Coronavirus disease 2019 (COVID-19), the novel respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with severe morbidity and mortality. The ...rollout of diagnostic testing in the United States was slow, leading to numerous cases that were not tested for SARS-CoV-2 in February and March 2020 and necessitating the use of serological testing to determine past infections. Here, we evaluated the Abbott SARS-CoV-2 IgG test for detection of anti-SARS-CoV-2 IgG antibodies by testing 3 distinct patient populations. We tested 1,020 serum specimens collected prior to SARS-CoV-2 circulation in the United States and found one false positive, indicating a specificity of 99.90%. We tested 125 patients who tested reverse transcription-PCR (RT-PCR) positive for SARS-CoV-2 for whom 689 excess serum specimens were available and found that sensitivity reached 100% at day 17 after symptom onset and day 13 after PCR positivity. Alternative index value thresholds for positivity resulted in 100% sensitivity and 100% specificity in this cohort. We tested specimens from 4,856 individuals from Boise, ID, collected over 1 week in April 2020 as part of the Crush the Curve initiative and detected 87 positives for a positivity rate of 1.79%. These data demonstrate excellent analytical performance of the Abbott SARS-CoV-2 IgG test as well as the limited circulation of the virus in the western United States. We expect that the availability of high-quality serological testing will be a key tool in the fight against SARS-CoV-2.
Efforts to minimize COVID-19 exposure during the current SARS-CoV-2 pandemic have led to limitations in access to medical care and testing. The Tasso-SST kit includes all of the components necessary ...for remote, capillary blood self-collection. In this study, we sought to investigate the accuracy and reliability of the Tasso-SST device as a self-collection device for measurement of SARS-CoV-2 IgG antibodies. Capillary blood was obtained via unsupervised and supervised application of the Tasso-SST device, and venous blood was collected by standard venipuncture. Unsupervised self-collected blood samples underwent either extreme summer or winter-simulated shipping conditions prior to testing. Sera obtained by all three methods were tested concurrently using the EuroImmun anti-SARS-CoV-2 S1 IgG assay in a CLIA-certified clinical laboratory. Successful Tasso-SST capillary blood collection by unsupervised and supervised administration was completed by 93.4% and 94.5% of participants, respectively. Sera from 56 participants, 55 with documented (PCR+) COVID-19, and 33 healthy controls were then tested for anti-SARS-CoV-2 IgG antibodies. Compared to venous blood results, Tasso-SST-collected (unstressed) and the summer- and winter-stressed blood samples demonstrated Deming regression slopes of 1.00 (95% CI: 0.99-1.02), 1.00 (95% CI: 0.98-1.01), and 0.99 (95% CI: 0.97-1.01), respectively, with an overall accuracy of 98.9%. Capillary blood self-collection using the Tasso-SST device had a high success rate. Moreover, excellent concordance was found for anti-SARS-CoV-2 IgG results between Tasso-SST capillary and standard venous blood-derived sera. The Tasso-SST device should enable widespread collection of capillary blood for testing without medical supervision, facilitating epidemiologic studies.
Many serologic tests are now available for measuring severe acute respiratory syndrome coronavirus 2 antibodies to evaluate potential protective immunity and for seroprevalence studies. We describe ...an approach to standardizing positivity thresholds and quantitative values for different assays that uses z-scores to enable rapid and efficient comparison of serologic test performance.
Silymarin, also known as milk thistle extract, inhibits hepatitis C virus (HCV) infection and also displays antioxidant, anti-inflammatory, and immunomodulatory actions that contribute to its ...hepatoprotective effects. In the current study, we evaluated the hepatoprotective actions of the seven major flavonolignans and one flavonoid that comprise silymarin. Activities tested included inhibition of: HCV cell culture infection, NS5B polymerase activity, TNF-α-induced NF-κB transcription, virus-induced oxidative stress, and T-cell proliferation. All compounds were well tolerated by Huh7 human hepatoma cells up to 80 μM, except for isosilybin B, which was toxic to cells above 10 μM. Select compounds had stronger hepatoprotective functions than silymarin in all assays tested except in T cell proliferation. Pure compounds inhibited JFH-1 NS5B polymerase but only at concentrations above 300 μM. Silymarin suppressed TNF-α activation of NF-κB dependent transcription, which involved partial inhibition of IκB and RelA/p65 serine phosphorylation, and p50 and p65 nuclear translocation, without affecting binding of p50 and p65 to DNA. All compounds blocked JFH-1 virus-induced oxidative stress, including compounds that lacked antiviral activity. The most potent compounds across multiple assays were taxifolin, isosilybin A, silybin A, silybin B, and silibinin, a mixture of silybin A and silybin B. The data suggest that silymarin- and silymarin-derived compounds may influence HCV disease course in some patients. Studies where standardized silymarin is dosed to identify specific clinical endpoints are urgently needed.
Background & Aims Although the incidence of hepatocellular carcinoma (HCC) is increasing in the United States, data from large prospective studies are limited. We evaluated the Hepatitis C Antiviral ...Long-Term Treatment Against Cirrhosis (HALT-C) cohort for the incidence of HCC and associated risk factors. Methods Hepatitis C virus-positive patients with bridging fibrosis or cirrhosis who did not respond to peginterferon and ribavirin were randomized to groups that were given maintenance peginterferon for 3.5 years or no treatment. HCC incidence was determined by Kaplan–Meier analysis, and baseline factors associated with HCC were analyzed by Cox regression. Results 1,005 patients (mean age, 50.2 years; 71% male; 72% white race) were studied; 59% had bridging fibrosis, and 41% had cirrhosis. During a median follow-up of 4.6 years (maximum, 6.7 years), HCC developed in 48 patients (4.8%). The cumulative 5-year HCC incidence was similar for peginterferon-treated patients and controls, 5.4% vs 5.0%, respectively ( P = .78), and was higher among patients with cirrhosis than those with bridging fibrosis, 7.0% vs 4.1%, respectively ( P = .08). HCC developed in 8 (17%) patients whose serial biopsy specimens showed only fibrosis. A multivariate analysis model comprising older age, black race, lower platelet count, higher alkaline phosphatase, esophageal varices, and smoking was developed to predict the risk of HCC. Conclusions We found that maintenance peginterferon did not reduce the incidence of HCC in the HALT-C cohort. Baseline clinical and laboratory features predicted risk for HCC. Additional studies are required to confirm our finding of HCC in patients with chronic hepatitis C and bridging fibrosis.
Immunopathology may play a significant role in the pathogenesis of Coronavirus-Induced Disease-19 (COVID-19). Immune-mediated tissue damage could result from development of rapid autoimmune ...responses, characterized by production of self-reactive autoantibodies. In this study, we tested specimens from acutely ill patients hospitalized with COVID-19 for autoantibodies against nuclear, vasculitis-associated, and phospholipid antigens. Detectable autoantibodies were present in 30% of the patients in our cohort, with the majority of reactive specimens demonstrating antibodies to nuclear antigens. However, antinuclear antibodies were only weakly reactive and directed to single antigens, as is often seen during acute infection. We identified strongly reactive antibodies to nuclear antigens only in patients with a prior history of autoimmune disease. In our cohort, the prevalence of antiphospholipid antibodies was low, and we did not detect any vasculitis-associated autoantibodies. We found similar levels of inflammatory markers and total immunoglobulin levels in autoantibody positive versus negative patients, but anti-SARS-CoV-2 antibody levels were increased in autoantibody positive patients. Together, our results suggest that acute COVID-19 is not associated with a high prevalence of clinically significant autoantibody responses of the type usually associated with autoimmune rheumatic disease.
•Autoantibodies against nuclear antigens are detectable in 25% of patients hospitalized with acute COVID-19.•Anti-nuclear antigen antibodies were weakly reactive and most often directed to single antigens.•Vasculitis-associated autoantibodies were not detected in specimens from patients with acute COVID-19.•Anti-phospholipid antibodies were infrequently detected in patients with acute COVID-19.
VTX-2337 (USAN: motolimod) is a selective toll-like receptor 8 (TLR8) agonist, which is in clinical development as an immunotherapy for multiple oncology indications, including squamous cell ...carcinoma of the head and neck (SCCHN). Activation of TLR8 enhances natural killer cell activation, increases antibody-dependent cell-mediated cytotoxicity, and induces Th1 polarizing cytokines. Here, we show that VTX-2337 stimulates the release of mature IL-1β and IL-18 from monocytic cells through coordinated actions on both TLR8 and the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome complex. In vitro, VTX-2337 primed monocytic cells to produce pro-IL-1β, pro-IL-18, and caspase-1, and also activated the NLRP3 inflammasome, thereby mediating the release of mature IL-1β family cytokines. Inhibition of caspase-1 blocked VTX-2337-mediated NLRP3 inflammasome activation, but had little impact on production of other TLR8-induced mediators such as TNFα. IL-18 activated natural killer cells and complemented other stimulatory pathways, including FcγRIII and NKG2D, resulting in IFNγ production and expression of CD107a. NLRP3 activation in vivo was confirmed by a dose-related increase in plasma IL-1β and IL-18 levels in cynomolgus monkeys administered VTX-2337. These results are highly relevant to clinical studies of combination VTX-2337/cetuximab treatment. Cetuximab, a clinically approved, epidermal growth factor receptor-specific monoclonal antibody, activates NK cells through interactions with FcγRIII and facilitates ADCC of tumor cells. Our preliminary findings from a Phase I open-label, dose-escalation, trial that enrolled 13 patients with recurrent or metastatic SCCHN show that patient NK cells become more responsive to stimulation by NKG2D or FcγRIII following VTX-2337 treatment. Together, these results indicate that TLR8 stimulation and inflammasome activation by VTX-2337 can complement FcγRIII engagement and may augment clinical responses in SCCHN patients treated with cetuximab.
ClinicalTrials.gov NCT01334177.
Background. Long-lasting protection resulting from hepatitis vaccine, despite loss of antibody against hepatitis virus (HBV) surface antigen (anti-HBs), is undetermined. Methods. We recruited persons ...from a cohort vaccinated with plasma-derived hepatitis vaccine in 1981 who have been followed periodically since. We performed serological testing for anti-HBs and microRNA-155 and assessed HBV-specific T-cell responses by enzyme-linked immunospot and cytometric bead array. Study subgroups were defined 32 years after vaccination as having an anti-HBs level of either ≥ 10 mlU/mL (group 1; n= 13) or <10 mlU/mL (group 2; n = 31). Results. All 44 participants, regardless of anti-HBs level, tested positive for tumor necrosis factor a, interleukin 10, or interleukin 6 production by HBV surface antigen-specific T cells. The frequency of natural killer T cells correlated with the level of anti-HBs (P = .008). The proportion of participants who demonstrated T-cell responses to HBV core antigen varied among the cytokines measured, suggesting some natural exposure to HBV in the study group. No participant had evidence of breakthrough HBV infection. Conclusions. Evidence of long-lasting cellular immunity, regardless of anti-HBs level, suggests that protection afforded by primary immunization with plasma-derived hepatitis vaccine during childhood and adulthood lasts at least 32 years.
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