Based on current evidence, recent guidelines of the National Institute of Health, USA indicated the use of remdesivir and dexamethasone for the treatment of COVID-19 patients with mild-moderate ...disease, not requiring high-flow oxygen. No therapeutic agent directed against the immunologic pathogenic mechanisms related to the cytokine release syndrome complicating the disease was indicated.
The purpose of this review was to assess the clinical impact of different therapies for COVID-19; thus, helping to identify the optimal management of the disease. To explain the rationale for the different therapeutic approaches, the characteristics of SARS-CoV-2, the pathogenesis of COVID-19, and the immune response triggered by SARS-CoV-2 infection were reported.
The efficacy assessment of the different treatments was performed by a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Available English language published articles including randomised controlled trials, open-label trials of antivirals and immune therapies extracted from Medline, Google Scholar, and MedRxiv databases were analysed. For inclusion, the primary end point of the trials had to be the efficacy as measured by the improvement of clinical features, or mortality, or the Intensive Care Unit Admission rate, or the discharge number. Case reports, paediatric studies, and studies without control group were excluded. The literature search was extended up to August 15, 2020.
After the removal of duplicate articles, and the exclusion of studies not meeting the eligibility criteria, 2 trials of lopinavir/ritonavir, 1 of favipiravir, 3 of remdesivir, 1 of dexamethasone, 3 of hydroxychloroquine, 2 of colchicine, 6 of tocilizumab, 1 of sarilumab, 1 of siltuximab, 2 of anakinra, 3 of baricitinib, 1 of ruxolitinib, 1 of mavrilimumab, and 1 of itolizumab were suitable for the review. Among antivirals, only remdesivir significantly reduced the time to recovery, and mortality. Data for chloroquine and hydroxychloroquine were largely inconclusive. In a large trial, dexamethasone 6 mg/day reduced mortality by one-third. Trials of tocilizumab and sarilumab did not definitively demonstrate efficacy. Anakinra significantly reduced the mortality in 2 trials. Three retrospective trials on a cumulative number of 145 patients, reported the efficacy of baricitinib, with significant reduction of intensive care unit admission, and deaths. These results were recently confirmed by the ACTT-2 trial. Due to paucity of studies and to the small size clinical series, the results of other immune therapies were not conclusive.
Beyond the supportive therapy, up to now the best therapeutic approach for COVID-19 may be a three-step combination therapy, including remdesivir 100 mg/day (200 mg loading dose on first day) in the first stage of the disease, and combined dexamethasone 6 mg/day plus baricitinib 4 mg/day to target the immune dysregulation triggered by the SARS-CoV-2 infection. The promising results of anakinra should be confirmed by the ongoing RCTs.
Estimated 2017 tuberculosis (TB) incidence is 10 million and mainly depends on the reservoir of individuals with latent TB infection (LTBI). QuantiferonⓇ-TB Gold in-Tube (QFT-GIT) is one of the tests ...used for LTBI detection. Since 2015 a new version, QuantiferonⓇ-TB Gold Plus (QFT-Plus) is available.
To perform a systematic review and meta-analysis to assess the diagnostic accuracy for TB of QFT-Plus compared to QFT-GIT.
PubMed and Scopus were used to detect records related to predefined strings from 2015 to 2018. Full text articles dealing with the sensitivity and/or specificity of the QFT-Plus vs. QFT-GIT for active-TB and LTBI detection were analyzed. Scientific quality and risk of bias were assessed using QADAS-2.
We selected 15 articles. Studies were mainly observational and cross-sectional, performed in 8 countries. Sample size differed in the TB group (27 to 164) compared to LTBI group (29 to 1031). Pooled sensitivity of QFT-Plus for active-TB was 0.94 (0.91 and 0.95 for TB1 and TB2, respectively), whereas pooled specificity for healthy status was 0.96. Pooled sensitivity and specificity for LTBI was 0.91 and 0.95, respectively.
We show that QFT-Plus is more sensitive compared to QFT-GIT for detecting M. tuberculosis infection, mainly due to TB2 responses.
New approaches to control the spread of tuberculosis (TB) are needed, including tools to predict development of active TB from latent TB infection (LTBI). Recent studies have described potential ...correlates of risk, in order to inform the development of prognostic tests for TB disease progression. These efforts have included unbiased approaches employing "omics" technologies, as well as more directed, hypothesis-driven approaches assessing a small set or even individual selected markers as candidate correlates of TB risk. Unbiased high-throughput screening of blood RNAseq profiles identified signatures of active TB risk in individuals with LTBI, ≥1 year before diagnosis. A recent infant vaccination study identified enhanced expression of T-cell activation markers as a correlate of risk prior to developing TB; conversely, high levels of Ag85A antibodies and high frequencies of interferon (IFN)-γ specific T-cells were associated with reduced risk of disease. Others have described CD27
IFN-γ
CD4
T-cells as possibly predictive markers of TB disease. T-cell responses to TB latency antigens, including heparin-binding haemagglutinin and DosR-regulon-encoded antigens have also been correlated with protection.Further studies are needed to determine whether correlates of risk can be used to prevent active TB through targeted prophylactic treatment, or to allow targeted enrolment into efficacy trials of new TB vaccines and therapeutic drugs.
Tuberculosis (TB) still represents an important issue for public health in underdeveloped countries, but the use of antitumor necrosis factor agents (anti-TNF) for the treatment of inflammatory ...rheumatic disorders has reopened the problem also in countries with low TB incidence, due to the increased risk of TB reactivation in subjects with latent tuberculosis infection (LTBI). Over the last 5 years, several non-anti-TNF-targeted biologics have been licensed for the treatment of rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. We reviewed the epidemiology of TB, the role of different cytokines and of the immune system cells involved in the immune response against TB infection, the methods to detect LTBI, and the risk of TB reactivation in patients exposed to non-anti-TNF-targeted biologics. Given the limited role exerted by the cytokines different from TNF, as expected, data from controlled trials, national registries of biologics, and postmarketing surveillance show that the risk of TB reactivation in patients receiving non-anti-TNF-targeted biologics is negligible, hence raising the question whether the screening procedures for LTBI would be necessary.
•TB and COVID-19 coinfection does not affect M. tuberculosis-specific response.•TB and COVID-19 coinfection limits the ability to in vitro respond to SARS-CoV-2.•Latent TB infection does not affect ...the ability to in vitro respond to SARS-CoV-2.
The interaction of COVID-19 and tuberculosis (TB) are still poor characterized. Here we evaluated the immune response specific for Micobacterium tuberculosis (Mtb) and SARS-CoV-2 using a whole-blood-based assay-platform in COVID-19 patients either with TB or latent TB infection (LTBI).
We evaluated IFN-γ level in plasma from whole-blood stimulated with Mtb antigens in the Quantiferon-Plus format or with peptides derived from SARS-CoV-2 spike protein, Wuhan-Hu-1 isolate (CD4-S).
We consecutively enrolled 63 COVID-19, 10 TB-COVID-19 and 11 LTBI-COVID-19 patients.
IFN-γ response to Mtb-antigens was significantly associated to TB status and therefore it was higher in TB-COVID-19 and LTBI-COVID-19 patients compared to COVID-19 patients (p ≤ 0.0007).
Positive responses against CD4-S were found in 35/63 COVID-19 patients, 7/11 LTBI-COVID-19 and only 2/10 TB-COVID-19 patients. Interestingly, the responders in the TB-COVID-19 group were less compared to COVID-19 and LTBI-COVID-19 groups (p = 0.037 and 0.044, respectively). Moreover, TB-COVID-19 patients showed the lowest quantitative IFN-γ response to CD4-S compared to COVID-19-patients (p = 0.0336) and LTBI-COVID-19 patients (p = 0.0178).
Our data demonstrate that COVID-19 patients either TB or LTBI have a low ability to build an immune response to SARS-CoV-2 while retaining the ability to respond to Mtb-specific antigens.
Latent tuberculosis infection was the term traditionally used to indicate tuberculosis (TB) infection. This term was used to define "a state of persistent immune response to stimulation by
antigens ...through tests such as the tuberculin skin test (TST) or an interferon-γ release assay (IGRA) without clinically active TB". Recent evidence indicates that the spectrum from TB infection to TB disease is much more complex, including a "continuum" of situations didactically reported as uninfected individual, TB infection, incipient TB, subclinical TB without signs/symptoms, subclinical TB with unrecognised signs/symptoms, and TB disease with signs/symptoms. Recent evidence suggests that subclinical TB is responsible for important
transmission. This review describes the different stages described above and their relationships. It also summarises the new developments in prevention, diagnosis and treatment of TB infection as well as their public health and policy implications.
To describe the evolution of the definition of "tuberculosis infection" and didactically describe the continuum of stages existing between TB infection and disease.To discuss the recommended approaches to prevent, diagnose and treat TB infection.
•Whole-blood interferon-γ-release assay (IGRA) enabled the response to SARS-CoV-2 peptides to be evaluated.•Spike protein was the best stimulus to discriminate COVID-19 from NO-COVID-19.•A ...SARS-CoV-2-specific response is rarely observed in NO-COVID-19 individuals.•This SARS-CoV-2 IGRA has the potential to be a powerful diagnostic tool.
To identify the best experimental approach to detect a SARS-CoV-2-specific T cell response using a whole-blood platform.
Whole-blood from 56 COVID-19 and 23 “NO-COVID-19” individuals were stimulated overnight with different concentrations (0.1 or 1 μg/mL) of SARS-CoV-2 PepTivator® Peptide Pools, including spike (pool S), nucleocapsid (pool N), membrane (pool M), and a MegaPool (MP) of these three peptide pools. ELISA was used to analyse interferon (IFN)-γ levels.
The IFN-γ-response to every SARS-CoV-2 peptide pool was significantly increased in COVID-19 patients compared with NO-COVID-19 individuals. Pool S and MegaPool were the most potent immunogenic stimuli (median: 0.51, IQR: 0.14–2.17; and median: 1.18, IQR: 0.27–4.72, respectively) compared with pools N and M (median: 0.22, IQR: 0.032–1.26; and median: 0.22, IQR: 0.01−0.71, respectively). The whole-blood test based on pool S and MegaPool showed a good sensitivity of 77% and a high specificity of 96%. The IFN-γ-response was mediated by both CD4+ and CD8+ T cells, and independently detected of clinical parameters in both hospitalized and recovered patients.
This easy-to-use assay for detecting SARS-CoV-2-specific T cell responses may be implemented in clinical laboratories as a powerful diagnostic tool.
B-cells not only produce immunoglobulins and present antigens to T-cells, but also additional key roles in the immune system. Current knowledge on the role of B-cells in infections caused by ...intracellular bacteria is fragmentary and contradictory. We therefore analysed the phenotypical and functional properties of B-cells during infection and disease caused by Mycobacterium tuberculosis (Mtb), the bacillus causing tuberculosis (TB), and included individuals with latent TB infection (LTBI), active TB, individuals treated successfully for TB, and healthy controls. Patients with active or treated TB disease had an increased proportion of antibodies reactive with mycobacteria. Patients with active TB had reduced circulating B-cell frequencies, whereas only minor increases in B-cells were detected in the lungs of individuals deceased from TB. Both active TB patients and individuals with LTBI had increased relative fractions of B-cells with an atypical phenotype. Importantly, these B-cells displayed impaired proliferation, immunoglobulin- and cytokine- production. These defects disappeared upon successful treatment. Moreover, T-cell activity was strongest in individuals successfully treated for TB, compared to active TB patients and LTBI subjects, and was dependent on the presence of functionally competent B-cells as shown by cellular depletion experiments. Thus, our results reveal that general B-cell function is impaired during active TB and LTBI, and that this B-cell dysfunction compromises cellular host immunity during Mtb infection. These new insights may provide novel strategies for correcting Mtb infection-induced immune dysfunction towards restored protective immunity.
•Baricitinib has been suggested as a promising therapy for COVID-19.•Baricitinib modulates in vitro SARS-CoV-2-specific-response in a whole blood platform.•Baricitinib decreases ...viral-specific-response mainly in mild/moderate COVID-19.
Baricitinib seems a promising therapy for COVID-19. To fully-investigate its effects, we in-vitro evaluated the impact of baricitinib on the SARS-CoV-2-specific-response using the whole-blood platform.
We evaluated baricitinib effect on the IFN-γ-release and on a panel of soluble factors by multiplex-technology after stimulating whole-blood from 39 COVID-19 patients with SARS-CoV-2 antigens. Staphylococcal Enterotoxin B (SEB) antigen was used as a positive control.
In-vitro exogenous addition of baricitinib significantly decreased IFN-γ response to spike- (median: 0.21, IQR: 0.01–1; spike+baricitinib 1000 nM median: 0.05, IQR: 0–0.18; p < 0.0001) and to the remainder-antigens (median: 0.08 IQR: 0–0.55; remainder-antigens+baricitinib 1000 nM median: 0.03, IQR: 0–0.14; p = 0.0013). Moreover, baricitinib significantly decreased SEB-induced response (median: 12.52, IQR: 9.7–15.2; SEB+baricitinib 1000 nM median: 8, IQR: 1.44–12.16; p < 0.0001). Baricitinib did modulate other soluble factors besides IFN-γ, significantly decreasing the spike-specific-response mediated by IL-17, IL-1β, IL-6, TNF-α, IL-4, IL-13, IL-1ra, IL-10, GM-CSF, FGF, IP-10, MCP-1, MIP-1β (p ≤ 0.0156). The baricitinib-decreased SARS-CoV-2-specific-response was observed mainly in mild/moderate COVID-19 and in those with lymphocyte count ≥1 × 103/µl.
Exogenous addition of baricitinib decreases the in-vitro SARS-CoV-2-specific response in COVID-19 patients using a whole-blood platform. These results are the first to show the effects of this therapy on the immune-specific viral response.
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The QuantiFERON-TB Gold Plus (QFT-Plus) is a new test for latent tuberculosis infection (LTBI) diagnosis, in which has been added a new tube containing shorter peptides stimulating CD8 T-cells and ...CD4-stimulating-peptides. Measurement of alternative biomarkers to Interferon-γ (IFN-γ) in QFT-Plus may improve its sensitivity. Interferon-γ inducible protein 10 (IP-10), has been proposed as a tuberculosis (TB) biomarker. We aimed to evaluate the IP-10 accuracy in QFT-Plus for LTBI diagnosis.
QFT-Plus was performed in 36 active TB, 31 LTBI and 16 healthy donors (HD). IP-10 was detected by ELISA.
IP-10 is increased in TB1 and TB2 tubes in subjects with active TB and LTBI compared to HD. A ROC analysis comparing active TB and HD was performed and a cut-off of 1174 pg/mL for TB1 and 928.8 pg/mL for TB2 identified active TB with 86% sensitivity (Se) and 94% specificity (Sp). Moreover, increased IP-10 in response to TB1 was found in subjects with LTBI compared to those with active TB. A cut-off point of ≥16,108 pg/mL was chosen to maximize the test performance. However, the test predicted LTBI only with 58% Se and 61% Sp.
These results suggest that IP-10 is an alternative biomarker to IFN-γ in the QFT-Plus format.
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