (PF). ALCL exhibits a polymorphic cytological appearance, ranging from "doughnut" cells to Hodgkin-like cells, very large cells, and small cells, with this polymorphism being particularly pronounced in ALK (-) forms. The detection of cytotoxic CD4+ T-cells by FCM aids in confirming the diagnosis, especially in small cell forms, which typically correspond to circulating phases. Cytological orientation, particularly for LNB, helps optimize the FCM panel to be used and ensures that ALCL, which frequently shows a loss of pan-T markers, is not overlooked. In conclusion, while the final diagnosis is histological, cytological analysis combined with FCM provides an initial diagnostic orientation for ALCL and guides complementary genetic analyses.

Bacterial vaginosis, one of the most common pathologies in adult women, is defined as a chronic polymicrobial condition resulting from dysbiosis of the vaginal microbiota. Despite 70 % of patients being asymptomatic, diagnosis of this condition relies on clinico-microbiological tools. Despite being considered a gold standard technique, the Nugent score, established during microscopic examination of vaginal smears, has shown a lack of standardization and reproducibility. The discovery of new bacteria not included in the microscopic Nugent score, such as BVAB1,2,3, Atopobium sp., and Megaspheara sp., undetectable by conventional techniques, has highlighted a lack of specificity and sensitivity of the score currently provided to clinicians. This has spurred the development of new PCR kits to perform Nugent scores via molecular biology and address the shortcomings of microscopic techniques. This study has shed light on the contribution of molecular biology to the diagnosis of bacterial vaginosis, as well as the performance and limitations of the Allplex™ Bacterial Vaginosis kit marketed by Seegen® compared to microscopic examination.

This observation reports the case of an occupational allergic asthma in a laboratory technician, caused by exposure to formaldehyde. She experienced feelings of discomfort during low exposure, below the regulatory exposure thresholds. Sent to occupational medicine, signs of an asthma attack were noted by the doctor. Respiratory function tests showed bronchial hyperactivity. The diagnosis of formaldehyde asthma was made due to the recurrence of signs during exposure and the absence of other allergies. This type of occupational asthma is rare nowly and this case is an opportunity to recall what the different occupational asthmas are and which are the most common among laboratory technicians.

The Working Group Preanalytical Phase of the European Federation of Clinical Chemistry and Laboratory Medicine advises suppressing haemolysis-sensitive tests when haemolysis is clinically significant, as improper specimen handling can rupture red blood cells, increasing potassium levels. Thus, a correctly repeated blood sample should show lower potassium levels than a haemolysed one. This study aimed to determine the prevalence of haemolysed samples with potassium levels below the reference range and whether this predicts hypokalemia in repeated collections. From March 2022 to March 2024, 396,640 non-haemolysed samples (H-index < 2 UA) were analyzed. Samples with an H-index ≥ 2 AU were classified as haemolysed, and potassium values were suppressed. Warnings were issued for haemolysed samples with potassium below the reference range (3.4-4.5 mmol/L), advising new sample collection. Twenty-five (0.01%) repeat samples were taken within 24 hours of a previously haemolysed sample with low potassium. Severe and moderate hypokalemia were more common in these repeats, with severe hypokalemia (≤2.5 mmol/L) found in 48% of repeat tests, compared to 0.3% in all samples. Though rare, a decrease in potassium in haemolysed samples often precedes hypokalemia diagnosis. Implementing a simple and cost-effective LIS algorithm to alert clinicians could potentially reduce diagnosis and treatment time.

Clostridioides difficile is a Gram-positive, spore-forming anaerobic enteropathogen responsible for a wide spectrum of clinical diseases ranging from mild diarrhoea to pseudomembranous colitis. It is the first cause of healthcare-associated diarrhoeas, but community-associated Clostridioides difficile infections (CDI) are increasingly reported in patients without the common risk factors (age > 65 years, previous antibiotic treatment). The main C. difficile virulence factors are toxins A (TcdA) and B (TcdB), and in some cases the binary toxin. The CDI incidence has increased in Europe since the early 2000s, then decreased to reach approximately 4 cases/10,000 patients/days. C. difficile should be tested only in diarrheal stools. Children less than 3 years old are frequently colonized, therefore CDI diagnosis should be carried out only in specific cases (outbreak, Hirschsprung disease). No stand-alone method can be used for the CDI diagnosis. The European Society for Clinical Microbiology and Infectious Diseases (ESCMID) recommends a two-step algorithm with a sensitive screening test (molecular assay or glutamate dehydrogenase immunochromatographic assay). If the screening test is negative, the CDI diagnosis can be ruled out. If the screening test is positive, a second highly specific test should be used, such as toxin A/B immunochromatographic assay.