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

Background: Due to their wide application in the SARS-CoV-2 pandemic, we verified and compared three qualitative serological methods in order to select the most optimal that will best serve its purpose under laboratory conditions.

Methods: We assessed the diagnostic characteristics of two automated serological methods (Roche Elecsys^® Anti-SARS-CoV-2 and Abbott SARS-CoV-2 IgG) and a POCT test (Colloidal Gold Method SARS-CoV-2 IgM/IgG Antibody Assay Kit). In the process of verification, analytical precision was also assessed for the automated assays.

Results: Diagnostic characteristics were determined by measuring antibodies against SARS-CoV-2 in 91 RT-PCR-negative and 60 RT-PCR-positive samples. The POCT test gave the highest number of false positive cases (8.61%). Roche Elecsys^® Anti-SARS-CoV-2 gave only 2.65% false positivity and showed the highest diagnostic sensitivity of 98.33% (95% CI: 91.06-99.96), while Abbott SARS-CoV-2 IgG method showed 100.00% (95% CI: 96.03-100.00) diagnostic specificity and an almost perfect agreement with Roche Elecsys^® Anti-SARS-CoV-2. When assessing the precision of the automated methods, we observed some variability in the positive control samples, but the values did not affect clinical interpretation.

Conclusion: Both automated methods demonstrate superior diagnostic characteristics compared to the Colloidal Gold Method, and this POCT test is not considered as an appropriate choice for routine testing. The two automated methods showed low variability without altering the results and their interpretation.

Introduction: Laboratory medicine has an important role in the management of COVID-19. The aim of this study was to analyze routinely available blood parameters in intensive care unit COVID-19 patients and to evaluate their prognostic value.

Patients and methods: This is a retrospective, observational, single-center study including consecutive severe COVID-19 patients who were admitted into the intensive care unit of Ben Arous Regional Hospital in Tunisia from 28 September 2020 to 31 May 2021. The end point of the study was either hospital discharge or in-hospital death. We defined two groups based on the outcome: survivors (Group 1) and non-survivors (Group 2). Demographical, clinical, and laboratory data on admission were collected and compared between the two groups. Univariate and multivariate logistic regression analysis were performed to determine the predictive factors for COVID-19 disease mortality.

Results: A total of 150 patients were enrolled. Eighty patients (53.3%) died and 70 (46.7%) survived during the study period. Based on statistical analysis, median age, Simplified Acute Physiology Score (SAPS II) with the serum levels of urea, creatinine, total lactate dehydrogenase (LDH), creatine kinase, procalcitonin and hs-troponin I were significantly higher in non-survivors compared to survivors. On multivariate analysis, LDH activity ≥ 484 U/L (OR=17.979; 95%CI [1.119-2.040]; p = 0.09) and hs-troponin I ≥ 6.55 ng/L (OR=12.492; 95%CI [1.691-92.268]; p = 0.013) independently predicted COVID-19 related mortality.

Conclusion: Total LDH and hs-troponin I were independent predictors of death. However, further clinical investigations with even larger number of patients are needed for the evaluation of other laboratory biomarkers which could aid in assessing the prediction of mortality.

The Coronavirus Disease 2019 (COVID-19) pandemic is caused by the SARS-CoV-2 RNA virus. Nucleic acid amplification testing (NAAT) is the mainstay to confirm infection. A large number of reverse transcriptase polymerase chain reaction (RT-PCR) assays are currently available for qualitatively assessing SARS-CoV-2 infection. Although these assays show variation in cycle threshold values (Ct), advocacy for reporting Ct values (in addition to the qualitative result) is tabled to guide patient clinical management decisions. This article provides critical commentary on qualitative RT-PCR laboratory and clinical considerations for Ct value reporting. Factors contributing to Ct variation are discussed by considering relevant viral life-cycle factors, patient factors and the laboratory total testing processes that contribute to the Ct variation and mitigate against the reporting of Ct values by qualitative NAAT.

Background: Coronavirus Disease 2019 (COVID-19) patients can present with a wide array of symptoms. For laboratory investigation of these patients several biochemical tests are routinely requested. Here we wanted to evaluate the utility of procalcitonin (PCT), ferritin, D-dimer, interleukin 6 (IL-6) and total lactate dehydrogenase (LDH) activity in predicting severe COVID-19 infection.

Patients and methods: This study was undertaken at a tertiary care medical hospital in Tamil Nadu, India representing 183 COVID-19 RT-PCR positive patients, who were grouped based on their disease severity as mild (n=21), moderate (n=115) and severe (n=47) cohorts. All routine clinical chemistry analysis was performed as part of routine baseline assessment. Biomarkers of inflammation and infection were tested via the measurement of IL-6, PCT, ferritin, and D-dimer. Serum IL-6 concentration was estimated by ELISA, while total LDH activity was analyzed by kinetic colorimetric assay. Serum ferritin, PCT and D-dimer were measured by fluorescent immunoassay by sandwich immuno-detection method.

Results: Biomarkers were significantly different among subgroups, and the highest concentrations were found in those with intensive care unit (ICU) admission. Serum PCT showed the best power to predict the need for ICU treatment followed by D-dimer, IL-6 and total LDH. Based on the AUC-ROC analysis, mortality was most effectively indicated by D-dimer followed by PCT, LDH, IL-6 and ferritin.

Conclusion: Our study highlights the utility of some routinely available biochemical tests in the management of severe COVID-19. The higher baseline values of these biomarkers hint towards the probability of severe infection and a larger risk of death.

Background: In this serosurveillance study, we investigated the variation of total anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) antibodies in healthcare workers receiving primary BNT162b2 vaccination and homologous booster.

Methods: A total number of 524 subjects (median age, 46 years; 65.3% females), were studied. All received primary BNT162b2 vaccination (two doses) and homologous booster (one dose) >8 months after completing the primary cycle. Blood samples were collected before the first and second vaccine doses, at 1, 3 and 6 months after the second dose, as well as before and 1 month after booster. Total anti-SARS-CoV-2 neutralizing antibodies were assayed with Roche Elecsys Anti-SARS-CoV-2 S chemiluminescent immunoassay.

Results: Overall, 65.1% subjects were baseline (i.e., pre-vaccination) SARS-CoV-2 seronegative and always tested SARS-CoV-2 negative ("N/N"), 16.2% were baseline SARS-CoV-2 seronegative but tested SARS-CoV-2 positive after receiving the vaccine booster dose ("N/P"), whilst 18.7% were baseline SARS-CoV-2 seropositive and always tested SARS-CoV-2 negative afterwards ("P/N"). All groups displayed a similar trend of total anti-SARS-CoV-2 S antibodies throughout the study period, though the P/N cohort exhibited higher values compared to the other two groups until receiving the booster, after which the levels become similar in all cohorts. Significant differences in total anti-SARS-CoV-2 S antibodies values were not found between N/N and N/P groups, neither 1 month after booster. The rate of subjects with protective antibodies values become 100% in all groups after booster.

Conclusions: Although baseline seropositivity is associated with more pronounced humoral immune response following primary vaccination compared to never infected subjects, SARS-CoV-2 infection after booster does not significantly foster antibody titers.

Background: Quantification of SARS-CoV-2 antigens by means of rapid, high-throughput and fully-automated techniques has been proposed as a feasible alternative to overcome the current shortage of resources for routine molecular diagnostics. To this end, we provide here a systematic review of diagnostic accuracy of DiaSorin Liaison SARS-CoV-2 antigen immunoassay.

Methods: An electronic search was conduced in Medline and Scopus, with no language or date restrictions (up to January 20, 2022), for identifying all published studies articles in which the diagnostic performance of the DiaSorin Liaison SARS-CoV-2 antigen immunoassay was compared with molecular diagnostic techniques.

Results: The electronic search identified a final number of 11 studies, totalling 4449 oro- and naso-pharyngeal specimens. The pooled diagnostic sensitivity, specificity and area under the curve (AUC) of the Liaison SARS-CoV-2 antigen immunoassay in all samples were 0.51 (95%CI, 0.49-0.54), 1.00 (95%CI, 1.00-1.00) and 0.994 (95%CI, 0.990-0.998), respectively, whilst the overall concordance with molecular diagnostics was 82.1%. The pooled diagnostic sensitivity, specificity and AUC of the Liaison SARS-CoV-2 antigen immunoassay in specimens with high viral load (i.e., cycle threshold values <25-30) were 0.79 (95%CI, 0.75-0.82), 1.00 (95%CI, 0.99-1.00) and 0.911 (95%CI, 0.879-0.943), respectively, whilst the overall concordance with molecular diagnostics in such samples increased to 94.2%.

Conclusion: The results of this systematic literature review suggest that there is sufficient accuracy of the DiaSorin Liaison SARS-CoV-2 antigen immunoassay in samples with high viral loads that would enable its reliable usage for identifying superspreaders, who are responsible for the vast majority of transmission events.

Objective: Pediatric laboratory medicine is a unique practice serving a vulnerable group of patients including highly specialized testing aiming to detect and treat inherited conditions early to avoid adverse outcomes. Data on the actual impact of COVID-19 pandemic on this speciality is lacking.

Methods: A survey was conducted by the IFCC Committee on Emerging Technologies in Pediatric Laboratory Medicine in partnership with the Society for the Study of Inborn Errors of Metabolism and International Society for Neonatal Screening, to assess the impact on the clinical service provision during the initial wave (January to July 2020) of the COVID-19 pandemic and to gather experiences learned in order to improve laboratory preparedness for future outbreaks.

Results: 217 survey responses were received from 69 regions. Sixty-three laboratories (29%) reported a restriction or suspension of service for a median period of four months. The common tests/ services suspended were new-born screening program, body fluids and sweat testing. The reasons for the suspension were related to bio-safety risks of COVID-19 transmission, manpower constraints and supplies disruption. A minority (9-10%) of laboratories did observe delayed/missed diagnoses or a more severe presentation of a clinical disorder. The critical operational decisions that helped manage the initial wave of COVID-19 included modifying work shift patterns, split-teams arrangement, use of personal protection equipment and social distancing.

Conclusion: The provision and delivery of pediatric laboratories services were affected during the initial wave of the COVID-19 pandemic. Manpower preparedness for future potential disruptions to pediatric laboratory services is a key finding and recommendation from this survey.

Patients suffering from malignant diseases have a high risk of developing severe or critical forms of COVID-19 (Coronavirus Disease 2019). Chronic lymphocytic leukaemia (CLL) is characterized by dysregulated adaptive and innate immune responses, because both T and B cells, the function of phagocytes and the activity of the complement system may be affected. Severe SARS-CoV-2 infection also influences the immunological functions mainly via causing the depletion of CD4+ and CD8+ T cells. We present the cases of two patients, whose de novo CLL were observed during severe COVID-19 pneumonia. A 43-year-old man with IDDM (Insulin dependent diabetes mellitus) was sent to hospital in February 2021. He had a bilateral severe COVID-19 pneumonia. There was a suspected sign of malignancy on a thoracic vertebra in his chest CT, and haematological consultation was requested. In parallel, a 53-year-old man was hospitalized in March of 2021 because of severe COVID-19 pneumonia. CLL was suspected based on his haematology test results (WBC: 123 G/L, lymphocytes: 91%, haemoglobin: 107 g/L). Flow cytometric analysis revealed CLL in both cases. Based on the result of the molecular genetic tests, the first patient had a good prognosis in Rai 0 stage, while the other patient suffered from Rai I stage with a worse prognosis. Both patients recovered from bilateral COVID-19 pneumonia without the need for intensive care unit treatment. The follow-up of these CLL patients that manifested during symptomatic COVID-19 disease further enriched our knowledge on such clinical conditions where the immune system is dysfunctional due to different simultaneous causes.