Analytical and clinical evaluations of SNIBE Maglumi chemiluminescent immunoassay for the detection of SARS-CoV-2 antigen in salivary samples.

OBJECTIVES: In this study, we describe the analytical and clinical performances of the SNIBE Maglumi SARS-CoV-2 antigen fully-automated chemiluminescent immunoassay (MAG-CLIA) on salivary samples. METHODS: Limit of detection (LOD), linearity and precision were tested for values close to or below the declared LOD. Clinical performance of MAG-CLIA was evaluated on leftover salivary samples from the healthcare workers (HCW) surveillance program, at the University-Hospital of Padova. Salivary samples were analyzed by Lumipulse G SARS-CoV-2 Ag, and in case where the values exceeded 0.41 ng/L, further testing was conducted using TaqPathTM COVID-19 RT-PCR (Applied Biosystems, Thermo Fisher Scientific). RESULTS: The estimated MAG-CLIA LOD was 3 ng/L, with repeatability of 7.5 %. Good linearity was demonstrated by diluting two samples at 52.7 ng/L and 211.4 ng/L. Of the 228 HCW samples, 59/228 (25.9 %) were positive, 169/228 (74.1 %) were negative. MAG-CLIA SARS-CoV-2 sAg median level (and interquartile range [IQR]) was 5.03 ng/L (<0.001-35.8 ng/L) for positive and <0.001 ng/L (<0.001 ng/L) for negative samples. MAG-CLIA AUC was 0.795 (95 % CI: 0.720-0.871). Using the best cut-off, 3.5 ng/L, sensitivity and specificity were 57.1 % (95 % CI: 42.2-71.2 %) and 97.0 % (95 % CI: 93.2-99.0 %), respectively. The agreement with the molecular assay was 88.1 % (Cohen's kappa 0.606 [SE=0.066, p<0.001]). CONCLUSIONS: The analytical performances of MAG-CLIA are satisfactory, also when values below LOD were tested. In saliva samples, although specificity was elevated, clinical performance was not comparable with that on nasopharyngeal swabs (NPS).

SARS-CoV-2 specific T-cell humoral response assessment after COVID-19 vaccination using a rapid direct real-time PCR amplification.

OBJECTIVES: The SARS-CoV-2 immune response is mediated by both humoral and cellular immunity. In this study, SARS-CoV-2 specific cellular immunity was tested by a novel direct real-time PCR (dRT-PCR) assay, targeting mRNA of CXCL10, and compared with respect to an ELISA measuring interferon gamma (IFN-γ) release. METHODS: Whole blood (Li-He) and serum samples were collected from 92 healthcare workers (HCW), with three doses of homologous (Pfizer/BioNTech, n=74) or heterologous (Pfizer/BioNTech and Vaxzevria or Moderna, n=18) vaccinations. Li-He samples were incubated with SCV2 PANEL-1-T-ACTIVATION (Hyris srl, Lodi, Italy), or CoV-2 IGRA TUBE ELISA (Euroimmune, Lubeck, Germany). CXCL10 mRNA expression was analyzed by bCube/bApp (Hyris), while IFN-γ was evaluated by quant-T-Cell SARS-CoV-2 ELISA (Euroimmune). Anti-SARS-CoV-2 S-RBD IgG levels were measured in sera using a CLIA assay (Snibe, Shenzen, China). RESULTS: Imprecision of dRT-PCR assay was found to be satisfactory, and the two methods for measuring T cell immunity to SARS-CoV-2 peptides agreed in 82/87 (94.2%) of results. At qualitative dRT-PCR analyses, 81 subjects (93.2%) resulted as reactive to SARS-CoV-2 peptides, 3 (3.4%) were borderline and 3 were negative (3.4%). At univariate and multivariate analyses of quantitative dRT-PCR mRNA of CXCL10 and IFN-γ release results showed no difference between HCW with previous infection, homologous/heterologous vaccination, or demographical features. Anti-SARS-CoV-2 S-RBD IgG was associated with the previous infection and the time between the last vaccination or positivity. CONCLUSIONS: Direct RT-PCR appeared accurate for determining the presence or absence of immunoreactivity of SARS-CoV-2 specific T cells, especially when rapid analyses are required, such as for organ transplantation.

Endothelial dysfunction and Mid-Regional proAdrenomedullin: What role in SARS-CoV-2 infected Patients?

BACKGROUND: Endothelial dysfunction, a major complication of SARS-CoV-2 infectionplaying a key-role in multi-organ damage, carries high risk of mortality. AIM: To investigate the potential role of Mid-Regional pro-Adrenomedullin (MR-proADM) in detecting endothelial damage with a view to stratifying the risk of adverse events (length of stay, death, admission in Intensive Care Unit) and/or disease resolution. MATERIALS AND METHODS: In 135 consecutive patients with SARS-CoV-2 infection, MR-proADM was measured in EDTA-K2 plasma samples using B.R.A.H.M.S. KRYPTOR® COMPACT Plus method (Thermo Fisher Scientific, Hennigsdorf, Germany) RESULTS: Patients were subdivided into three groups based on their MR-proADM value (nmol/L): 1 (n = 20, MR-proADM ≤ 0.55); 2 (n = 82, 0.55 < MR-proADM ≤ 1.50); 3 (n = 33, MR-proADM > 1.50). The higher the MR-proADM value, the greater the patients' age, the more frequent the occurrence of pneumonia, the requiring of more aggressive treatment, the longer the hospitalization and the more frequent a fatal event. Significant differences were found between the three groups for MR-proADM, White-blood cell count, Neutrophil count, D-dimer, C-reactive Protein, Procalcitonin and hs-Troponin I. At logistic regression,it was found that MR-proADM and Log10D-dimer were the most significant predictors of adverse events. CONCLUSION: The findings made in the present study highlight the relevance of MR-proADM values in providing clinically useful information, particularly for stratifying COVID-19 patients according to the risk of a more severe form of disease and to the development of adverse events.

Assessment of alcohol consumption in liver transplant candidates and recipients: the best combination of the tools available.

The detection of alcohol consumption in liver transplant candidates (LTCs) and liver transplant recipients (LTRs) is required to enable a proper assessment of transplant eligibility and early management of alcohol relapse, respectively. In this clinical setting, urinary ethyl glucuronide (uEtG), the Alcohol Use Disorders Identification Test for Alcohol Consumption (AUDIT-c), serum ethanol, urinary ethanol, carbohydrate-deficient transferrin (CDT), and other indirect markers of alcohol consumption were evaluated and compared prospectively in 121 LTCs and LTRs. Alcohol consumption was diagnosed when AUDIT-c results were positive or it was confirmed by a patient's history in response to abnormal results. Alcohol consumption was found in 30.6% of the patients. uEtG was found to be the strongest marker of alcohol consumption (odds ratio = 414.5, P < 0.001) and provided a more accurate prediction rate of alcohol consumption [area under receiving operating characteristic (ROC) curve = 0.94] than CDT (area under ROC curve = 0.63, P < 0.001) and AUDIT-c (area under ROC curve = 0.73, P < 0.001). The combination of uEtG and AUDIT-c showed higher accuracy in detecting alcohol consumption in comparison with the combination of CDT and AUDIT-c (area under ROC curve = 0.98 versus 0.80, P < 0.001). Furthermore, uEtG was the most useful marker for detecting alcohol consumption in patients with negative AUDIT-c results. In conclusion, the combination of AUDIT-c and uEtG improves the detection of alcohol consumption in LTCs and LTRs. Therefore, they should be used routinely for these patients.

Laboratory medicine and sports: between Scylla and Charybdis.

Laboratory medicine is complex and contributes to the diagnosis, therapeutic monitoring and follow-up of acquired and inherited human disorders. The regular practice of physical exercise provides important benefits in heath and disease and sports medicine is thereby receiving growing focus from almost each and every clinical discipline, including laboratory medicine. Sport-laboratory medicine is a relatively innovative branch of laboratory science, which can provide valuable contributions to the diagnosis and follow-up of athletic injuries, and which is acquiring a growing clinical significance to support biomechanics and identify novel genomics and "exercisenomics" patterns that can help identify specific athlete's tendency towards certain types of sport traumas and injuries. Laboratory medicine can also provide sport physicians and coaches with valuable clues about personal inclination towards a certain sport, health status, fitness and nutritional deficiencies of professional, elite and recreational athletes in order to enable a better and earlier prediction of sport injuries, overreaching and overtraining. Finally, the wide armamentarium of laboratory tests represents the milestone for identifying cheating athletes in the strenuous fight against doping in sports.

Autoantibodies against oxidized LDLs and atherosclerosis in type 2 diabetes.

OBJECTIVE: The aim of our study was to examine, in type 2 diabetic patients, the relationship between autoantibodies against oxidatively modified LDL (oxLDL Ab) and two indexes of atherosclerosis, intimal-medial thickness of the common carotid artery (CCA-IMT), which reflects early atherosclerosis, and the ankle-brachial index (ABI), which reflects advanced atherosclerosis. RESEARCH DESIGN AND METHODS: Thirty newly diagnosed type 2 diabetic patients, 30 type 2 diabetic patients with long duration of disease, and 56 control subjects were studied. To detect oxLDL Ab, the ImmunoLisa Anti-oxLDL Antibody ELISA was used. ABI was estimated at rest by strain-gauge plethysmography. Carotid B-mode imaging was performed on a high-resolution imaging system (ATL HDI 5000). RESULTS: In patients with long duration of disease, IgG oxLDL Ab were significantly higher and ABI significantly lower compared with the other two groups. We found a correlation between IgG oxLDL Ab and CCA-IMT in all diabetic patients. A significant inverse correlation between IgG oxLDL Ab and ABI only in patients with long duration of disease was seen, demonstrating a close relationship between these autoantibodies and advanced atherosclerosis. CONCLUSIONS: IgG OxLDL Ab may be markers of the advanced phase of the atherosclerotic process and the response of the immunological system to the oxLDL, which are present within atherosclerotic lesions.

Amphetamines and 3,4-methylendioxymetamphetamine (MDMA): evaluation of KIMS (kinetic interaction of microparticles in solution) assay at two cut-off levels.

Two screening methods for the assay of amphetamines and their derivatives have been applied to the same analytical instrument for their evaluation. In addition to an assay at a cut-off of 1000 microg/l, a new specific reagent was evaluated for an ultra-sensitive assay of amphetamines and 3,4-methylendioxymetamphetamine with a cut-off of 300 microg/l. The assay confirmation was performed using high-performance liquid chromatography and gas chromatography/ mass spectrometry techniques. The results were positive for both screening methods, confirming the efficacy of two simultaneous methods with different cut-off levels.