COVID-19 has a broad spectrum of clinical manifestations, from asymptomatic or mild/moderate symptoms to severe symptoms and death. The mechanisms underlying its clinical evolution are still unclear. Upon SARS-CoV-2 infection, host factors, such as the inflammasome system, are activated by the presence of the virus inside host cells. The search for COVID-19 risk factors is of relevance for clinical management. In this study, we investigated the impact of inflammasome single-nucleotide polymorphisms (SNPs) in SARS-CoV-2-infected individuals with distinct severity profiles at clinical presentation. Patients were divided into two groups according to disease severity at clinical presentation based on the WHO Clinical Progression Scale. Group 1 included patients with mild/moderate disease ( WHO < 6 ; n = 76 ), and group 2 included patients with severe/critical COVID-19 ( WHO ≥ 6 ; n = 357 ). Inpatients with moderate to severe/critical profiles were recruited and followed-up at Hospital Center for COVID-19 Pandemic – National Institute of Infectology (INI)/FIOCRUZ, RJ, Brazil, from June 2020 to March 2021. Patients with mild disease were recruited at Oswaldo Cruz Institute (IOC)/FIOCRUZ, RJ, Brazil, in August 2020. Genotyping of 11 inflammasome SNPs was determined by real-time PCR. Protection and risk estimation were performed using unconditional logistic regression models. Significant differences in NLRP3 rs1539019 and CARD8 rs2043211 were observed between the two groups. Protection against disease severity was associated with the A/A genotype ( OR adj = 0.36 ; P = 0.032 ), allele A ( OR adj = 0.93 ; P = 0.010 ), or carrier-A ( OR adj = 0.45 ; P = 0.027 ) in the NLRP3 rs1539019 polymorphism; A/T genotype ( OR adj = 0.5 ; P = 0.045 ), allele T ( OR adj = 0.93 ; P = 0.018 ), or carrier-T ( OR adj = 0.48 ; P = 0.029 ) in the CARD8 rs2043211 polymorphism; and the A-C-G-C-C ( OR adj = 0.11 ; P = 0.018 ), A-C-G-C-G ( OR adj = 0.23 ; P = 0.003 ), C-C-G-C-C ( OR adj = 0.37 ; P = 0.021 ), and C-T-G-A-C ( OR adj = 0.04 ; P = 0.0473 ) in NLRP3 genetic haplotype variants. No significant associations were observed for the other polymorphisms. To the best of our knowledge, this is the first study demonstrating an association between CARD8 and NLRP3 inflammasome genetic variants and protection against COVID-19 severity, contributing to the discussion of the impact of inflammasomes on COVID-19 outcomes.

Tuberculosis (TB) is the most common comorbidity and the leading cause of death among HIV-infected individuals. Although the combined antiretroviral therapy (cART) during TB treatment improves the survival of TB/HIV patients, the occurrence of immune reconstitution inflammatory syndrome (IRIS) in some patients poses clinical and scientific challenges. This work aimed to evaluate blood innate lymphocytes during therapeutic intervention for both diseases and their implications for the onset of IRIS. Natural killer (NK) cells, invariant NKT cells (iNKT), γδ T cell subsets, and in vitro NK functional activity were characterized by multiparametric flow cytometry in the following groups: 33 TB/HIV patients (four with paradoxical IRIS), 27 TB and 25 HIV mono-infected subjects (prior to initiation of TB treatment and/or cART and during clinical follow-up to 24 weeks), and 25 healthy controls (HC). Concerning the NK cell repertoire, several activation and inhibitory receptors were skewed in the TB/HIV patients compared to those in the other groups, especially the HCs. Significantly higher expression of CD158a ( p = 0.025), NKp80 ( p = 0.033), and NKG2C ( p = 0.0076) receptors was detected in the TB/HIV IRIS patients than in the non-IRIS patients. Although more NK degranulation was observed in the TB/HIV patients than in the other groups, the therapeutic intervention did not alter the frequency during follow-up (weeks 2–24). A higher frequency of the γδ T cell population was observed in the TB/HIV patients with inversion of the Vδ2 + /Vδ2 − ratio, especially for those presenting pulmonary TB, suggesting an expansion of particular γδ T subsets during TB/HIV co-infection. In conclusion, HIV infection impacts the frequency of circulating NK cells and γδ T cell subsets in TB/HIV patients. Important modifications of the NK cell repertoire were observed after anti-TB treatment (week 2) but not during the cART/TB follow-up (weeks 6–24). An increase of CD161 + NK cells was related to an unfavorable outcome. Despite the low number of cases, a more preserved NK cell profile was detected in IRIS patients previous to treatment, suggesting a role for these cells in IRIS onset. Longitudinal evaluation of the NK repertoire showed the impact of TB treatment and implicated these cells in TB pathogenesis in TB/HIV co-infected patients.

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COVID-19 has challenged the scientific community in the search for biological markers and information that can contribute to the early management of the severe disease. Given the global scale of COVID-19, including reports of reinfection even in the presence of effective vaccines, we have not yet been able to eradicate the disease. This factor implies the emergence of new waves and an increasing number of hospitalizations. This study aimed to characterize the neutralizing antibody (Nab) geometric mean titers (GMTs) in hospitalized patients with COVID-19 and to evaluate the association with length of stay, comorbidities, and patient outcome. Among the 103 participants, 84 (81.5%) had some previous condition associated with worsening health, and 31 (30%) died. We found that neutralization potency varied greatly across individuals and was significantly higher in patients discharged before 14 days than in patients who stayed longer in the hospital. During the study period, 15 people living with HIV (PLWH) were hospitalized, and no significant difference in clinical characteristics or anti-SARS-CoV-2 Nabs was observed. However, PLWH with severe COVID-19 were younger (41.7, IQR=17.5) than other hospitalized COVID-19 patients (59.3, IQR=22,P<0.01). A high anti-HIV-1 antibody GMT of 583.9 (95% CI: 344-990) was detected, demonstrating maintenance of anti-HIV-1 Nab production among PLWH coinfected with SARS-CoV-2. Therefore, these results indicate that neutralizing antibodies are not the only immunological response capable of controlling disease progression. Nevertheless, these data highlight the importance of more Nab screening studies to predict shorter hospital stays.

Background COVID-19 has a broad spectrum of clinical manifestations, from asymptomatic to mild or moderate symptoms, reaching the most severe forms and death. The mechanisms underlying the SARS-CoV-2 infection and its clinical evolution are still unclear. Once SARS-CoV-2 infects individuals, host factors are activated by the presence of the virus inside the cells, such as the inflammasome system. The search of risk factors for COVID-19 is of relevance for clinical management. In this study, we investigated the impact of 11 single-base polymorphisms (SNPs) in the NLRP3, CARD8, AIM2, CASP-1, IFI16, and IL-1β inflammasome genes in SARS-CoV-2 infected individuals with distinct disease outcomes. Methods Patients were divided into two groups: (1) inpatients, with severe/critical disease (Hospitalized group, n=451), and (2) convalescent volunteers with prior SARS-CoV-2 infection and a history of asymptomatic to mild symptoms (Mild group, n=43). Patients hospitalized were followed up at a Hospital Center for COVID-19 Pandemic – National Institute of Infectology (INI)/FIOCRUZ, Rio de Janeiro, Brazil, from June 2020 to March 2021. The Mild group was recruited at Oswaldo Cruz Institute (IOC)/FIOCRUZ, Rio de Janeiro, Brazil, in 2020. Genotyping of the SNPs was determined by Real-Time PCR. Protection and risk estimations were performed by unconditional logistic regression models. Results Among the genotyped SNPs, significant differences in the NLRP3 rs1539019 and rs10754558 frequencies were observed between the groups. The C/C genotype (ORadj=6.31; Padj=0.026) or allele C (ORadj=1.05; Padj=0.002) in rs1539019 polymorphism were associated with the risk for hospitalization, while the C/G genotype (ORadj=0.16; Padj=0.016) or carrier-G (ORadj=0.2; Padj=0.028) in rs10754558 polymorphism were associated with protection for hospitalization. Regarding the NLRP3 genetic variants, the A-C-G-C-G haplotype (ORadj=0.14; Padj= 0.030) was associated with protection for hospitalization. No significant association was observed for the other polymorphisms. Conclusions As of our knowledge, this is the first study demonstrating the association of inflammasome NLRP3 variants with risk and/or protection for hospitalization in COVID-19. Studies linking the NLRP3 inflammasome and SARS-CoV-2 infection are still scarce due to the recent emergence of this pathogen. Our results contribute to the discussion of the impact of inflammasomes in the clinical evolution of COVID-19.