An evaluation of the performance of the Point of Care Test iCHROMA™ AFP method: Precision and accuracy

The estimation of serum alpha-fetoprotein (AFP) is useful in the diagnosis and monitoring of primary hepatocellular carcinoma, hepatoblastoma, non-seminomatous testicular germ cell tumours and other germ cell tumours. The iCHROMA™ AFP is a lateral flow chromatography, fluorescence immunoassay (FIA) for the quantitative determination of AFP in serum or plasma. In this study, the Boditech iCHROMA™ AFP assay had a very good precision of 9.8%. It showed a very good correlation with the following 12 methods: Abbott Architect (r2 = 0.9705), BioMerieux VIDAS (r2 = 0.9717), Roche Cobas 6000/8000 (r2 = 0.9738), Siemens Centaur XP/XPT/Classic (r2 = 0.9654), Siemens/DPC/Immulite 2000/2500 (r2 = 0.9673), Siemens/DPC/Immulite 1000 (r2 = 0.9670), Beckman Dxl 600/800 (r2 = 0.9676), Roche Elecsys (r2 = 0.9683), Roche Cobas 4000/e411 (r2 = 0.9688), Roche Modular E170 (r2 = 0.9692), SNIBE Maglumi (r2 = 0.9457) and Ortho Vitros 3600/5600/ECi (r2 = 0.9714). In summary, the iCHROMA™ AFP, a rapid point of care test method, has a within-run precision value of less than 10% and excellent correlations with traditional laboratory methods. There is a consistent overestimation with the iCHROMA™ method, which must be taken into consideration when setting a reference range.

Hypoglycemia screening of asymptomatic newborns on the 2nd day of life

BACKGROUND: Neonatal hypoglycemia management in the first 48 hours is guided by the American Academy of Pediatrics (AAP) and Pediatric Endocrine Society (PES) recommendations. Our aim was to determine the incidence of hypoglycemia via point of care test (POCT) on the 2nd day of life (DOL) among healthy, asymptomatic neonates regardless of risk factors. METHODS: In this prospective observational study, preprandial point of care glucose concentration was measured on the 2nd DOL in 150 healthy, asymptomatic neonates in the newborn nursery. We used 50 mg/dl (2.8 mmol/L) as the hypoglycemia threshold based on PES recommendations. RESULTS: The incidence of hypoglycemia on the second DOL was 10% among asymptomatic neonates (no risk factors = 8% ; late preterm birth (LPT) + small for gestational age (SGA) = 16% ; large for gestational age (LGA) + infant of diabetic mother (IDM) = 6%). SGA + LPT neonates accounted for the majority of the hypoglycemic cases (53.3%) and exhibited a trend towards the lowest glucose concentration (p = 0.09). CONCLUSION: The incidence of hypoglycemia on DOL 2 among asymptomatic neonates is high and of unclear significance in the absence of dedicated neurodevelopmental follow-up.

Prevalence and Trajectory of COVID-19-Associated Hypercoagulability Using Serial Thromboelastography in a South African Population

Introduction. The coagulation abnormalities resulting from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been attributed to inflammation and subsequent cytokine storm. Thromboelastography (TEG) is a point-of-care test used to assess clot formation and degradation in whole blood and is an indicator of the overall real-time coagulopathic state of the patient. Methods. A single-centre, prospective, observational cohort study was conducted in South Africa, analysing the coagulation patterns of 41 patients with hypoxia related to SARS-CoV-2 using serial thromboelastography (TEG) on admission, after 48 hours, and at resolution of hypoxia/day 10. Results: Two-thirds (n = 26) were women. The median age was 61 (IQR 50–67), and the majority (88%) were Black patients. Almost half (22) of the patients were critically ill and ventilated, with median SOFA and SAPS2 scores of 3 and 22 (IQR2-4 and 18–30), respectively. The prevalence of hypercoagulability was 0.54 (95% CI 0.46–0.62), whilst 29/41 (0.71, CI 0.64–0.78)) met the definition of hypofibrinolysis. Differences between the hypercoagulable (HC) and non-hypercoagulable groups remained apparent at 48 hours after anticoagulation. At this time point, the K time was significantly lower ( p ˂ 0,01), and the α-angle ( p ˂ 0,01) and maximum amplitude (MA) ( p ˂ 0,01) were significantly higher in the HC cohort. At resolution of hypoxia, or day 10, only MA was significantly higher in the hypercoagulable group compared to the non-hypercoagulable group (p = 0.01). The initial impairment in fibrinolysis (Ly30), α angle, and MA were significantly associated with mortality, with p values of 0.006, 0.031, and 0.04, respectively. Conclusions. In this South African population, hypercoagulability was a highly prevalent phenomenon in COVID-19 disease. It was typified by hypofibrinolysis and a persistently elevated MA, despite anticoagulation therapy.

A Patient Self-Made Point-of-Care Fecal Test Improves Diagnostic Accuracy Compared with Fecal Calprotectin Alone in Inflammatory Bowel Disease Patients

Background: Monitoring inflammatory bowel disease patients may be challenging. Fecal calprotectin is one of the most performed tests. Other fecal biomarkers are less used in clinical practice. Rapid fecal tests that could be performed by patients may be a useful strategy to closely monitor disease activity. Methods: We performed a prospective observational study including consecutive inflammatory bowel disease patients referred for colonoscopy in a single center. Certest FOB + Transferrin + Calprotectin + Lactoferrin® (Certest Biotec S.L, Zaragoza, Spain), a one-step point-of-care test which simultaneously detects these four biomarkers was performed. Endoscopic inflammatory activity was defined using the Mayo score (≥1) in ulcerative colitis, SES-CD (>3) and Rutgeerts scores (≥1) for Crohn’s disease. Results: Out of a total of 106 patients (56.5% female, mean age 51 years), 54 (50.9%) were diagnosed with ulcerative colitis and 52 (49.1%) with Crohn’s disease. Endoscopic activity was detected in 42 patients (39.0%). Fecal calprotectin provided the best sensitivity (97.6%), with limited specificity (34.4%). Compared to calprotectin, the other 3 fecal biomarkers showed better specificity (87.5–92.1%) and lower sensitivity (45.2–59.5%). Patients with a negative result in all biomarkers (19/106—17.9%) had 100% (CI 95% 97.4–100) negative predictive value, while patients with the 4 biomarkers positive (13/106—12.3%) had 100% (CI 95% 96.1–100) positive predictive value of endoscopic inflammatory activity. AUROC of this 4 biomarker point-of-care test was 0.845 (95% CI 0.771–0.920), significantly higher than the AUROCs of any of the 4 biomarkers. Conclusions: This test may be a useful strategy to monitor inflammatory activity in clinical practice by excluding or prioritizing patients in need of a colonoscopy.

A rapid and affordable point of care test for antibodies against SARS-CoV-2 based on hemagglutination and artificial intelligence interpretation

Diagnostic tests that detect antibodies (AB) against SARS-CoV-2 for evaluation of seroprevalence and guidance of health care measures are important tools for managing the COVID-19 pandemic. Current tests have certain limitations with regard to turnaround time, costs and availability, particularly in point-of-care (POC) settings. We established a hemagglutination-based AB test that is based on bi-specific proteins which contain a dromedary-derived antibody (nanobody) binding red blood cells (RBD) and a SARS-CoV-2-derived antigen, such as the receptor-binding domain of the Spike protein (Spike-RBD). While the nanobody mediates swift binding to RBC, the antigen moiety directs instantaneous, visually apparent hemagglutination in the presence of SARS-CoV-2-specific AB generated in COVID-19 patients or vaccinated individuals. Method comparison studies with assays cleared by emergency use authorization demonstrate high specificity and sensitivity. To further increase objectivity of test interpretation, we developed an image analysis tool based on digital image acquisition (via a cell phone) and a machine learning algorithm based on defined sample-training and -validation datasets. Preliminary data, including a small clinical study, provides proof of principle for test performance in a POC setting. Together, the data support the interpretation that this AB test format, which we refer to as ‘NanoSpot.ai’, is suitable for POC testing, can be manufactured at very low costs and, based on its generic mode of action, can likely be adapted to a variety of other pathogens.

Dual electrochemical sensing of spiked virus and SARS-CoV-2 using natural bed-receptor (MV-gal1)

It has been necessary to use methods that can detect the specificity of a virus during virus screening. In this study, we use a dual platform to identify any spiked virus and specific SARS-CoV-2 antigen, sequentially. We introduce a natural bed-receptor surface as Microparticle Vesicle-Galactins1 (MV-gal1) with the ability of glycan binding to screen every spiked virus. MV are the native vesicles which may have the gal-1 receptor. Gal-1 is the one of lectin receptor which can bind to glycan. After dropping the MV-gal1 on the SCPE/GNP, the sensor is turned on due to the increased electrochemical exchange with [Fe(CN)6]−3/−4 probe. Dropping the viral particles of SARS-CoV-2 cause to turn off the sensor with covering the sugar bond (early screening). Then, with the addition of Au/Antibody-SARS-CoV-2 on the MV-gal1@SARS-CoV-2 Antigen, the sensor is turned on again due to the electrochemical amplifier of AuNP (specific detection).For the first time, our sensor has the capacity of screening of any spike virus, and the specific detection of COVID-19 (LOD: 4.57 × 102 copies/mL) by using the natural bed-receptor and a specific antibody in the point of care test.

Assessment of the Field Utility of a Rapid Point-of-Care Test for SARS-CoV-2 Antibodies in a Household Cohort

Point-of-care (POC) tests to detect SARS-CoV-2 antibodies offer quick assessment of serostatus after natural infection or vaccination. We compared the field performance of the BioMedomics COVID-19 IgM/IgG Rapid Antibody Test against an ELISA in 303 participants enrolled in a SARS-CoV-2 household cohort study. The rapid antibody test was easily implemented with consistent interpretation across 14 users in a variety of field settings. Compared with ELISA, detection of seroconversion lagged by 5 to 10 days. However, it retained a sensitivity of 90% (160/177, 95% confidence interval [CI] 85–94%) and specificity of 100% (43/43, 95% CI 92–100%) for those tested 3 to 5 weeks after symptom onset. Sensitivity was diminished among those with asymptomatic infection (74% [14/19], 95% CI 49–91%) and early in infection (45% [29/64], 95% CI 33–58%). When used appropriately, rapid antibody tests offer a convenient way to detect symptomatic infections during convalescence.