Annales de biologie clinique最新文献

Detection of schistocytes is an important first step in the differential diagnosis of thrombotic microangiopathy. It is however labor intensive and prone to subjectivity. To improve and standardize the detection and quantification of schistocytes, we studied its automated analysis by digital microscopy DM1200 (CellaVision®) on 63 positive and 102 negative smears obtained from SP-50 (Sysmex®). Easy to use and very useful for staff training, it showed a lower between-observer coefficient of variation than usually described for manual counting (25% vs. 50%). Very sensitive (100%) in pre-classification, the detection of schistocytes was highly sensitive (98.4%) and specific (96.8%) after reclassification (AUCROC = 0.9929), showing a good correlation with manual microscopy. TAT was comparable to manual counting. For positive smears, the percentage of schistocytes was similar between pre- and post-classification. However, 29.6% of pre-classified schistocytes were removed and 21.8% were added. For negative smears a significative overestimation of schistocytes (292%) was observed. Except poikilocytosis, on negative smears, the most common error of the software (24.9%) was due to platelets classified in schistocytes. Were also observed for example erroneous divisions of the image (3.2%) or artifactual schistocytes resulting from scratches in the smear (2.6%). Another limit is the high number of red blood cells not analyzed (46.8% for high-density smears), which might false the schistocytes percentage. To conclude, CellaVision® technology showed many benefits, but also limits that the operator needs to know.

Tuberculosis remains one of the leading causes of mortality worldwide. Microscopy and culture still the references of Tuberculosis diagnosis. Microscopy has a low sensitivity, specificity and culture is time consuming. For this reason, rapid and reliable diagnosis of the disease is required. We describe a retrospective comparison study of tuberculosis diagnosis by PCR IS6110 directly from blood samples of patients with suspected Tuberculosis with Acid-Fast-Bacilli and culture. From 80 patients enrolled, culture results were positive for 25, acid fast bacilli were positive for 15 and blood PCR were positive for 45. Comparing blood PCR result with acid fast bacilli, the sensitivity and specificity were respectively 35% and 87.5% (PPV = 9%, PNV = 21.1%) for PTB. The specificity of blood PCR was 100% (PNV = 72.73%), for EPTB. In comparison with culture blood PCR have a high sensitivity and specificity better than with the acid fast, they were respectively 57.89%, 100% for PTB and 50%, 100% for EPTB. This study is the first established in Tunisia and in Africa aiming to diagnose TB from blood. B-PCR results has shown a high correlation with culture that illustrates the usefulness of B-PCR as a rapid and early diagnostic, combined with others serological results B-PCR can be a solid, rapid and efficient TB diagnostic tools.

Since 1960, Williams and Trotman had dreamed of automating all technical manipulations in bacteriology. However, this switch to automation took several decades to realize. The high cost of instruments and the attachment to classical bacteriology were the main obstacles. Automation began with blood culture incubators, and paved the way for automation in other areas of bacteriology, notably cytology, culture, identification and antibiotic susceptibility testing. Medical laboratories have been quick to recognize the efficiency of these systems and their many advantages. The reduction in turnaround times for bacteriological examinations is one of the changes that have revolutionized laboratory practice. In addition, sensitivity, safety, traceability and quality are more assured with automation. The second revolution is the integration of artificial intelligence into the processing and interpretation of bacteriological analyses. We are currently witnessing the total automation of laboratories and a reduction in human intervention. In this article, we have attempted to address all aspects of bacteriology affected by automation, and the impact of this change on current laboratory practice and quality of healthcare.

Hemoglobin (Hb) measurement is a fundamental biological test, especially in emergency situations where rapid medical decisions are required. Portable hemoglobinometers, such as HemoCue®, provide a delocalized solution for capillary whole blood. The SFBC's POCT News and Issues working group designed and conducted two national surveys to assess the use and management of these devices, both on the clinical and biological side, with 306 and 160 responses respectively. The surveys revealed little effective or desired network connection, heterogeneity in management and training, and only 7% of sites fully accredited, although a quality approach is being structured in 45% of cases. Nearly 80% of biologists suggest reclassification as a rapid diagnostic test, citing difficult standards management and inadequate human resources. However, its daily use goes beyond the simple diagnostic orientation of anemia; blood transfusion decisions without laboratory verification are made by 53% of physicians, while 18% of users are unaware of minimum maintenance procedures, underscoring the need for a rigorous quality approach. The SFBC working group proposes a list of tips to help medical biologists implement this approach, a guarantee of reliable results, in the context of medical decision-making. The selected points are fleet mapping, relations with biomedical and clinical departments, quality documents and minimum method verification, user management, QC management and traceability of results.

A new direction of research was established due to biofilms' infections caused by a mixture of fungal and bacterial species. Diagnosis of these infections becomes more difficult and high doses of drugs are used in treatment, especially in critically ill patients. The aim of the current study was to examine the effects of amphotericin B, in combination with imipenem or colistin against Candida albicans - Acinetobacter baumannii- Proteus mirabilis and Candida tropicalis - Acinetobacter baumannii -Proteus mirabilis polymicrobial biofilms. According to the microdilution method of the Clinical Laboratory Standards Institute (CLSI) published in documents M27-A3 (2008) and M07-A10 (2015) respectively, the susceptibility of the clinical isolates Candida yeasts to amphotericin B and Gram-negative bacteria to imipenem and colistin was determined. A Checkerboard assay was employed to evaluate the efficacy of drugs combinations. The 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyl tetrazolium bromide (MTT) reduction assay was used to quantify the biofilms. The combination amphotericin B/colistin and amphotericin B/imipenem did not produce obvious effects against the polymicrobial biofilms formed for 48 hours. Whereas colistin alone produced strong effects against Candida albicans-Acinetobacter baumannii and Candida albicans - Acinetobacter baumannii -Proteus mirabilis compared to Candida tropicalis - Acinetobacter baumannii and Candida tropicalis - Acinetobacter baumannii - Proteus mirabilis polymicrobial biofilms. For mixed Candida spp. bacterial biofilms, these results point to the difficulties in eradicating these biofilms, as well as in preventing their development.

Edoxaban is a direct oral anticoagulant available in Europe but not in France. Given the high tourist traffic in France, understanding the pharmacology of edoxaban and the availability of its laboratory testing seemed crucial in emergency situations. The aim of this work was to describe the methodology for measuring the anti-Xa activity of edoxaban, highlighting pre-analytical and analytical aspects, along with essential clinico-biological data for therapeutic guidance. The analysis was performed using the chromogenic method on the STAR-Max analyzer, with the STA®-Liquid ANTI-Xa kit (Diagnostica Stago®). Anti-Xa Edoxaban level measurement has a detection limit of 15 ng/mL, a quantification limit of 20 ng/mL and a linearity limit of 400 ng/mL. Repeatability, intermediate precision, accuracy, and measurement uncertainty studies were conducted to assess method performance, meeting quality requirements. The comparison between two STAR-Max® analyzers showed excellent results with linear regression and a low bias with good precision and no loss of dispersion regardless of edoxaban levels. In conclusion, although the measurement of edoxaban level may be rarely necessary in clinical practice, its implementation is straightforward. The availability of edoxaban in neighboring countries, underscores the importance of having its measurement available in hospital laboratories.