Differential host responses within the upper respiratory tract and peripheral blood of children and adults with SARS-CoV-2 infection.

Unlabelled: Age is among the strongest risk factors for severe outcomes from SARS-CoV-2 infection. We sought to evaluate associations between age and both mucosal and systemic host responses to SARS-CoV-2 infection. We profiled the upper respiratory tract (URT) and peripheral blood transcriptomes of 201 participants (age range of 1 week to 83 years), including 137 non-hospitalized individuals with mild SARS-CoV-2 infection and 64 uninfected individuals.

The Cabarrus County COVID-19 Prevalence and Immunity (C3PI) Study: design, methods, and baseline characteristics.

Objectives: Coronavirus Disease 2019 (COVID-19) is a viral illness with public health importance. The Cabarrus County COVID-19 Prevalence and Immunity (C3PI) Study is a prospective, longitudinal cohort study designed to contribute valuable information on community prevalence of active COVID-19 infection and SARS-CoV-2 antibodies as the pandemic and responses to it have and continue to evolve. We present the rationale, study design, and baseline characteristics of the C3PI Study.

Implementation of a Pooled Surveillance Testing Program for Asymptomatic SARS-CoV-2 Infections on a College Campus - Duke University, Durham, North Carolina, August 2-October 11, 2020.

On university campuses and in similar congregate environments, surveillance testing of asymptomatic persons is a critical strategy (1,2) for preventing transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). All students at Duke University, a private research university in Durham, North Carolina, signed the Duke Compact (3), agreeing to observe mandatory masking, social distancing, and participation in entry and surveillance testing. The university implemented a five-to-one pooled testing program for SARS-CoV-2 using a quantitative, in-house, laboratory-developed, real-time reverse transcription-polymerase chain reaction (RT-PCR) test (4,5).

Severe Acute Respiratory Syndrome Coronavirus 2 Infections Among Children in the Biospecimens from Respiratory Virus-Exposed Kids (BRAVE Kids) Study.

Background: Child with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection typically have mild symptoms that do not require medical attention, leaving a gap in our understanding of the spectrum of SARS-CoV-2-related illnesses that the viruses causes in children.

Methods: We conducted a prospective cohort study of children and adolescents (aged <21 years) with a SARS-CoV-2-infected close contact. We collected nasopharyngeal or nasal swabs at enrollment and tested for SARS-CoV-2 using a real-time polymerase chain reaction assay.

SARS-CoV-2 Infections Among Children in the Biospecimens from Respiratory Virus-Exposed Kids (BRAVE Kids) Study.

Background: Children with SARS-CoV-2 infection typically have mild symptoms that do not require medical attention, leaving a gap in our understanding of the spectrum of illnesses that the virus causes in children.

Methods: We conducted a prospective cohort study of children and adolescents (<21 years of age) with a SARS-CoV-2-infected close contact. We collected nasopharyngeal or nasal swabs at enrollment and tested for SARS-CoV-2 using a real-time PCR assay.

Laboratory Accuracy Improvement in the UK NEQAS Leucocyte Immunophenotyping Immune Monitoring Program: An Eleven-Year Review via Longitudinal Mixed Effects Modeling.

Background: The United Kingdom National External Quality Assessment Service (UK NEQAS) for Leucocyte Immunophenotyping Immune Monitoring Programme, provides external quality assessment (EQA) to non-U.S. laboratories affiliated with the NIH NIAID Division of AIDS (DAIDS) clinical trials networks.

Maternal HIV-1 envelope-specific antibody responses and reduced risk of perinatal transmission.

Despite the wide availability of antiretroviral drugs, more than 250,000 infants are vertically infected with HIV-1 annually, emphasizing the need for additional interventions to eliminate pediatric HIV-1 infections. Here, we aimed to define humoral immune correlates of risk of mother-to-child transmission (MTCT) of HIV-1, including responses associated with protection in the RV144 vaccine trial. Eighty-three untreated, HIV-1-transmitting mothers and 165 propensity score-matched nontransmitting mothers were selected from the Women and Infants Transmission Study (WITS) of US nonbreastfeeding, HIV-1-infected mothers.

The Center for HIV/AIDS Vaccine Immunology (CHAVI) multi-site quality assurance program for cryopreserved human peripheral blood mononuclear cells.

The Center for HIV/AIDS Vaccine Immunology (CHAVI) consortium was established to determine the host and virus factors associated with HIV transmission, infection and containment of virus replication, with the goal of advancing the development of an HIV protective vaccine. Studies to meet this goal required the use of cryopreserved Peripheral Blood Mononuclear Cell (PBMC) specimens, and therefore it was imperative that a quality assurance (QA) oversight program be developed to monitor PBMC samples obtained from study participants at multiple international sites. Nine site-affiliated laboratories in Africa and the USA collected and processed PBMCs, and cryopreserved PBMC were shipped to CHAVI repositories in Africa and the USA for long-term storage.

VERITAS?: A time for VERIQAS™ and a new approach to training, education, and the quality assessment of CD4+ T lymphocyte counting (I).

Background: The aim of clinical laboratories is to produce accurate and reproducible results to enable effective and reliable clinical practice and patient management. The standard approach is to use both internal quality control (IQC) and external quality assessment (EQA). IQC serves, in many instances, as a "go, no go" tool to provide real time assurance that instruments and reagent or test systems are performing within defined specifications.

Optimization of storage and shipment of cryopreserved peripheral blood mononuclear cells from HIV-infected and uninfected individuals for ELISPOT assays.

Functional immunologic assays using cryopreserved peripheral blood mononuclear cells (PBMC) are influenced by blood processing, storage and shipment. The objective of this study was to compare the viability, recovery and ELISPOT results of PBMC stored and shipped in liquid nitrogen (LN/LN) or stored in LN and shipped on dry ice (LN/DI) or stored at -70°C for 3 to 12 weeks and shipped on DI (70/DI 3 to 12); and to assess the effect of donor HIV infection status on the interaction between storage/shipment and the outcome measures. PBMC from 12 HIV-infected and 12 uninfected donors showed that LN/LN conferred higher viability and recovery than LN/DI or 70/DI 3, 6, 9 or 12.

Evaluation of the blood stabilizers TransFix and Cyto-Chex BCT for low-cost CD4 T-cell methodologies.

TransFix(TM) and Cyto-Chex((R)) BCT (blood collection tube) reagents have been shown to maintain whole blood integrity for delayed immunophenotyping by flow cytometry. We evaluated the ability of these blood-stabilizing reagents to preserve HIV-seropositive blood for delayed CD4(+) T-cell quantification utilizing the Dynal((R)) Biotech T4 Quant Kit. TransFix was added to EDTA-anticoagulated whole blood and tested at a 1:10 dilution over 7 d using the Dynal (n = 21) manual method.

Optimization and limitations of use of cryopreserved peripheral blood mononuclear cells for functional and phenotypic T-cell characterization.

The goals of this study were to optimize processing methods of cryopreserved peripheral blood mononuclear cells (PBMC) for immunological assays, identify acceptance parameters for the use of cryopreserved PBMC for functional and phenotypic assays, and to define limitations of the information obtainable with cryopreserved PBMC. Blood samples from 104 volunteers (49 human immunodeficiency virus-infected and 55 uninfected) were used to assess lymphocyte proliferation in response to tetanus, candida, and pokeweed-mitogen stimulation and to enumerate CD4(+) and CD8(+) T cells and T-cell subpopulations by flow cytometry. We determined that slowly diluting the thawed PBMC significantly improved viable cell recovery, whereas the use of benzonase improved cell recovery only sometimes.

A North American multilaboratory study of CD4 counts using flow cytometric panLeukogating (PLG): a NIAID-DAIDS Immunology Quality Assessment Program Study.

Background: The global HIV/AIDS pandemic and guidelines for initiating anti-retroviral therapy (ART) and opportunistic infection prophylaxis demand affordable, reliable, and accurate CD4 testing. A simple innovative approach applicable to existing technology that has been successfully applied in resource-challenged settings, PanLeukogated CD4 (PLG), could offer solutions for cost saving and improved precision.

Methods: Day-old whole blood from 99 HIV+ donors was simultaneously studied in five North-American laboratories to compare the performance of their predicate methods with the dual-platform PLG method.

Quality assurance program for peripheral blood mononuclear cell cryopreservation.

Seven Brazilian sites participating in the Pediatric AIDS Clinical Trials Group international cryopreservation quality assurance pilot program cryopreserved and shipped peripheral blood mononuclear cells (PBMC) to a central U.S. laboratory for analysis.