Insights Regarding the Role of Inflammasomes in Leukemia: What Do We Know?

Inflammation is a physiological mechanism of the immune response and has an important role in maintaining the hematopoietic cell niche in the bone marrow. During this process, the participation of molecules produced by innate immunity cells in response to a variety of pathogen-associated molecular patterns and damage-associated molecular patterns is observed. However, chronic inflammation is intrinsically associated with leukemogenesis, as it induces DNA damage in hematopoietic stem cells and contributes to the creation of the preleukemic clone. Several factors influence the malignant transformation within the hematopoietic microenvironment, with inflammasomes having a crucial role in this process, in addition to acting in the regulation of hematopoiesis and its homeostasis. Inflammasomes are intracellular multimeric complexes responsible for the maturation and secretion of the proinflammatory cytokines interleukin-1ß and interleukin-18 and the cell death process via pyroptosis. Therefore, dysregulation of the activation of these complexes may be a factor in triggering several diseases, including leukemias, and this has been the subject of several studies in the area. In this review, we summarized the current knowledge on the relationship between inflammation and leukemogenesis, in particular, the role of inflammasomes in different types of leukemias, and we describe the potential therapeutic targets directed at inflammasomes in the leukemic context.

Investigation of fluconazole heteroresistance in clinical and environmental isolates of Cryptococcus neoformans complex and Cryptococcus gattii complex in the state of Amazonas, Brazil.

Heteroresistance, defined as the occurrence of apparently homogeneous subpopulations of microbial cells showing different levels of antimicrobial susceptibility is a problem that has been associated with therapeutical failure in cryptococcosis. The purpose of the study was an investigation on the level of heteroresistance to fluconazole (LHF) as observed in clinical and environmental C. neoformans/C. gattii complex species isolates from Amazonas State (AM), Brazil. A total of 45 isolates and 9 type strains were analyzed. The assessments comprised testing for minimal inhibitory concentrations (MICs), for LHFs, for the strains' capacity of adaptation to high fluconazole (FLC) concentrations above the LHF, and for the stability of the heteroresistance phenomenon. The mean MICs for clinical isolates of C. gattii (6.4 µg/ml) were higher than those observed for environmental C. gattii strains (1.7 µg/ml) and clinical (3.7 µg/ml) as well as environmental (1.5 µg/ml) C. neoformans isolates. The phenomenon of heteroresistance to FLC was recorded for all isolates. On average, the LHF (8-256 µg/ml) of the isolates was 16 times higher than the FLC MICs (0.5-16 µg/ml) and a proportion of 85% isolates showed LHFs ≥ 16 µg/ml, 40% even ≥ 32 µg/ml. According to the adaptation assay, a considerable number of isolates (58%) showed the capacity of adaptation to MICs even higher than the initially recorded LHF. After the adaptation experiment, the adaptative-LHF values (8-512 µg/ml) were about 60 times higher than the original MIC values. After nine subsequent passages in drug-free broth, the isolates had their adaptative-LHF reduced. However, the LHF did not revert to the initially measured level. Our findings challenge the clinical interpretation of the antifungal MIC testing and motivate future studies correlating the levels of heteroresistance and parameters like LHF and adaptative-LHF with cryptococcosis-associated morbidity and mortality. LAY SUMMARY: Cryptococcosis affects many people and is caused by fungi of the Cryptococcus neoformans/Cryptococcus gattii complexes. These agents appear to become more resistant to antifungals when exposed to increasing concentrations of antifungals due to a phenomenon called heteroresistance.

A genetic variant in the TRAF1/C5 gene lead susceptibility to active pulmonary tuberculosis by decreased TNF-α levels.

Host genetics are important to consider in the role of resistance or susceptibility for developing active pulmonary tuberculosis (TB). Several association studies have reported the role of variants in STAT4 and TRAF1/C5 as risk factors to autoimmune diseases. Nevertheless, more data is needed to elucidate the role of these gene variants in infectious disease. Our data reports for the first time, variant rs10818488 in the TRAF1/C5 gene (found 47% of the population worldwide), is associated with susceptibility (OR = 1.51) to development TB. Multivariate analysis evidenced association between rs10818488 TRAF1/C5 and risk to multibacillary TB (OR = 4.18), confers increased bacteria load in the lung, indicates a decreased ability to control pathogen levels in the lung, and spread of the pathogen to new hosts. We showed that the "loss-of-function" variant in TRAF1/C5 led to susceptibility for TB by decreased production of TNF-α. Our results suggest the role of variant TRAF1/C5 in susceptibility to TB as well as in clinical presentation of multibacillary TB.

Inflammasome genes polymorphisms may influence the development of hepatitis C in the Amazonas, Brazil.

Hepatitis C is considered a major public health problem caused by the hepatitis C virus (HCV). Viral infections are known to induce production of IL1ß through the signaling pathway of inflammasomes. Emerging evidences suggest that Inflammasome genes may influence the immune response against HCV as the host genetic background may contribute to the balance between acute and chronic inflammation. We investigated in 151 patients with chronic hepatitis C and 206 healthy blood donors' individuals (HD). Polymorphisms in the IL1B and IL18 genes were genotyped by PCR-RFLP, while NLRP3, CARD8, CTSB and AIM2 by RT- PCR. Serum assay of IL-1ß cytokine was performed by ELISA. 84 patients presented mild fibrosis (

Genetic polymorphisms of inflammasome genes associated with pediatric acute lymphoblastic leukemia and clinical prognosis in the Brazilian Amazon.

The immune system plays an important role in the control of cancer development. To investigate the possible association of inflammasome genes to childhood leukemia we performed a case-control study with 158 patients with acute lymphoblastic leukemia and 192 healthy individuals. The IL1B and IL18 genetic polymorphisms were genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and NLRP1, NLRP3 and P2RX7 were genotyped using Real Time quantitative PCR (qPCR). The IL1B C/T rs19644 genotype was associated with the risk of developing ALL (C/C vs. C/T + T/T OR: 2.48 [95% CI: 1.26-4.88, p = 0.006]; C/C vs C/T OR: 2.74 [95% CI: 1.37-5.51, p = 0.003]) and the NLRP1 A/T rs12150220 (OR: 0.37 [95% CI: 0.16-0.87, p = 0.023]) was associated with protection against infectious comorbidities. It was not found association between NLRP3 and P2RX7 polymorphisms and acute lymphoblastic leukemia in our study. Our results suggest that the inflammasome single-variant polymorphisms (SNVs) may play a role in the development and prognostic of childhood leukemia. However, this finds requires further study within a larger population in order to prove it.

Single-Nucleotide Variants in the AIM2 - Absent in Melanoma 2 Gene (rs1103577) Associated With Protection for Tuberculosis.

Tuberculosis (TB) remains a serious public health burden worldwide. TB is an infectious disease caused by the Mycobacterium tuberculosis Complex. Innate immune response is critical for controlling mycobacterial infection. NOD-like receptor pyrin domain containing 3/ absent in melanoma 2 (NLRP3/AIM2) inflammasomes are suggested to play an important role in TB. NLRP3/AIM2 mediate the release of pro-inflammatory cytokines IL-1ß and IL-18 to control M. tuberculosis infection. Variants of genes involved in inflammasomes may contribute to elucidation of host immune responses to TB infection. The present study evaluated single-nucleotide variants (SNVs) in inflammasome genes AIM2 (rs1103577), CARD8 (rs2009373), and CTSB (rs1692816) in 401 patients with pulmonary TB (PTB), 133 patients with extrapulmonary TB (EPTB), and 366 healthy control (HC) subjects with no history of TB residing in the Amazonas state. Quantitative Real Time PCR was performed for allelic discrimination. The SNV of AIM2 (rs1103577) is associated with protection for PTB (padj: 0.033, ORadj: 0.69, 95% CI: 0.49-0.97). CTSB (rs1692816) is associated with reduced risk for EPTB when compared with PTB (padj: 0.034, ORadj: 0.50, 95% CI: 0.27-0.94). Serum IL-1ß concentrations were higher in patients with PTB than those in HCs (p = 0,0003). The SNV rs1103577 of AIM2 appeared to influence IL-1ß release. In a dominant model, individuals with the CC genotype (mean 3.78 ± SD 0.81) appeared to have a higher level of IL-1ß compared to carriers of the T allele (mean 3.45 ± SD 0.84) among the patients with PTB (p = 0,0040). We found that SNVs of AIM2 and CTSB were associated with TB, and the mechanisms involved in this process require further study.

Monocyte-Derived Dendritic Cells Can Revert In Vitro Antigen-Specific Cellular Anergy in Active Human Paracoccidioidomycosis.

We investigated the in vitro effects of two Paracoccidioides brasiliensis antigens on monocyte-derived dendritic cells (moDCs) from patients with paracoccidioidomycosis (PCM). MoDCs from patients with active or treated PCM and non-PCM subjects were generated, stimulated with TNF-α, and P. brasiliensis antigens, 43 kDa glycoprotein (gp43) and cell-free antigen (CFA), and analyzed by flow cytometry and enzyme-linked immunosorbent assays (ELISA). Our data revealed that patients with PCM had a high frequency of HLA-DR+ cells, but the treated group had more CD86+ cells with increased IL-12p40. Patients with active PCM had more CD80+ moDCs, and as a novel finding, large amounts of chemokine (C-C motif) ligand 18 (CCL18) in the supernatants from their in vitro moDC cultures. Both gp43- and CFA-stimulated moDCs from the patients with PCM successfully reverted the in vitro antigen-specific anergy, inducing a proliferative response. However, CFA-stimulated moDCs led to higher lymphoproliferation, with increased IFN-γ and TNF-α in the cells from the patients with active PCM compared with gp43. These original results combined with constant IL-10 and increased IL-12p40 levels suggest that a more complex antigen, such as CFA, may be a better inducer of the protective Th1 immune response than purified gp43 is, and a suitable target for future studies on anti-P. brasiliensis dendritic cell (DC)-based vaccines.

Combining Host Genetics and Functional Analysis to Depict Inflammasome Contribution in Tuberculosis Susceptibility and Outcome in Endemic Areas.

The interplay between M. tuberculosis (Mtb) and humans is multifactorial. The susceptibility/resistance profile and the establishment of clinical tuberculosis (TB) still remains elusive. The gain-of-function variant rs10754558 in the NLRP3 gene (found in 30% of the world population) confers protection against the development of TB, indicating a prominent role played by NLRP3 inflammasome against Mtb. Through genotype-guided assays and various Mtb strains (BCG, H37Rv, Beijing-1471, MP287/03), we demonstrate that Mtb strains activate inflammasome according to the NLRP3/IL-1ß or NLRC4/IL18 preferential axis. NLRP3 and NLRC4 genetic variants contribute to the presentation of TB. For the first time, we have shown that loss-of-function variants in NLRC4 significantly contribute to the development of extra-pulmonary TB. The analysis of inflammasome activation in a cohort of TB patients and their "household contacts" (CNT) revealed that plasma IL-1ß/IFN-α ratio lets us distinguish patients from Mtb-exposed-but-healthy individuals from an endemic region. Moreover, NLRP3 inflammasome seemed "exhausted" in TB patients compared to CNT, indicating a more efficient activation of inflammasome in resistant individuals. These findings suggest that inflammasome genetics as well as virulence-dependent level of inflammasome activation contribute to the onset of a susceptible/resistant profile among Mtb-exposed individuals.

Polymorphism in the Promoter Region of the IL18 Gene and the Association With Severity on Paracoccidioidomycosis.

Paracoccidioidomycosis (PCM) is an important endemic, systemic disease in Latin America caused by Paracoccidioides spp. This mycosis has been associated with high morbidity and sequels, and its clinical manifestations depend on the virulence of the infecting strain, the degree and type of immune response, infected tissues, and intrinsic characteristics of the host. The T helper(Th)1 and Th17/Th22 cells are related to resistance and control of infection, and a Th2/Th9 response is associated with disease susceptibility. In this study, we focused on interleukin(IL)-12p35 (IL12A), IL-18 (IL18), and IFN-γ receptor 1 (IFNGR1) genetic polymorphisms because their respective roles have been described in human PCM. Real-time PCR was employed to analyze IL12A-504 G/T (rs2243115), IL18-607 C/A (rs1946518), and IFNGR1-611 A/G (rs1327474) single nucleotide polymorphisms (SNP). One hundred forty-nine patients with the acute form (AF), multifocal chronic (MC), or unifocal chronic (UC) forms of PCM and 110 non-PCM individuals as a control group were included. In the unconditional logistic regression analysis adjusted by ethnicity and sex, we observed a high risk of the IL18-607 A-allele for both AF [p = 0.015; OR = 3.10 (95% CI: 1.24-7.77)] and MC groups [p = 0.023; OR = 2.61 (95% CI: 1.14-5.96)] when compared with UC. The IL18-607 A-allele associated risk for the AF and MC groups as well as the protective role of the C-allele in UC are possibly linked to higher levels of IL-18 at different periods of the course of the disease. Therefore, a novel role of IL18-607 C/A SNP is shown in the present study, highlighting its importance in the outcome of PCM.

Toll-Like Receptor-1 Single-Nucleotide Polymorphism 1805T/G Is Associated With Predisposition to Multibacillary Tuberculosis.

Tuberculosis (TB), caused by mycobacterial species of the Mycobacterium tuberculosis complex, is a serious global health issue. Brazil is among the 22 countries with the highest number of TB cases, and the state of Amazonas has the highest incidence of TB cases in the country. Toll-like receptors (TLRs) are important pattern recognition receptors of the innate immunity and play a key role in orchestrating an effective immune response. We investigated whether the single-nucleotide polymorphisms (SNPs) 1805T/G TLR1, 2258G/A TLR2, 896A/G and 1196C/T of TLR4, 745T/C TLR6, and -1237A/G and -1486A/G of TLR9 are associated with the predisposition to TB and/or bacillary load. The SNPs genotyping was performed by nucleotide sequencing in 263 TB patients and 232 healthy controls residing in the state of Amazonas. Alleles and genotypes frequencies were similar between patients and healthy individuals for most of the investigated SNPs. Stratification of the TB patients according to their bacillary load showed that the genotype 1805TT TLR1 (rs5743618) was prevalent among paucibacillary patients [odds ratio (OR) = 0.38; 95% confidence interval (CI) = 0.19-0.76; p = 0.009] while the genotype 1805TG was common among multibacillary patients (OR = 3.72; CI = 1.65-8.4; p = 0.004). Comparison of demographic characteristics of patients to controls showed that TB is strongly associated with smoking (OR = 6.55; 95% CI = 3.2-13.6; p < 0.0001); alcohol use disorder (OR = 7.14; 95% CI = 3.7-13.9; p < 0.0001); and male gender (OR = 3.66; 95% CI = 2.52-5.3; p < 0.0001). Multivariate logistic regression demonstrated that alcoholism (OR = 2.93; 95% CI = 1.05-8.16; p = 0.03) and the 1805G allele (OR = 2.75; 95% CI = 1.33-5.7; p = 0.006) are predictive variables for multibacillary TB. Altogether, we suggest that the TLR1 1805G allele may be a relevant immunogenetic factor for the epidemiology of TB together with environmental, sociodemographic, and behavioral factors.

Immune response in Mansonella ozzardi infection modulated by IL-6/IL-10 axis in Amazon region of Brazil.

Mansonellosis is an endemic disease in the South and Central America. In Brazil, one of the etiological agents is Mansonella ozzardi. This filarial infection is yet poorly understood, with a controversial morbity, presenting since a oligosymptoms, malaria-like signs or without complaint in humans. The knowledge of the human immune response to microfilariae infection is limited mainly by different evolutionary cycles of the parasite in the host. In addition, the prevalence of this filarial parasite infection is high in several regions of Amazonas State. A cross-sectional study was conducted in an endemic area for microfilariae of M. ozzardi (MF) infection in the Amazonas State, Brazil. Proinflammatory and regulatory cytokines (IL-2, IL-4, IL-6, IL-10, TNF, IFN-gamma, and IL-17A) were measured in cryopreserved serum using the Cytometric Bead Array techniques (CBA) in 54 patients diagnosed with M. ozzardi infection and 55 individuals without the infection were included in the study (Controls). The IL-4, IL-6 and IL-10 level increased in infected patients with MF infection, while IL-17A increased in control only. When we compared controls to patients with high or low parasite load, the increased level of IL-6 and IL-10 were maintained. IL-6 contributes to the proinflammatory activity and IL-10 modulates Th1, Th2 and Th17 immune response. Furthermore, IL-4 was detected as a marker in the MF infection and MF patients with low parasite load, indicating the action of the Th2 cell response. The complex network of cytokines acting during M. ozzardi infection depends on a fine balance to determine a host protective effect or filarial persistence. Therefore, these results suggest that the immune response in MF infection is modulated by IL-6/IL-10 axis.

Polymorphisms in SIGLEC1 contribute to susceptibility to pulmonary active tuberculosis possibly through the modulation of IL-1ß.

Siglec-1/CD169 is a sialoadhesin expressed by macrophages thought to function in cell-to-cell interactions. In the lung, the expression of Siglec-1 is specific for alveolar macrophages and single nucleotide polymorphisms (SNPs) in SIGLEC1 have been recently associated with asthma severity. Taking in account the role of alveolar macrophages in the control of M. tuberculosis and the poor literature about the contribution of SIGLEC1 genetics in M. tuberculosis susceptibility and development of pulmonary active TB, selected SNPs in SIGLEC1 were analysed in a case/control cohort from a TB endemic area of Brazil Amazon. Our findings evidenced for the first time the novel association between SIGLEC1 rs3859664 SNP and active pulmonary TB. Intriguingly, carriers of the polymorphism produced less IL-1ß than non-carriers, suggesting the possible involvement of Siglec-1 signalling pathway with inflammasome complex.

Frequency of CCR5Δ32 mutation in blood donor candidates from the Fundação Hospitalar de Hematologia e Hemoterapia do Amazonas, Brazil

The chemokine receptor CCR5 is a major co-receptor for HIV-1 entry into the host cell. Deletion of 32 bp (Δ32) alters the receptor structure and is associated with the protection against infection. The distribution of allelic variant depends on several factors influencing the epidemiology of HIV infections. Thus, the present study sought to estimate the allelic frequency of the CCR5 gene variant / CCR5Δ32 in blood donor candidates with and without positive serology for HIV-1+ at the HEMOAM Foundation. 239 candidates were enrolled and divided into two groups, HIV-1+ (101 individuals) and HIV- controls (138 individuals). After collecting peripheral blood, DNA was extracted and allele-specific PCR for identification of CCR5Δ32 polymorphism, was performed. The results obtained were analyzed using Stata (v.13). The groups were of similar ages, predominantly male and the distribution of genotypes and alleles were in Hardy-Weinberg equilibrium (p=0.725 and p=0.879, respectively). The highest frequency was wild genotype, followed by the heterozygous genotype in both groups (control and the HIV-1+ ). When the frequencies in HIV-1+ subgroups were analyzed, the absence of the allelic variant CCR5Δ32 subgroup ELISA(+) Westen Blot(+) was noted. Therefore, our data indicate that CCR5Δ32 polymorphism has a low frequency in the population studied.

Alleles of HLA-DRB1*04 Associated with Pulmonary Tuberculosis in Amazon Brazilian Population.

Immunogenetic host factors are associated with susceptibility or protection to tuberculosis (TB). Strong associations of HLA class II genes with TB are reported. We analyzed the HLA-DRB1*04 alleles to identify subtypes associated with pulmonary TB and their interaction with risk factors such as alcohol, smoking, and gender in 316 pulmonary TB patients and 306 healthy individuals from the Brazilian Amazon. The HLA-DRB1*04 was prevalent in patients with pulmonary TB (p<0.0001; OR = 2.94; 95% CI = 2.12 to 4.08). Direct nucleotide sequencing of DRB1 exon 2 identified nine subtypes of HLA-DRB1*04. The subtype HLA-DRB1*04:11:01 (p = 0.0019; OR = 2.23; 95% CI = 1.34 to 3.70) was associated with susceptibility to pulmonary TB while DRB1*04:07:01 (p<0.0001; OR = 0.02; 95% CI = 0.001 to 0.33) to protection. Notably, the interaction between alcohol and HLA-DRB1*04:11:01 increased the risk for developing pulmonary TB (p = 0.0001; OR = 51.3; 95% CI = 6.81 to 386). Multibacillary pulmonary TB, the clinical presentation of disease transmission, was strongly associated with interaction to alcohol (p = 0.0026; OR = 11.1; 95% CI = 3.99 to 30.9), HLA-DRB1*04:11:01 (p = 0.0442; OR = 2.01; 95% CI = 1.03 to 3.93) and DRB1*04:92 (p = 0.0112; OR = 8.62; 95% CI = 1.63 to 45.5). These results show that HLA-DRB1*04 are associated with pulmonary TB. Interestingly, three subtypes, DRB1*04:07:01, DRB1*04:11:01 and DRB1*04:92 of the HLA-DRB1*04 could be potential immunogenetic markers that may help to explain mechanisms involved in disease development.

Combined impact of hepatitis C virus genotype 1 and interleukin-6 and tumor necrosis factor-α polymorphisms on serum levels of pro-inflammatory cytokines in Brazilian HCV-infected patients.

We investigated the association between hepatitis C virus (HCV) genotypes and host cytokine gene polymorphisms and serum cytokine levels in patients with chronic hepatitis C. Serum IL-6, TNF-α, IL-2, IFN-γ, IL-4, IL-10, and IL-17A levels were measured in 67 HCV patients (68.2% genotype 1 [G1]) and 47 healthy controls. The HCV patients had higher IL-6, IL-2, IFN-γ, IL-10, and IL-17A levels than the controls. HCV G1 patients had higher IL-2 and IFN-γ levels than G2 patients. The -174IL6G>C, -308TNFαG>A, and -1082IL10A>G variants were similarly distributed in both groups. However, HCV patients with the -174IL6GC variant had higher IL-2 and IFN-γ levels than patients with the GG and CC variants. Additionally, HCV patients with the -308TNFαGG genotype had higher IL-17A levels than patients with the AG genotype, whereas patients with the -1082IL10GG variant had higher IL-6 levels than patients with the AA and AG variants. A significant proportion of HCV patients had high levels of both IL-2 and IFN-γ. The subgroup of HCV patients with the G1/IL6CG/TNFαGG association displayed the highest proportions of high producers of IL-2 and IFN-γ whereas the subgroup with the G1/TNFαGG profile showed high proportions of high producers of IL-6 and IL-17A. HCV patients with other HCV/cytokine genotype associations showed no particular cytokine profile. Our results suggest that HCV genotype G1 and IL-6 and TNF-α polymorphisms have a clinically relevant influence on serum pro-inflammatory cytokine profile (IL-2 and IFN-γ) in HCV patients.

The robust and modulated biomarker network elicited by the Plasmodium vivax infection is mainly mediated by the IL-6/IL-10 axis and is associated with the parasite load.

BACKGROUND: Recent studies have shown that the inflammatory process, including the biomarker production, and the intense activation of innate immune responses are greater in the malaria caused by Plasmodium vivax than other species. Here, we examined the levels of serum biomarkers and their interaction during acute malaria. MATERIAL AND METHODS: Blood samples were collected from P. vivax-infected patients at admission and from healthy donors. Levels of serum biomarkers were measured by Cytometric Bead Assay or ELISA. RESULTS: P. vivax infection triggered the production of both inflammatory and regulatory biomarkers. Levels of IL-6, CXCL-8, IFN-γ, IL-5, and IL-10 were higher in P. vivax-infected patients than in healthy donors. On the other hand, malaria patients produced lower levels of TNF-α, IL-12p70, and IL-2 than healthy individuals. While the levels of IL-10 and IL-6 were found independent on the number of malaria episodes, higher levels of these cytokines were seen in patients with higher parasite load. CONCLUSION: A mixed pattern of proinflammatory and regulatory biomarkers is produced in P. vivax malaria. Analysis of biomarker network suggests that IL-10 and IL-6 are a robust axis in malaria patients and that this interaction seems to be associated with the parasite load.

Association between the PTPN22 1858C/T gene polymorphism and tuberculosis resistance.

Previous studies identified the functional polymorphism 1858C/T in the gene PTPN22 in association with several autoimmune diseases and with resistance to tuberculosis (TB). This study is the first to investigate the association between pulmonary TB and the PTPN22 1858C/T polymorphism in the Brazilian Amazon. We conducted a case-control study involving a group of 413 individuals, comprised of 208TB carriers and 205 controls. No significant association between the PTPN22 1858T allele frequency in controls (2.4%) and TB carriers (2.7%, p=0.982, odds ratio (OR)=0.89, 95% confidence interval=0.37-2.13) was identified in the Brazilian Amazon population. An additional evaluation by meta-analysis, however, suggested a protective role of the T allele in relation to TB (pooled OR=0.44, p=0.011). These results suggest that the PTPN22 1858T allele serves as a protective genetic factor for TB in those individuals who carry this minor allele.

The influence of a TNF gene polymorphism on the severity of rheumatoid arthritis in the Brazilian Amazon.

PURPOSE: The aim of this study was to investigate the influence of the TNF -308 G/A polymorphism in the promoter region of the tumor necrosis factor-α gene on the susceptibility and severity of rheumatoid arthritis (RA) in individuals from the Brazilian Amazon. METHODS: A total of 323 individuals-192 healthy controls without arthritis and 131 individuals suffering from arthritis-were genotyped for this polymorphism using a methodology based on PCR-RFLP. RESULTS: The frequency of the A allele (TNF2) in rheumatoid arthritis sufferers was not significantly higher than in the controls (p=0.926; OR=0.97; confidence interval 0.54-1.76). However, using a logistic regression model, when the patients were stratified according to whether the manifestations were preponderantly articular or systemic, there was a strong association between the TNF2 allele and systemic arthritis (p=0.001; OR=5.89; confidence interval=1.98-17.5) as well as the use of anti-TNF immunotherapy (p=0.023; OR=1.10; confidence interval=1.00-1.14). The main factors that were found to influence the risk of extra-articular disease were age greater than or equal to 60 years (p=0.008; OR=4.06; confidence interval=1.45-11.38), disease duration greater than 10 years (p=0.031; OR=3.10; confidence interval=1.11-8.63) and positive rheumatoid factor (p=0.035; OR=2.07; confidence interval=1.05-4.09). CONCLUSIONS: These results suggest that the TNF2 allele is associated with the more serious forms of the disease in individuals from the Brazilian Amazon but not with a risk for developing RA.

Frecuencia y etiología de la dermatofitosis en niños de entre 0 y 12 años en el estado de Amazonas, Brasil / Frequency and aetiology of dermatophytosis in children age 12 and under in the state of Amazonas, Brazil

Antecedentes. Apenas se dispone de estudios científicos que hayan investigado las dermatofitosis en niños que viven en el estado de Amazonas o en la región más septentrional de Brasil. Objetivos. El objetivo de este estudio fue investigar la frecuencia y la etiología de las dermatofitosis en niños de 12 años de edad o menores, que fueron examinados entre marzo de 1996 y noviembre de 2005 en el Laboratorio de Micología del Instituto Nacional de Investigaciones de Amazonia. Métodos. Para el diagnóstico micológico, se utilizaron muestras de escamas epidérmicas y/o cabello. Una parte de la muestra se trasladó a un portaobjetos y se añadió una solución de hidróxido de potasio para examen microscópico directo. La otra parte de la muestra se sembró en medio de cultivo (Mycobiotic Agar) para el aislamiento de los dermatofitos. Resultados. De las 590 muestras analizadas, en 210 se aislaron dermatofitos mediante examen microscópico directo y cultivo. La tiña del cuero cabelludo (153 casos) fue la dermatofitosis más frecuente, y Trichophyton tonsurans (121 casos) fue el patógeno aislado más habitual. En 48 casos se detectó tiña corporal, siendo también T. tonsurans el hongo aislado más frecuente (17 casos), y las regiones corporales más afectadas fueron la cara, extremidades superiores y tronco. El laboratorio confirmó un pie de atleta en 6 casos y los principales hongos aislados fueron Trichophyton rubrum (3) y Trichophyton mentagrophytes (3). La tiña crural solo se confirmó en 3 casos, en los que se aislaron T. rubrum, T. tonsurans y Epidermophyton floccosum. Conclusiones. En los niños examinados, la tiña del cuero cabelludo fue la afectación principal y el patógeno responsable de estas dermatofitosis fue T. tonsurans(AU)

Background. Few scientific studies have evaluated dermatophytosis among children in the state of Amazonas or in the greater northern region of Brazil. Aims. The aim of this study was to research the frequency and aetiology of dermatophytosis in children age 12 and under, who were seen between March 1996 and November 2005 at the Mycology Laboratory of the National Institute of Amazonian Research. Methods. For mycological diagnoses, epidermal scales and/or hairs were used. A portion of this material was treated with potassium hydroxide for direct examination, and another portion was cultivated in Mycobiotic Agar for the isolation of dermatophytes. Results. Of the 590 samples analysed, 210 showed positive diagnoses by direct examination and cultivation. Tinea capitis (153 cases) was the most frequent type of dermatophytosis, and Trichophyton tonsurans (121 cases) was the most frequently isolated fungal agent. Tinea corporis was observed in 48 cases where the most frequently isolated fungal agent was also T. tonsurans (17 cases), and the corporal regions most affected were the face, arms and trunk. The laboratory confirmed tinea pedis in 6 cases, and the principal fungal agents isolated were Trichophyton rubrum (3) and Trichophyton mentagrophytes (3). The presence of tinea cruris was confirmed in 3 cases, and T. rubrum, T. tonsurans and Epidermophyton floccosum were isolated from these cases. Conclusions. The children examined were primarily affected by tinea capitis, and the main fungal agent for this dermatophytosis was T. tonsurans(AU)

Interaction between smoking and HLA-DRB1*04 gene is associated with a high cardiovascular risk in Brazilian Amazon patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid Arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the joints that affects approximately 1% of the population worldwide. The HLA-DRB1 gene locus plays a major role in genetic susceptibility to RA, a condition that has been associated with a high cardiovascular morbidity and mortality in many studies. METHODOLOGY/PRINCIPAL FINDINGS: The aim of this work was to investigate which types of HLA class II genes are associated with RA in patients from the Brazilian Amazon and their influence on high cardiovascular risk status in this population. For this purpose, a case-control study was carried out with a total of 350 non-Indian individuals made up of a cohort of 132 consecutive RA sufferers and 218 healthy controls. A χ(2) test showed that HLADRB1*04 (p<0.0016; OR = 1.89; 95% CI = 1.29-2.79) and HLADRB1*10 (p = 0.0377; OR = 3.81; 95% CI = 1.16-12.50) are the major HLA genes associated with susceptibility to RA. A logistic regression model also showed that the interaction between HLADRB1*04 (p = 0.027; OR = 6.02; 95% CI = 1.21-29.7), age (p = 0.0001; OR = 1.26; 95% CI = 1.13-1.39) and smoking (p = 0.0001; OR = 23.6; 95% CI = 4.25-32.1) is associated with a probability of a high cardiovascular risk status at an early age. CONCLUSIONS/SIGNIFICANCE: The results of this study show for the first time that HLA class II type is associated with RA in Brazilian Amazon populations and that a specific interaction between the HLA-DRB1*04 gene and smoking is associated with a high cardiovascular risk status, as initially reported in the European population. This study therefore contributes to an understanding of gene-environment interactions in RA patients.