Annales de biologie clinique最新文献

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.

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.

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.

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.

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.

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.

Anti-Jo1 antibodies are usually known markers of myositis. However, they can be associated with different pathologies. We aimed to determine the immuno-clinical characteristics of patients with positive anti-Jo1. We enrolled 31 anti-Jo1 positive patients, selected from 10429 cases tested for antinuclear antibodies (ANA) by indirect immunofluorescence. The anti-Jo1 identification was motivated by the ANA pattern or the clinical data of patients. The average age of patients was 36.9 ± 10 years (F/M sex ratio: 3.4). The overall prevalence of anti-Jo1 was 0.3% among all ANA-tested cases. The ANA pattern associated with the presence of anti-Jo1 was heterogeneous with ANA negative in 38.7 % of cases. They were associated with different autoantibody specificities in 64.5 % of cases and were alone in 35.5% of cases. When confronted with clinical data, anti-Jo1 positivity was associated with autoimmune (77,4%) and non-autoimmune (22,6%) clinical conditions. Our study shows a low overall prevalence of anti-Jo1. These antibodies must be systematically tested for in the context of myositis even if ANA is negative. Nevertheless, their positivity in other systemic or even non-autoimmune diseases requires further studies to better understand their clinical significance.

The diagnosis of subarachnoid hemorrhage (SAH) is extremely important for appropriate management. Cerebral computed tomography (CT), used as the first-line investigation to detect bleeding, has excellent sensitivity if performed promptly, but its sensitivity falls sharply with the time elapsed since the onset of SAH. Oxyhemoglobin and bilirubin, the breakdown products of heme, are detectable in cerebrospinal fluid (CSF) by spectrophotometric absorption, which defines the search for xanthochromia pigment in CSF. Both parameters can be sought when imaging is negative or doubtful with a strong suspicion of SAH based on clinical signs. In this context, our working group at the Société Française de Biologie Clinique (SFBC) is proposing recommendations to provide medical biologists with support for the implementation and validation of "oxyhemoglobin and bilirubin in CSF" test and enabling them to play their part in the diagnostic process. From the pre-analytical stages through to the delivery of results, we will summarize the pitfalls to be avoided, the main decision values and different physiological and pathological profiles.

The relevant and correct prescribing of medical biology is a major public health issue. Correct prescribing is a legal obligation under article L6211-8 of the French Public Health Code and is an integral part of the biologist's daily work, already specified in the 2012 (section 4.7) and 2022 (section 5.3.3) versions of the NF EN ISO 15189 standard. COFRAC document SH REF 02 v08 specifies the requirements for consultancy services. The adaptation of the prescriptions is a revision of the contract with the prescriber, which makes it possible to optimize patient care and ensure the satisfaction of the laboratory users. Although essential, accurate prescribing is time consuming. "Chronophage" is the term that has been used for almost a decade. At present, the work of biologists in this area is not valued. In fact, there is no evaluation system to highlight this regulation control activity. To date, no work has been published to estimate this time, this chronophagy, and to evaluate its impact. Cost measurement using Time-Driven Activity-Based Costing (TDABC), a variant of Activity-Based Costing (ABC), is based on a process approach. The main contribution of TDABC is that it uses a single cost driver: time. Serum immunofixation is a test used to confirm and monitor plasma cell dyscrasias, the archetype of which is multiple myeloma. The learned societies and the IMWG provide explicit diagnostic criteria, but the guidelines do not address the frequency of follow-up. In particular, the frequency of repeat and follow-up serum immunofixation remains unaddressed from an evidence-based medicine perspective. This work has made it possible to highlight the savings made between 1st January and 31th August 2023 thanks to the involvement of the biologist and to highlight his essential role in the process of controlling the overall expenditure (reagents, human resources, time and money) in the specialized biochemistry sector (bench: proteins) and to strengthen the role of the biologist within the institution. The various players in the healthcare sector - prescribing physicians, biologists, hospital administrators and, last but not least, patients - all have an essential role to play in maximizing value for patients and in the healthcare economy.