Characterisation of the novel HLA-B*18:37:03 allele, first identified in a Brazilian individual.

The novel HLA-B*18:37:03 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-DQB1*06:02:62 allele using short- and long-read sequencing technologies.

The novel HLA-DQB1*06:02:62 allele, first described in an individual from Brazil.

Characterisation of the novel HLA-C*01:273 allele, first identified in a Brazilian individual.

The novel HLA-C*01:273 allele, first described in a potential bone marrow donor from Brazil.

Association between HLA alleles and haplotypes with age at diagnosis of type 1 diabetes in an admixed Brazilian population: A nationwide study.

To investigate the potential relationship between HLA alleles and haplotypes and the age at diagnosis of type 1 diabetes (T1DAgeD) in an admixed Brazilian population. This nationwide study was conducted in public clinics across 12 Brazilian cities. We collected demographic and genetic data from 1,600 patients with T1D. DNA samples were utilised to determine genomic ancestry (GA) and perform HLA typings for DRB1, DQA1 and DQB1. We explored allele and haplotype frequencies and GA in patients grouped by T1DAgeD categories (<6 years, ≥6-<11 years, ≥11-<19 years and ≥19 years) through univariate and multivariate analyses and primary component analyses. Additionally, we considered self-reported colour-race and identified a familiar history of T1D in first-degree relatives. The homozygosity index for DRB1~DQA1~DQB1 haplotypes exhibited the highest variation among T1DAgeD groups, and the percentages of Sub-Saharan African and European ancestries showed opposite trends in principal component analysis (PCA) analyses. Regarding the association of alleles and haplotypes with T1DAgeD, risk alleles such as HLA-DQB1*03:02g, -DQA1*03:01g, -02:01g, DRB1*04:05g and -04:02g were more frequently observed in heterozygosity or homozygosity in T1D patients with an early disease onset. Conversely, alleles such as DRB1*07:01g, -13:03g, DQB1*06:02g and DQA1*02:01 were more prevalent in older T1D patients. The combination DR3/DR4.5 was significantly associated with early disease onset. However, gender, GA, familiar history of T1D and self-reported colour-race identity did not exhibit significant associations with the onset of T1D. It is worth noting that the very common risk haplotype DRB1*03:01g~DQA1*05:01g~DQB1*02:01g did not differentiate between T1DAgeD groups. In the admixed Brazilian population, the high-risk haplotype DRB1*04:05~DQA1*03:01~DQB1*03:02 was more prevalent in individuals diagnosed before 6 years of age. In contrast, the protective alleles DQA1*01:02g, DQB1*06:02g, DRB1*07:01g and DRB1*13:03g and haplotypes DRB1*13:03g~DQA1*05:01g~DQB1*03:01g and DRB1*16:02g~DQA1*01:02g~DQB1*05:02g were more frequently observed in patients diagnosed in adulthood. Notably, these associations were independent of factors such as sex, economic status, GA, familiar history of T1D and region of birth in Brazil. These alleles and haplotypes contribute to our understanding of the disease onset heterogeneity and may have implications for early interventions when detected in association with well-known genomic risk or protection factors for T1D.

CCR5Δ32 and HLA allele diversity in bone marrow donors from southern Brazil.

Transplantation of stem cells derived from donors with CCR5Δ32 homozygous genotype is a potential strategy to achieve both the control of malignant hematological disease as well as sustained remission of the HIV infection, and researchers in different countries are looking for CCR5Δ32 homozygous donors to replicate such a 'double-target' strategy. We determined the frequency of the CCR5Δ32 variant in a sample of 1,398 bone marrow donors from Rio Grande do Sul State, Brazil. This study also evaluated whether HLA-A, HLA-B and HLA-DRB1 genotypes are homogeneously distributed between CCR5Δ32 carriers and non-carriers in a population characterized by a significant genetic admixture. The CCR5Δ32 allele frequency was 7.4% (CI0.95 6.4-8.4%), and the frequency of the Δ32/Δ32 homozygous genotype was 0.72% (CI0.95 0.34-1.31%). In general, HLA genotypes are homogeneously distributed between CCR5Δ32 carriers and non-carriers. Considering the large number of bone marrow donors in Brazil and the high CCR5Δ32 allele frequency observed in our study, our results clearly indicate the existence of a considerable amount of potential CCR5Δ32 homozygous bone marrow donors in southern Brazil, suggesting that an active search for these donors is not only feasible but an attractive and promising strategy towards effective HIV infection control and treatment.

Characterisation of the novel HLA-A*33:01:21 allele, first identified in a Brazilian individual.

The novel HLA-A*33:01:21 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-DRB1*03:215 allele using short- and long-read sequencing technologies.

The novel HLA-DRB1*03:215 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-B*18:243 allele using short- and long-read sequencing technologies.

The novel HLA-B*18:243 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-DQB1*03:01:61 allele, first identified in a Brazilian individual.

The novel HLA-DQB1*03:01:61 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-A*02:1140 allele, first identified in a Brazilian individual.

The novel HLA-A*02:1140 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-C*15:274 allele using short and long-read sequencing technologies.

The novel HLA-C*15:274 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-C*08:275 allele, first identified in a Brazilian individual.

The novel HLA-C*08:275 allele, first described in a potential bone marrow donor from Brazil.

Characterisation of the novel HLA-B*35:593 allele using short and long-read sequencing technologies.

The novel HLA-B*35:593 allele, first described in a potential bone marrow donor from Brazil.

Immune response stability to the SARS-CoV-2 mRNA vaccine booster is influenced by differential splicing of HLA genes.

Many molecular mechanisms that lead to the host antibody response to COVID-19 vaccines remain largely unknown. In this study, we used serum antibody detection combined with whole blood RNA-based transcriptome analysis to investigate variability in vaccine response in healthy recipients of a booster (third) dose schedule of the mRNA BNT162b2 vaccine against COVID-19. The cohort was divided into two groups: (1) low-stable individuals, with antibody concentration anti-SARS-CoV IgG S1 below 0.4 percentile at 180 days after boosting vaccination; and (2) high-stable individuals, with antibody values greater than 0.6 percentile of the range in the same period (median 9525 [185-80,000] AU/mL). Differential gene expression, expressed single nucleotide variants and insertions/deletions, differential splicing events, and allelic imbalance were explored to broaden our understanding of the immune response sustenance. Our analysis revealed a differential expression of genes with immunological functions in individuals with low antibody titers, compared to those with higher antibody titers, underscoring the fundamental importance of the innate immune response for boosting immunity. Our findings also provide new insights into the determinants of the immune response variability to the SARS-CoV-2 mRNA vaccine booster, highlighting the significance of differential splicing regulatory mechanisms, mainly concerning HLA alleles, in delineating vaccine immunogenicity.

Characterisation of the novel HLA-A*30:218 allele using two different sequencing technologies.

The novel HLA-A*30:218 allele, first described in a potential bone marrow donor from Brazil.

Type 1 Diabetes Brazilian patients exhibit reduced frequency of recent thymic emigrants in regulatory CD4+CD25+Foxp3+T cells.

To control immune responses, regulatory CD4+CD25+Foxp3+ T cells (Treg) maintain their wide and diverse repertoire through continuous arrival of recent thymic emigrants (RTE). However, during puberty, the activity of RTE starts to decline as a natural process of thymic involution, introducing consequences, not completely described, to the repertoire. Type 1 diabetes (T1D) patients show quantitative and qualitative impairments on the Treg cells. Our aim was to evaluate peripheral Treg and RTE cell frequencies, in T1D patients from two distinct age groups (young and adults) and verify if HLA phenotypes are concomitant associated. To this, blood samples from Brazilian twenty established T1D patients (12 young and 8 adults) and twenty-one healthy controls (11 young and 10 adults) were analyzed, by flow cytometry, to verify the percentages of CD4, Treg (CD4+CD25+Foxp3+) and the subsets of CD45RA+ (naive) and CD31+(RTE) within then. Furthermore, the HLA typing was also set. We observed that the young established T1D patients feature decreased frequencies in total Treg cells and naive RTE within Treg cells. Significant prevalence of HLA alleles, associated with risk, in T1D patients, was also identified. Performing a multivariate analysis, we confirmed that the cellular changes described offers significant variables that distinct T1D patients from the controls. Our data collectively highlight relevant aspects about homeostasis imbalances in the Treg cells of T1D patients, especially in young, and disease prognosis; that might contribute for future therapeutic strategies involving Treg cells manipulation.

Prevalence of autoimmune diseases in an admixed population of patients with type 1 diabetes: a multicenter study in Brazil.

BACKGROUND/OBJECTIVES: The primary aim of this study was to evaluate the prevalence of autoimmune diseases (AIDs) and its associated factors in an admixed Brazilian population of patients with type 1 diabetes (T1D). The secondary one was to determine the relationship between AIDs and the occurrence of diabetes-related chronic complications (DRCC). METHODS: This cross-sectional, nationwide survey was conducted in 13 public clinics in 11 Brazilian cities. Overall, 1,760 patients were included; 967 females (55.9%), 932 (54%) Caucasians, aged 29.9 ± 11.9 years, age at diagnosis 14.8 ± 8.9 years, diabetes duration 15.5 ± 9.3 years and 12.2 ± 3.8 years of school attendance. AIDs were retrieved from medical records or self-report and stratified as follows: absence of AIDs, only autoimmune thyroid disease (AITD), and other AIDs including the combination with AITD (hyper or hypothyroidism). RESULTS: The prevalence of AIDs was 19.5% being AITDs (16.1%), the most frequently found. A higher prevalence of hypertension, dyslipidemia and overweight or obesity was found in patients who had exclusively AITDs. A higher prevalence of diabetic retinopathy (DR) was observed in patients with AITDs and patients with other AIDs in combination with AITDs. Chronic kidney disease (CKD) was more prevalent in patients with only AITDs. Lower levels of HbA1C, were observed in patients with isolated AITDs or with other AIDs, regardless of the presence of AITD. Hierarchical multivariate analysis, showed that AIDs were associated with female gender, older age, and longer diabetes duration, self-reported color-race (White and Brown), geographic region (Brazilian North/Northeast region) and higher anti-TPO levels (≥ 35 UI/ml). CONCLUSIONS: In conclusion, Brazilian patients with T1D, belonging to a highly ethnically admixed population, had an important prevalence of AIDs, mostly AITDs, that was associated with female gender, self-reported color-race, older age and longer diabetes duration. Moreover, these patients also had a higher prevalence of DRCC. Even though we highlight the importance of investigating the presence of AIDs at diagnosis and at regular intervals, it is unclear whether screening and early detection of additional AIDs may improve the clinical outcomes in individuals with T1D. Future prospective studies are necessary to establish the interplay between T1D, AIDs and DRCC.

Evaluation of HNF1B, KLK3, ELAC2, TMPRSS2-ERG, and CTNNB1 polymorphisms associated with prostate cancer in samples of patients from HUPE-UERJ.

PURPOSE: Prostate cancer (PCa) is the leading cause of death among men in 48 countries. Genetic alterations play a significant role in PCa carcinogenesis. For the hypothesis of this research, five unique polymorphisms (SNP) were investigated in different genes that showed to be associated in different ways with PCa: rs4430796, rs2735839, rs4792311, rs12329760, and rs28931588, respectively for the genes HNF1B, KLK3, ELAC2, TMPRSS2-ERG, and CTNNB1. PATIENTS AND METHODS: Blood samples from 426 subjects were evaluated: 290 controls (161 females and 129 males) and 136 PCa patients. SNP were determined by real-time polymerase chain reaction. TaqMan SNP genotyping assay. In the control samples, the SNPs were defined in association with the self-reported ethnicity, and in 218 control samples with markers with ancestry indicators. The genes were in Hardy-Weinberg equilibrium. One hundred and seventy control samples were matched by ethnicity for comparison with the PCa samples. RESULTS: The G allele at rs28931588 was monomorphic in both patients and controls studied. Significant differences were observed in allelic and genotypic frequencies between the control and Pca samples in rs2735839 (KLK3; p = 0.002 and χ2 = 8.73 and p = 0.01, respectively), by the global frequency and in the dominant model rs2735839_GG (odds ratio [OR] = 0.51, p = 0.02). AA and GA genotypes at rs4792311 (ELAC2) were more frequent in patients with Gleason 7(4 + 3), 8, and 9 (n = 37%-59.7%) compared to patients with Gleason 6 and 7(3 + 4) (n = 26%-40.0%) conferring a protective effect on the GG genotype (OR = 0.45, p = 0.02). The same genotype showed an OR = 2.71 (p = 0.01) for patients with low severity. The HNF1B-KLK3-ELAC2-TMPRSS2-ERG haplotypes: GAAT, AAAT, GAGT, and AAGT were more frequent in patients with Pca with OR ranging from 4.65 to 2.48. CONCLUSIONS: Higher frequencies of risk alleles were confirmed in the SNPs, KLK3 rs2735839_A, ELAC2 rs4792311_A, and TMPRSS2 rs12329760_T in patients with Pca. Rs2735839_A was associated with risk of Pca and rs4792311_A with severity and Gleason score of 7(4 + 3) or greater. There is a need for careful observation of rs2735839 and rs4792311 in association with the prostatic biopsy due to the increased risk of Pca.

Serum Anti-Spike Antibodies Are Not Affected by Immunosuppressants in SARS-CoV-2 Vaccinations Given to Brazilian Patients with Inflammatory Bowel Disease.

This study aimed to evaluate humoral responses after vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) of patients with inflammatory bowel disease (IBD). Patients with IBD enrolled in a tertiary outpatient unit were followed up between September 2021 and September 2022 via serial blood collection. Immunoglobulin G antibody titers against SARS-CoV-2 were measured before administration and 1 and 6 months after the administration of two doses of different vaccination regimens. The results were compared with those of a healthy control group obtained during the same period. The mean pre-vaccination antibody titers were 452.0 and 93.3 AU/mL in the IBD (n = 42) and control (n = 89) groups, respectively. After two doses of the vaccine, the titers significantly increased in both groups (IBD, 8568.0 AU/mL; control, 7471.0 AU/mL; p < 0.001). One month after the second dose, no significant differences were observed between the two groups (p = 0.955). Significant differences between vaccination schemes in the IBD group were observed, with higher titers in those who received Pfizer, younger patients (p < 0.005), and those with a previous coronavirus disease 2019 (COVID-19) infection (p < 0.012). The use of immunosuppressants and immunobiologicals did not affect the overall humoral response to COVID-19 vaccine in patients with IBD, but specific vaccine regimens, age, and previous coronavirus infection significantly did. This study reinforces the positive impact of booster doses and the safety of SARS-CoV-2 vaccination.

HLA haplotypes and differential regional mortality caused by COVID-19 in Brazil: an ecological study based on a large bone marrow donor bank dataset.

The coronavirus disease 2019 (COVID-19) mortality rates varied among the states of Brazil during the course of the pandemics. The human leukocyte antigen (HLA) is a critical component of the antigen presentation pathway. Individuals with different HLA genotypes may trigger different immune responses against pathogens, which could culminate in different COVID-19 responses. HLA genotypes are variable, especially in the highly admixed Brazilian population. In this ecological study, we aimed to investigate the correlation between HLA haplotypes and the different regional distribution of COVID-19 mortality in Brazil. HLA data was obtained from 4,148,713 individuals registered in The Brazilian Voluntary Bone Marrow Donors Registry. COVID-19 data was retrieved from epidemiological bulletins issued by State Health Secretariats via Brazil's Ministry of Health from February/2020 to July/2022. We found a positive significant correlation between the HLA-A*01~B*08~DRB1*03 haplotype and COVID-19 mortality rates when we analyzed data from 26 states and the Federal District. This result indicates that the HLA-A*01~B*08~DRB1*03 haplotype may represent an additional risk factor for dying due to COVID-19. This haplotype should be further studied in other populations for a better understanding of the variation in COVID-19 outcomes across the world.