The relationship between serum astroglial and neuronal markers and AQP4 and MOG autoantibodies.

BACKGROUND: Certain demyelinating disorders, such as neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) exhibit serum autoantibodies against aquaporin-4 (αAQP4) and myelin oligodendrocyte glycoprotein (αMOG). The variability of the autoantibody presentation warrants further research into subtyping each case. METHODS: To elucidate the relationship between astroglial and neuronal protein concentrations in the peripheral circulation with occurrence of these autoantibodies, 86 serum samples were analyzed using immunoassays. The protein concentration of glial fibrillary acidic protein (GFAP), neurofilament light chain (NFL) and tau protein was measured in 3 groups of subcategories of suspected NMOSD: αAQP4 positive (n = 20), αMOG positive (n = 32) and αMOG/αAQP4 seronegative (n = 34). Kruskal-Wallis analysis, univariate predictor analysis, and multivariate logistic regression with ROC curves were performed. RESULTS: GFAP and NFL concentrations were significantly elevated in the αAQP4 positive group (p = 0.003; p = 0.042, respectively), and tau was elevated in the αMOG/αAQP4 seronegative group (p < 0.001). A logistic regression model to classify serostatus was able to separate αAQP4 seropositivity using GFAP + tau, and αMOG seropositivity using tau. The areas under the ROC curves (AUCs) were 0.77 and 0.72, respectively. Finally, a combined seropositivity versus negative status logistic regression model was generated, with AUC = 0.80. CONCLUSION: The 3 markers can univariately and multivariately classify with moderate accuracy the samples with seropositivity and seronegativity for αAQP4 and αMOG.

COVID-19 Recovery: Consistent Absence of Cerebrospinal Fluid Biomarker Abnormalities in Patients With Neurocognitive Post-COVID Complications.

BACKGROUND: To investigate evidence of residual viral infection, intrathecal immune activation, central nervous system (CNS) injury, and humoral responses in cerebrospinal fluid (CSF) and plasma in patients recovering from coronavirus disease 2019 (COVID-19), with or without neurocognitive post-COVID condition (PCC). METHODS: Thirty-one participants (25 with neurocognitive PCC) underwent clinical examination, lumbar puncture, and venipuncture ≥3 months after COVID-19 symptom onset. Healthy volunteers were included. CSF and plasma severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid and spike antigen (N-Ag, S-Ag), and CSF biomarkers of immune activation and neuronal injury were analyzed. RESULTS: SARS-CoV-2 N-Ag or S-Ag were undetectable in all samples and no participant had pleocytosis. We detected no significant differences in CSF and plasma cytokine concentrations, albumin ratio, IgG index, neopterin, ß2M, or in CSF biomarkers of neuronal injury and astrocytic damage. Furthermore, principal component analysis (PCA1) analysis did not indicate any significant differences between the study groups in the marker sets cytokines, neuronal markers, or anti-cytokine autoantibodies. CONCLUSIONS: We found no evidence of ongoing viral replication, immune activation, or CNS injury in plasma or CSF in patients with neurocognitive PCC compared with COVID-19 controls or healthy volunteers, suggesting that neurocognitive PCC is a consequence of events suffered during acute COVID-19 rather than persistent viral CNS infection or residual CNS inflammation.

The relationship between serum astroglial and neuronal markers and AQP4 and MOG autoantibodies.

Background: Certain demyelinating disorders, such as neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) exhibit serum autoantibodies against aquaporin-4 (αAQP4) and myelin oligodendrocyte glycoprotein (αMOG). The variability of the autoantibody presentation warrants further research into subtyping each case. Methods: To elucidate the relationship between astroglial and neuronal protein concentrations in the peripheral circulation with occurrence of these autoantibodies, 86 serum samples were analyzed using immunoassays. The protein concentration of glial fibrillary acidic protein (GFAP), neurofilament light chain (NFL) and tau protein was measured in 3 groups of subcategories of suspected NMOSD: αAQP4 positive (n = 20), αMOG positive (n = 32) and αMOG/αAQP4 seronegative (n = 34). Kruskal-Wallis analysis, univariate predictor analysis, and multivariate logistic regression with ROC curves were performed. Results: GFAP and NFL concentrations were significantly elevated in the αAQP4 positive group (p = 0.003; p = 0.042, respectively), and tau was elevated in the αMOG/αAQP4 seronegative group (p < 0.001). A logistic regression model to classify serostatus was able to separate αAQP4 seropositivity using GFAP + tau, and αMOG seropositivity using tau. The areas under the ROC curves (AUCs) were 0.77 and 0.72, respectively. Finally, a combined seropositivity versus negative status logistic regression model was generated, with AUC = 0.80. Conclusion: The 3 markers can univariately and multivariately classify with moderate accuracy the samples with seropositivity and seronegativity for αAQP4 and αMOG.

Efficacy and safety of degludec U100 versus glargine U300 for the early postoperative management of patients with type 2 diabetes mellitus undergoing coronary artery bypass graft surgery: A non-inferiority randomized trial.

AIMS: To compare the efficacy and safety of degludec U100 versus glargine U300 for the early postoperative management of patients with type 2 diabetes mellitus (T2D) undergoing coronary artery bypass graft (CABG) surgery. METHODS: A total of 239 patients were randomly assigned (1:1) to receive a basal-bolus regimen in the early postoperative period using degludec U100 (n = 122) or glargine U300 (n = 117) as basal and glulisine before meals. The primary outcome was mean differences between groups in their daily BG concentrations. The major safety outcome was the occurrence of hypoglycemia. RESULTS: There were no differences in mean daily BG concentrations (157 vs. 162 mg/dl), mean percentage of readings within target BG of 70-180 mg/dl (74% vs. 73%), daily basal insulin dose (19 vs. 21 units/day), length of stay (median [IQR]: 9 vs. 9 days), or hospital complications (21.3% vs. 21.4%) between treatment groups. There were no differences in the proportion of patients with BG <70 mg/dl (15.6% vs. 23.1%) or <54 mg/dl (1.6% vs. 4.3%) between degludec-100 and glargine-300 groups. CONCLUSIONS: Treatment with degludec U100 is as effective and safe as glargine U300 for the early postoperative hospital management of patients with T2D undergoing CABG.

Sensitive Serology Measurements in the Saliva of Individuals with COVID-19 Symptoms Using a Multiplexed Immunoassay.

BACKGROUND: There are numerous benefits to performing salivary serology measurements for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen for coronavirus disease 2019 (COVID-19). Here, we used a sensitive multiplex serology assay to quantitate salivary IgG against 4 SARS-CoV-2 antigens: nucleocapsid, receptor-binding domain, spike, and N-terminal domain. METHODS: We used single samples from 90 individuals with COVID-19 diagnosis collected at 0 to 42 days postsymptom onset (PSO) and from 15 uninfected control subjects. The infected individuals were segmented in 4 groups (0-7 days, 8-14 days, 15-21 days, and >21 days) based on days PSO, and values were compared to controls. RESULTS: Compared to controls, infected individuals showed higher levels of antibodies against all antigens starting from 8 days PSO. When applying cut-offs with at least 93.3% specificity at every time interval segment, nucleocapsid protein serology had the best sensitivity at 0 to 7 days PSO (60% sensitivity [35.75% to 80.18%], ROC area under the curve [AUC] = 0.73, P = 0.034). Receptor-binding domain serology had the best sensitivity at 8 to 14 days PSO (83.33% sensitivity [66.44%-92.66%], ROC AUC = 0.90, P < 0.0001), and all assays except for N-terminal domain had 92% sensitivity (75.03%-98.58%) at >14 days PSO. CONCLUSIONS: This study shows that our multiplexed immunoassay can distinguish infected from uninfected individuals and reliably (93.3% specificity) detect seroconversion (in 60% of infected individuals) as early as the first week PSO, using easy-to-collect saliva samples.

Patients with severe COVID-19 do not have elevated autoantibodies against common diagnostic autoantigens.

OBJECTIVES: Infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative pathogen of coronavirus disease 2019 (COVID-19) presents occasionally with an aberrant autoinflammatory response, including the presence of elevated circulating autoantibodies in some individuals. Whether the development of autoantibodies against self-antigens affects COVID-19 outcomes remains unclear. To better understand the prognostic role of autoantibodies in COVID-19, we quantified autoantibodies against 23 markers that are used for diagnosis of autoimmune disease. To this end, we used serum samples from patients with severe [intensive care unit (ICU)] and moderate (ward) COVID-19, across two to six consecutive time points, and compared autoantibody levels to uninfected healthy and ICU controls. METHODS: Acute and post-acute serum (from 1 to 26 ICU days) was collected from 18 ICU COVID-19-positive patients at three to six time points; 18 ICU COVID-19-negative patients (sampled on ICU day 1 and 3); 21 ward COVID-19-positive patients (sampled on hospital day 1 and 3); and from 59 healthy uninfected controls deriving from two cohorts. Levels of IgG autoantibodies against 23 autoantigens, commonly used for autoimmune disease diagnosis, were measured in serum samples using MSD® U-PLEX electrochemiluminescence technology (MSD division Meso Scale Discovery®), and results were compared between groups. RESULTS: There were no significant elevations of autoantibodies for any of the markers tested in patients with severe COVID-19. CONCLUSIONS: Sample collections at longer time points should be considered in future studies, for assessing the possible development of autoantibody responses following infection with SARS-CoV-2.

Ultrasensitive assay for saliva-based SARS-CoV-2 antigen detection.

OBJECTIVES: Widespread SARS-CoV-2 testing is invaluable for identifying asymptomatic/pre-symptomatic individuals. There remains a technological gap for highly reliable, easy, and quick SARS-CoV-2 diagnostic tests suitable for frequent mass testing. Compared to nasopharyngeal (NP) swab-based tests, saliva-based methods are attractive due to easier and safer sampling. Current saliva-based SARS-CoV-2 rapid antigen tests (RATs) are hindered by limited analytical sensitivity. Here, we report one of the first ultrasensitive, saliva-based SARS-CoV-2 antigen assays with an analytical sensitivity of <0.32 pg/mL, corresponding to four viral RNA copies/µL, which is comparable to that of PCR-based tests. METHODS: Using the novel electrochemiluminescence (ECL)-based immunoassay, we measured the SARS-CoV-2 nucleocapsid (N) antigen concentration in 105 salivas, obtained from non-COVID-19 and COVID-19 patients. We then verified the results with a second, independent cohort of 689 patients (3.8% SARS-CoV-2 positivity rate). We also compared our method with a widely used point-of-care rapid test. RESULTS: In the first cohort, at 100% specificity, the sensitivity was 92%. Our assay correctly identified samples with viral loads up to 35 CT cycles by saliva-based PCR. Paired NP swab-based PCR results were obtained for 86 cases. Our assay showed high concordance with saliva-based and NP swab-based PCR in samples with negative (<0.32 pg/mL) and strongly positive (>2 pg/mL) N antigen concentrations. In the second cohort, at 100% specificity, sensitivity was also 92%. Our assay is about 700-fold more sensitive than the Abbott Panbio Rapid Test. CONCLUSIONS: We demonstrated the ultrasensitivity and specificity assay and its concordance with PCR. This novel assay is especially valuable when compliance to frequent swabbing may be problematic.

Measurement of Severe Acute Respiratory Syndrome Coronavirus 2 Antigens in Plasma of Pediatric Patients With Acute Coronavirus Disease 2019 or Multisystem Inflammatory Syndrome in Children Using an Ultrasensitive and Quantitative Immunoassay.

BACKGROUND: Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in blood has high sensitivity in adults with acute coronavirus disease 2019 (COVID-19), but sensitivity in pediatric patients is unclear. Recent data suggest that persistent SARS-CoV-2 spike antigenemia may contribute to multisystem inflammatory syndrome in children (MIS-C). We quantified SARS-CoV-2 nucleocapsid (N) and spike (S) antigens in blood of pediatric patients with either acute COVID-19 or MIS-C using ultrasensitive immunoassays (Meso Scale Discovery). METHODS: Plasma was collected from inpatients (<21 years) enrolled across 15 hospitals in 15 US states. Acute COVID-19 patients (n = 36) had a range of disease severity and positive nasopharyngeal SARS-CoV-2 RT-PCR within 24 hours of blood collection. Patients with MIS-C (n = 53) met CDC criteria and tested positive for SARS-CoV-2 (RT-PCR or serology). Controls were patients pre-COVID-19 (n = 67) or within 24 hours of negative RT-PCR (n = 43). RESULTS: Specificities of N and S assays were 95-97% and 100%, respectively. In acute COVID-19 patients, N/S plasma assays had 89%/64% sensitivity; sensitivities in patients with concurrent nasopharyngeal swab cycle threshold (Ct) ≤35 were 93%/63%. Antigen concentrations ranged from 1.28-3844 pg/mL (N) and 1.65-1071 pg/mL (S) and correlated with disease severity. In MIS-C, antigens were detected in 3/53 (5.7%) samples (3 N-positive: 1.7, 1.9, 121.1 pg/mL; 1 S-positive: 2.3 pg/mL); the patient with highest N had positive nasopharyngeal RT-PCR (Ct 22.3) concurrent with blood draw. CONCLUSIONS: Ultrasensitive blood SARS-CoV-2 antigen measurement has high diagnostic yield in children with acute COVID-19. Antigens were undetectable in most MIS-C patients, suggesting that persistent antigenemia is not a common contributor to MIS-C pathogenesis.

Measurement of SARS-CoV-2 antigens in plasma of pediatric patients with acute COVID-19 or MIS-C using an ultrasensitive and quantitative immunoassay.

BACKGROUND: Detection of SARS-CoV-2 antigens in blood has high sensitivity in adults with acute COVID-19, but sensitivity in pediatric patients is unclear. Recent data suggest that persistent SARS-CoV-2 spike antigenemia may contribute to multisystem inflammatory syndrome in children (MIS-C). We quantified SARS-CoV-2 nucleocapsid (N) and spike (S) antigens in blood of pediatric patients with either acute COVID-19 or MIS-C using ultrasensitive immunoassays (Meso Scale Discovery). METHODS: Plasma was collected from inpatients (<21 years) enrolled across 15 hospitals in 15 US states. Acute COVID-19 patients (n=36) had a range of disease severity and positive nasopharyngeal SARS-CoV-2 RT-PCR within 24 hours of blood collection. Patients with MIS-C (n=53) met CDC criteria and tested positive for SARS-CoV-2 (RT-PCR or serology). Controls were patients pre-COVID-19 (n=67) or within 24h of negative RT-PCR (n=43). RESULTS: Specificities of N and S assays were 95-97% and 100%, respectively. In acute COVID-19 patients, N/S plasma assays had 89%/64% sensitivity, respectively; sensitivity in patients with concurrent nasopharyngeal swab cycle threshold (Ct) ≤ 35 were 93%/63%. Antigen concentrations ranged from 1.28-3,844 pg/mL (N) and 1.65-1,071 pg/mL (S) and correlated with disease severity. In MIS-C, antigens were detected in 3/53 (5.7%) samples (3 N-positive: 1.7, 1.9, 121.1 pg/mL; 1 S-positive: 2.3 pg/mL); the patient with highest N had positive nasopharyngeal RT-PCR (Ct 22.3) concurrent with blood draw. CONCLUSIONS: Ultrasensitive blood SARS-CoV-2 antigen measurement has high diagnostic yield in children with acute COVID-19. Antigens were undetectable in most MIS-C patients, suggesting that persistent antigenemia is not a common contributor to MIS-C pathogenesis. KEY POINTS: In a U.S. pediatric cohort tested with ultrasensitive immunoassays, SARS-CoV-2 nucleocapsid antigens were detectable in most patients with acute COVID-19, and spike antigens were commonly detectable. Both antigens were undetectable in almost all MIS-C patients.

Elevated Graves' Disease-Specific Thyroid-Stimulating Immunoglobulin and Thyroid Stimulating Hormone Receptor Antibody in a Patient With Subacute Thyroiditis.

Subacute thyroiditis can be rarely associated with autoimmune thyroid disorders. It includes Graves' disease which is characterized by the presence of a highly specific antibody known as thyroid-stimulating hormone (TSH) receptor antibody (TRAb). There are three types of TRAb: TSH receptor stimulating antibody (TSAb) which stimulates the TSH receptor causing Graves' disease, TSH receptor blocking antibody (TBAb) which blocks the TSH receptor causing hypothyroidism, and a neutralizing antibody which does not alter the thyroid function. There are two assays used to check the TRAb: the thyroid-stimulating immunoglobulin (TSI) assay and the TSH receptor-binding inhibitor immunoglobulin (TBII) assay out of which the TSI assay measures the stimulating antibody which is specific for graves' disease. Although autoimmune thyroid disorders can rarely occur following subacute thyroiditis, their clinical presentation is usually compatible with the type of antibody detected in the patient's serum. We present a unique case of a 44-year-old patient who presented with subacute thyroiditis followed by the development of persistent hypothyroidism even in the presence of elevated Graves' disease-specific TSI and TRAb.

Denosumab can be used successfully as a bridge to surgery in patients with severe hypercalcemia due to primary hyperparathyroidism.

Severe hypercalcemia is a medical emergency that requires immediate and aggressive management. Primary hyperparathyroidism (PHPT) often causes severe hypercalcemia. Volume resuscitation, parenteral salmon calcitonin, and administration of intravenous bisphosphonates are common measures used to stabilize patients. However, the use of these measures is inadequate in several patients and may even be contraindicated in individuals with renal insufficiency or severe systemic illness. This study demonstrated the efficacy and safety of denosumab in patients with severe hypercalcemia due to PHPT, when immediate surgery was not feasible. We present four patients with severe hypercalcemia due to PHPT. Immediate surgery was not feasible because the patients had severe systemic illness, such as seizures and altered sensorium (case 1); acute severe pancreatitis (cases 2 and 3); or coronavirus disease 2019 pneumonia (case 4). Intravenous normal saline and parenteral salmon calcitonin were inadequate for controlling hypercalcemia. Intravenous bisphosphonates were avoided because of severe systemic illness in all cases and impaired renal function in three cases. Denosumab was administered to control hypercalcemia and allow the stabilization of patients for definitive surgical management. Following denosumab administration, serum calcium levels normalized, and general condition improved in all patients. Three patients underwent parathyroidectomy after two weeks and another patient after eight weeks. The use of denosumab for the management of severe hypercalcemia due to PHPT is efficacious and safe in patients when immediate surgical management is not feasible due to severe systemic illness.

Prevalence of clinically relevant liver fibrosis due to nonalcoholic fatty liver disease in Indian individuals with type 2 diabetes.

BACKGROUND AND AIM: Type 2 diabetes (T2D) in associated with higher prevalence and worse outcomes of nonalcoholic fatty liver disease (NAFLD). However, data regarding the prevalence of clinically relevant liver fibrosis (CRLF) in Indian individuals with T2D are scarce. We investigated the prevalence of, and factors associated with, CRLF in Indians with T2D. METHODS: We conducted a prospective study of 601 consecutive adults with T2D. Steatosis was diagnosed using ultrasonography. Liver stiffness measurement (LSM) by transient elastography of ≥8.0 kPa was taken as cutoff suggesting CRLF. Individuals with LSM > 13.0 kPa underwent dynamic magnetic resonance imaging (MRI) of liver for detecting changes consistent with cirrhosis. RESULTS: The prevalence of steatosis was 84.2%. Higher body mass index (BMI, P = 0.022), alanine aminotransferase (ALT; P = 0.001), and lower high-density lipoprotein (HDL; P = 0.002) were independent factors associated with steatosis. The prevalence of CRLF was 28.2%. Higher BMI (P = 0.001), aspartate aminotransferase (AST; P < 0.0001), gamma-glutamyl transpeptidase (GGT; P < 0.0001), and concomitant hypertension (P = 0.03) were independent factors associated with CRLF. Elevated ALT and AST (≥40 units/L) levels were present in 70.6 and 51.6% individuals with CRLF, respectively. Thirty-one (7.2%) individuals had LSM > 13.0 kPa. Among them, 25 individuals underwent dynamic MRI of liver, which revealed features consistent with cirrhosis in 18 patients. CONCLUSION: CRLF, an established risk factor for cirrhosis and overall mortality, affects at least one out of four (25%) Indians with T2D. These results support screening of all patients with T2D and NAFLD for liver fibrosis.

Low skeletal muscle mass is associated with liver fibrosis in individuals with type 2 diabetes and nonalcoholic fatty liver disease.

BACKGROUND AND AIM: Type 2 diabetes (T2D) and low skeletal muscle mass (SMM) are associated with increased risk of nonalcoholic fatty liver disease (NAFLD). However, data regarding the association between low SMM and NAFLD-related liver fibrosis in individuals with T2D are scarce. Therefore, we aimed to investigate the association between low SMM and liver fibrosis in individuals with T2D and NAFLD. METHODS: Controlled attenuation parameter (CAP) of ≥ 248 dB/m was taken as cutoff suggesting NAFLD. Clinically relevant liver fibrosis and advanced liver fibrosis were defined as liver stiffness measurement (LSM) by transient elastography (TE) of ≥ 8.0 and ≥ 9.6 kPa, respectively. SMM was measured using dual energy X-ray absorptiometry (DEXA). Low SMM was defined as appendicular SMM index of < 7.0 kg/m2 for men and < 5.4 kg/m2 for women. RESULTS: Of the 487 consecutive patients with T2D, 366 (75.1%) had NAFLD. Among individuals with NAFLD, 118 (32.2%) and 64 (17.5%) had clinically relevant liver fibrosis and advanced liver fibrosis, respectively. Low SMM was diagnosed in 78 (21.3%) individuals with NAFLD. Patients with low SMM were older (56.1 vs 52.8 years) and had longer duration of diabetes (10.3 vs 8.1 years). Low SMM was an independent risk factor associated with clinically relevant liver fibrosis (P = 0.002) and advanced liver fibrosis (P ≤ 0.0001). Associations between low SMM and clinically relevant- and advanced liver fibrosis were maintained even after sequential adjustment for confounding variables through the multivariate regression analysis. CONCLUSIONS: Low SMM is independently associated with liver fibrosis in individuals with T2D and NAFLD.

Parent satisfaction and acceptability of telehealth consultations in pediatric ophthalmology: initial experience during the COVID-19 pandemic.

Telehealth in pediatric ophthalmology has predominantly been utilized and reported in the setting of clinician-to-clinician opinion or store-and-forward of images, particularly in the diagnosis and management of retinopathy of prematurity (ROP). We present our initial experience of using a telehealth model of care to deliver real-time specialist pediatric ophthalmology services during the COVID-19 pandemic. Over a 5-week period, parents were invited to complete an anonymous survey following a telehealth ophthalmology consultation for their child. The survey explored their satisfaction, acceptance, and feedback relating to their experience. With an overall response rate of 49.4%, satisfaction was high (43.8% very satisfied; 38.2% satisfied). Most parents (71.9%) would consider telehealth for future ophthalmology consultations for their child.

Correlation of SARS-CoV-2 Nucleocapsid Antigen and RNA Concentrations in Nasopharyngeal Samples from Children and Adults Using an Ultrasensitive and Quantitative Antigen Assay.

Diagnosis of COVID-19 by PCR offers high sensitivity, but the utility of detecting samples with high cycle threshold (CT ) values remains controversial. Currently available rapid diagnostic tests (RDTs) for SARS-CoV-2 nucleocapsid antigens (Ag) have sensitivity well below PCR. The correlation of Ag and RNA quantities in clinical nasopharyngeal (NP) samples is unknown. An ultrasensitive, quantitative electrochemiluminescence immunoassay for SARS-CoV-2 nucleocapsid (the MSD S-PLEX SARS-CoV-2 N assay) was used to measure Ag in clinical NP samples from adults and children previously tested by PCR. The S-PLEX Ag assay had a limit of detection (LOD) of 0.16 pg/ml and a cutoff of 0.32 pg/ml. Ag concentrations measured in clinical NP samples (collected in 3.0 ml of media) ranged from less than 160 fg/ml to 2.7 µg/ml. Log-transformed Ag concentrations correlated tightly with CT values. In 35 adult and 101 pediatric PCR-positive samples, the sensitivities were 91% (95% confidence interval, 77 to 98%) and 79% (70 to 87%), respectively. In samples with a CT of ≤35, the sensitivities were 100% (88 to 100%) and 96% (88 to 99%), respectively. In 50 adult and 40 pediatric PCR-negative specimens, the specificities were 100% (93 to 100%) and 98% (87 to 100%), respectively. Nucleocapsid concentrations in clinical NP samples span 8 orders of magnitude and correlate closely with RNA concentrations (CT values). The S-PLEX Ag assay showed 96 to 100% sensitivity in samples from children and adults with CT values of ≤35, and a specificity of 98 to 100%. These results clarify Ag concentration distributions in clinical samples, providing insight into the performance of Ag RDTs and offering a new approach to diagnosis of COVID-19.

Probing the Role of Cu(II) Ions on Protein Aggregation Using Two Model Proteins.

Copper is an essential trace element for human biology where its metal dyshomeostasis accounts for an increased level of serum copper, which accelerates protein aggregation. Protein aggregation is a notable feature for many neurodegenerative disorders. Herein, we report an experimental study using two model proteins, bovine serum albumin (BSA) and human serum albumin (HSA), to elucidate the mechanistic pathway by which serum albumins get converted from a fully folded globular protein to a fibril and an amorphous aggregate upon interaction with copper. Steady-state fluorescence, time-resolved fluorescence studies, and Raman spectroscopy were used to monitor the unfolding of serum albumin with increasing copper concentrations. Steady-state fluorescence studies have revealed that the fluorescence quenching of BSA/HSA by Cu(II) has occurred through a static quenching mechanism, and we have evaluated both the quenching constants individually. The binding constants of BSA-Cu(II) and HSA-Cu(II) were found to be 2.42 × 104 and 0.05 × 104 M-1, respectively. Further nanoscale morphological changes of BSA mediated by oligomers to fibril and HSA to amorphous aggregate formation were studied using atomic force microscopy. This aggregation process correlates with the Stern-Volmer plots in the absence of discernible lag phase. Raman spectroscopy results obtained are in good agreement with the increase in antiparallel ß-sheet structures formed during the aggregation of BSA in the presence of Cu(II) ions. However, an increase in α-helical fractions is observed for the amorphous aggregate formed from HSA.

Denosumab can be used successfully as a bridge to surgery in patients with severe hypercalcemia due to primary hyperparathyroidism

SUMMARY Severe hypercalcemia is a medical emergency that requires immediate and aggressive management. Primary hyperparathyroidism (PHPT) often causes severe hypercalcemia. Volume resuscitation, parenteral salmon calcitonin, and administration of intravenous bisphosphonates are common measures used to stabilize patients. However, the use of these measures is inadequate in several patients and may even be contraindicated in individuals with renal insufficiency or severe systemic illness. This study demonstrated the efficacy and safety of denosumab in patients with severe hypercalcemia due to PHPT, when immediate surgery was not feasible. We present four patients with severe hypercalcemia due to PHPT. Immediate surgery was not feasible because the patients had severe systemic illness, such as seizures and altered sensorium (case 1); acute severe pancreatitis (cases 2 and 3); or coronavirus disease 2019 pneumonia (case 4). Intravenous normal saline and parenteral salmon calcitonin were inadequate for controlling hypercalcemia. Intravenous bisphosphonates were avoided because of severe systemic illness in all cases and impaired renal function in three cases. Denosumab was administered to control hypercalcemia and allow the stabilization of patients for definitive surgical management. Following denosumab administration, serum calcium levels normalized, and general condition improved in all patients. Three patients underwent parathyroidectomy after two weeks and another patient after eight weeks. The use of denosumab for the management of severe hypercalcemia due to PHPT is efficacious and safe in patients when immediate surgical management is not feasible due to severe systemic illness.

Short term follow-up of patients presenting with acute onset diabetes and diabetic ketoacidosis during an episode of COVID-19.

BACKGROUND AND AIMS: Acute onset diabetes and diabetic ketoacidosis (DKA) can be precipitated by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in individuals with no history of diabetes. However, data regarding the follow-up of these individuals are scarce. METHODS: Three patients (data of two patients already published) with acute onset diabetes and DKA, precipitated by coronavirus disease 2019 (COVID-19), were followed for 14 weeks to assess the behavior of the diabetes. Detailed history, anthropometry, laboratory investigations, imaging studies, clinical course and outcomes were documented. RESULTS: Three individuals developed symptoms suggestive of SARS CoV-2 infection. After a few days, they were detected to have COVID-19 pneumonia, based on reverse transcription-polymerase chain reaction (RT-PCR) assay and chest imaging. In the meantime, they also developed acute onset diabetes and DKA, which were precipitated by COVID-19. They responded well to treatment, including intravenous fluids and insulin. After around one week, they were transitioned to multiple shots of subcutaneous insulin. After about 4-6 weeks, their insulin requirement diminished and oral antihyperglycemic drugs were initiated. At the last follow-up (14 months), they had controlled glycemia with oral antihyperglycemic medicines. CONCLUSIONS: COVID-19 can induce acute onset diabetes and DKA in some individuals with no history of diabetes. These features resemble type 1 diabetes. However, after 4-6 weeks, their requirement for exogenous insulin diminishes and respond to oral antihyperglycemic medications. Long term follow up is required to further understand the type of diabetes induced by SARS CoV-2 infection in these individuals.

Utility of a Fifth-Generation Ultrasensitive Prostate-Specific Antigen Assay for Monitoring Prostate Cancer Patients after Radical Prostatectomy with 3 Years of Follow-Up.

BACKGROUND: We investigated an ultrasensitive prostate-specific antigen (uPSA) immunoassay (MesoScale; lower limit of detection (LLD) of 0.0035 pg/mL) to monitor patients with prostate cancer (PCa) following radical prostatectomy (RP) and to examine whether changes in PSA in the conventionally undetectable range (<1 pg/mL) can predict biochemical relapse (BCR). METHODS: We measured uPSA in serial serum samples (N = 100) collected from 20 RP cases with a third-generation ELISA (LLD of 1 pg/mL) and the fifth-generation MesoScale assay. We analyzed the PSA nadir changes to classify patients into BCR or non-BCR groups, observed the trends in PSA kinetics, and associated BCR status with clinicohistopathological features. RESULTS: The ELISA could quantify PSA in only 38% of the RP samples, detecting BCR in 7 of 20 patients with PCa. The MesoScale assay quantified PSA in all samples, showing 8 of 20 patients with BCR. However, there was no significant difference between the median time to BCR detection based on ELISA (1016 days) compared with MesoScale data (949 days). Gleason scores were higher in the BCR groups compared with non-BCR. There was no significant difference for other clinicohistopathological parameters. CONCLUSIONS: The uPSA MesoScale technology could track miniscule changes in serum PSA in the range of 0.003-1 pg/mL in all RP cases. However, PSA kinetics and nadir at concentrations <2 pg/mL fluctuated, and increases below this range could not reliably suggest signs of BCR. Instead, ultrasensitive fifth-generation PSA assays may hold clinical potential for measuring the low concentrations of PSA in women for various medical contexts.