Acute SARS-CoV-2 Infection Impairs Dendritic Cell and T Cell Responses.

The SARS-CoV-2 pandemic has resulted in millions of infections, yet the role of host immune responses in early COVID-19 pathogenesis remains unclear. By investigating 17 acute and 24 convalescent patients, we found that acute SARS-CoV-2 infection resulted in broad immune cell reduction including T, natural killer, monocyte, and dendritic cells (DCs). DCs were significantly reduced with functional impairment, and ratios of conventional DCs to plasmacytoid DCs were increased among acute severe patients. Besides lymphocytopenia, although neutralizing antibodies were rapidly and abundantly generated in patients, there were delayed receptor binding domain (RBD)- and nucleocapsid protein (NP)-specific T cell responses during the first 3 weeks after symptoms onset. Moreover, acute RBD- and NP-specific T cell responses included relatively more CD4 T cells than CD8 T cells. Our findings provided evidence that impaired DCs, together with timely inverted strong antibody but weak CD8 T cell responses, could contribute to acute COVID-19 pathogenesis and have implications for vaccine development.

Heparin Does Not Regulate Circulating Human PCSK9 (Proprotein Convertase Subtilisin-Kexin Type 9) in a General Population-Brief Report.

BACKGROUND: PCSK9 (proprotein convertase subtilisin-kexin type 9) chaperones the hepatic LDLR (low-density lipoprotein receptor) for lysosomal degradation, elevating serum LDL (low-density lipoprotein) cholesterol and promoting atherosclerotic heart disease. Though the major effect on the hepatic LDLR comes from secreted PCSK9, the details of PCSK9 reuptake into the hepatocyte remain unclear. In both tissue culture and animal models, HSPGs (heparan sulfate proteoglycans) on hepatocytes act as co-receptors to promote PCSK9 reuptake. We hypothesized that if this PCSK9:HSPG interaction is important in humans, disrupting it with unfractionated heparin (UFH) would acutely displace PCSK9 from the liver and increase plasma PCSK9. METHODS: We obtained remnant plasma samples from 160 subjects undergoing cardiac catheterization before and after administration of intravenous UFH. PCSK9 levels were determined using a commercial enzyme-linked immunosorbent assay. RESULTS: Median plasma PCSK9 was 113 ng/mL prior to UFH and 119 ng/mL afterward. This difference was not significant (P=0.83 [95% CI, -6.23 to 6.31 ng/mL]). Equivalence testing provided 95% confidence that UFH would not raise plasma PCSK9 by > 4.7%. Among all subgroups, only subjects with the lowest baseline PCSK9 concentrations exhibited a response to UFH (8.8% increase, adj. P=0.044). A modest correlation was observed between baseline plasma PCSK9 and the change in plasma PCSK9 due to UFH (RS=-0.3634; P<0.0001). CONCLUSIONS: Administration of UFH does not result in a clinically meaningful effect on circulating PCSK9 among an unselected population of humans. The results cast doubt on the clinical utility of disrupting the PCSK9:HSPG interaction as a general therapeutic strategy for PCSK9 inhibition. However, the observations suggest that in selected populations, disrupting the PCSK9:HSPG interaction could still affect PCSK9 reuptake and offer a therapeutic benefit.

Serum free light chains among twin siblings: is the kappa/lambda ratio genetically determined?

BACKGROUND: Serum kappa, lambda, the K/λ light chain concentrations are used for screening, diagnosis, and monitoring of patients with multiple myeloma and other plasma cell disorders. Biological variation studies conducted on healthy subjects showed that free light chains have a low within and high between-individual variation. We determined if this variation were genetically linked. METHODS: We obtained a single serum sample from 16 pairs of identical twins, 8 neonate twins, and 19 presumed directly-related siblings children, measured Κ and λ light chains and computed the Κ/λ ratio. RESULTS: As expected, Κ/λ results from each twin neonate were near identical (reflecting maternal/placental transfer). For older children and adult twins, the Κ/λ ratio form a cluster of results that were a subset of the reference range. There was one outlier, a female with a high, different from her twin sister. She likely had a monoclonal gammopathy (no followup was possible). Excluding this pair, results from neonate twins (14.4% ±10.3%) and non-neonate twins (18.0 ± 15.3%) were not significantly different. Results between non-twin siblings were more scattered (53.2%±53.4%) and different from neonate and non-neonate twin adult and children. CONCLUSION: We suggest that the Κ/λ free light chains may be genetically linked.

Potential medical impact of unrecognized in vitro hypokalemia due to hemolysis: a case series.

OBJECTIVES: The destruction of red cells during blood collection or with the processing of the sample continues to occur at a high rate, especially among emergency department (ED) patients. This can produce pre-analytical laboratory errors, particularly for potassium. We determined the incidence of hemolyzed samples and discuss the potential medical impact for hypokalemic patients who potassium level is artificially normal (pseudoeukalemia). METHODS: Potassium results were obtained for a 6-month period. Using a measured hemolysis index (HI), hemolysis was present in 3.1 % for all potassium ordered (n=94,783) and 7.5 % for ED orders (n=22,770). Most of these samples were reported as having high normal result or were hyperkalemic. There were 22 hemolytic samples with a potassium of <3.5 mmol/L, and 57 hemolytic samples with a potassium in lower limit of normal (3.5-3.8 mmol/L). From this group, we examined the medical histories of 8 selected patients whose initially normal potassium levels were subsequently confirmed to have a potassium values that were below, at, or just above the lower limit of normal due to hemolysis. RESULTS: The primary complaint for these patients were: necrotizing soft tissue infection, pancreatitis, volume overload from heart failure with reduced ejection fraction, hypertension treated with hydrochlorothiazide, and presence of a short bowel syndrome. A subsequent non-hemolyzed sample was collected demonstrating hypokalemia in all of these patients. Within these cases, there was a potential for harm had hemolysis detection not been performed. CONCLUSIONS: We demonstrate the medical importance of detecting hemolysis for patients who have pseudoeukalemia. This is relevant because the HI cannot be obtained when electrolytes are tested using whole blood samples, and a normal potassium may lead to inappropriate patient management.

EVALUATING ULTRA-WIDEFIELD IMAGING UTILITY IN THE DETECTION OF TREATMENT-REQUIRING PERIPHERAL RETINAL TEARS AND HOLES.

PURPOSE: To determine the utility of ultra-widefield (UWF) imaging in detecting pathologic peripheral retinal tears and holes. METHODS: This was a retrospective, observational study. One-hundred ninety-eight eyes of 198 patients diagnosed with acute posterior vitreous detachment were included. Eyes were divided into two groups: 89 eyes with peripheral retinal holes and tears treated with laser retinopexy (treatment group) and 109 control eyes. Patients underwent UWF imaging and indirect ophthalmoscopy with scleral depression. UWF images from both groups were reviewed by two blinded graders and then compared with funduscopic examination and medical records. RESULTS: UWF imaging identified 60 of the 89 eyes (sensitivity of 67.4%) found to have treatment-requiring peripheral retinal lesions and 107 of the 109 control eyes (specificity of 98.2%).The distribution of misses based on octant location did reach statistical significance ( P = 0.004). Lesions anterior to the equator were more likely to be missed (21/41 eyes, 51.2%) compared with those located posterior to the equator (4/20 eyes, 25.0%) and at the equator (4/28, 14.3%), P = 0.002. The combined discordance rate between graders in the entire cohort was 12.1% (24/198 eyes) yielding an interrater agreement of 87.9%. CONCLUSION: UWF imaging showed a moderate sensitivity and high specificity in detecting treatment-requiring retinal tears and holes, with high interrater agreement. Given there is only a moderate sensitivity in identifying treatment-requiring retinal tears and holes, UWF imaging can assist with clinical examination, but a 360-degree scleral depressed examination should remain the gold standard.

Early Treatment of High-Risk Hospitalized Coronavirus Disease 2019 (COVID-19) Patients With a Combination of Interferon Beta-1b and Remdesivir: A Phase 2 Open-label Randomized Controlled Trial.

BACKGROUND: Early antiviral therapy was effective in the treatment of coronavirus disease 2019 (COVID-19). We assessed the efficacy and safety of combined interferon beta-1b and remdesivir treatment in hospitalized COVID-19 patients. METHODS: We conducted a multicentre, prospective open-label, randomized-controlled trial involving high-risk adults hospitalized for COVID-19. Patients were randomly assigned to a 5-day interferon beta-1b 16 million units daily and remdesivir 200 mg loading on day 1 followed by 100 mg daily on day 2 to 5 (combination group), or to remdesivir only of similar regimen (control group) (1:1). The primary endpoint was the time to complete alleviation of symptoms (NEWS2 = 0). RESULTS: Two-hundred and twelve patients were enrolled. The median days of starting treatment from symptom onset was 3 days. The median age was 65 years, and 159 patients (75%) had chronic disease. The baseline demographics were similar. There was no mortality. For the primary endpoint, the combination group was significantly quicker to NEWS2 = 0 (4 vs 6.5 days; hazard ratio [HR], 6.59; 95% confidence interval [CI], 6.1-7.09; P < .0001) when compared to the control group. For the secondary endpoints, the combination group was quicker to negative nasopharyngeal swab (NPS) viral load (VL) (6 vs 8 days; HR, 8.16; 95% CI, 7.79-8.52; P < .0001) and to develop seropositive immunoglobulin G (IgG) (8 vs 10 days; HR, 10.78; 95% CI, 9.98-11.58; P < .0001). All adverse events resolved upon follow-up. Combination group (HR, 4.1 95% CI, 1.9-8.6, P < .0001) was the most significant independent factor associated with NEWS2 = 0 on day 4. CONCLUSIONS: Early treatment with interferon beta-1b and remdesivir was safe and better than remdesivir only in alleviating symptoms, and in shortening viral shedding and hospitalization with earlier seropositivity in high-risk COVID-19 patients. CLINICAL TRIALS REGISTRATION: NCT04647695.

Cocaine Use is Associated With Increased LVMI in Unstably Housed Women With Polysubstance Use.

BACKGROUND: While substance use is known to influence cardiovascular health, most prior studies only consider one substance at a time. We examined associations between the concurrent use of multiple substances and left ventricular mass index (LVMI) in unhoused and unstably housed women. METHODS: Between 2016 and 2019, we conducted a cohort study of unstably housed women in which measurements included an interview, serum/urine collection, vital sign assessment, and a single transthoracic echocardiogram at baseline. We evaluated independent associations between 39 separate substances confirmed through toxicology and echocardiography-confirmed LVMI. RESULTS: The study included 194 participants with a median age of 53.5 years and a high proportion of women of color (72.6%). Toxicology-confirmed substance use included: 69.1% nicotine, 56.2% cocaine, 28.9% methamphetamines, 28.9% alcohol, 23.2% opioid analgesics, and 9.8% opioids with catecholaminergic effects. In adjusted analysis, cocaine was independently associated with higher LVMI (Adjusted linear effect: 18%; 95% CI 9.9, 26.6). Associations with other substances did not reach levels of significance and did not significantly interact with cocaine. CONCLUSION: In a population of vulnerable women where the use of multiple substances is common, cocaine stands out as having particularly detrimental influences on cardiac structure. Blood pressure did not attenuate the association appreciably, suggesting direct effects of cocaine on LVMI. Routinely evaluating stimulant use as a chronic risk factor during risk assessment and preventive clinical care planning may reduce end organ damage, particularly in highly vulnerable women.

COVID-19 is Observed in Older Children During the Omicron Wave in New York City.

BACKGROUND: The Omicron variant of SARS-CoV-2 has a predilection for the upper airways, causing symptoms such as sore throat, hoarse voice, and stridor. OBJECTIVE: We describe a series of children with COVID-19-associated croup in an urban multicenter hospital system. METHODS: We conducted a cross-sectional study of children ≤18 years of age presenting to the emergency department during the COVID-19 pandemic. Data were extracted from an institutional data repository comprised of all patients who were tested for SARS-CoV-2. We included patients with a croup diagnosis by International Classification of Diseases, 10th revision code and a positive SARS-CoV-2 test within 3 days of presentation. We compared demographics, clinical characteristics, and outcomes for patients presenting during a pre-Omicron period (March 1, 2020-December 1, 2021) to the Omicron wave (December 2, 2021-February 15, 2022). RESULTS: We identified 67 children with croup, 10 (15%) pre-Omicron and 57 (85%) during the Omicron wave. The prevalence of croup among SARS-CoV-2-positive children increased by a factor of 5.8 (95% confidence interval 3.0-11.4) during the Omicron wave compared to prior. More patients were ≥6 years of age in the Omicron wave than prior (19% vs. 0%). The majority were not hospitalized (77%). More patients ≥6 years of age received epinephrine therapy for croup during the Omicron wave (73% vs. 35%). Most patients ≥6 years of age had no croup history (64%) and only 45% were vaccinated against SARS-CoV-2. CONCLUSION: Croup was prevalent during the Omicron wave, atypically affecting patients ≥6 years of age. COVID-19-associated croup should be added to the differential diagnosis of children with stridor, regardless of age. © 2022 Elsevier Inc.

In Vitro Susceptibility of Typhoidal, Nontyphoidal, and Extended-Spectrum-ß-Lactamase-Producing Salmonella to Ceftolozane/Tazobactam.

Both typhoidal and nontyphoidal salmonellae are included in the top 15 drug-resistant threats described by the U.S. Centers for Disease Control and Prevention. There is an urgent need to look for alternative antibiotics for the treatment of Salmonella infections. We used the broth microdilution test to examine the in vitro susceptibilities of typhoidal and nontyphoidal salmonellae, including isolates positive for extended-spectrum ß-lactamase (ESBL), to ceftolozane/tazobactam and six other antibiotics. Of the 313 (52 typhoidal and 261 nontyphoidal) Salmonella isolates tested, 98.7% were susceptible to ceftolozane/tazobactam. Based on the overall MIC50/90 values, Salmonella isolates were more susceptible to ceftolozane/tazobactam (0.25/0.5 mg/L) than all the comparator agents: ampicillin (≥64/≥64 mg/L), levofloxacin (0.25/1 mg/L), azithromycin (4/16 mg/L), ceftriaxone (≤0.25/4 mg/L), chloramphenicol (8/≥64 mg/L), and trimethoprim/sulfamethoxazole (1/≥8 mg/L). Comparison of the activities of the antimicrobial agents against nontyphoidal Salmonella isolates according to their serogroups showed that ceftolozane/tazobactam had the highest activity (100%) against Salmonella serogroup D, G, I, and Q isolates, whereas the lowest activity (85.7%) was observed against serogroup E isolates. All 10 ESBL-producing Salmonella isolates (all nontyphoidal), of which 8 were CTX-M-55 producers and 2 were CTX-M-65 producers, were sensitive to ceftolozane/tazobactam, albeit with MIC50/90 values higher (1/2 mg/L) than those for non-ESBL producers (0.25/0.5 mg/L). In summary, our data indicate that ceftolozane/tazobactam is active against most strains of both typhoidal and nontyphoidal salmonellae and also against ESBL-producing salmonellae.

The Clinical Utility of Two High-Throughput 16S rRNA Gene Sequencing Workflows for Taxonomic Assignment of Unidentifiable Bacterial Pathogens in Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

Bacterial pathogens that cannot be identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) are occasionally encountered in clinical laboratories. The 16S rRNA gene is often used for sequence-based analysis to identify these bacterial species. Nevertheless, traditional Sanger sequencing is laborious, time-consuming, and low throughput. Here, we compared two commercially available 16S rRNA gene sequencing tests that are based on Illumina and Nanopore sequencing technologies, respectively, in their ability to identify the species of 172 clinical isolates that failed to be identified by MALDI-TOF MS. Sequencing data were analyzed by the respective built-in programs (MiSeq Reporter software of Illumina and Epi2me of Nanopore) and BLAST+ (v2.11.0). Their agreement with Sanger sequencing on species-level identification was determined. Discrepancies were resolved by whole-genome sequencing. The diagnostic accuracy of each workflow was determined using the composite sequencing result as the reference standard. Despite the high base-calling accuracy of Illumina sequencing, we demonstrated that the Nanopore workflow had a higher taxonomic resolution at the species level. Using built-in analysis algorithms, the concordance of Sanger 16S with the Illumina and Nanopore workflows was 33.14% and 87.79%, respectively. The agreement was 65.70% and 83.14%, respectively, when BLAST+ was used for analysis. Compared with the reference standard, the diagnostic accuracy of Nanopore 16S was 96.36%, which was identical to that of Sanger 16S and better than that of Illumina 16S (69.07%). The turnaround time of the Illumina workflow and the Nanopore workflow was 78 h and 8.25 h, respectively. The per-sample cost of the Illumina and Nanopore workflows was US$28.5 and US$17.7, respectively.

Point of care CYP2C19 genotyping after percutaneous coronary intervention.

Loss-of-function CYP2C19 variants are associated with increased cumulative ischemic outcomes warranting CYP2C19 genotyping prior to clopidogrel administration. TAILOR-PCI was an international, multicenter (40 sites), prospective, randomized trial comparing rapid point of care (POC) genotype-guided vs. conventional anti-platelet therapy. The performance of buccal-based rapid CYP2C19 genotyping performed by non-laboratory-trained staff in TAILOR-PCI was assessed. Pre-trial training and evaluation involved rapid genotyping of 373 oral samples, with 99.5% (371/373) concordance with Sanger sequencing. During TAILOR-PCI, 5302 patients undergoing PCI were randomized to POC rapid CYP2C19 *2, *3, and *17 genotyping versus no genotyping. At 12 months post-PCI, TaqMan genotyping determined 99.1% (2,364/2,385) concordance with the POC results, with 90.7-98.8% sensitivity and 99.2-99.6% specificity. In conclusion, non-laboratory personnel can be successfully trained for on-site instrument operation and POC rapid genotyping with analytical accuracy and precision across multiple international centers, thereby supporting POC genotyping in patient-care settings, such as the cardiac catheterization laboratory.Clinical Trial Registration: https://www.clinicalTrials.gov (Identifier: NCT01742117).

Evaluation of Neutralizing Antibodies against SARS-CoV-2 Variants after Infection and Vaccination Using a Multiplexed Surrogate Virus Neutralization Test.

BACKGROUND: The SARS-CoV-2 virus has mutated and evolved since the inception of the COVID-19 pandemic bringing into question the future effectiveness of current vaccines and antibody therapeutics. With evolution of the virus updated methods for the evaluation of the immune response in infected and vaccinated individuals are required to determine the durability of the immune response to SARS-CoV-2 variants. METHODS: We developed a multiplexed surrogate virus neutralization test (plex-sVNT) that simultaneously measures the ability of antibodies in serum to inhibit binding between angiotensin converting enzyme-2 (ACE2) and 7 SARS-CoV-2 trimeric spike protein variants, including wild type, B.1.1.7(α), B.1.351(ß), P.1(γ), B.1.617.2(δ), B.1.617.1(κ), and B.1.429(ε). The assay was validated against a plaque reduction neutralization test (PRNT).We evaluated 170 samples from 97 COVID-19 patients and 281 samples from 188 individuals that received the Pfizer-BioNTech or Moderna mRNA vaccines. RESULTS: The plex-sVNT demonstrated >96% concordance with PRNT. Antibody neutralization activity was significantly reduced for all SARS-CoV-2 variants compared to wild type in both the infected and vaccinated cohorts. There was a decline in overall antibody neutralization activity, within both cohorts, out to 5 months post infection or vaccination, with the rate of decline being more significant for the vaccinated. CONCLUSIONS: The plex-sVNT provides a correlative measure to PRNT and a convenient approach for evaluating antibody neutralization against SARS-CoV-2 variants. Neutralization of SARS-CoV-2 variants is reduced compared to wild type and declines over the ensuing months after exposure or vaccination within each cohort, however it is still unknown what degree of neutralizing capacity is protective.

Pediatric Epilepsy Learning Healthcare System Quality of Life (PELHS-QOL-2): A novel health-related quality of life prompt for children with epilepsy.

OBJECTIVE: Pediatric epilepsy is often associated with diminished health-related quality of life (HRQOL). Our aim was to establish the validity of the Pediatric Epilepsy Learning Healthcare System Quality of Life (PELHS-QOL-2) questions, a novel two-item HRQOL prompt for children with epilepsy, primarily for use in clinical care. METHODS: We performed a multicenter cross-sectional study to validate the PELHS-QOL-2. Construct validity was established through bivariate comparisons with four comparator measures and known drivers of quality of life in children with epilepsy, as well as by creating an a priori multivariable model to predict the Quality of Life in Childhood Epilepsy Questionnaire (QOLCE-55). Validity generalization was established through bivariate comparisons with demographic and clinical information. Content validity and clinical utility were established by assessing how well the PELHS-QOL-2 met eight design criteria for an HRQOL prompt established by a multistakeholder group of experts. RESULTS: The final participant sample included 154 English-speaking caregivers of children with epilepsy (mean age = 9.7 years, range = .5-18, 49% female, 70% White). The PELHS-QOL-2 correlated with the four comparator instruments (ρ = .44-.56), was significantly associated with several known drivers of quality of life in children with epilepsy (p < .05), and predicted QOLCE-55 scores in the multivariate model (adjusted R2 = .54). The PELHS-QOL-2 item was not associated with the age, sex, and ethnicity of the children nor with the setting and location of data collection, although PELHS-QOL-Medications was significantly associated with race (worse for White race). Following both quantitative and qualitative analysis, the PELHS-QOL-2 met seven of eight design criteria. SIGNIFICANCE: The PELHS-QOL-2 is a valid HRQOL prompt and is well suited for use in clinical care as a mechanism to routinely initiate conversations with caregivers about quality of life in children with epilepsy. The association of PELHS-QOL-Medications with race merits further study.

Impact of multiple substance use on circulating ST2, a biomarker of adverse cardiac remodelling, in women.

CONTEXT: Cardiovascular disease (CVD) and heart failure (HF) are major causes of mortality in low-income populations and differ by sex. Risk assessment that incorporates cardiac biomarkers is common. However, research evaluating the utility of biomarkers rarely includes controlled substances, which may influence biomarker levels and thus influence CVD risk assessment. MATERIALS AND METHODS: We identified the effects of multiple substances on soluble "suppression of tumorigenicity 2" (sST2), a biomarker of adverse cardiac remodelling, in 245 low-income women. Adjusting for CVD risk factors, we examined associations between substance use and sST2 over six monthly visits. RESULTS: Median age was 53 years and 74% of participants were ethnic minority women. An sST2 level > 35 ng/mL (suggesting cardiac remodelling) during ≥1 study visit was observed in 44% of participants. In adjusted analysis, higher sST2 levels were significantly and positively associated with the presence of cocaine (Adjusted Linear Effect [ALE]:1.10; 95% CI:1.03-1.19), alcohol (ALE:1.10; 95% CI:1.04-1.17), heroin (ALE:1.25; 95% CI:1.10-1.43), and the interaction between heroin and fentanyl use. CONCLUSION: Results suggest that the use of multiple substances influences the level of sST2, a biomarker often used to evaluate cardiovascular risk. Incorporating substance use alongside cardiac biomarkers may improve CVD risk assessment in vulnerable women.

Biomarkers Enhance Discrimination and Prognosis of Type 2 Myocardial Infarction.

BACKGROUND: The observed incidence of type 2 myocardial infarction (T2MI) is expected to increase with the implementation of increasingly sensitive cTn assays. However, it remains to be determined how to diagnose, risk-stratify, and treat patients with T2MI. We aimed to discriminate and risk-stratify T2MI using biomarkers. METHODS: Patients presenting to the emergency department with chest pain, enrolled in the CHOPIN study (Copeptin Helps in the early detection Of Patients with acute myocardial INfarction), were retrospectively analyzed. Two cardiologists adjudicated type 1 MI (T1MI) and T2MI. The prognostic ability of several biomarkers alone or in combination to discriminate T2MI from T1MI was investigated using receiver operating characteristic curve analysis. The biomarkers analyzed were cTnI, copeptin, MR-proANP (midregional proatrial natriuretic peptide), CT-proET1 (C-terminal proendothelin-1), MR-proADM (midregional proadrenomedullin), and procalcitonin. The prognostic utility of these biomarkers for all-cause mortality and major adverse cardiovascular event (a composite of acute myocardial infarction, unstable angina pectoris, reinfarction, heart failure, and stroke) at 180-day follow-up was also investigated. RESULTS: Among the 2071 patients, T1MI and T2MI were adjudicated in 94 and 176 patients, respectively. Patients with T1MI had higher levels of baseline cTnI, whereas those with T2MI had higher baseline levels of MR-proANP, CT-proET1, MR-proADM, and procalcitonin. The area under the receiver operating characteristic curve for the diagnosis of T2MI was higher for CT-proET1, MR-proADM, and MR-proANP (0.765, 0.750, and 0.733, respectively) than for cTnI (0.631). Combining all biomarkers resulted in a similar accuracy to a model using clinical variables and cTnI (0.854 versus 0.884, P=0.294). Addition of biomarkers to the clinical model yielded the highest area under the receiver operating characteristic curve (0.917). Other biomarkers, but not cTnI, were associated with mortality and major adverse cardiovascular event at 180 days among all patients, with no interaction between the diagnosis of T1MI or T2MI. CONCLUSIONS: Assessment of biomarkers reflecting pathophysiologic processes occurring with T2MI might help differentiate it from T1MI. All biomarkers measured, except cTnI, were significant predictors of prognosis, regardless of the type of myocardial infarction.

Kinetics of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Antibody Avidity Maturation and Association with Disease Severity.

The kinetics of IgG avidity maturation during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was studied. The IgG avidity assay, using a novel label-free immunoassay technology, revealed a strong correlation between IgG avidity and days since symptom onset. Peak readings were significantly higher in severe than mild disease cases.

Magnitude and Kinetics of Anti-Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Responses and Their Relationship to Disease Severity.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can be detected indirectly by measuring the host immune response. For some viruses, antibody concentrations correlate with host protection and viral neutralization, but in rare cases, antiviral antibodies can promote disease progression. Elucidation of the kinetics and magnitude of the SARS-CoV-2 antibody response is essential to understand the pathogenesis of coronavirus disease 2019 (COVID-19) and identify potential therapeutic targets. METHODS: Sera (n = 533) from patients with real-time polymerase chain reaction-confirmed COVID-19 (n = 94 with acute infections and n = 59 convalescent patients) were tested using a high-throughput quantitative immunoglobulin M (IgM) and immunoglobulin G (IgG) assay that detects antibodies to the spike protein receptor binding domain and nucleocapsid protein. Individual and serial samples covered the time of initial diagnosis, during the disease course, and following recovery. We evaluated antibody kinetics and correlation between magnitude of the response and disease severity. RESULTS: Patterns of SARS-CoV-2 antibody production varied considerably. Among 52 patients with 3 or more serial specimens, 44 (84.6%) and 42 (80.8%) had observed IgM and IgG seroconversion at a median of 8 and 10 days, respectively. Compared to those with milder disease, peak measurements were significantly higher for patients admitted to the intensive care unit for all time intervals between 6 and 20 days for IgM, and all intervals after 5 days for IgG. CONCLUSIONS: High-sensitivity assays with a robust dynamic range provide a comprehensive picture of host antibody response to SARS-CoV-2. IgM and IgG responses were significantly higher in patients with severe than mild disease. These differences may affect strategies for seroprevalence studies, therapeutics, and vaccine development.

Unique Clusters of Severe Acute Respiratory Syndrome Coronavirus 2 Causing a Large Coronavirus Disease 2019 Outbreak in Hong Kong.

After 2 months of relative quiescence, a large coronavirus disease 2019 outbreak occurred in Hong Kong in July 2020 after gradual relaxation of social distancing policy. Unique severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) phylogenetic clusters have been identified among locally acquired cases, with most genomes belonging to cluster HK1, which is phylogenetically related to SARS-CoV-2 reported overseas.

Territorywide Study of Early Coronavirus Disease Outbreak, Hong Kong, China.

Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10-3 substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread.

Triple combination of interferon beta-1b, lopinavir-ritonavir, and ribavirin in the treatment of patients admitted to hospital with COVID-19: an open-label, randomised, phase 2 trial.

BACKGROUND: Effective antiviral therapy is important for tackling the coronavirus disease 2019 (COVID-19) pandemic. We assessed the efficacy and safety of combined interferon beta-1b, lopinavir-ritonavir, and ribavirin for treating patients with COVID-19. METHODS: This was a multicentre, prospective, open-label, randomised, phase 2 trial in adults with COVID-19 who were admitted to six hospitals in Hong Kong. Patients were randomly assigned (2:1) to a 14-day combination of lopinavir 400 mg and ritonavir 100 mg every 12 h, ribavirin 400 mg every 12 h, and three doses of 8 million international units of interferon beta-1b on alternate days (combination group) or to 14 days of lopinavir 400 mg and ritonavir 100 mg every 12 h (control group). The primary endpoint was the time to providing a nasopharyngeal swab negative for severe acute respiratory syndrome coronavirus 2 RT-PCR, and was done in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT04276688. FINDINGS: Between Feb 10 and March 20, 2020, 127 patients were recruited; 86 were randomly assigned to the combination group and 41 were assigned to the control group. The median number of days from symptom onset to start of study treatment was 5 days (IQR 3-7). The combination group had a significantly shorter median time from start of study treatment to negative nasopharyngeal swab (7 days [IQR 5-11]) than the control group (12 days [8-15]; hazard ratio 4·37 [95% CI 1·86-10·24], p=0·0010). Adverse events included self-limited nausea and diarrhoea with no difference between the two groups. One patient in the control group discontinued lopinavir-ritonavir because of biochemical hepatitis. No patients died during the study. INTERPRETATION: Early triple antiviral therapy was safe and superior to lopinavir-ritonavir alone in alleviating symptoms and shortening the duration of viral shedding and hospital stay in patients with mild to moderate COVID-19. Future clinical study of a double antiviral therapy with interferon beta-1b as a backbone is warranted. FUNDING: The Shaw-Foundation, Richard and Carol Yu, May Tam Mak Mei Yin, and Sanming Project of Medicine.