Electronic Journal of the International Federation of Clinical Chemistry and Laboratory Medicine最新文献

Multiple myeloma (MM) is a neoplasm characterized by malignant proliferation of plasma cells that produce excessive quantities of a single type of immunoglobulin (Ig) called as monoclonal immunoglobulin or M-protein or paraprotein. M-protein produced can be either an intact antibody with both heavy and light-chain components or only light chains or rarely only heavy chains. Presence of M-protein in serum protein electrophoresis (PEP) is useful in the diagnosis, prognosis, and treatment of MM and other plasma cell dyscrasias. These M-proteins are identified commonly in beta and gamma regions and very rarely in alpha 2 region, appearing as a narrow band in agarose electrophoresis or as a sharp symmetric spike (M-spike) or peak in capillary zone electrophoresis. Here, we present an unusual case of monoclonal light chains producing two M- spikes in the alpha 2 globulin region in capillary zone electrophoresis.

Background: Carbohydrate Antigen 125 (CA125) is the most widely used biomarker in ovarian cancer screening. In patients with heart failure (HF), increased levels of CA125 have been observed and related to disease severity. Our objective was to determine the association of CA125 levels with two biomarkers of adverse remodeling in HF patients with reduced ejection fraction (HFrEF).

Methods: CA125 circulating levels were determined with an electrochemiluminscent immunoassay. Concentrations of B-type natriuretic peptide (BNP), N-terminal proBNP (Nt-proBNP), Galectin-3 and Fibroblast Growth Factor 23 (FGF23) were also measured by immunoassays.

Results: CA125 levels were increased in HFrEF, were associated to disease severity according NYHA classes. Median CA125 concentration was also significantly related to cardiovascular mortality. CA125 concentrations were positively and significantly associated to Galectin-3 and FGF23.

Conclusions: Concentrations of CA125 are increased in patients with HFrEF, associated to disease severity and adverse cardiovascular outcomes. CA125 levels are also correlated to Galectin-3 and FGF-23, two biomarkers related to fibrosis and cardiovascular remodeling.

The strict monitoring of examinations and evaluation of newer methods or instruments is a daily routine in clinical laboratory. The automated analyzers accumulate an enormous amount of data from patients' examinations and quality control procedures. This laboratory data is meaningless if it does not generate the information that we can extend to the population of our interest. In an analytical work, the most important operation is the comparison of data, to quantify accuracy and precision and to generate meaningful explanation for clinician and patients queries. Most of the information needed in the regular laboratory work can be obtained with the use of simple convenient statistical tools. This article describes the basics of laboratory statistics, the knowledge of which answers about the application of quality control in laboratory, accuracy and diagnostic power of our examinations, variability in reports, comparison of different methods and derivation of a biological reference interval for an analyte.

Vitamin B12 deficiency may cause neurological and hematological alterations. Its assessment should be easy considering that the access to its measurement is available in majority of the clinical laboratories. The presence of technical interference when measuring vitamin B12 can lead to an erroneous or a more difficult diagnosis of conditions as pernicious anemia. We report a case in which an interference in the evaluation of vitamin B12 concentration led to the realization of invasive tests and almost a misdiagnosis of a patient who actually had pernicious anemia. Professionals need to be aware of these interferences when we assess outcomes.

Introduction: Pulmonary alveolar proteinosis (PAP) is a disease characterized by the accumulation of lipoprotein-aceous material in the alveoli as a consequence of deficient processing of pulmonary surfactant. It is classified into primary, secondary, and congenital forms. Primary PAP (autoimmune origin) is characterized by the presence of antibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF), while secondary PAP is due to multiple causes such as exposure to certain environmental substances. We present a case of a patient with probable mixed PAP, primary and secondary, due to exposure at the patient's workplace.

Case presentation: A 35-year-old male patient attends the outpatient clinic of pulmonology due to symptoms of exertional dyspnea for one year. Pulmonary function tests are performed, and the chest X-ray reveals diffuse bilateral lung involvement with a ground-glass pattern. Incision and excision lung biopsy show findings compatible with predominant PAP in the left lower lobe (LLL). Additionally, a positive anti-GM-CSF antibody result is obtained. The patient is treated with bronchoalveolar lavage (BAL) and nebulized sargramostim. The patient shows satisfactory progress.

Discussion: The clinical, analytical, radiological, and histological manifestations were compatible with the diagnosis of autoimmune PAP, and there was suspicion of secondary PAP due to exposure to rock wool. The role of the laboratory, in this case, was essential for the diagnostic confirmation of PAP by performing the determination of anti-GM-CSF antibodies.

Objective: The performance of the platelet times neutrophil-to-lymphocyte ratio, namely systemic immune inflammation (SII) index, is an inflammatory index that shows controversial results as a predicting indicator of the poor outcomes of COVID-19. In this study, this indicator was analyzed in 3280 patients admitted at a COVID-19 reference hospital in Quito (Ecuador).

Methods: The Receiver Operating Characteristic (ROC) curve analysis was conducted on SII values upon admission to identify the most appropriate cut-off values in discriminating COVID-19 severity and in-hospital mortality.

Results: SII was higher in both severe patients and in those who finally died (cut-off points of 757.3 and 808.5 respectively). However, the AUC-ROC analysis (0.60-0.67) demonstrated a modest discriminating performance of SII for COVID-19 severity (61.2% sensitivity and 61.5% specificity), which sensibly improved for COVID-19 mortality (AUC-ROC: 0.73-0.83, sensitivity: 80.6% specificity; 63.6%).

Conclusion: SII index may well be an indicator of inflammatory conditions secondary to COVID-19 leading to a higher mortality, rather than a predictor of severe forms of the disease.

Background: This article presents a critical literature review and meta-analysis of diagnostic performance of Quidel Sofia SARS antigen Fluorescent Immunoassay (FIA), a rapid diagnostic antigen test (RDT-Ag) adapted for automatic reading with portable instruments, thus potentially combining the advantages of point-of-care testing with those of a laboratory-based immunoassay.

Methods: We conducted an electronic search in PubMed and Scopus with the keywords "Quidel" OR "SOFIA" AND "Antigen" AND "SARS-CoV-2" OR "COVID-19" up to March 24, 2023, for identifying articles containing data on accuracy of Quidel Sofia SARS antigen FIA for diagnosing acute SARS-CoV-2 infections. We selected those where test accuracy was compared to that of a reference SARS-CoV-2 molecular assay, and with sufficient information for constructing a 2×2 table.

Results: A total number of 18 articles (48165 samples; 9.8% positive at molecular testing) were included in this meta-analysis, averaging 24 sample cohorts. The diagnostic accuracy (summary area under the curve), sensitivity and specificity were 0.980, 0.76 and 1.00 in all samples, 0.981, 0.81 and 0.99 in samples collected from symptomatic patients, 0.931, 0.55 and 1.00 in those taken from asymptomatic patients, and 0.960, 0.77 and 0.99 in samples from mixed cohorts of patients, respectively. Minor and clinically negligible differences of accuracy could be found by comparing test results in nasal and nasopharyngeal swabs.

Conclusion: Quidel Sofia SARS Ag FIA meets the minimum performance criteria of accuracy for SARS-CoV-2 antigenic testing, thus combining satisfactory diagnostic performance with the advantages of being potentially used as a portable device.

The method we respond to pandemics is still inadequate for dealing with the point of care testing (POCT) requirements of the next large epidemic. The proposed framework highlights the importance of having defined policies and procedures in place for non-integrated POCT to protect patient safety. In the absence of a pathology laboratory, this paradigm may help in the supply of diagnostic services to low-resource centers. A review of the literature was used to construct this POCT framework for non-integrated and/or unconnected devices. It also sought professional advice from the Chemical Pathology faculty, quality assurance laboratory experts and international POCT experts from the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Our concept presents a comprehensive integrated and networked approach to POCT with direct and indirect clinical laboratory supervision, particularly for outpatient and inpatient care in low-resource health care settings.

Background: Breath analyser tests are used worldwide to obtain proof of alcohol intoxication and often used in the conviction of traffic violators. These tests are conducted to quickly and painlessly determine the existing concentration of alcohol in arterial blood by measuring the amount of ethanol in exhaled breath, which can be identified with an electrochemical sensor.At present, the calibration and maintenance of analysers used for these tests are typically performed regularly but lack quality control. Consequently, test results may not be accurate because of calibration deterioration.The aim of this study was to develop and evaluate the uncertainty of control materials used in breath-alcohol testing at the Bangkok Metropolitan Police Station.

Material and methods: Ethyl alcohol (99.99%; Certified Reference Material grade) diluted at three different concentrations was kept under design conditions. The concentrations were 28, 67, and 134 mg/dL, determined by performing headspace gas chromatography, and the uncertainty was set as ±1.3925, ±2.8736, and ±1.8231 mg/dL (±4.97%, ±4.29%, and ±2.72% for the concentrations, respectively), as per ISO Guide 35:2017.

Results: The total error percentages of the developed control materials were 4.97%, 4.29%, and 2.72% for concentrations of 28, 67, and 134 mg/dL, respectively. Each concentration of the materials was tested by using measurements from 70 breath-alcohol analysers belonging to the Bangkok Metropolitan Police Station.

Conclusion: These control materials are applicable to quality assurance and standards tests and may help to ensure the accuracy of breath-alcohol testing in the future.