ABSTRACT
The minisequencing technique offers accuracy and robustness to genotyping of polymorphic DNA variants, being an excellent option for the identification and analyses of prognostic/susceptibility markers in human diseases. Two multiplex minisequencing assays were designed and standardized to screen 23 candidate SNPs in cytokine, chemokine receptor and ligand genes previously associated with susceptibility to cancer and autoimmune disorders as well as to infectious diseases outcome. The SNPs were displayed in two separate panels (panel 1-IL2 rs2069762, TNFα rs1800629, rs361525; IL4 rs2243250; IL6 rs1800795; IL10 rs1800896, rs1800872; IL17A rs8193036, rs2275913 and panel 2-CCR3 rs309125, CCR4 rs6770096, rs2228428; CCR6 rs968334; CCR8 rs2853699; CXCR3 rs34334103, rs2280964;CXCR6 rs223435, rs2234358; CCL20 rs13034664, rs6749704; CCL22 rs4359426; CXCL10/IP-10 rs3921, rs56061981). A total of 305 DNA samples from healthy individuals were genotyped by minisequencing. To validate the minisequencing technique and to encompass the majority of the potential genotypes for all 23 SNPs, 20 of these samples were genotyped by Sanger sequencing. The results of both techniques were 100% in agreement. The technique of minisequencing showed high accuracy and robustness, avoiding the need for high quantities of DNA template samples. It was easily to be conducted in bulk samples derived from a highly admixed human population, being therefore an excellent option for immunogenetic studies.
Subject(s)
Cytokines/genetics , Immunogenetics/methods , Receptors, Chemokine/genetics , Sequence Analysis, DNA/methods , Autoimmune Diseases/genetics , Autoimmune Diseases/immunology , Autoimmune Diseases/physiopathology , Communicable Diseases/genetics , Communicable Diseases/immunology , Communicable Diseases/physiopathology , Genetic Association Studies , Genetic Predisposition to Disease , Genotype , Humans , Ligands , Male , Neoplasms/genetics , Neoplasms/immunology , Neoplasms/physiopathology , Polymorphism, Single NucleotideABSTRACT
Background Systemic lupus erythematosus (SLE) is an autoimmune disease marked by the disruption of the immune homeostasis. Patients exhibit a wide range of clinical manifestations, and environmental and genetic factors are involved in SLE pathogenesis. Evidence suggests that abnormalities in the cellular and molecular events that coordinate apoptosis may favour the generation of autoantigens involved in autoimmunity. In this way, the apoptotic deregulation may be affected by polymorphic variants in apoptotic-related genes. Methods We analyzed FAS, FASL, BCL-2 and BAX polymorphisms in order to correlate to SLE susceptibility and clinical features. A total of 427 SLE patients from the Hospital de Clínicas de Porto Alegre and 543 controls from southern Brazil were evaluated. Results We observed higher frequencies of the FASL -844CC genotype and -844C allele, as well as of the FASL-844C/IVS2nt-124A haplotype in African-derived SLE patients when compared to controls ( P < 0.001). FASL -844C, which is related to high FasL expression, could contribute to increased apoptosis and to the breakdown of immunological tolerance, favouring autoantibody production and inflammation. On the other hand, the BAX -248GA genotype and the -248A allele , related to low protein expression, were observed as a protective factor against SLE in this same population. The rate of apoptosis and cell death was evaluated in peripheral lymphocytes, and SLE patients presented a higher percentage of dead lymphocytes (CD3+Annexin V+ 7-AAD+) compared to the control group. Conclusion Our data support a role for apoptosis in SLE susceptibility.
Subject(s)
Apoptosis/genetics , Genetic Predisposition to Disease , Lupus Erythematosus, Systemic/genetics , Lymphocytes/pathology , Adult , Alleles , Brazil , Case-Control Studies , Disease Progression , Female , Genotype , Humans , Lupus Erythematosus, Systemic/physiopathology , Male , Middle Aged , Polymorphism, GeneticABSTRACT
The major pathological hallmark of the systemic sclerosis (SSc) is skin and internal organ fibrosis, which results from normal tissue architecture alterations and extracellular matrix (ECM) protein deposition. ECM components are degraded by matrix metalloproteinases (MMP). Promoter region polymorphisms in MMP genes may influence gene expression, resulting in an imbalance between ECM protein production and degradation. Here, we analyzed MMP1 -1607 1G/2G (rs1799750), MMP3 -1171 5A/6A (rs3025058), and MMP9 -1562 C/T (rs3918242) polymorphisms in relation to susceptibility to SSc and its clinical features. The patient group included 98 individuals with longstanding or recently diagnosed disease, meeting the American College of Rheumatology or LeRoy and Medsger criteria for SSc; the control group included 100 healthy blood donors. All participants were of European descent. Genotyping was performed by polymerase chain reaction followed by restriction digestion. Genotype and allele frequencies of MMP polymorphisms were similar between the two groups. In secondary analyses, significantly higher frequency of 1G/2G genotype from MMP1 polymorphism was observed for patients testing positive for antinuclear autoantibodies (P = 0.007), while 1G/1G genotype was associated with interstitial lung disease development (P = 0.018). The 6A/6A genotype from MMP3 polymorphism was absent in patients with calcinosis (P = 0.011), while the MMP3 5A/5A genotype correlated with the presence of anti-topoisomerase I antibodies (P = 0.009) and reduced diffusing capacity for carbon monoxide (P = 0.024). These results suggest that MMP polymorphisms are not associated with SSc susceptibility, although MMP1 and MMP3 variants are associated with specific SSc clinical and laboratory features.
Subject(s)
Matrix Metalloproteinase 1/genetics , Matrix Metalloproteinase 3/genetics , Matrix Metalloproteinase 9/genetics , Polymorphism, Single Nucleotide , Scleroderma, Systemic/genetics , Adult , Case-Control Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Promoter Regions, Genetic , Scleroderma, Systemic/pathologyABSTRACT
Human leukocyte antigen G (HLA-G) is an immunomodulatory molecule with important roles both physiologically as well as an escape mechanism of cancer cells. In this study, we evaluated the impact of eight polymorphisms at the 3' untranslated region (3'UTR) of the HLA-G gene in the development of prostate cancer (PCa) and benign prostatic hyperplasia (BPH). A total of 468 DNA samples of Brazilian men predominantly Euro-descendant with PCa (N = 187), BPH (N = 152) and healthy control individuals (N = 129) were evaluated. The HLA-G 3'UTR region was amplified by polymerase chain reaction (PCR), sequenced and genotyped to identify the 14 bp insertion/deletion (rs371194629), +3003T/C (rs1707), +3010C/G (rs1710), +3027A/C (rs17179101), +3035C/T (rs17179108), +3142G/C (rs1063320), +3187A/G (rs9380142) and +3196C/G (rs1610696) polymorphisms. Regression logistic and chi-square tests were performed to verify the influence of single nucleotide polymorphisms (SNPs) in PCa and/or BPH susceptibility, as well as in PCa progression (clinicopathological status). Our data showed the UTR-4 haplotype as a risk factor to PCa in comparison with control [odds ratio (OR) 2.35, 95% confidence interval (CI) 1.39-3.96, P adjusted = 0.003) and BPH groups (OR 1.82, 95% CI 1.15-2.86, P adjusted = 0.030). Further, the 'non-14bp Ins_ + 3142G_+3187A' haplotype (OR 1.56, 95% CI 1.10-2.20, P adjusted = 0.036), the +3003CT genotype (OR 4.44, 95% CI 1.33-4.50, P adjusted = 0.032) and the +3003C allele (OR 2.33, 95% CI 1.38-3.92, P adjusted = 0.016) also conferred susceptibility to PCa. Our data suggest an important influence of HLA-G 3'UTR polymorphisms in PCa susceptibility and support the use of the +3003 variant as a tag SNP for PCa risk.
Subject(s)
HLA-G Antigens/genetics , Neoplasm Proteins/genetics , Polymorphism, Single Nucleotide , Prostatic Hyperplasia/genetics , Prostatic Neoplasms/genetics , 3' Untranslated Regions , Adult , Aged , Aged, 80 and over , Case-Control Studies , Genotype , Humans , Male , Middle AgedABSTRACT
In this study, we sought to investigate the genetic influence of two HLA-G 3'-untranslated region (3'-UTR) polymorphisms - 14 bp (rs66554220) and +3142C>G (rs1063320) and their compounding haplotypes in susceptibility to rheumatoid arthritis (RA) in a two-region Brazilian study comprising of 539 patients and 489 controls. All subjects were polymerase chain reaction (PCR) genotyped for the referred polymorphisms and logistic regression models controlling for sex, city and age were performed. Homozygozity for the +3142G allele was associated with an increased risk of RA [odds ratio (OR) = 1.45, 95% confidence interval (CI) = 1.075-1.959, P(Bonf) = 0.030], whereas no association was observed for the 14 bp polymorphism. Haplotype comparisons between patients and controls showed a decreased frequency of the delC haplotype in patients (OR = 0.70, 95% CI = 0.521-0.946, P(Bonf) = 0.040), which remained significant in the rheumatoid factor (RF)-positive group (OR = 0.66, 95% CI = 0.482-0.900, P(Bonf) = 0.018), but not in the RF-negative group. These results corroborate the hypothesis of an involvement of HLA-G in the susceptibility of RA. The +3142G allele is associated with haplotype lineages that share high identity and are regarded as low producers. The presence of the G allele in homozygosis could be responsible for a low HLA-G expression profile that could favor the triggering of RA.
Subject(s)
3' Untranslated Regions , Alleles , Arthritis, Rheumatoid/genetics , Gene Frequency , HLA-G Antigens/genetics , Polymorphism, Genetic , Adult , Aged , Brazil , Female , Humans , Male , Middle Aged , Polymerase Chain ReactionABSTRACT
The aim of this study was to analyze the allelic and genotypic frequencies of the CCR5delta32 polymorphism in systemic lupus erythematosus (SLE) patients and to investigate a possible association of this allele with SLE susceptibility and clinical outcome. A total of 367 SLE patients and 435 healthy controls were genotyped for the CCR5delta32 polymorphism. We observed that, in European-derived individuals, the frequency of the CCR5delta32 allele was smaller in patients than in controls (2.7% vs. 7.5%, OR 0.34, 95% CI 0.17-0.65, p Bonf=0.002), suggesting that this allele could be considered a protective factor for the disease. Regarding clinical manifestations, we observed that CCR5delta32 female African-derived carrier patients presented a higher predisposition to class IV nephritis when compared with absent nephritis/other class group (13.8% vs. 3.8%, OR 37.1, 95% CI 2.8-1854.7, p Bonf=0.030). A multivariate analysis including all female patients and controlling for the presence or absence of anti-dsDNA antibodies, ethnicity and age at diagnosis showed an increased relative risk of 3.9 times for patients carrying the CCR5delta32 allele to develop class IV nephritis as compared with noncarriers. Our data suggest that the CCR5delta32 allele is a protective factor for the disease in European-derived patients and a susceptibility factor to class IV nephritis in African-derived female patients.
Subject(s)
Genetic Predisposition to Disease , Lupus Erythematosus, Systemic/genetics , Lupus Nephritis/genetics , Receptors, CCR5/genetics , Adult , Alleles , Black People , Brazil , Case-Control Studies , Female , Genotype , Humans , Male , Middle Aged , Multivariate Analysis , Polymorphism, Genetic , Sex Factors , White PeopleABSTRACT
Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrotic, immunological and vascular abnormalities. Nuclear factor-kB (NFKB), as a key transcription factor involved in the regulation of immune responses, appears to be a good candidate for studies on the pathogenesis of autoimmune diseases, as well as the interleukin-10 (IL-10) polymorphism, which other studies have suggested an association with SSc. Our objective was to study the association of NFKB and IL-10 gene polymorphisms with SSc. One hundred and fifty-one SSc patients and 147 healthy bone marrow donors were enrolled in a case-control study. Blood was collected for DNA extraction; typing of IL-10 genes was made by polymerase chain reaction with sequence-specific primers (PCR-SSP), and NFKB gene typing was made by restriction fragment length polymorphism (RFLP). Patients underwent clinical evaluation, serology, Doppler echocardiography and chest high-resolution computed tomography. The frequency of IL-10 (-1082) GG genotype was found to be significantly higher in SSc patients (36.4%) as compared to healthy controls (22.4%) (P = 0.012). The frequency of heterozygous genotype GA was significantly lower (P = 0.004) in patients (38.4%) in comparison with control subjects (55.8%). A predominance of the high-producing IL-10 phenotype (GCC(+) /GCC(+) ) was observed in SSc patients compared with healthy controls (37.7% versus 24.5%, respectively; OR: 1.87, 95% CI: 1.10-3.19, P = 0.019). No significant difference was found in the allelic and genotype distribution of the NFKB promoter polymorphism between patients and controls. No statistically significant associations were found between IL-10 or NFKB polymorphisms clinical and laboratory features of SSc. Our results confirmed the association of the high-producing phenotype (GCC(+) /GCC(+) ) with increased risk for SSc, but found no correlation with NFKB polymorphisms.
Subject(s)
Interleukin-10/genetics , NF-kappa B p50 Subunit/genetics , Polymorphism, Single Nucleotide , Promoter Regions, Genetic , Scleroderma, Systemic/genetics , Alleles , Case-Control Studies , Epistasis, Genetic , Gene Frequency , Genotype , Haplotypes , Humans , Phenotype , Scleroderma, Systemic/diagnosisABSTRACT
Vitamin D deficiency has been described in systemic lupus erythematosus (SLE). BsmI VDR (vitamin D receptor) gene polymorphism was associated with SLE in Asian patients. Studies in Brazilian populations have not been realized. A case-control study with 195 SLE patients and 201 healthy controls was conducted to investigate the influence of BsmI and FokI VDR gene polymorphisms on susceptibility to SLE. In addition, 25-hydroxyvitamin D [25(OH)D] was measured in SLE patients to evaluate possible associations with VDR polymorphic variants and clinical and laboratory expressions of disease. Genotyping was performed by RFLP-PCR. The measurement of 25(OH)D was performed by chemiluminescence. There was no statistically significant difference in genotype and allelic frequencies of BsmI and FokI polymorphisms between European-derived cases and controls. The mean serum levels of 25(OH)D were 25.51 ± 11.43 ng/ml in SLE patients. According to genotype distribution, 25(OH)D concentrations were significantly higher in patients carrying the FokI f/f genotype compared with patients carrying the F/F genotype (31.6 ± 14.1 ng/ml versus 23.0 ± 9.2 ng/ml, p = 0.004), reinforcing its role in the functional activity of VDR. This feature may be considered in future clinical and experimental studies involving vitamin D measurements. Therefore, genetic-specific definitions of ideal levels of vitamin D in SLE need to be established in future studies.
Subject(s)
Deoxyribonucleases, Type II Site-Specific/metabolism , Lupus Erythematosus, Systemic/blood , Lupus Erythematosus, Systemic/genetics , Polymorphism, Genetic , Receptors, Calcitriol/genetics , Vitamin D/analogs & derivatives , Adult , Brazil , Case-Control Studies , Female , Genetic Predisposition to Disease , Genotype , Humans , Male , Middle Aged , Vitamin D/blood , White PeopleABSTRACT
Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease and can affect several organs and systems. It is characterized by high production of autoantibodies against nuclear compounds. TLR7/8/9 are responsible for nucleic acid recognition and they trigger proinflammatory responses through activation of NK-kappaB and Type I IFN production, making a bridge between the innate and the adaptative immune systems. We analyzed the frequency of TLR7 rs179008, TLR8 rs3764880, TLR9 rs5743836 and rs352140 in 370 patients with SLE and 415 healthy controls from southern Brazil. All analyses were conducted with regard to gender and ethnicity. Genotypic and allelic frequencies were different for TLR7 rs179008 (0.253 vs. 0.163, p = 0.020 and p = 0.003, OR for T allele: 1.74 CI 95% 1.12-2.70) and TLR9 rs5743836 (0.174 vs. 0.112, p = 0.045 and p = 0.017, OR for C allele: 1.59, CI 95% 0.99-2.57) between European-derived female groups. A higher frequency was observed for the presence of Anti-SSa/Ro for TRL9 rs5743836 C allele carriers (0.228 vs 0.126, Bonferroni corrected p = 0.06). No statistical differences were found for TLR9 haplotypic analyses. We suggest that TLR7 rs179008 and TLR9 rs5743836 can be considered SLE susceptibility factors for women of European descent in our population.
Subject(s)
Lupus Erythematosus, Systemic/genetics , Toll-Like Receptor 7/genetics , Toll-Like Receptor 8/genetics , Toll-Like Receptor 9/genetics , Alleles , Black People/genetics , Brazil , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Haplotypes , Humans , Lupus Erythematosus, Systemic/immunology , Male , Polymorphism, Genetic , Sex Factors , White People/geneticsABSTRACT
Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease that affects several organs and systems. Its etiology remains unknown, although it is probably multifactorial. The human leukocyte antigen G (HLA-G) is a nonclassic major histocompatibility complex I molecule characterized by restricted expression and low DNA polymorphism. HLA-G plays a role in immunosuppression through different mechanisms. In inflammatory diseases, it has been postulated that HLA-G expression may be a possible mechanism of tissue protection against exacerbated inflammatory response. On the 3' untranslated region (3' UTR) of the HLA-G gene, there is an insertion/deletion polymorphism of 14 bp (rs1704) that was shown to influence the mRNA stability. The influence of this polymorphism in disease susceptibility is controversial. Also in the 3' UTR there is a single nucleotide polymorphism C/G (rs1063320) on the position +3142, at a possible binding site for microRNAs (miRNAs) and having an influence on miRNA affinity. In this study, we analyzed the +3142C>G and the 14 bp polymorphisms in 195 SLE European-derived female patients. Our findings show a significant increase of the +3142G allele frequency among patients as compared with controls (0.58 vs 0.47, P = 0.011). Also, patients presented a higher frequency of the GG genotype (OR = 1.90, 95% CI: 1.08-3.42). Double heterozygotes for the two polymorphisms presented a milder mean systemic lupus erythematosus disease activity index (SLEDAI) than heterozygotes for only one of the variants or non-heterozygous individuals (1.56 vs 3.15 and 3.26, respectively, corrected P = 0.044). These results suggest the involvement of the HLA-G molecule on SLE susceptibility and outcome.
Subject(s)
HLA Antigens/genetics , Histocompatibility Antigens Class I/genetics , Lupus Erythematosus, Systemic/genetics , Lupus Erythematosus, Systemic/immunology , Polymorphism, Genetic , 3' Untranslated Regions , Adult , Alleles , Binding Sites , Case-Control Studies , Exons , Female , Gene Frequency , Genotype , HLA-G Antigens , Heterozygote , Humans , Immunosuppression Therapy , Male , MicroRNAs/metabolism , Middle AgedABSTRACT
Systemic lupus erythematosus (SLE) is an autoimmune disorder of the connective tissue with a wide and heterogeneous spectrum of manifestations, with renal and neurological involvement usually related to worse prognosis. SLE more frequently affects females of reproductive age, and a high prevalence and renal manifestation seem to be associated with non-European ethnicity. The present study aims to investigate candidate loci to SLE predisposition and evaluate the influence of ethnic ancestry in the disease risk and clinical phenotypic heterogeneity of lupus at onset. Samples represented by 111 patients and 345 controls, originated from the city of Belém, located in the Northern Region of Brazil, were investigated for polymorphisms in HLA-G, HLA-C, SLC11A1, MTHFR, CASP8 and 15 KIR genes, in addition to 89 Amerindian samples genotyped for SLC11A1. We also investigated 48 insertion/deletion ancestry markers to characterize individual African, European and Amerindian ancestry proportions in the samples. Predisposition to SLE was associated with GTGT deletion at the SLC11A1 3'UTR, presence of KIR2DS2 +/KIR2DS5 +/KIR3DS1 + profile, increased number of stimulatory KIR genes, and European and Amerindian ancestries. The ancestry analysis ruled out ethnic differences between controls and patients as the source of the observed associations. Moreover, the African ancestry was associated with renal manifestations.
Subject(s)
Cation Transport Proteins/genetics , Ethnicity/genetics , Genetic Markers , Genetic Predisposition to Disease , Lupus Erythematosus, Systemic/genetics , Polymorphism, Genetic , Receptors, KIR/genetics , Adult , Age of Onset , Brazil , Cities , Female , Gene Frequency , Humans , Lupus Erythematosus, Systemic/ethnology , Male , Receptors, KIR3DS1/geneticsSubject(s)
Arthritis, Rheumatoid/genetics , Cardiovascular Diseases/epidemiology , Nitric Oxide Synthase Type III/genetics , Polymorphism, Genetic/genetics , Cardiovascular Diseases/genetics , HLA-DR Antigens/genetics , HLA-DRB1 Chains , Humans , Nitric Oxide Synthase Type II/genetics , Risk FactorsABSTRACT
A previous study has suggested that the combination KIR2DS2(+)/KIR2DL2(-) was related to increased risk for systemic sclerosis (SSc), while others have failed to reproduce this finding. Our objective was to study this matter further and test the association of other KIR genes with SSc. One hundred and ten SSc patients and 115 healthy bone marrow donors were enrolled in a case-control study. Blood was collected for DNA extraction; typing of 15 KIR genes and human leucocyte antigen-C (HLA-C) was made by polymerase chain reaction with sequence specific primers (PCR-SSP), followed by electrophoresis on agarose gel. Patients underwent clinical evaluation, serology, Doppler echocardiography and chest high-resolution computed tomography. The frequency of the inhibitory KIR2DL2 was significantly lower in patients [29.1% versus 65.2% in controls, P < 0.0001; odds ratio (OR) = 0.22, 95% confidence interval 0.12-0.40]. When combinations of activating and inhibitory KIR genes were analysed, the presence of KIR2DS2 in the absence of KIR2DL2 (KIR2DS2(+)/KIR2DL2(-)) was more frequent in patients than in controls (25.5% versus 1.7%, respectively; P < 0.0001; OR = 19.29, 4.24-122.26). However, the presence of both KIR2DS2 and KIR2DL2 (KIR2DS2(+)/KIR2DL2(+)) was more frequent in controls (57.4%) than in patients (28.2%, P < 0.0001), suggesting a preponderant protective effect of KIR2DL2 over KIR2DS2. Stratification for HLA-C1 status did not change these results. No statistically significant associations were found between KIR phenotypes and clinical and laboratory features of SSc. Our results suggest a protective role of KIR2DL2(+) phenotype and confirmed the association of the combination KIR2DS2(+)/KIR2DL2(-) with increased risk for SSc.
Subject(s)
HLA-C Antigens/genetics , Receptors, KIR2DL2/genetics , Receptors, KIR/genetics , Scleroderma, Systemic/genetics , Adult , Aged , Case-Control Studies , Female , Gene Frequency/immunology , HLA-C Antigens/immunology , Humans , Male , Middle Aged , Radiography , Receptors, KIR/immunology , Receptors, KIR2DL2/immunology , Risk Factors , Scleroderma, Systemic/diagnostic imaging , Scleroderma, Systemic/immunology , UltrasonographyABSTRACT
Malaria affects thousands of people around the world representing a critical issue regarding health policies in tropical countries. Similarly, also haemolytic diseases such as sickle cell disease and thalassemias are a concern in different parts of the globe. It is well established that haemolytic diseases, such as sickle cell disease (SCD) and thalassemias, represent a resistance factor to malaria, which explains the high frequencies of such genetic variants in malaria endemic areas. In this context, it has been shown that the rate limiting enzyme heme oxygenase I (HO-1), responsible for the catabolism of the free heme in the body, is an important resistance factor in malaria and is also important in the physiopathology of haemolytic diseases. Here, we suggest that allelic variants of HO-1, which display significant differences in terms of protein expression, have been selected in endemic malaria areas since the HO-1 enzyme can enhance the protection against malaria conferred by haemolytic diseases This protection apply mainly in what concerns protection against severe malaria forms. Therefore, HO-1 genotyping would be fundamental to determine resistance of a given individual to lethal forms of malaria as well as to common clinical complications typical to haemolytic diseases and would be helpful in the establishment of public health politics.
Subject(s)
Anemia, Hemolytic, Congenital/physiopathology , Heme Oxygenase-1/genetics , Immunity, Innate/genetics , Malaria/immunology , Polymorphism, Genetic , Anemia, Hemolytic, Congenital/immunology , Heme/metabolism , Heme Oxygenase-1/metabolism , Humans , Immunity, Innate/immunology , Molecular Structure , Selection, GeneticABSTRACT
The mannose-binding lectin gene (MBL-2) has emerged as a candidate for systemic lupus erythematosus susceptibility, but studies in Brazilian population have not been conducted. To examine potential associations of mannose-binding lectin alleles G57E, G54D, IVSnt5, R52C and R52H with susceptibility to and clinical expression of systemic lupus erythematosus in southern Brazilian patients, we conducted a case-control study with 327 consecutive patients with diagnosis of systemic lupus erythematosus and 345 healthy controls. Genotyping was performed by restriction fragment length polymorphism-polymerase chain reaction assay. A statistically significant difference in the frequencies of allele R52C was observed in European-derived systemic lupus erythematosus patients when compared with controls (9.6% vs. 3.3%, p < 0.001, odds ratio: 3.15, 95% confidence interval: 1.76-5.62, p < 0.05). The frequencies of alleles G54D and G57E were not different between European-derived systemic lupus erythematosus patients and controls. There were no differences between clinical and laboratory features in systemic lupus erythematosus patients according to the presence or absence of mannose-binding lectin allelic variants. These results support an increased risk of systemic lupus erythematosus in European-derived individuals carrying allele R52C. Patients carrying this allele have an approximately three-fold higher odds ratio of developing systemic lupus erythematosus when compared with controls. Our data do not support associations between the mannose-binding lectin allelic variants studied and clinical expression of systemic lupus erythematosus.
Subject(s)
Genetic Predisposition to Disease , Lupus Erythematosus, Systemic/genetics , Mannose-Binding Lectin/genetics , Adult , Alleles , Brazil , Case-Control Studies , Female , Genotype , Humans , Male , Middle Aged , Polymerase Chain Reaction , Polymorphism, Genetic , Polymorphism, Restriction Fragment LengthABSTRACT
Despite its well known monogenic etiopathogenesis, sickle cell disease (SCD) is characterized by a striking variability of clinical presentation. There is growing evidence that genetic factors may be involved in this variability. Human leukocyte antigen (HLA)-G is a non-classical HLA molecule which was shown to be expressed at sites of inflammation and in inflammatory diseases. Besides its large and highly polymorphic promoter region, the 3' UTR region seems also to play an important role on regulating HLA-G expression. We investigated the influence of the 14 pb (rs1704) and the +3142 (rs1063320) HLA-G polymorphisms in 93 SCD patients in order to evaluate its potential role on clinical parameters. Twenty-one patients presented an HCV infection. Among all SCD patients 16 (22.2%) were homozygous for the +3142C genotype, none of them hepatitis C (HCV) positive. Controlling for blood transfusions in the last year, the C allele represented a dose dependent protection effect for HCV infection (PR = 0.41; 95% CI: 0.24-0.71). The +3142C allele was also underrepresented among patients with history of respiratory-tract infections. Our results support a role of the +3142 polymorphism in the susceptibility to infections, in particular to HCV infection, and suggest a possible interference of the HLA-G molecule in the response to infections, among SCD patients.
Subject(s)
Anemia, Sickle Cell/genetics , Anemia, Sickle Cell/virology , HLA Antigens/genetics , Hepacivirus/genetics , Hepatitis C/genetics , Histocompatibility Antigens Class I/genetics , Polymorphism, Genetic/genetics , Adult , Anemia, Sickle Cell/immunology , Case-Control Studies , Disease Susceptibility , Female , HLA-G Antigens , Hepatitis C/complications , Hepatitis C/immunology , Humans , Male , Young AdultABSTRACT
Human leukocyte antigen-G (HLA-G) is a nonclassical class I major histocompatibility complex molecule which is induced at the course of inflammatory pathologies, and its expression has been suggested as a possible mechanism of tissue protection against autoimmune inflammatory responses, therefore acting as a mechanism of immune surveillance. We investigated the influence of the 14 bp polymorphism of the HLA-G gene on systemic lupus erythematosus (SLE) by analyzing 293 patients with SLE and 460 healthy controls. The patient's group was not in Hardy-Weinberg equilibrium, presenting an excess of heterozygotes (P = 0.014). The heterozygote group exhibited lower systemic lupus erythematosus disease activity indexes than the homozygous deletion group and the homozygous insertion group (mean value = 2.29 against 2.97 and 3.4, respectively, P = 0.035). Photosensitive patients showed a higher frequency of heterozygotes and an equivalent lower frequency of homozygotes for deletion; on the other hand, patients without arthritis presented a higher frequency of heterozygotes than the arthritis group and also a lower frequency of the del/del genotype. Overall, our results support the idea of a role of the HLA-G insertion/deletion polymorphism and therefore a role for the HLA-G molecule, on the pathology of SLE.