Corrigendum: VIDIIA Hunter: a low-cost, smartphone connected, artificial intelligence-assisted COVID-19 rapid diagnostic platform approved for medical use in the UK.

[This corrects the article DOI: 10.3389/fmolb.2023.1144001.].

VIDIIA Hunter diagnostic platform: a low-cost, smartphone connected, artificial intelligence-assisted COVID-19 rapid diagnostics approved for medical use in the UK.

Introduction: Accurate and rapid diagnostics paired with effective tracking and tracing systems are key to halting the spread of infectious diseases, limiting the emergence of new variants and to monitor vaccine efficacy. The current gold standard test (RT-qPCR) for COVID-19 is highly accurate and sensitive, but is time-consuming, and requires expensive specialised, lab-based equipment. Methods: Herein, we report on the development of a SARS-CoV-2 (COVID-19) rapid and inexpensive diagnostic platform that relies on a reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay and a portable smart diagnostic device. Automated image acquisition and an Artificial Intelligence (AI) deep learning model embedded in the Virus Hunter 6 (VH6) device allow to remove any subjectivity in the interpretation of results. The VH6 device is also linked to a smartphone companion application that registers patients for swab collection and manages the entire process, thus ensuring tests are traced and data securely stored. Results: Our designed AI-implemented diagnostic platform recognises the nucleocapsid protein gene of SARS-CoV-2 with high analytical sensitivity and specificity. A total of 752 NHS patient samples, 367 confirmed positives for coronavirus disease (COVID-19) and 385 negatives, were used for the development and validation of the test and the AI-assisted platform. The smart diagnostic platform was then used to test 150 positive clinical samples covering a dynamic range of clinically meaningful viral loads and 250 negative samples. When compared to RT-qPCR, our AI-assisted diagnostics platform was shown to be reliable, highly specific (100%) and sensitive (98-100% depending on viral load) with a limit of detection of 1.4 copies of RNA per µL in 30 min. Using this data, our CE-IVD and MHRA approved test and associated diagnostic platform has been approved for medical use in the United Kingdom under the UK Health Security Agency's Medical Devices (Coronavirus Test Device Approvals, CTDA) Regulations 2022. Laboratory and in-silico data presented here also indicates that the VIDIIA diagnostic platform is able to detect the main variants of concern in the United Kingdom (September 2023). Discussion: This system could provide an efficient, time and cost-effective platform to diagnose SARS-CoV-2 and other infectious diseases in resource-limited settings.

Cellular immunity to SARS-CoV-2 following intrafamilial exposure in seronegative family members.

Introduction: Family studies of antiviral immunity provide an opportunity to assess virus-specific immunity in infected and highly exposed individuals, as well as to examine the dynamics of viral infection within families. Transmission of SARS-CoV-2 between family members represented a major route for viral spread during the early stages of the pandemic, due to the nature of SARS-CoV-2 transmission through close contacts. Methods: Here, humoral and cellular immunity is explored in 264 SARS-CoV-2 infected, exposed or unexposed individuals from 81 families in the United Kingdom sampled in the winter of 2020 before widespread vaccination and infection. Results: We describe robust cellular and humoral immunity into COVID-19 convalescence, albeit with marked heterogeneity between families and between individuals. T-cell response magnitude is associated with male sex and older age by multiple linear regression. SARS-CoV-2-specific T-cell responses in seronegative individuals are widespread, particularly in adults and in individuals exposed to SARS-CoV-2 through an infected family member. The magnitude of this response is associated with the number of seropositive family members, with a greater number of seropositive individuals within a family leading to stronger T-cell immunity in seronegative individuals. Discussion: These results support a model whereby exposure to SARS-CoV-2 promotes T-cell immunity in the absence of an antibody response. The source of these seronegative T-cell responses to SARS-CoV-2 has been suggested as cross-reactive immunity to endemic coronaviruses that is expanded upon SARS-CoV-2 exposure. However, in this study, no association between HCoV-specific immunity and seronegative T-cell immunity to SARS-CoV-2 is identified, suggesting that de novo T-cell immunity may be generated in seronegative SARS-CoV-2 exposed individuals.

A simple, robust flow cytometry-based whole blood assay for investigating sex differential interferon alpha production by plasmacytoid dendritic cells.

Central to sex differences observed in outcome from infection and vaccination is the innate immune response, and specifically production of type I interferons by plasmacytoid dendtiric cells (pDCs), the main producers of IFN-α. Evaluation of IFN-α production by pDCs is therefore critical for studies of innate immune function. However, reliable measurement of pDC IFN-α is hampered by reduced cell yields and cytokine production after cryopreservation or after even short delays in stimulating freshly isolated cells. We here describe a simple yet robust method for measuring IFN-α production in pDCs that preserves cell activation and cytokine production through immediate stimulation of whole blood and subsequent maintenance at 37 °C.

Associations between selected immune-mediated diseases and tuberculosis: record-linkage studies.

BACKGROUND: Previous studies have suggested that there may be an association between some immune-mediated diseases and risk of tuberculosis (TB). METHODS: We analyzed a database of linked statistical records of hospital admissions and death certificates for the whole of England (1999 to 2011), and a similar database (the Oxford Record Linkage Study (ORLS)) for a region of southern England in an earlier period. Rate ratios for TB were determined, comparing immune-mediated disease cohorts with comparison cohorts. RESULTS: In the all-England dataset, there were significantly elevated risks of TB after hospital admission for the following individual immune-mediated diseases: Addison's disease, ankylosing spondylitis, autoimmune hemolytic anemia, chronic active hepatitis, coeliac disease, Crohn's disease, dermatomyositis, Goodpasture's syndrome, Hashimoto's thyroiditis, idiopathic thrombocytopenia purpura (ITP), myasthenia gravis, myxedema, pemphigoid, pernicious anemia, polyarteritis nodosa, polymyositis, primary biliary cirrhosis, psoriasis, rheumatoid arthritis, scleroderma, Sjögren's syndrome, systemic lupus erythematosus (SLE), thyrotoxicosis and ulcerative colitis. Particularly high levels of risk were found for Addison's disease (rate ratio (RR) = 11.9 (95% CI 9.5 to 14.7)), Goodpasture's syndrome (RR = 10.8 (95% CI 4.0 to 23.5)), SLE (RR = 9.4 (95% CI 7.9 to 11.1)), polymyositis (RR = 8.0 (95% CI 4.9 to 12.2)), polyarteritis nodosa (RR = 6.7 (95% CI 3.2 to 12.4)), dermatomyositis (RR = 6.6 (95% CI 3.0 to 12.5)), scleroderma (RR = 6.1 (95% CI 4.4 to 8.2)) and autoimmune hemolytic anemia (RR = 5.1 (95% CI 3.4 to 7.4)). CONCLUSIONS: These two databases show that patients with some immune-mediated diseases have an increased risk of TB, although we cannot explicitly state the direction of risk or exclude confounding. Further study of these associations is warranted, and these findings may aid TB screening, control and treatment policies.

Hypereosinophilia and acute bilateral facial palsy: an unusual presentation of a common disease.

A 60-year-old man presented with an acute, pruritic, erythematous rash associated with marked hypereosinophilia (2.34×10(9)/l (0.04-0.40)). There was eosinophilic infiltration on hepatic, bone marrow and lymph node biopsies, with multiple lung nodules and mild splenomegaly. However, extensive investigation excluded parasitic or bacterial causes, specific allergens or the Fip1L1 mutation seen in myeloproliferative hypereosinophilia. Six months into the illness, he developed an acute, left, complete lower motor neurone facial palsy over hours, and an acute right lower motor neurone facial palsy 2 weeks later, without recovery. Over the subsequent 3 months, he developed complex partial seizures, a transient 72-h non-epileptic encephalopathy and episodic vertigo with ataxia. Further investigation showed bilateral enhancement of the VII nerves and labyrinthis on gadolinium-enhanced MR brain scan, cerebrospinal fluid lymphocytosis and neurophysiological evidence of polyradicolopathy. His eosinophil count fell with corticosteroids, hydroxycarbamide, imatinib and ultimately mepolezumab, but without symptomatic improvement. Repeat lymph node biopsy showed Kaposi's sarcoma, leading to a diagnosis of HIV-1 infection with a modestly reduced CD4 count of 413×10(6)/l (430-1690). Hypereosinophila and eosinophilic folliculitis are recognised features of advanced HIV infection, and transient bilateral facial palsy occasionally occurs at the time of seroconversion. This is the first report of a chronic bilateral facial palsy likely due to primary HIV infection, not occurring during seroconversion and in association with hypereosinophilia. This case emphasises the protean manifestations of HIV infection and the need for routine testing in atypical clinical presentations.

Reciprocal recognition of an HLA-Cw4-restricted HIV-1 gp120 epitope by CD8+ T cells and NK cells.

OBJECTIVES: The HIV-1 Nef protein selectively downregulates human leukocyte antigen (HLA)-A and HLA-B but not HLA-C molecules on the surface of infected cells. This allows HIV-infected cells to evade recognition by most cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. We investigated the recognition of an HLA-Cw4-restricted HIV-1 gp120 epitope SFNCGGEFF (SF9) and its variant SFNCGGEFL (SL9) by T cells and NK receptors. DESIGN AND METHOD: Recognition of HIV-1 gp120 peptides (SF9 and SL9) by T-cell clones was measured by staining with HLA-Cw4-peptide tetrameric complexes and cytolytic assays using target cell pulsed with either peptides. KIR2DL1 binding to these two peptides was measured using surface plasmon resonance and tetramer staining of an NK cell line. RESULT: : CTLs could recognize SF9 better than the variant SL9, as shown by both tetramer staining and cytolytic assays. Intriguingly, an HLA-Cw4 tetramer folded with the 'escape' variant SL9 could bind to KIR2DL1 on NK cell lines with higher affinity than HLA-Cw4-SF9. The binding of KIR2DL1 to its ligand results in inhibition of NK cell function. Our results indicate that the HIV-1 gp120 variant peptide SL9 could potentially escape both from NK cell and CTL recognition by increasing its affinity for KIR2DL1 binding. CONCLUSION: These data suggest that HIV-1 can acquire mutations that are capable of escaping from both CTL and NK cell recognition, a phenomenon we have termed 'double escape'.

HIV-specific cytotoxic T cells from long-term survivors select a unique T cell receptor.

HIV-specific cytotoxic T lymphocytes (CTL) are important in controlling HIV replication, but the magnitude of the CTL response does not predict clinical outcome. In four donors with delayed disease progression we identified Vbeta13.2 T cell receptors (TCRs) with very similar and unusually long beta-chain complementarity determining region 3 (CDR3) regions in CTL specific for the immunodominant human histocompatibility leukocyte antigens (HLA)-B8-restricted human immunodeficiency virus-1 (HIV-1) nef epitope, FLKEKGGL (FL8). CTL expressing Vbeta13.2 TCRs tolerate naturally arising viral variants in the FL8 epitope that escape recognition by other CTL. In addition, they expand efficiently in vitro and are resistant to apoptosis, in contrast to FL8-specific CTL using other TCRs. Selection of Vbeta13.2 TCRs by some patients early in the FL8-specific CTL response may be linked with better clinical outcome.