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Introduction: Current approved COVID-19 vaccines, notably mRNA and adenoviral vectored technologies, still fail to fully protect against infection and transmission of various SARS-CoV-2 variants. The mucosal immunity at the upper respiratory tract represents the first line of defense against respiratory viruses such as SARS-CoV-2 and is thus critical to develop vaccine blocking human-to-human transmission. Methods: We measured systemic and mucosal Immunoglobulin A (IgA) response in serum and saliva from 133 healthcare workers from Percy teaching military hospital following a mild infection (SARS-CoV-2 Wuhan strain, n=58) or not infected (n=75), and after SARS-CoV-2 vaccination (Vaxzevria®/Astrazeneca and/or Comirnaty®/Pfizer). Results: While serum anti-SARS-CoV-2 Spike IgA response lasted up to 16 months post-infection, IgA response in saliva had mostly fallen to baseline level at 6 months post-infection. Vaccination could reactivate the mucosal response generated by prior infection, but failed to induce a significant mucosal IgA response by itself. Early post-COVID-19 serum anti-Spike-NTD IgA titer correlated with seroneutralization titers. Interestingly, its saliva counterpart positively correlated with persistent smell and taste disorders more than one year after mild COVID-19. Discussion: As breakthrough infections have been correlated with IgA levels, other vaccine platforms inducing a better mucosal immunity are needed to control COVID-19 infection in the future. Our results encourage further studies to explore the prognosis potential of anti-Spike-NTD IgA in saliva at predicting persistent smell and taste disorders. [ABSTRACT FROM AUTHOR]

They are also responsible for ensuring that the samples sent to the laboratory during the test are processed properly and in due time. Keywords: competence; ISO 15189; simulation model EN competence ISO 15189 simulation model e67 e70 4 01/30/23 20230301 NES 230301 To the Editor, In laboratory medicine, quality is fundamental. [Extracted from the article]

Background: The objectives of this study are to estimate the prevalence of iron deficiency (ID) among French whole‐blood (WB) donors to identify factors associated with ID and to generate decision trees. Study design and methods: A prospective National multicentre study was performed on WB donors from March 11, to April 5th, 2019. Samples were selected randomly to perform serum ferritin. ID was defined as ferritin value under 26 ng/ml. All results were stratified by sex. Factors associated with ID were analysed using multivariate logistic regression model. CART algorithm was used for decision trees. Results: Eleven thousand two hundred fifty eight WB donors were included. ID was more frequent in women (39·5%) than in men (18·0%). Among 7200 repeated donors, women below 50 yo had a higher risk (OR = 2·37; [1·97–2·85] IC95) than those above 50 yo. Factors associated with ID were: haemoglobin level under the threshold at donation n‐1 except for women and n‐2 donation; a low mean corpuscular haemoglobin at n‐1 and n‐2 donations; a shorter interval since n‐1 donation and between n‐1 and n‐2 donations except for women; and women who had given three or four times in the last year. CART algorithm defined high risk of ID subgroups within three populations of donors, new female donors, repeated male donors and repeated female donors. In these identified subgroups, prevalence of ID was up to 72·1%. Conclusions: Our study showed the high prevalence of ID among French WB donors, identified well‐known and new factors associated with ID and defined algorithms predicting ID in three populations. [ABSTRACT FROM AUTHOR]

Background: Within the framework of routine fitness examinations, French Air Force military crew underwent urine testing for 3,4 methylenedioxymetamphetamine (MDMA [ecstasy]). The cross-reactivity of a dyslipidemic drug, fenofibrate, with an MDMA immunoassay was studied and confirmed on a large population sample.Methods: A 3-year retrospective study was performed on the MDMA DRI Ecstasy Assay on the Unicel DXC 600. In the event of positive test result, a confirmatory testing was carried out by gas chromatography/mass spectrometry (GC/MS) to establish the presence of MDMA. When analysis by GC/MS did not confirm the presence of MDMA, a false-positive result was suspected and the samples were analyzed by high-performance liquid chromatography-mass spectrometry to identify a potential interfering substance.Results: A total of 15,169 urine samples, from 7,803 patients, were tested for 3 years. Of the tested samples, 22 (0.15%) were positive by DRI Ecstasy Assay. None of them were positive by GC/MS. A cross-reactivity of fenofibrate's metabolite with MDMA using this assay was systematically found.Conclusion: Fenofibrate's interference with MDMA immunoassay was confirmed. Fenofibrate being widely prescribed, physicians had to be alerted that this treatment could lead to false-positive results. [ABSTRACT FROM AUTHOR]

The effect of purine nucleosides on the in vitro growth of Cryptosporidium parvum was studied. Culturing the parasite in THP-1 cells for 72 h in growth medium supplemented with adenosine or inosine improved the parasite yields especially in the first 48 h. Similar results were obtained with parasites cultured in Madin–Darby bovine kidney cells and incubated for 24 h with inosine. The addition of inosine to 72-h cultures enhanced the growth of C. parvum in THP-1 cells, especially the trophic stages, whereas the analogue formycin B was toxic to the parasites and induced a marked decrease in the gamont stages. The monitoring of the added purine nucleosides by high performance liquid chromatography showed that at 37°C in the presence of THP-1 cells, a rapid uptake of inosine occurred with hypoxanthine being the main purine present after 2 h in the medium. [Copyright &y& Elsevier]

The article presents a diagnosis of a1-antitrypsin (AIAT) deficiency using capillary zone electrophoresis on patients prescribed with serum electrophoresis as part of an initial battery of diagnostic laboratory tests. Topics include the parameters within which diagnosis of A1AT was suspected, other causes of low a1-globulin levels on electrophesis such as malnutrition and excessive renal excretion, and why serum electrophoresis is not recommended for diagnosing A1AT deficiency.

A letter to the editor is presented discussing the strategies of preventing preanalytical false-positive increases of cardiac troponin I on the Unicel Dxl 800 analyzer.

Introduction: In the French armed forces, the biological checkup required during the recruitment process comprises a urinalysis (urinary dipstick), a complete blood count (CBC), and measurement of serum levels of aspartate aminotransferase, alanine aminotransferase, fasting blood glucose, and creatinine. This study aimed to evaluate the benefits of this biological checkup and to determine the most relevant parameters.Materials and Methods: We conducted a monocentric retrospective study of all standardized and systematically conducted blood tests (CBC and measurement of aspartate aminotransferase, alanine aminotransferase, fasting blood glucose, and creatinine) over a 15-month period among 726 French Army recruits.Results: The population included mainly young males (85.4%, mean age 21.6 years). More than half (54.1%) of the blood tests had at least one abnormal parameter, most often concerning the CBC. Anemia occurred in 5.3% of the population and was mostly normocytic. Microcytosis was mostly not associated with anemia (72.3% of cases). Lymphopenia occurred in 20.1% of the population and was mostly mild. Eosinophilia was present in 5.1% of the population and was never severe. Thrombocytopenia occurred in 0.7% of the population and was never severe. Serum levels of aminotransferases were elevated in 8.1% of the population. Fasting plasma glucose averaged 84 mg/dL (SD: 0.07) ranging from 64 to 123 mg/dL, was abnormal in 0.4% of the population, and one case of diabetes was diagnosed. Serum creatinine concentration was elevated in 0.7% of the population.Conclusion: CBCs gave useful information but iron deficiency was common and insufficiently detected by this single analysis. Assessing aminotransferase levels without screening for viral hepatitis and systematic measurement of fasting plasma glucose levels did not appear to be efficient. In addition, the only interest in systematic measurement of creatinine serum levels was to obtain a reference level for long-term follow-up. In addition to the urinary dipstick, the systematic biological checkup at recruitment could be limited to a CBC with measurement of plasma ferritin levels and Hepatitis B virus serology, providing that any CBC abnormalities, in particular cytopenia, eosinophilia, and microcytosis, are systematically investigated. For a public health approach, systematic screening for other sexually transmitted infections could be proposed. [ABSTRACT FROM AUTHOR]

Amyloidosis results from extra-cellular deposition of proteins which interfere with tissue function. We report the case of a patient with pathological heart involvement which is caused by immunoglobulin D amyloidosis, and review current data on the amyloidois diagnosis and management.

Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics.