Commercial Interferon-gamma release assay to assess the immune response to first and second doses of mRNA vaccine in previously COVID-19 infected versus uninfected individuals.

We analysed immunological response during vaccination by using quantitative anti-spike IgG antibodies (qAbs) and Interferon-gamma (IFNγ) production by SARS-CoV-2-specific CD4+ and CD8+ T cells (QuantiFERON® assay). Blood samples were collected at four time points: a day before the reception of first (T0) and second (T1) BNT162b2 doses, 14 (T2) and 28 days (T3) after second dose. Fifty individuals were included: 34 previously infected by SARS-CoV-2 (CoV2+) and 16 that were not (CoV2-). Among CoV2+, we only observed significant differences after the first dose in both qAbs and IFNγ+ T cells. CoV2- showed differences after each dose, and the response was lower than CoV2+. Older people presented a higher response in CoV2+, while in CoV2, young people responded best. Our results suggest that the second BNT162b2 vaccine dose is not a priority in people with previous COVID-19. QuantiFERON® is a good option to monitor T-cell immunity to SARS-CoV-2.

Activating Killer-Cell Immunoglobulin-Like Receptors Are Associated With the Severity of Coronavirus Disease 2019.

BACKGROUND: Etiopathogenesis of the clinical variability of the coronavirus disease 2019 (COVID-19) remains mostly unknown. In this study, we investigate the role of killer cell immunoglobulin-like receptor (KIR)/human leukocyte antigen class-I (HLA-I) interactions in the susceptibility and severity of COVID-19. METHODS: We performed KIR and HLA-I genotyping and natural killer cell (NKc) receptors immunophenotyping in 201 symptomatic patients and 210 noninfected controls. RESULTS: The NKcs with a distinctive immunophenotype, suggestive of recent activation (KIR2DS4low CD16low CD226low CD56high TIGIThigh NKG2Ahigh), expanded in patients with severe COVID-19. This was associated with a higher frequency of the functional A-telomeric activating KIR2DS4 in severe versus mild and/or moderate patients and controls (83.7%, 55.7% and 36.2%, P < 7.7 × 10-9). In patients with mild and/or moderate infection, HLA-B*15:01 was associated with higher frequencies of activating B-telomeric KIR3DS1 compared with patients with other HLA-B*15 subtypes and noninfected controls (90.9%, 42.9%, and 47.3%; P < .002; Pc = 0.022). This strongly suggests that HLA-B*15:01 specifically presenting severe acute respiratory syndrome coronavirus 2 peptides could form a neoligand interacting with KIR3DS1. Likewise, a putative neoligand for KIR2DS4 could arise from other HLA-I molecules presenting severe acute respiratory syndrome coronavirus 2 peptides expressed on infected an/or activated lung antigen-presenting cells. CONCLUSIONS: Our results support a crucial role of NKcs in the clinical variability of COVID-19 with specific KIR/ligand interactions associated with disease severity.

Inhaled bronchodilators use and clinical course of adult inpatients with Covid-19 pneumonia in Spain: A retrospective cohort study.

BACKGROUND: In the current coronavirus health crisis, inhaled bronchodilators(IB) have been suggested as a possible treatment for patients hospitalized. Patients with evidence of Covid-19 pneumonia worldwide have been prescribed these medications as part of therapy for the disease, an indication for which this medications could be ineffective taken on account the pathophysiology and mechanisms of disease progression. OBJECTIVE: The main objective was to evaluate whether there is an association between IB use and length of stay. Primary end points were the number of days that a patient stayed in the hospital and death as a final event in a time to event analysis. Pneumonia severity, oxygen requirement, involved drugs, comorbidity, historical or current respiratory diagnoses and other drugs prescribed to treat coronavirus pneumonia were also evaluated. METHODS: A descriptive, observational, cross-sectional study was performed in this tertiary hospital in Madrid (Spain). Data were obtained regarding patients hospitalized with Covid-19, excluding those who were intubated. The primary and secondary outcomes such as duration of hospitalization and death were compared in patients who received IB with those in patients who did not. RESULTS: 327 patients were evaluated, mean age was 64.4 ± 15.8 years. Median length of hospitalization stay was 10 days. Of them 292 (89.3%) overcame the disease, the remaining 35 died. Patients who had received IB did not have less mortality rate (odds ratio 0.839; 95% CI: 0.401 to 1.752) and less hospitalization period when compared with patients who did not received IB (odds ratio 1.280; 95% CI: 0.813 to 2.027). There was no significant association between IB use and recovery or death. Hypertension and diabetes were the most common comorbidities. The prevalence of chronic respiratory disease in our cohort was low (21.1%). Anticholinergics were the IB more frequently prescribed for Covid-19 pneumonia. Better response in patients treated with inhaled corticosteroids was not observed. CONCLUSION: Off-label indication of inhaled-bronchodilators for Covid-19 patients are common in admitted patients. Taken on account our results, the use of IB for coronavirus pneumonia apparently is not associated with a significantly patient's improvement. Our study confirms the hypothesis that inhaled bronchodilators do not improve clinical outcomes or reduce the risk of Covid-19 mortality. This could be due to the fact that the virus mainly affects the lung parenchyma and the pulmonary vasculature and probably not the airway. More researches are necessary in order to fill the gap in evidence for this new indication.