Assessment of the neutralizing antibody response in Omicron breakthrough cases in healthcare workers who received the homologous booster of Moderna mRNA-1273.

Vaccines against SARS-CoV-2 were developed during the pandemic including the BNT162b2 and the mRNA-1273. We evaluated the levels of binding antibodies against the receptor binding domain and the levels of NAbs in individuals who developed a breakthrough infection after having received three doses of mRNA-1273. A total of 51 participants were included. The breakthrough group was compared to a 1:1 matched-control group. Among the 51 individuals, 18 (35%) developed a breakthrough infection. The GMT of NAbs against the BA.1 in the BK population was 278.1 (95%CI: 168.1-324.1). This titer was significantly lower compared to the matched-control group when considering all data (GMT = 477.4; 95%CI: 316.2-541.0; p = 0.0057). Results were similar for the BA.5 (GMT = 152.0 (95%CI: 76.9-172.9) for breakthrough and 262.0 (95%CI: 171.3-301.8) for control (p = 0.0043)). Our study found that individuals receiving the mRNA-1273 booster and who developed a breakthrough infection presented lower levels of binding antibodies and NAbs before the infection as compared to a matched-control group.

Added value of a connected glucose meter for glycorrhachia assessment.

Objectives: The aim of this study was to demonstrate the performance and added value of rapid glucose determination in cerebrospinal fluid using a connected glucometer. Design and Methods: Intra-assay and inter-assay accuracies were calculated using residual clinical samples. Accuracies were measured by comparing the results obtained with the glucometer to those from the central laboratory on a large routine chemistry platform. Results: The intra-assay coefficients of variation were between 6.1% and 6.2% for low values (18 mg/dL) and between 5.6% and 6.8% for high values (58 mg/dL). The inter-assay coefficients of variation were between 9.4% and 16.3% for the low values (18 mg/dL) and between 5.7% and 8.7% for the high values (pool; ±75 mg/dL). The regression equation by comparison to the central laboratory was y = 4.08 + 0.82 x, with a coefficient of determination (r2) of 0.95. Conclusions: The measurement of glycorrhachia with a connected glucometer before the analysis in the central laboratory allows a rapid orientation in the deferential diagnosis of a meningitis of viral vs bacterial origin. The response time is fast (6 s) and requires only a small amount of fluid (1.2 µL), which is important in infants, especially since lumbar puncture is an integral part of the investigation of the origin of a fever in this population.

Clinical evaluation of a dermatophyte RT-PCR assay and its impact on the turn-around-time: A prospective study.

Onychomycosis is an important public health problem whose prevalence continues to grow and impact public health at several levels. Nevertheless, today the main diagnostic methods used in routine practice have many drawbacks. The aim of this study was to evaluate, for the first time, the clinical performance of a new multiplex polymerase chain reaction (PCR) (Novaplex®) in the identification of the causative agent on nail samples, and its impact on the turnaround time, compared to our traditional laboratory methods. From June 2022 to December 2022, all nail samples sent to our laboratory for suspected onychomycosis were included in this prospective study. We collected for each sample the results obtained with the Novaplex® PCR method and with the traditional direct microscopy examination and culture. Each discordant result was checked using a third method, which is another PCR method (DermaGenius® kit) as a resolver. For culture-positive samples, a turnaround time was calculated and compared to the one obtained with the Novaplex® method. A total of 131 samples were included. Among them, 5 were positive (3.8%) on direct microscopy, 33 were positive (25.2%) after culture, and 98 were negative (74.8%). All positive (n = 33) and negative (n = 69) cultures were also positive/negative with the Novaplex® PCR. Twenty-nine samples were positive with the Novaplex® method but negative with culture (discordant results). The percentage agreement between the culture and the Novaplex® methods was 77.9% (102 out of 131). While tested with the resolver (DermaGenius® PCR), 28 out of 29 discordant results were similarly found positive. The percentage agreement between the two PCR methods (Novaplex® and DermaGenius®) was 96.6%. The Novaplex® PCR method evaluated proved to be very reliable and allowed the direct identification of 62 out of 131 positive samples (47.3%) with the following distribution: 79.0% of Trichophyton rubrum complex, 11.3% of Trichophyton mentagrophytes complex, 6.5% of both Trichophyton rubrum complex and Trichophyton mentagrophytes complex, and 3.2% of Candida albicans. The median time [± 95% CI] for positive culture (between incubation and validation of the final identification) was 15 [12-23] days, while the turnaround time for the Novaplex® method adapted to our clinical laboratory routine is ≤7 days. Laboratory confirmation of onychomycosis is crucial and should always be obtained before starting treatment. The evaluated PCR method offered a rapid, reliable, robust, and inexpensive method of identification of the causative agent compared to traditional methods.

The aim of this study was to evaluate the clinical performance of a multiplex PCR in the identification of the causative agent of onychomycosis on nail samples, and its impact on the turnaround time, compared to our traditional laboratory methods. This new method is rapid, reliable, robust, and inexpensive.

Management of sickle cell disease during pregnancy: experience in a third-level hospital and future recommendations.

OBJECTIVE: To describe the outcomes of sickle-cell disease in pregnancy according to the different treatments adopted before and during pregnancy and to propose a systematic approach to treat sickle-cell disease (SCD) during pregnancy. METHODS: A retrospective descriptive study compared pregnancy outcomes among women with SCD who stopped hydroxyurea (HU) once pregnant (Group 1), were never treated before and during pregnancy (Group 2) or were treated by HU before conception who received prophylactic transfusion during pregnancy (Group 3). For each group we recorded the population's characteristics and the transfusion-related, obstetrical, perinatal and SCD complications. RESULTS: We found 11 patients for group 1 (9/11 with at least 3 painful crises during the 12 months before conception), 4 for group 2 (3/4 with no sickle-cell complications during the year before pregnancy) and 2 for group 3 (one with previous multiorgan failure (MOF), one with previous stroke). No transfusion-related complication occurred. Group 1 and 2 developed SCD complications and a high number of acute transfusions and hospital admissions. Group 3 showed none of these complications, but one patient developed preeclampsia and preterm birth. Several obstetrical and perinatal complications occurred in group 1. CONCLUSION: Not treating sickle-cell during pregnancy increases maternal and perinatal morbidity, even in mildly affected women. All sickle-cell pregnancies should be treated, according to the treatment adopted before but also to patient's SCD-history. We propose chronic transfusion to women with previous stroke or MOF or already under transfusion program, and HU for severely and mildly affected patients, respectively from the second and third trimesters. Additional prospective studies are needed to validate the results of the proposed protocol.

The challenge of screening SARS-CoV-2 variants of concern with RT-qPCR: One variant can hide another.

INTRODUCTION: Following the emergence of SARS-CoV-2 variants of concern (VOCs) worldwide, it is important to monitor local epidemiology to better understand the occurrence of clusters, reinfections, or infection after vaccination. Detecting mutations by specific RT-qPCR is a rapid and affordable alternative to sequencing. However, care must be taken to ensure that the techniques used are up-to-date and adapted to the variants circulating in the studied population. MATERIAL AND METHODS: All samples tested positive for SARS-CoV-2 were screened for detection of mutations of the spike protein using the Novaplex™ SARS-CoV-2 Variants I Assay from week 11 of 2021. Target sought were deletion H69/V70 and mutations N501Y and E484K. From week 18 we used in addition the new Novaplex™ SARS-CoV-2 Variants II Assay for samples with no targets found with the Variants I assay or with the mutation E484K alone, in order to screen the mutations L452R, K417N/T and W152C. RESULTS: Between weeks 11 and 25, 2239 positive samples out of 54,317 were tested with the Variants I Assay. Between weeks 18 and 25, 94 samples met the criteria for being tested with the Variants II Assay. Of these, 47 had the L452R mutation without the W152C mutation, typical in the B.1.617 variant. At week 25, this profile was found in 45.5 % of the samples and was the most frequent. CONCLUSION: According to our observations, variant B.1.617 has become predominant in our institution and most probably in our region. In the absence of the use of the Variants II Assay, they would have been considered wild.

Immunogenicity of mRNA-1273 COVID vaccine after 6 months surveillance in health care workers; a third dose is necessary.

OBJECTIVES: Scarce data are currently available on the kinetics of antibodies after vaccination with mRNA vaccines as a whole and, with mRNA-1273, in particular. We report here an ad-interim analysis of data obtained after a 6-month follow-up in a cohort of healthcare workers (HCWs) who received the mRNA-1273 vaccine. These new data provide more insight into whether and in whom a 3rd dose could be necessary. METHODS: Our study compared the anti-S antibody kinetics at 2 weeks (T1), 3 months (T3) and 6 months (T4) after the first injection, and 2 weeks after the second injection (T2). The 201 participating HCWs were stratified according to their initial serological status. The vaccine effectiveness was also assessed through a medical questionnaire. RESULTS: We report here a marked and statistically significant antibody decrease (P < 0.05) between T3 and T4, especially in naïve vaccinees. The analysis of potential confounding factors or known risk factors for severe COVID-19 disease did not reveal any influence on the drop observed. Six-month after vaccination, only one, symptomatic, infection was reported in our cohort. CONCLUSIONS: In a supply-limited environment, our results plead for reserving the 3rd dose scheme, in the upcoming months, to seronegative individuals prior to vaccination, especially when the serological status is easily accessible.

Efficacy comparison of three rapid antigen tests for SARS-CoV-2 and how viral load impact their performance.

More and more rapid antigen tests for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) appear in the market with varying performance. The sensitivity of these tests heavily depends on the viral load, extrapolated by the threshold cycle (Ct). It is therefore essential to verify their performance before their inclusion in routine. The Coronavirus Ag Rapid Test Cassette Bio-Rad, the GSD NovaGen SARS-CoV-2 (COVID-19) Antigen Rapid Test, and the Aegle Coronavirus Ag Rapid Test Cassette were evaluated on 199 samples: 150 fresh samples from the routine and positive in quantitative reverse-transcription polymerase chain reaction (RT-qPCR), nine fresh samples negative in RT-qPCR, and 40 frozen samples, taken before the discovery of SARS-CoV-2 but positive for other respiratory viruses. Positive RT-qPCR samples were categorized according to their Ct: Ct < 20 (18.7%), ≥ 20-< 25 (27.3%), ≥ 25-< 30 (18.7%), ≥ 30-35 (17.3%), and > 35 (18.0%). Sensitivities (95% confidence interval) for Ct below 25 were 95.7% (92.4-98.9), 97.1% (94.4-99.8), and 97.1% (94.4-99.8) for GSD NovaGen, Bio-Rad, and Aegle, respectively but drastically dropped when Ct exceeded 27. Among samples with previously diagnosed viruses, seven false-positive results were found with GSD NovaGen only (specificity 85.7%). Equivalent, high sensitivities were observed with the highest viral load samples. The GSD NovaGen assay showed less specificity. Although the three kits tested in this study are inadequate for routine testing in a high throughput laboratory, they can help to quickly identify the most infectious patients and screen their close contacts in an environment where molecular tests are not readily available.

Performance evaluation of a new Stago® automated haemostasis analyser: The STA R Max® 2.

INTRODUCTION: The STA R Max® 2 is a new coagulation analyser developed by Diagnostica Stago, able to perform clotting, chromogenic and immuno-turbidimetric tests. A pre-analytical module build into the cap-piercing needle performs the sample integrity verification (sample tube filling and measurement of haemolysis, icterus, lipaemia). The STA R Max® 2 analyser incorporates an accreditation program tools to assist technical validation of the analyser. We assessed the analytical performance of the STA R Max® 2. MATERIALS AND METHODS: The following tests were assessed: prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, factor V (FV), antithrombin (AT), D-dimers (DDI) and von Willebrand factor antigen. The assay precisions were assessed using fresh plasma samples or internal quality controls. An inter-analyser comparison was performed with a STA-R Evolution® analyser or, for the FV, with a BCS® XP System. Haemolysis and icterus detection were also verified. RESULTS: For the intra-assay precision, the coefficients of variation (CV%) were all less than 5% and for DDI, the standard deviation (SD) was less than 0.1. For the inter-assay study, all CV% were less than 5%, with the exception of FV and AT (FV: 6.68% and 5.27%; AT: 7% and 12.14% for normal and pathological values, respectively). SD was less than 0.1 for DDI. The inter-analyser comparison demonstrated good results. Haemolysis and icterus were detected correctly for all our assessed samples. CONCLUSION: According to our methods validation's recommendations, the results demonstrated a good technical and analytical performance of the STA R Max® 2 analysers for the tests assessed.

[Large granular lymphocytic leukemia CD3-CD56-: a challenge for the biologist and the physician]. / Leucémie à grands lymphocytes granuleux CD3-CD56- : un défi pour le biologiste et le clinicien.

Large granular lymphocyte leukemia (LGL) are chronic lymphoproliferative disorders classified into three main groups: T-cell LGL leukemia (T-LGL), aggressive NK-cell leukemia and chronic lymphoproliferative disorder of NK cells (NK-LGL). Patients with LGL leukemia exhibit chronic (>3 months) and moderate (<1G/L) to substantial monoclonal expansion of large granular lymphocytes in the peripheral blood. Cytologically, large granular lymphocytes are medium to large cells which are further characterized by an eccentric nucleus and a slightly basophilic cytoplasm containing azurophilic granules. Typically, T-LGL (CD3-and mostly CD8+) can be differentiated from NK-LGL disorders (CD3-) based on flow cytometry analysis. However, distinction between LGL leukemias can be tricky. We report here the case of a 47-year-old woman patient diagnosed with large granular lymphocytes leukemia associated with atypical CD3-CD56- immunophenotyping and clinical manifestations of pseudo-Felty's syndrome.