Assessing SARS-CoV-2-specific T-cell reactivity in late convalescents and vaccinees: Comparison and combination of QuantiFERON and activation-induced marker assays, and relation with antibody status.

OBJECTIVES: Monitoring of SARS-CoV-2 spread and vaccination strategies have relied on antibody (Ab) status as a correlate of protection. We used QuantiFERON™ (QFN) and Activation-Induced Marker (AIM) assays to measure memory T-cell reactivity in unvaccinated individuals with prior documented symptomatic infection (late convalescents) and fully vaccinated asymptomatic donors (vaccinees). METHODS: Twenty-two convalescents and 13 vaccinees were enrolled. Serum anti-SARS-CoV-2 S1 and N Abs were measured using chemiluminescent immunoassays. QFN was performed following instructions and interferon-gamma (IFN-γ) measured by ELISA. AIM was performed on aliquots of antigen-stimulated samples from QFN tubes. SARS-CoV-2-specific memory CD4+CD25+CD134+, CD4+CD69+CD137+ and CD8+CD69+CD137+ T-cell frequencies were measured by flow cytometry. RESULTS: In convalescents, substantial agreement was observed between QFN and AIM assays. IFN-γ concentrations and AIM+ (CD69+CD137+) CD4+ T-cell frequencies correlated with each other, with Ab levels and AIM+ CD8+ T-cell frequencies, whereas AIM+ (CD25+CD134+) CD4+ T-cell frequencies correlated with age. AIM+ CD4+ T-cell frequencies increased with time since infection, whereas AIM+ CD8+ T-cell expansion was greater after recent reinfection. QFN-reactivity and anti-S1 titers were lower, whereas anti-N titers were higher, and no statistical difference in AIM-reactivity and Ab positivity emerged compared to vaccinees. CONCLUSIONS: Albeit on a limited sample size, we confirm that coordinated, cellular and humoral responses are detectable in convalescents up to 2 years after prior infection. Combining QFN with AIM may enhance detection of naturally acquired memory responses and help stratify virus-exposed individuals in T helper 1-type (TH1)-reactive (QFNpos AIMpos Abshigh), non-TH1-reactive (QFNneg AIMpos Abshigh/low), and pauci-reactive (QFNneg AIMneg Abslow).

Immunotherapy of COVID-19: Inside and Beyond IL-6 Signalling.

Acting on the cytokine cascade is key to preventing disease progression and death in hospitalised patients with COVID-19. Among anti-cytokine therapies, interleukin (IL)-6 inhibitors have been the most used and studied since the beginning of the pandemic. Going through previous observational studies, subsequent randomised controlled trials, and meta-analyses, we focused on the baseline characteristics of the patients recruited, identifying the most favourable features in the light of positive or negative study outcomes; taking into account the biological significance and predictivity of IL-6 and other biomarkers according to specific thresholds, we ultimately attempted to delineate precise windows for therapeutic intervention. By stimulating scavenger macrophages and T-cell responsivity, IL-6 seems protective against viral replication during asymptomatic infection; still protective on early tissue damage by modulating the release of granzymes and lymphokines in mild-moderate disease; importantly pathogenic in severe disease by inducing the proinflammatory activation of immune and endothelial cells (through trans-signalling and trans-presentation); and again protective in critical disease by exerting homeostatic roles for tissue repair (through cis-signalling), while IL-1 still drives hyperinflammation. IL-6 inhibitors, particularly anti-IL-6R monoclonal antibodies (e.g., tocilizumab, sarilumab), are effective in severe disease, characterised by baseline IL-6 concentrations ranging from 35 to 90 ng/mL (reached in the circulation within 6 days of hospital admission), a ratio of partial pressure arterial oxygen (PaO2) and fraction of inspired oxygen (FiO2) between 100 and 200 mmHg, requirement of high-flow oxygen or non-invasive ventilation, C-reactive protein levels between 120 and 160 mg/L, ferritin levels between 800 and 1600 ng/mL, D-dimer levels between 750 and 3000 ng/mL, and lactate dehydrogenase levels between 350 and 500 U/L. Granulocyte-macrophage colony-stimulating factor inhibitors might have similar windows of opportunity but different age preferences compared to IL-6 inhibitors (over or under 70 years old, respectively). Janus kinase inhibitors (e.g., baricitinib) may also be effective in moderate disease, whereas IL-1 inhibitors (e.g., anakinra) may also be effective in critical disease. Correct use of biologics based on therapeutic windows is essential for successful outcomes and could inform future new trials with more appropriate recruiting criteria.

Ferritin as prognostic marker in COVID-19: the FerVid study.

BACKGROUND: In COVID-19 patients the progressive clinical deterioration seems secondary to the activation of a cytokine storm. Ferritin is considered a direct mediator of the immune system and some evidences suggested a shared physio-pathogenic basis between COVID-19 and 'Hyperferritinemic Syndromes.' The aim of our study was to evaluate the prognostic role of ferritin in COVID-19 patients. METHODS: We retrospectively studied consecutive COVID-19 patients admitted to four Italian Internal Medicine Units. Role of potential prognostic markers was evaluated with binary logistic regression analysis and results were expressed as odds ratios (ORs) with the corresponding 95% confidence intervals (CIs). Poor outcome was defined as death or need to transfer in the intensive care unit. RESULTS: Two hundred patients were included (mean age 68.75 ± 13.22 years). Ferritin value was highly elevated (>3000 ng/mL) in 8% of our population; 13% of patients were transferred to intensive care units and 12% of patients died. At multivariate analysis, highly elevated ferritin levels (OR 16.67 C.I. 4.89-57.57 p < 0.001) and hemoglobin < 10 g/dL (OR 8.88 C.I. 2.02-39.09 p = 0.004) were independently associated with a bad outcome.Patients with ferritin values > 3000 ng/ml appeared to have an inflammatory activation with elevated values of CRP and D-dimer and low values of lymphocyte count. CONCLUSION: Our results confirm the prognostic role of ferritin in hospitalized COVID-19 patients. Patients with high ferritin levels should be considered critically ill and treated in an adequate setting. Furthermore, COVID-19 seems to share some characteristics with hyperferritinemic syndromes with potential therapeutic implications.

Anti-IL6 treatment of serious COVID-19 disease: A monocentric retrospective experience.

ABSTRACT: COVID-19 is causing a high influx of patients suffering from serious respiratory complications leading the necessity to find effective therapies. These patients seem to present with cytokine perturbation and high levels of IL6. Tocilizumab and sarilumab could be effective in this condition.We retrospectively collected data about 112 consecutive hospitalized in a single center.Fifty (IL6 group) treated with tocilizumab (8 mg/kg intravenously [IV], 2 infusions 12 hours apart) or sarilumab 400 mg IV once and 62 treated with the standard of care but not anti-cytokine drugs (CONTROL group).To determine whether anti-IL6 drugs are effective in improving prognosis and reducing hospitalization times and mortality in COVID-19 pneumonia.To date 84% (42/50) of IL6 group patients have already been discharged and only 2/50 are still recovered and intubated in intensive care. Six/fifty patients (12%) died: 5/6 due to severe respiratory failure within a framework of severe acute respiratory distress syndrome (ARDS), 1 suffered an acute myocardial infarction, and 1 died of massive pulmonary thromboembolism. There were no adverse treatment events or infectious complications. Compared to the CONTROL group they showed a lower mortality rate (12% versus 43%), for the same number of complications and days of hospitalization.Anti-IL6 drugs seem to be effective in the treatment of medium to severe forms of COVID-19 pneumonia reducing the risk of mortality due to multi-organ failure, acting at the systemic level and reducing inflammation levels and therefore microvascular complications. However, it is essential to identify the best time for treatment, which, if delayed, is rendered useless as well as counterproductive. Further studies and ongoing clinical trials will help us to better define patients eligible as candidates for more aggressive intervention.

Good's syndrome, a rare form of acquired immunodeficiency associated with thymomas.

Good's syndrome (GS) or thymomaassociated immunodeficiency is a rare clinical entity that should be ruled out in patients with thymoma who develop severe, recurrent bacterial infections and opportunistic viral and fungal infections. There are no treatment protocols established, hence, early recognition is imperative to avoid complications. We report the case of a 42-year-old female, known for a previous thymectomy for giant thymoma who has suffered for a long time from recurrent pulmonary and urinary tract infections and cold sores. In March 2016 she referred to our unit complaining of fever, cough, chest pain, and cold sores due to Herpes simplex virus (HSV), confirmed serologically as HSV-1. Chest X-ray showed left pneumonia due to Streptococcus pneumoniae. She started antibiotics (amoxicillin/clavulanic acid associated with azithromycin) with gradual improvement. Given her history she was studied for an underlying immunodeficiency: IgG, IgA, and IgM were significantly low or absent, as well as all IgG subclasses; blood and bone marrow aspirate leucocyte immunophenotyping showed complete absence of B lymphocytes and reduced CD4+ T cells. In light of: i) thymoma; ii) B lymphocyte deficit; iii) hypogammaglobulinemia; iv) recurrent infections, GS was diagnosed and pre-emptive immunoglobulin treatment, associated with HSV and Pneumocystis jiroveci prophylaxis (Acyclovir for HSV and Sulfamethoxazole- Trimethoprim for P. jiroveci) were started. Since then the patient has no longer presented any infectious episodes.