The Expression Levels of TREX1 and IFN-α Are Associated with Immune Reconstitution in HIV-1-Infected Individuals.

TREX1 acts in the initial prevention of an autoimmune response, but it may contribute to the permissiveness of retrovirus infections. This study investigated the association between the levels of TREX1 gene expression with the polymorphisms TREX1 rs3135941 (T/C) and TREX1 rs3135945 (G/A), and the presence of antinuclear antibodies (ANA) in antiretroviral therapy (ART)-naïve individuals and after 1 year of treatment. Blood samples from 119 individuals with HIV-1 were subjected to genotyping of polymorphisms and quantification of TREX1 gene expression and HIV-1 viral load by qPCR. The concentration of IFN-α and the number of CD4+/CD8+ T lymphocytes were determined by ELISA and flow cytometry, respectively; ANA was investigated by immunofluorescence. A control group of 167 seronegative individuals was used for the comparison of genotypic frequencies. The frequency of the polymorphisms were not associated with HIV infection or with variations in the expression of TREX1 and IFN-α (p > 0.05). ART-naïve individuals exhibited higher TREX1 expression and lower IFN-α expression. After 1 year of ART, TREX1 levels were reduced, while IFN-α and CD4+ T lymphocytes were elevated (p < 0.05). Some individuals on ART presented ANA. These results suggest that ART-mediated restoration of immune competence is associated with a reduction in TREX1 expression, which may induce the development of ANA, regardless of the polymorphism investigated.

Association of the IFNG +874T/A Polymorphism with Symptomatic COVID-19 Susceptibility.

Tumor necrosis factor (TNF) and interferon-gamma (IFNγ) are important inflammatory mediators in the development of cytokine storm syndrome (CSS). Single nucleotide polymorphisms (SNPs) regulate the expression of these cytokines, making host genetics a key factor in the prognosis of COVID-19. In this study, we investigated the associations of the TNF -308G/A and IFNG +874T/A polymorphisms with COVID-19. We analyzed the frequencies of the two polymorphisms in the control groups (CG: TNF -308G/A, n = 497; IFNG +874T/A, n = 397), a group of patients with COVID-19 (CoV, n = 222) and among the subgroups of patients with nonsevere (n = 150) and severe (n = 72) COVID-19. We found no significant difference between the genotypic and allelic frequencies of TNF -308G/A in the groups analyzed; however, both the frequencies of the high expression genotype (TT) (CoV: 13.51% vs. CG: 6.30%; p = 0.003) and the *T allele (CoV: 33.56% vs. CG: 24. 81%; p = 0.001) of the IFNG +874T/A polymorphism were higher in the COVID-19 group than in the control group, with no differences between the subgroups of patients with nonsevere and severe COVID-19. The *T allele of IFNG +874T/A (rs2430561) is associated with susceptibility to symptomatic COVID-19. These SNPs provided valuables clues about the potential mechanism involved in the susceptibility to developing symptomatic COVID-19.

Association of Polymorphisms of IL-6 Pathway Genes (IL6, IL6R and IL6ST) with COVID-19 Severity in an Amazonian Population.

Interleukin-6 has been recognized as a major role player in COVID-19 severity, being an important regulator of the cytokine storm. Hence, the evaluation of the influence of polymorphisms in key genes of the IL-6 pathway, namely IL6, IL6R, and IL6ST, may provide valuable prognostic/predictive markers for COVID-19. The present cross-sectional study genotyped three SNPs (rs1800795, rs2228145, and rs7730934) at IL6. IL6R and IL6ST genes, respectively, in 227 COVID-19 patients (132 hospitalized and 95 non-hospitalized). Genotype frequencies were compared between these groups. As a control group, published data on gene and genotype frequencies were gathered from published studies before the pandemic started. Our major results point to an association of the IL6 C allele with COVID-19 severity. Moreover, IL-6 plasmatic levels were higher among IL6 CC genotype carriers. Additionally, the frequency of symptoms was higher at IL6 CC and IL6R CC genotypes. In conclusion, the data suggest an important role of IL6 C allele and IL6R CC genotype on COVID-19 severity, in agreement with indirect evidence from the literature about the association of these genotypes with mortality rates, pneumonia, and heightening of protein plasmatic levels pro-inflammatory driven effects.

Thrombophilia and Immune-Related Genetic Markers in Long COVID.

Aiming to evaluate the role of ten functional polymorphisms in long COVID, involved in major inflammatory, immune response and thrombophilia pathways, a cross-sectional sample composed of 199 long COVID (LC) patients and a cohort composed of 79 COVID-19 patients whose follow-up by over six months did not reveal any evidence of long COVID (NLC) were investigated to detect genetic susceptibility to long COVID. Ten functional polymorphisms located in thrombophilia-related and immune response genes were genotyped by real time PCR. In terms of clinical outcomes, LC patients presented higher prevalence of heart disease as preexistent comorbidity. In general, the proportions of symptoms in acute phase of the disease were higher among LC patients. The genotype AA of the interferon gamma (IFNG) gene was observed in higher frequency among LC patients (60%; p = 0.033). Moreover, the genotype CC of the methylenetetrahydrofolate reductase (MTHFR) gene was also more frequent among LC patients (49%; p = 0.045). Additionally, the frequencies of LC symptoms were higher among carriers of IFNG genotypes AA than among non-AA genotypes (Z = 5.08; p < 0.0001). Two polymorphisms were associated with LC in both inflammatory and thrombophilia pathways, thus reinforcing their role in LC. The higher frequencies of acute phase symptoms among LC and higher frequency of underlying comorbidities might suggest that acute disease severity and the triggering of preexisting condition may play a role in LC development.

Antibody Response to the SARS-CoV-2 Spike and Nucleocapsid Proteins in Patients with Different COVID-19 Clinical Profiles.

The first case of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in Brazil was diagnosed on February 26, 2020. Due to the important epidemiological impact of COVID-19, the present study aimed to analyze the specificity of IgG antibody responses to the S1, S2 and N proteins of SARS-CoV-2 in different COVID-19 clinical profiles. This study enrolled 136 individuals who were diagnosed with or without COVID-19 based on clinical findings and laboratory results and classified as asymptomatic or as having mild, moderate or severe disease. Data collection was performed through a semistructured questionnaire to obtain demographic information and main clinical manifestations. IgG antibody responses to the S1 and S2 subunits of the spike (S) protein and the nucleocapsid (N) protein were evaluated using an enzyme-linked immunosorbent assay (ELISA) according to the manufacturer's instructions. The results showed that among the participants, 87.5% (119/136) exhibited IgG responses to the S1 subunit and 88.25% (120/136) to N. Conversely, only 14.44% of the subjects (21/136) displayed S2 subunit responses. When analyzing the IgG antibody response while considering the different proteins of the virus, patients with severe disease had significantly higher antibody responses to N and S1 than asymptomatic individuals (p ≤ 0.0001), whereas most of the participants had low antibody titers against the S2 subunit. In addition, individuals with long COVID-19 showed a greater IgG response profile than those with symptomatology of a short duration. Based on the results of this study, it is concluded that levels of IgG antibodies may be related to the clinical evolution of COVID-19, with high levels of IgG antibodies against S1 and N in severe cases and in individuals with long COVID-19.

Cytokine Profiles Associated With Acute COVID-19 and Long COVID-19 Syndrome.

The duration and severity of COVID-19 are related to age, comorbidities, and cytokine synthesis. This study evaluated the impact of these factors on patients with clinical presentations of COVID-19 in a Brazilian cohort. A total of 317 patients diagnosed with COVID-19 were included; cases were distributed according to clinical status as severe (n=91), moderate (n=56) and mild (n=170). Of these patients, 92 had acute COVID-19 at sample collection, 90 had already recovered from COVID-19 without sequelae, and 135 had sequelae (long COVID syndrome). In the acute COVID-19 group, patients with the severe form had higher IL-6 levels (p=0.0260). In the post-COVID-19 group, there was no significant difference in cytokine levels between groups with different clinical conditions. In the acute COVID-19 group, younger patients had higher levels of TNF-α, and patients without comorbidities had higher levels of TNF-α, IL-4 and IL-2 (p<0.05). In contrast, patients over age 60 with comorbidities had higher levels of IL-6. In the post-COVID-19 group, subjects with long COVID-19 had higher levels of IL-17 and IL-2 (p<0.05), and subjects without sequelae had higher levels of IL-10, IL-6 and IL- 4 (p<0.05). Our results suggest that advanced age, comorbidities and elevated serum IL-6 levels are associated with severe COVID-19 and are good markers to differentiate severe from mild cases. Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 and IL-10 appear to constitute a cytokine profile of long COVID-19, and these markers are potential targets for COVID-19 treatment and prevention strategies.

Seroprevalence and risk factors for COVID-19 in the metropolis of the Brazilian Amazon.

The devastating effect of health system overload was observed after cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) peaked in April 2020 in Belém, a capital metropolis in the Brazilian Amazon. Our results showed a high seroprevalence (39.24%) of anti-SARS-CoV-2 IgG antibodies among the population of the capital of the state of Pará after the first wave of the pandemic. Old age, mixed race, a high school education level, low income and contact with infected individuals are risk factors and may be driving seropositivity and exposure to SARS-CoV-2 in this population. This study is one of the first to provide important information to understand the socioeconomic inequalities, behavioral characteristics and viral transmission dynamics associated with the risk of SARS-CoV-2 infection in the capital of the state of Pará, northern Brazil.

The Complexity of SARS-CoV-2 Infection and the COVID-19 Pandemic.

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the death of millions of people worldwide and thousands more infected individuals developed sequelae due to the disease of the new coronavirus of 2019 (COVID-19). The development of several studies has contributed to the knowledge about the evolution of SARS-CoV2 infection and the disease to more severe forms. Despite this information being debated in the scientific literature, many mechanisms still need to be better understood in order to control the spread of the virus and treat clinical cases of COVID-19. In this article, we carried out an extensive literature review in order to bring together, in a single article, the biological, social, genetic, diagnostic, therapeutic, immunization, and even socioeconomic aspects that impact the SAR-CoV-2 pandemic. This information gathered in this article will enable a broad and consistent reading of the main aspects related to the current pandemic.

Prevalence of JC and BK Polyomavirus Infection in Patients with Chronic Kidney Disease in the State of Pará, Brazil.

The polyomaviruses that infect humans, JC virus (JCV) and BK virus (BKV), can establish persistent infections in the cells that make up the renal system, causing nephritis and BKV-associated nephropathy in up to 10% of renal transplant patients, and of these, 90% lose the graft and return for hemodialysis. This study aimed to determine the prevalence of polyomaviruses (PyV) in the population with chronic kidney disease (CKD), classified into three groups (conservative, dialysis, and transplanted) and a control group. Urine samples were collected from 290 individuals, including 202 patients with CKD and 88 from the control group. PyV screening was performed by PCR amplification of a fragment of the VP1 region, and the JCV and BKV species were distinguished through enzymatic digestion with the restriction endonuclease BamHI from the amplification of a TAg region. All amplification products were visualized on a 3% agarose gel. The prevalence of PyV infection was correlated with clinical-epidemiological variables using the chi-squared and Fisher's exact tests. In the group with CKD, the prevalence of PyV was 30.2%, a higher rate being observed in conservative patients (36.66%; 22/60), followed by dialysis patients (30.48%; 25/82), and transplanted patients (20%; 12/60). In the control group, the prevalence was 46.59% (41/88). The differentiation between species revealed that JCV was present in 77.8% and BKV in 22.2% of the group with CKD. The prevalence of infection was higher in male patients (59.32%), whose most common pathology was systemic arterial hypertension (35.59%). In the group of transplanted patients, there was a statistically significant association between infection and the use of the immunosuppressant azathioprine (p = 0.015). The prevalence of PyV infection was higher in the control group than in the group with CKD, being predominant in males and in patients with systemic arterial hypertension.

HTLV-1/2 in Indigenous Peoples of the Brazilian Amazon: Seroprevalence, Molecular Characterization and Sociobehavioral Factors Related to Risk of Infection.

HTLV-1/2 infection is endemic in Indigenous peoples of the Americas. Its origin is attributed to the migratory flow of Amerindian ancestral peoples. The present study aimed to investigate the seroprevalence of HTLV-1/2 infection in Indigenous peoples of the Brazilian Amazon. A total of 3350 Indigenous people belonging to 15 communities were investigated. The investigation was performed using serological (ELISA), molecular (qPCR) and confirmatory (Western blot and/or Inno-Lia) tests to detect and differentiate the infection. The seroprevalence was 8.3% for HTLV-1/2 infection, with 0.1% of individuals seropositive for HTLV-1 and 8.1% for HTLV-2. The prevalence of infection was statistically higher in women (10.1%) than in men (6.5%) (p = 0.0002). This female predominance was observed in all age groups; in females the prevalence was significant from 41 years old (p < 0.0001) and in males from 51 years old (p < 0.0001). Here, we present a prevalence of HTLV-1/2 among Indigenous peoples of the Brazilian Amazon. The endemic infection in these groups must reflect the different epidemiological profiles observed in these peoples, such as sexual transmission through rejection of condom use, breastfeeding, especially in cases of cross-breastfeeding, and the high rate of pregnancy in the villages.

Assessment of Anti-SARS-CoV-2 Antibodies Post-Coronavac Vaccination in the Amazon Region of Brazil.

The present study evaluated the frequency of seropositivity for anti-SARS-CoV-2 (S1 and S2) total antibodies and anti-SARS-CoV-2 (receptor binding domain-RBD-S1) neutralizing antibodies in individuals vaccinated with the immunizing agent Coronavac. This was a cross-sectional study involving 358 individuals divided into two groups. Group 1 consisted of 205 volunteers who were tested for anti-SARS-CoV-2 total antibodies; group 2 consisted of 153 individuals tested for the presence of anti-SARS-CoV-2 neutralizing antibodies. Seropositivity was greater than 70% in both groups, although 17.6% and 20.9% of individuals showed no neutralizing or total antibody reactivity, respectively. The frequency of anti-SARS-CoV-2 total antibodies displayed a significantly different distribution between the sexes but not according to age. The frequency of anti-SARS-CoV-2 neutralizing antibodies was 93.3% (95% CI 68.1-99.8) in the age group from 21 to 40 years but significantly decreased with advancing age, and was 76.2% (95% CI 52.8-91.8) for 41 to 60 years, 72.5% (95% CI 62.8-80.9) for 61 to 80 years, and 46.7% (95% CI 21.3-73.4) for >80 years. Our results reveal a high prevalence of anti-SARS-CoV-2 total antibodies and anti-SARS-CoV-2 neutralizing antibodies in individuals who received both doses of the Coronavac vaccine, suggesting a lower effectiveness of the humoral immune response among those older than 60 years of age, which might be associated with senescence of the immune system.

Dynamics of anti-SARS-CoV-2 IgG antibodies post-COVID-19 in a Brazilian Amazon population.

BACKGROUND: In this study, the prevalence and persistence of anti-SARS-CoV-2 (severe acute respiratory syndrome-coronavirus) IgG was evaluated in volunteers 90 days after COVID-19 (coronavirus disease 2019) diagnosis by correlating response dynamics with clinical conditions, epidemiological characteristics, and disease severity. METHODS: The study recruited 200 volunteers aged 18 years or older of both sexes diagnosed with COVID-19. Of the 200 volunteers initially selected, the 135 individuals who underwent serological testing for anti-SARS-CoV-2 antibodies on the first visit to the laboratory, were invited to return, after 90 days, and provide a new blood sample for a second assessment of the presence of anti-SARS-CoV-2 IgG antibody. Disease severity and longevity of symptoms were evaluated for each individual and associated with the serological profile. RESULTS: Among the 135 individuals who underwent a previous serological test for anti-SARS-CoV-2 antibody, 125 showed reactivity to IgG (92.6%). Of the 125 individuals with detectable IgG in the first test, 87 (69.6%) showed persistence of this antibody after 90 days and 38 (30.4%) lost IgG reactivity in the second evaluation. The frequency of all reported symptoms was higher in individuals who maintained IgG persistence after 90 days of symptoms. Symptom manifestations lasted ≥21 days in the group with a persistent IgG response (39.6%) and ≤ 7 days in the group with a nonpersistent IgG response (50.0%). The length of hospital stay and supplemental oxygen use were higher in individuals with a persistent IgG response. CONCLUSIONS: The results of the present study show a high frequency of loss of anti-SARS-CoV-2 IgG antibodies within 3 months after COVID-19 diagnosis in the Brazilian Amazon.

High prevalence of anti-SARS-CoV-2 IgG antibody in the Xikrin of Bacajá (Kayapó) indigenous population in the brazilian Amazon.

The COVID-19 pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) reached the Brazilian Amazon and spread among indigenous populations. In the present study, we demonstrate a high prevalence of infection among the Xikrin of Bacajá people (Kayapó). A sample of 100 individuals of both sexes (51 men and 49 women) with ages ranging from 2 to 82 years were clinically evaluated and tested for the presence of anti-SARS-CoV-2 IgG antibody. Among all investigated individuals, 58 were IgG-reactive (58 %) by a rapid test, and 73 (73 %) were reactive in an enzyme-linked immunosorbent assay, with no difference between sexes. Oxygen saturation ranged from 82 to 99 %, with the lowest value observed in a two-year-old girl. The results show that as expected, SARS-CoV-2 infection rapidly reached more than 70 % of the population, most likely because of the difficulties of maintaining social distance due to cultural characteristics. These results highlight the importance of indigenous health policies as a means of minimizing the impact of the pandemic on these communities.

Limitations in daily activities, risk awareness, social participation, and pain in patients with HTLV-1 using the SALSA and Participation scales.

BACKGROUND: Tropical spastic paraparesis or HTLV-associated myelopathy (TSP/HAM) may prevent, limit or restrict the performance of daily living activities, and as a consequence, several aspects of life are affected. OBJECTIVE: The aim of this study was to evaluate activity limitations, risk awareness, social participation, quality of life, and pain in individuals infected with HTLV-1. METHODS: This was an observational, descriptive, analytical, cross-sectional study with a quantitative approach. An interview questionnaire, the Screening of Activity Limitation and Safety Awareness (SALSA) scale, the Participation scale, a quality of life questionnaire (SF-36) and the Brief Pain Inventory were used. RESULTS: A total of 55 patients with HTLV-1 were interviewed (62% asymptomatic and 38% symptomatic). In both groups, there was a higher frequency of patients aged 41-50 years old (35.3% asymptomatic and 38.1% symptomatic), with complete secondary education (47.1% asymptomatic and 42.9% symptomatic), and married (64.7% asymptomatic and 52.4% symptomatic). Of the symptomatic patients, 33.3% were retired; among asymptomatic patients, 20.6% performed domestic activities. The majority of patients in both groups had not received blood transfusions. Sexual intercourse was still practiced by patients. After assessment, asymptomatic patients had no activity limitations (64.7%), and symptomatic patients presented limitations (90.5%). None of the groups showed good risk awareness. There was no restriction on social participation in 97.1% of asymptomatic patients and in 52.4% among symptomatics. Both groups complained of pain, being more frequent in the lumbar spine in asymptomatic patients and in the knees in symptomatic patients. Pain was more severe in symptomatic patients and affected aspects of quality of life. CONCLUSION: The clinical follow-up instruments must be adopted by healthcare professionals to monitor new symptoms so as to avoid the onset of limitations identified in symptomatic patients, in addition to enabling continuous surveillance of asymptomatic patients.

Allele frequency distributions of six hypervariable loci (D1S80, APOB, D4S43, vW1, F13A and DYS19) in two African-Brazilian communities from the Amazon region

The allele frequency distributions of three VNTR (D1S80, APOB and D4S43) and three STR (vW1, F13A1 and DYS19) loci were investigated in two Afro-Brazilian populations from the Amazon: Curiau and Pacoval. Exact tests for population differentiation revealed significant differences in allele frequency between populations only for the D1S80 and APOB loci. A statistically significant deviation from the Hardy-Weinberg equilibrium was observed only in the D1S80 locus of the Pacoval sample. A neighbor-joining tree was constructed based on DA genetic distances of allele frequencies in four Afro-Brazilian populations from the Amazon (Pacoval, Curiau, Trombetas, and Cametá), along with those from Congo, Cameroon, Brazilian Amerindians, and Europeans. This analysis revealed the usefulness of these Amp-FLPs for population studies - African and African-derived populations were closely grouped, and clearly separated from Amerindians and Europeans. Estimates of admixture components based on the gene identity method revealed the prevalence of the African component in both populations studied, amounting to 51 percent in Pacoval, and to 43 percent in Curiau. The Amerindian component was also important in both populations (37 percent in Pacoval, and 24 percent in Curiau). The European component reached 33 percent in Curiau