Serological Detection for Toxoplasmosis among Patients with Covid-19 in Thi-Qar Province

Covid-19 is a viral disease that affects humans caused by a type of virus belonging to the family Coronaviridae called the SARS-CoV-2 virus. The parasitic infection associated with this disease affects the host's immune response regulation. The levels of IgG and IgM of Toxoplasma gondii in the serum of patients with COVID-19 were measured by immunoassay of the patient's sera by ELISA. Also, the level of interferon-gamma (IFN-gamma) in a covid-19 patient with or without Toxoplasmosis was evaluated. 120 samples were collected, 60 were positive for COVID-19, confirmed by clinically and radiographic examination, and 30 were in the control group. The results showed a significant difference between the infection with Covid-19 and T. gondii during the chronic phase of Toxoplasmosis compared to the negative relationship in the acute phase. The results of INF-gamma levels among Covid-19 patients were positive for all samples included in the test (30 Covid-19 patients and 30 patients COVID-19(+)/T. gondii IgG) compared to the control group. The chronic form of Toxoplasma disease, due to change in the production of this interferon, the COVID-19 infection has changed.Copyright © 2023 by Razi Vaccine & Serum Research Institute.

Interferon gamma-1b for the prevention of hospital-acquired pneumonia in critically ill patients: a phase 2, placebo-controlled randomized clinical trial.

PURPOSE: We aimed to determine whether interferon gamma-1b prevents hospital-acquired pneumonia in mechanically ventilated patients. METHODS: In a multicenter, placebo-controlled, randomized trial conducted in 11 European hospitals, we randomly assigned critically ill adults, with one or more acute organ failures, under mechanical ventilation to receive interferon gamma-1b (100 µg every 48 h from day 1 to 9) or placebo (following the same regimen). The primary outcome was a composite of hospital-acquired pneumonia or all-cause mortality on day 28. The planned sample size was 200 with interim safety analyses after enrolling 50 and 100 patients. RESULTS: The study was discontinued after the second safety analysis for potential harm with interferon gamma-1b, and the follow-up was completed in June 2022. Among 109 randomized patients (median age, 57 (41-66) years; 37 (33.9%) women; all included in France), 108 (99%) completed the trial. Twenty-eight days after inclusion, 26 of 55 participants (47.3%) in the interferon-gamma group and 16 of 53 (30.2%) in the placebo group had hospital-acquired pneumonia or died (adjusted hazard ratio (HR) 1.76, 95% confidence interval (CI) 0.94-3.29; P = 0.08). Serious adverse events were reported in 24 of 55 participants (43.6%) in the interferon-gamma group and 17 of 54 (31.5%) in the placebo group (P = 0.19). In an exploratory analysis, we found that hospital-acquired pneumonia developed in a subgroup of patients with decreased CCL17 response to interferon-gamma treatment. CONCLUSIONS: Among mechanically ventilated patients with acute organ failure, treatment with interferon gamma-1b compared with placebo did not significantly reduce the incidence of hospital-acquired pneumonia or death on day 28. Furthermore, the trial was discontinued early due to safety concerns about interferon gamma-1b treatment.

Interferon gamma release assay results and outcomes in COVID-19 patients

Introduction/Aim: The interferon gamma release assay (IGRA), used in diagnosing latent tuberculosis infections (LTBI), relies on the release of interferon gamma from T-cells exposed to M. tuberculosis specific peptides. An 'indeterminate' IGRA result is most commonly due an inadequate control (or 'mitogen') response, which may reflect underlying T-cell dysfunction, that is potentially associated with markers of severity in patients with COVID-19. The aim of this study was to determine associations and predictors of an indeterminate IGRA in hospitalised patients with COVID-19. Method(s): We performed a single centre, retrospective study on COVID-19 patients admitted to a tertiary referral hospital who had IGRA testing performed over a 5 months period. Demographics, markers of COVID-19 severity and other parameters were recorded, along with outcomes of COVID-19 infection. The primary outcomes included predictors of indeterminate IGRA results and associations with COVID-19 outcomes (severity, length of stay and mortality). Result(s): A total of 181 patients were included for analysis. Outcomes of IGRA testing included negative (n = 117) and indeterminate (n = 60) results. Patients with a positive IGRA (n = 4) were excluded from analysis. The odds of an indeterminate IGRA were increased with a higher severity grade of COVID-19 (OR 2.5;95% CI 1.3-4.9), immunosuppression at baseline (OR 2.3;95% CI 1.1-4.7) and when IGRA testing was done after immunosuppression for COVID-19 was commenced (OR 1.4;95% CI 1.1-1.8). A longer length of stay was more likely with an indeterminate IGRA compared to a negative result (OR 1.08;95% CI 1.03-1.14), No difference in mortality between the two IGRA subgroups was found. Conclusion(s): Our study demonstrates an indeterminate IGRA was associated with markers of disease severity and immunosuppression. In this cohort an indeterminate result was also associated with worse COVID-19 outcomes in hospitalised patients. This result could potentially be used as a prognostic marker for patients admitted with COVID-19.

Longitudinal humoral and cell-mediated immune responses in a population-based cohort in Zurich, Switzerland between March and June 2022 - evidence for protection against Omicron SARS-CoV-2 infection by neutralizing antibodies and spike-specific T-cell responses.

OBJECTIVES: The correlate(s) of protection against SARS-CoV-2 remain incompletely defined. Additional information regarding the combinations of antibody and T cell-mediated immunity which can protect against (re)infection is needed. METHODS: We conducted a population-based, longitudinal cohort study including 1044 individuals of varying SARS-CoV-2 vaccination and infection statuses. We assessed spike (S)- and nucleocapsid (N)-immunoglobulin(Ig)G and wildtype, Delta, and Omicron-neutralizing antibody (N-Ab) activity. In a subset of 328 individuals, we evaluated S, membrane (M), and N-specific T cells. Three months later, we reassessed Ab (n = 964) and T cell (n = 141) responses and evaluated factors associated with protection from (re)infection. RESULTS: At the study start, >98% of participants were S-IgG seropositive. N-IgG and M/N-T-cell responses increased over time, indicating viral (re)exposure, despite existing S-IgG. Compared to N-IgG, M/N-T cells were a more sensitive measure of viral exposure. High N-IgG titers, Omicron-N-Ab activity, and S-specific-T-cell responses were all associated with a reduced likelihood of (re)infection over time. CONCLUSION: Population-level SARS-CoV-2 immunity is S-IgG-dominated, but heterogeneous. M/N-T-cell responses can distinguish previous infection from vaccination, and monitoring a combination of N-IgG, Omicron-N-Ab, and S-T-cell responses may help estimate protection against SARS-CoV-2 (re)infection.

Erythema nodosum -Expanding diagnostic workout in COVID-19 pandemic

Case report Erythema nodosum (EN) is considered a delayed type IV hypersensitivity reaction, triggered by exposure to an antigen, which diagnostic workout is usually challenging. Several conditions have been described as possible causes for EN, including infections, sarcoidosis, pregnancy, neoplasic and inflammatory diseases. Rarely, vaccines such as tetanus, diphtheria, BCG, hepatitis B, human papillomavirus, malaria, rabies, smallpox, typhoid, and cholera have been associated with subsequent EN. We present a 31-year- old leucodermic female with suppurative adenitis, who developed painful erythematous nodules on the pretibial area of the lower limbs. Ten days prior to presentation she had received the first dose of the COVID-19 mRNA-1273 vaccine. Fever, lymphadenopathy, fatigue, weight loss, arthritis, cough, diarrhoea, other organ-specifc symptoms and close contact with tuberculosis were excluded. She was under oral contraception for several years, that was not discontinued. Pregnancy was excluded. No positive signs were detected on physical examination besides the referred nodules. Laboratory tests revealed a normal complete blood count, erythrocyte sedimentation rate, C-reactive protein, antistreptolysin O titer, renal and hepatic tests. Interferon-gamma release assay was negative. Circulating rheumatoid factor was normal, anti-nuclear, anti-double stranded DNA and anti-neutrophil cytoplasmatic antibodies were negative. Angiotensin converting enzyme and protein electrophoresis were normal. Hepatitis B and C, HIV 1/2 and syphilis serologic profiles were negative. Urinalysis and fecal calprotectin were unremarkable. The patient was treated with naproxen and topic betamethasone dipropionate. Violaceous involution was reported, with complete resolution of the EN lesions over the following month. In the literature, there are rare reports of EN following SARS-COV2 infection and also after COVID-19 vaccination. To our knowledge this is the second report of EN after the COVID-19 mRNA-1273 vaccine. This case highlights the importance of clinical awareness for the possible association of COVID-19 vaccination and EN, adding to the already extensive list of causes included in the etiological investigation of these patients.

Advances in TB testing

Globally, tuberculosis (TB) was the leading cause of death from a single infectious agent until the coronavirus (COVID-19) pandemic. In 2020, an estimated 10 million people fell ill with TB and a total of 1.5 million people died from the disease. About one-quarter of the global population, almost two billion people, is estimated to be latently infected with Mycobacterium tuberculosis (MTB). Although latent TB infection (LTBI) is asymptomatic and noncontagious, about 5–10% of LTBI patients have a lifetime risk of progression to active TB. The diagnosis and treatment of active cases are extremely vital for TB control programs. However, achieving the End TB goal of 2035 without the ability to identify and treat the pool of latently infected individuals will be a big challenge. To do so, improved technology to provide more accurate diagnostic tools and accessibility are crucial. Therefore, this chapter covers the current WHO-endorsed tests and advances in diagnostic and screening tests for active and latent TB. © 2023

[In vitro activity of human recombinant interferon gamma against SARS-CoV-2 virus].

INTRODUCTION: The development of drugs against SARS-CoV-2 continues to be crucial for reducing the spread of infection and associated mortality. The aim of the work is to study the neutralization of the SARS-CoV-2 virus with interferon gamma preparations in vitro. MATERIALS AND METHODS: The activity of recombinant human interferon gamma for intramuscular and subcutaneous administration of 500,000 IU and for intranasal administration of 100,000 IU against the SARS-CoV-2 virus in vitro was studied. The methodological approach of this study is based on the phenomenon of a decrease in the number of plaques formed under the action of a potential antiviral drug. RESULTS: The antiviral activity of recombinant interferon gamma has been experimentally confirmed, both in preventive and therapeutic application schemes. The smallest number of plaques was observed with the preventive scheme of application of the tested object at concentrations of 1000 and 333 IU/ml. The semi-maximal effective concentration (EC50) with the prophylactic regimen was 24 IU/ml. DISCUSSION: The preventive scheme of application of the tested object turned out to be more effective than therapeutic one, which is probably explained by the launch of the expression of various interferon-stimulated genes that affect to a greater extent the steps of virus entry into the cell and its reproduction. CONCLUSION: Further study of the effect of drugs based on recombinant interferon gamma on the reproduction of the SARS-CoV-2 virus for clinical use for prevention and treatment is highly relevant.

Glucocorticoids selectively affect the memory T cell response to SARS-Cov2 spike in vaccinated and post-infected patients with systemic lupus erythematosus.

Immune response to vaccines and pathogens remains unclear in patients with systemic lupus erythematosus (SLE). To investigate this, a single-center retrospective study was conducted with 47 SLE patients vaccinated against COVID-19, including 13 who subsequently developed an asymptomatic/mild disease. As compared to controls, post-vaccine response against Spike was reduced in SLE patients when considering both memory T-cells in a whole blood interferon gamma release assay (IGRA-S) and IgG anti-Spike antibody (Ab) responses. The SLE-associated defective IGRA-S response was associated with a serum albumin level below 40 g/L and with the use of glucocorticoids, while a defective IgG anti-Spike Ab response was associated with lower levels of anti-dsDNA and anti-SSA/Ro 52 kDa Abs. IGRA-S and IgG anti-Spike responses were independent from SLE activity and clinical phenotype, low complement, hypergammaglobulinemia, and lymphopenia. As compared to controls, SLE patients showed a rapid decay of anti-Spike T-cell memory and stable IgG anti-Spike Ab responses. In conclusion, both T cell and humoral anti-Spike responses were independently affected in our SLE patients cohort, which supports the exploration of both responses in the follow-up of SLE patients and especially in those receiving glucocorticoids.

Evaluation of T cell responses with the QuantiFERON SARS-CoV-2 assay in individuals with 3 doses of BNT162b2 vaccine, SARS-CoV-2 infection, or hybrid immunity.

Cellular immunity after SARS-CoV-2 infection or immunization may be important for long-lasting protection against severe COVID-19 disease. We investigated cellular immune responses after SARS-CoV-2 infection and/or vaccination with an interferon-γ release assay (QuantiFERON, QFN), in parallel, with humoral immunity assessment. We recruited 41 participants: unvaccinated convalescent children and adults and vaccinated uninfected or vaccinated convalescent adults. All vaccinated adults had received three doses of the BNT162b2 COVID-19 vaccine at 6.2 to 10.9 months prior to their inclusion to the study. All the unvaccinated participants were tested negative with QFN. Regarding the vaccinated population, 50% (8/16) of the vaccinated uninfected adults and 57.1% (8/14) of the vaccinated convalescent adults were tested positive. QFN did not detect T cell responses in unvaccinated individuals and in a significant number of vaccinated individuals. Further comparative studies with different immunoassays are required to elucidate whether this is the result of waning immunity or low sensitivity of the assay.

Comparative analysis between STANDARD-E Covi-FERON ELISA with pre-existing IFN-γ release assays and determination of the optimum cutoff value for assessment of T-Cell response to SARS-CoV-2.

BACKGROUND: Interferon-gamma (IFN-γ) release assays (IGRAs) are useful for the assessment of the T-cell response to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). We aimed to assess the performance of the newly developed IGRA ELISA test compared to the pre-existing assays and to validate the cutoff value in real-world conditions. METHODS: We enrolled 219 participants and assessed agreement between STANDARD-E Covi-FERON ELISA with Quanti-FERON SARS-CoV-2 (QFN SARS-CoV-2), as well as with T SPOT Discovery SARS-CoV-2 based on Cohen's kappa-index. We further determined the optimal cutoff value for the Covi-FERON ELISA according to the immune response to vaccinations or infections. RESULTS: We found a moderate agreement between Covi-FERON ELISA and QFN SARS-CoV-2 before vaccination (kappa-index = 0.71), whereas a weak agreement after the first (kappa-index = 0.40) and second vaccinations (kappa-index = 0.46). However, the analysis between Covi-FERON ELISA and T SPOT assay demonstrated a strong agreement (kappa-index >0.7). The cut-off value of the OS (original spike) marker was 0.759 IU/mL with a sensitivity of 96.3% and specificity of 78.7%, and that of the variant spike (VS) marker was 0.663 IU/mL with a sensitivity and specificity of 77.8% and 80.6%, respectively. CONCLUSION: The newly determined cut-off value may provide an optimum value to minimize and prevent the occurrence of false-negative or false-positive during the assessment of T-cell immune response using Covi-FERON ELISA under real-world conditions.

Distinct profiles and kinetics of soluble infammatory markers in patients with acute and chronic HCV-infections and SARS-CoV-2-infections: Implications for the long-term consequences of viral infections?

Background and Aims Viral infections occur acutely but can also progress chronically, with the immune system having a central role in immunopathoge-nesis. The question arises whether all alterations in immune responses are reversible after viral elimination (spontaneously or by therapy). Therefore, the aim of this study is to compare soluble infammatory markers (SIM) during and after infection with SARS-CoV-2 and acute and chronic HCV-infections. Patients and Method Patients with acute HCV (n = 29), chronic HCV (n = 54), SARS-CoV-2 (n = 39) and 31 healthy-controls were included. Blood samples were tested at baseline, end of treatment/infection, and follow-up ( >= 9 months after baseline). IL-12p70, IL-1b, IL-4, IL-5, IL-6, IL-8, TNF, IFN-g, IL-10, IL-22, CXCL-10, MCP-1, MIP-1b, ITAC were quantified using the HD-SP-X Imaging and Analysis SystemTM. Results SIM profiles in patients with acute HCV were substantially elevated at baseline and the decrease during follow-up was considerably less compared to the SARS-CoV-2 cohort. In chronic HCV-patients, viral elimination by therapy resulted in a decrease in SIM, although not always to those of controls. Cirrhotic HCV patients had higher SIM levels after HCV elimination than non-cirrhotic chronic HCV-patients. In the SARS-CoV-2 cohort, most SIM returned to levels of controls 3 months after baseline. Conclusions SIM profiles and kinetics after viral elimination difer between blood-borne acute and chronic HCV- and respiratory SARS-CoV-2-infections. The immunologic imprint 9 months after cured HCV-infection (both acute and chronic) appears to be more pronounced than after SARS-CoV-2-infection. Further analysis is needed to correlate the SIM profle with the clinical pheno-type (long-HepC vs. long-COVID-19).

COVID-19 and Tuberculosis: Two Knives in a Sheath

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) has caused a global human outbreak, making it a more serious threat to human health than any other infectious disease. Coronavirus infectious disease 2019 (COVID-19) has severely affected the lifestyles of people around the world and caused high mortality throughout the world. In both pandemic and seasonal influenza, co-infection of COVID-19 with other diseases has been linked to worse outcomes. The literature revealed that it is char-acteristically associated with comorbidities such as hypertension, blood pressure, obesity, cardiovascular diseases, and other microbial infections. Furthermore, microbial coinfections worsen respiratory viral infections and are a common cause of death in influenza pandemics. Deplorably, Tuberculosis (TB) is also a dreadful lung infection and attains cytokine equilibrium with host cells to maintain the latent stage. Studies showed that human coronaviruses (hCoV) activate latent TB to an active state due to unregulated cytokine production, called a cytokine storm. The present review concisely discusses the reason and status of co-infection of COVID-19 with TB based on previous case reports, cohorts, and scientific studies. COVID-19 patients are prone to be infected with TB and vice-versa in TB-prone areas. The therapeutic opportunities for overcoming the COVID-19 induced cytokine storm have also been emphasized by the present clinical trial candidates. In conclusion, we recommend categorizing the patients based on their medical history and cured or latent TB patients should be particularly closely monitored. They should be tested for Interferon Gamma Release Assay (IGRA) regularly on and after COVID-19 infection.Copyright © 2022 Bentham Science Publishers.

Investigation of cellular and humoral immune responses following COVID-19 vaccination in respiratory healthcare professionals

Background: SARS-CoV-2 vaccines are expected to induce both cellular and humoral immune responses, however, the dynamics and correlation between the two types of immunity are not precisely understood. Aim(s): Assessing IgG levels and T-cell response induced by SARS-CoV-2 vaccines and investigating the correlation between cellular and humoral immune responses. Method(s): Blood samples were taken from 166 respiratory healthcare professionals at four time-points: first before administering the booster vaccine, then on day 28, 56 and 120 post-vaccination. For the assessment of humoral immune response anti-Spike protein IgG ELISA was used, while T-cell response was tested by interferon-gammarelease-assay. Result(s): Out of 166 patients, 120 individuals presented positive result for interferon-gamma, while 100 had positive results for IgG. The positivity rate of cellular immune response was found to be significantly higher than humoral between the second and third doses of anti-COVID vaccines (P<0,05). Participants, who have had SARS-CoV-2 infection before the first two shots, the immune response was detectable at a statistically higher rates than in the COVID naive group. The third dose triggered different dynamics regarding the IgG titers and T-cell response. Four months after the administration of the booster shot both humoral and cellular immune response were detectable simultaneously. Conclusion(s): After the first two doses, the cellular immune response was found to last longer than humoral, especially in previously infected individuals. Measuring the T-cell responses to SARS-CoV-2 vaccines may complement the antibody tests currently used in clinical practice.

Interferon-gamma Mediated Metabolic Pathways in Hospitalized Patients During Acute and Reconvalescent COVID-19.

Background: Fatigue, sleep disturbance, and neurological symptoms during and after COVID-19 are common and might be associated with inflammation-induced changes in tryptophan (Trp) and phenylalanine (Phe) metabolism. Aim: This pilot study investigated interferon gamma inducible biochemical pathways (namely Trp catabolism, neopterin, tyrosine [Tyr], and nitrite formation) during acute COVID-19 and reconvalescence. Patients and methods: Thirty one patients with moderate to severe COVID-19 admitted to the University Hospital of Innsbruck in early 2020 (March-May) were followed up. Neurotransmitter precursors Trp, Phe, Tyr as well as kynurenine (Kyn), neopterin, nitrite, and routine laboratory parameters were analyzed during acute infection and at a follow-up (FU) 60 days thereafter. Clinical symptoms of patients (neurological symptoms, fatigue, sleep disturbance) were recorded and associations with concentrations of laboratory parameters investigated. Results and conclusion: Almost half of the patients suffered from neurological symptoms (48.4%), the majority of patients experienced sleep difficulties (56.7%) during acute COVID-19. Fatigue was present in nearly all patients. C-reactive protein (CRP), interleukin-6 (IL-6), neopterin, Kyn, Phe concentrations were significantly increased, and Trp levels depleted during acute COVID-19. Patients with sleep impairment and neurological symptoms during acute illness presented with increased CRP and IL-6 concentrations, Trp levels were lower in patients with sleep disturbance. In general, inflammatory markers declined during reconvalescence. A high percentage of patients suffered from persistent symptoms at FU (neurological symptoms: 17.2%, fatigue: 51.7%, sleeping disturbance: 34.5%) and had higher CRP concentrations. Nitrite and Phe levels were lower in patients with sleeping difficulties at FU and Kyn/Trp ratio, as indicator of IDO activity, was significantly lower in patients with neurological symptoms compared to patients without them at FU. In summary, inflammation induced alterations of amino acid metabolism might be related to acute and persisting symptoms of COVID-19.

SARS-CoV-2 specific T-cell humoral response assessment after COVID-19 vaccination using a rapid direct real-time PCR amplification.

OBJECTIVES: The SARS-CoV-2 immune response is mediated by both humoral and cellular immunity. In this study, SARS-CoV-2 specific cellular immunity was tested by a novel direct real-time PCR (dRT-PCR) assay, targeting mRNA of CXCL10, and compared with respect to an ELISA measuring interferon gamma (IFN-γ) release. METHODS: Whole blood (Li-He) and serum samples were collected from 92 healthcare workers (HCW), with three doses of homologous (Pfizer/BioNTech, n=74) or heterologous (Pfizer/BioNTech and Vaxzevria or Moderna, n=18) vaccinations. Li-He samples were incubated with SCV2 PANEL-1-T-ACTIVATION (Hyris srl, Lodi, Italy), or CoV-2 IGRA TUBE ELISA (Euroimmune, Lubeck, Germany). CXCL10 mRNA expression was analyzed by bCube/bApp (Hyris), while IFN-γ was evaluated by quant-T-Cell SARS-CoV-2 ELISA (Euroimmune). Anti-SARS-CoV-2 S-RBD IgG levels were measured in sera using a CLIA assay (Snibe, Shenzen, China). RESULTS: Imprecision of dRT-PCR assay was found to be satisfactory, and the two methods for measuring T cell immunity to SARS-CoV-2 peptides agreed in 82/87 (94.2%) of results. At qualitative dRT-PCR analyses, 81 subjects (93.2%) resulted as reactive to SARS-CoV-2 peptides, 3 (3.4%) were borderline and 3 were negative (3.4%). At univariate and multivariate analyses of quantitative dRT-PCR mRNA of CXCL10 and IFN-γ release results showed no difference between HCW with previous infection, homologous/heterologous vaccination, or demographical features. Anti-SARS-CoV-2 S-RBD IgG was associated with the previous infection and the time between the last vaccination or positivity. CONCLUSIONS: Direct RT-PCR appeared accurate for determining the presence or absence of immunoreactivity of SARS-CoV-2 specific T cells, especially when rapid analyses are required, such as for organ transplantation.

Performance of an interferon-γ release assay-based test for cell-mediated immunity to SARS-CoV-2.

In search for immunological correlates of protection against acute coronavirus disease 2019 (COVID-19) there is a need for high through-put assays for cell-mediated immunity (CMI) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We established an interferon-γ release assay -based test for detection of CMI against SARS-CoV-2 spike (S) or nucleocapsid (NC) peptides. Blood samples obtained from 549 healthy or convalescent individuals were measured for interferon-γ (IFN-γ) production after peptide stimulation using a certified chemiluminescence immunoassay. Test performance was calculated applying cutoff values with the highest Youden indices in receiver-operating-characteristics curve analysis and compared to a commercially available serologic test. Potential confounders and clinical correlates were assessed for all test systems. 522 samples obtained from 378 convalescent in median 298 days after PCR-confirmed SARS-CoV-2 infection and 144 healthy control individuals were included in the final analysis. CMI testing had a sensitivity and specificity of up to 89% and 74% for S peptides and 89% and 91% for NC peptides, respectively. High white blood cell counts correlated negatively with IFN-γ responses but there was no CMI decay in samples obtained up to one year after recovery. Severe clinical symptoms at time of acute infection were associated with higher measures of adaptive immunity and reported hair loss at time of examination. This laboratory-developed test for CMI to SARS-CoV-2 NC peptides exhibits excellent test performance, is suitable for high through-put routine diagnostics, and should be evaluated for clinical outcome prediction in prospective pathogen re-exposure.

Guanylate-binding protein 1 restricts avian coronavirus infectious bronchitis virus-infected HD11 cells.

The Infectious Bronchitis Virus (IBV), a coronavirus, is a key avian pathogen that causes acute and highly infectious viral respiratory diseases. IBV is an enveloped, positive-sense RNA virus, and the host factors that restrict infection and replication of the virus remain poorly understood. Guanylate-binding protein 1 (GBP1), an interferon-gamma (IFN-γ)-inducible guanosine triphosphatase (GTPase), is a major player in host immunity and provides defense against viral replication. However, the role of chicken GBP1 (chGBP1) in the IBV-life cycle is not well understood. Therefore, this study aimed to reveal the potential role of IFN-γ-induced chGBP1 in mediating host anti-IBV infection responses. We identified the host restriction factor, chGBP1, in IBV-infected chicken macrophages HD11 cell lines. We showed that chGBP1 was upregulated by treatment with both IFN-γ and IBV in HD11 cells. chGBP1 inhibited IBV replication in a dose-dependent manner and enhanced IFN-γ anti-IBV activity. Importantly, the GTPase domain of chGBP1 played a pivotal role in its anti-IBV activity. Furthermore, chGBP1 interacts with IBV Nucleocapsids protein to degrade IBV-N protein through the autophagy pathway. Taken together, our results demonstrate a critical role of chGBP1 in anti-IBV in macrophages HD11 cells.

Comparison of Two Commercially Available Interferon-γ Release Assays for T-Cell-Mediated Immunity and Evaluation of Humoral Immunity against SARS-CoV-2 in Healthcare Workers.

Cellular immunity against SARS-CoV-2 is an important component of the immune response to the virus. At present, two such tests based on interferon-gamma release (interferon-γ release assays, IGRAs) are available-Quan-T-Cell SARS-CoV-2 by EUROIMMUN and T-SPOT.COVID by Oxford Immunotec. In this paper, we compared the results of these two tests in 90 subjects employed at the Public Health Institute Ostrava who had previously undergone COVID-19 infection or were vaccinated against that disease. To the best of our knowledge, this is the first head-to-head comparison of these two tests evaluating T-cell-mediated immunity against SARS-CoV-2. In addition, we also evaluated humoral immunity in the same individuals using the in-house virus neutralization test and IgG ELISA assay. The evaluation yielded similar results for both IGRAs, with Quan-T-Cell appearing to be insignificantly (p = 0.08) more sensitive (all 90 individuals were at least borderline positive) than T-SPOT.COVID (negative results found in five patients). The overall qualitative (presence/absence of immune response) agreement of both tests with virus neutralization test and anti-S IgG was also excellent (close or equal to 100% in all subgroups, with the exception of unvaccinated Omicron convalescents, a large proportion of whom, i.e., four out of six subjects, were IgG negative while at least borderline positive for T-cell-mediated immunity measured by Quan-T). This implies that the evaluation of T-cell-mediated immunity is a more sensitive indicator of immune response than the evaluation of IgG seropositivity. This is true at least for unvaccinated patients with a history of being infected only by the Omicron variant, but also likely for other groups of patients.

Mendelian Susceptibility to Mycobacterial Disease: Retrospective Clinical and Genetic Study in Mexico.

Mendelian susceptibility to mycobacterial disease (MSMD) is a rare genetic disorder characterized by impaired immunity against intracellular pathogens, such as mycobacteria, attenuated Mycobacterium bovis-Bacillus Calmette-Guérin (BCG) vaccine strains, and environmental mycobacteria in otherwise healthy individuals. Retrospective study reviewed the clinical, immunological, and genetic characteristics of patients with MSMD in Mexico. Overall, 22 patients diagnosed with MSMD from 2006 to 2021 were enrolled: 14 males (64%) and eight females. After BCG vaccination, 12 patients (70%) developed BCG infection. Furthermore, 6 (22%) patients developed bacterial infections mainly caused by Salmonella, as what is described next in the text is fungal infections, particularly Histoplasma. Seven patients died of disseminated BCG disease. Thirteen different pathogenic variants were identified in IL12RB1 (n = 13), IFNGR1 (n = 3), and IFNGR2 (n = 1) genes. Interleukin-12Rß1 deficiency is the leading cause of MSMD in our cohort. Morbidity and mortality were primarily due to BCG infection.