The critical importance of epigenetics in autoimmune-related skin diseases / 医学前沿

Autoimmune-related skin diseases are a group of disorders with diverse etiology and pathophysiology involved in autoimmunity. Genetics and environmental factors may contribute to the development of these autoimmune disorders. Although the etiology and pathogenesis of these disorders are poorly understood, environmental variables that induce aberrant epigenetic regulations may provide some insights. Epigenetics is the study of heritable mechanisms that regulate gene expression without changing DNA sequences. The most important epigenetic mechanisms are DNA methylation, histone modification, and noncoding RNAs. In this review, we discuss the most recent findings regarding the function of epigenetic mechanisms in autoimmune-related skin disorders, including systemic lupus erythematosus, bullous skin diseases, psoriasis, and systemic sclerosis. These findings will expand our understanding and highlight the possible clinical applications of precision epigenetics approaches.

Study of the association of lncRNA-GAS5 gene polymorphisms with systemic lupus erythematosus in Guangxi population / 中华医学遗传学杂志

OBJECTIVE@#To assess the association of rs55829688 and rs75315904 polymorphisms of the lncRNA-GAS5 gene with susceptibility to systemic lupus erythematosus (SLE) in Guangxi population.@*METHODS@#Peripheral venous blood samples were collected from the SLE group and control group. Following extraction of genomic DNA, SNPscan and Sanger sequencing were carried out to determine the genotypes for the rs55829688 and rs75315904 loci of the lncRNA-GAS5 gene.@*RESULTS@#No difference was found between the two groups with regard to the genotypic frequencies for rs55829688 and rs75315904 (P > 0.05). However, the frequencies of C allele of rs55829688 between the two groups was significantly different (P < 0.05). In the SLE group, the frequencies of C allele and CT+CC genotype for rs55829688 among SLE patients with nephritis were significantly lower than those of SLE patients without nephritis (P < 0.05). In addition, haplotype analysis showed that the frequency of rs55829688 C/rs75315904 A allele in the SLE group was lower than that of the control group (P < 0.05).@*CONCLUSION@#In Guangxi population, the carrier status of rs55829688 C allele of the lncRNA-GAS5 gene may reduce the risk of SLE and its complicated nephritis, and the rs55829688 C/rs75315904 A haplotype may reduce the risk for SLE.

Trans-ethnic Mendelian randomization study of systemic lupus erythematosus and common female hormone-dependent malignancies / 中华医学杂志(英文版)

BACKGROUND@#Observational research has reported that systemic lupus erythematosus (SLE) is related to common female hormone-dependent cancers, but the underlying causal effect remains undefined. This study aimed to explore the causal association of these conditions by Mendelian randomization (MR) analysis.@*METHODS@#We selected instrumental variables for SLE from genome-wide association studies (GWASs) conducted in European and East Asian populations. The genetic variants for female malignant neoplasms were obtained from corresponding ancestry GWASs. We utilized inverse variance weighted (IVW) as the primary analysis, followed by sensitivity analysis. Furthermore, we conducted multivariable MR (MVMR) to estimate direct effects by adjusting for the body mass index and estradiol. Finally, we implemented reverse direction MR analysis and gave a negative example to test the reliability of MR results.@*RESULTS@#We found SLE was significantly negatively associated with overall endometrial cancer risk (odds ratio [OR] = 0.961, 95% confidence interval [CI] = 0.935-0.987, P  = 3.57E-03) and moderately inversely related to endometrioid endometrial cancer (ENEC) (OR = 0.965, 95% CI = 0.936-0.995, P  = 0.024) risk in the European population by IVW. We replicated these results using other MR models and detected a direct effect by MVMR (overall endometrial cancer, OR = 0.962, 95% CI = 0.941-0.983, P  = 5.11E-04; ENEC, OR = 0.964, 95% CI = 0.940-0.989, P  = 0.005). Moreover, we revealed that SLE was correlated with decreased breast cancer risk (OR = 0.951, 95% CI = 0.918-0.986, P  = 0.006) in the East Asian population by IVW, and the effect was still significant in MVMR (OR = 0.934, 95% CI = 0.859-0.976, P  = 0.002). The statistical powers of positive MR results were all >0.9.@*CONCLUSION@#This finding suggests a possible causal effect of SLE on the risk of overall endometrial cancer and breast cancer in European and East Asian populations, respectively, by MR analysis, which compensates for inherent limitations of observational research.

Toll-like receptor 9 polymorphisms in brazilian patients with systemic lupus erythematosus: a pilot study / Polimorfismos do receptor toll-like 9 em pacientes brasileiros com lúpus eritematoso sistêmico: um estudo piloto

Abstract Toll-like receptor 9 (TLR9) is an important component of the innate immune system and have been associated with several autoimmune diseases, such as Systemic Lupus Erythematosus (SLE). The aim of this study was to investigate polymorphisms in TLR9 gene in a Brazilian SLE patients group and their association with clinical manifestation, particularly Jaccoud's arthropathy (JA). We analyzed DNA samples from 204 SLE patients, having a subgroup of them presenting JA (n=24). A control group (n=133) from the same city was also included. TLR9 single nucleotide polymorphisms (SNPs) (−1237 C>T and +2848 G>A) were identified by sequencing analysis. The TLR9 gene genotype frequency was similar both in SLE patients and the control group. In the whole SLE population, an association between the homozygosis of allele C at position −1237 with psychosis and anemia (p < 0.01) was found. Likewise, the homozygosis of allele G at position +2848 was associated with a discoid rash (p < 0.05). There was no association between JA and TLR9 polymorphisms. These data show that TLR9 polymorphisms do not seem to be a predisposing factor for SLE in the Brazilian population, and that SNPs are not associated with JA.

Resumo O receptor Toll-like 9 (TLR9) é um componente importante do sistema imunológico inato e tem sido associado a várias doenças autoimunes, como o Lúpus Eritematoso Sistêmico (LES). O objetivo deste estudo foi investigar polimorfismos no gene TLR9 em um grupo de pacientes brasileiros com LES e sua associação com a manifestação clínica, particularmente a artropatia de Jaccoud (JA). Foram analisadas amostras de DNA de 204 pacientes com LES, e um subgrupo com JA (n=24). Um grupo de controle (n=133) da mesma cidade também foi incluído. Os polimorfismos de nucleotídeos únicos TLR9 (SNPs) (−1237 C>T e +2848 G>A) foram identificados pela análise de sequenciamento. A frequência do genótipo genético TLR9 foi semelhante tanto em pacientes com LES quanto no grupo controle. Em toda a população de LES, foi encontrada associação entre a homozigose do alelo C na posição −1237 com psicose e anemia (p < 0,01). Da mesma forma, a homozigose do alelo G na posição +2848 foi associada a uma erupção cutânea discoide (p < 0,05). Não houve associação entre polimorfismos JA e TLR9. Esses dados mostram que os polimorfismos TLR9 não parecem ser um fator predisponível para o LES na população brasileira, e que os SNPs não estão associados ao JA.

Toll-like receptor 9 polymorphisms in brazilian patients with systemic lupus erythematosus: a pilot study / Polimorfismos do receptor toll-like 9 em pacientes brasileiros com lúpus eritematoso sistêmico: um estudo piloto

Toll-like receptor 9 (TLR9) is an important component of the innate immune system and have been associated with several autoimmune diseases, such as Systemic Lupus Erythematosus (SLE). The aim of this study was to investigate polymorphisms in TLR9 gene in a Brazilian SLE patients group and their association with clinical manifestation, particularly Jaccoud’s arthropathy (JA). We analyzed DNA samples from 204 SLE patients, having a subgroup of them presenting JA (n=24). A control group (n=133) from the same city was also included. TLR9 single nucleotide polymorphisms (SNPs) (−1237 C>T and +2848 G>A) were identified by sequencing analysis. The TLR9 gene genotype frequency was similar both in SLE patients and the control group. In the whole SLE population, an association between the homozygosis of allele C at position −1237 with psychosis and anemia (p < 0.01) was found. Likewise, the homozygosis of allele G at position +2848 was associated with a discoid rash (p < 0.05). There was no association between JA and TLR9 polymorphisms. These data show that TLR9 polymorphisms do not seem to be a predisposing factor for SLE in the Brazilian population, and that SNPs are not associated with JA.

O receptor Toll-like 9 (TLR9) é um componente importante do sistema imunológico inato e tem sido associado a várias doenças autoimunes, como o Lúpus Eritematoso Sistêmico (LES). O objetivo deste estudo foi investigar polimorfismos no gene TLR9 em um grupo de pacientes brasileiros com LES e sua associação com a manifestação clínica, particularmente a artropatia de Jaccoud (JA). Foram analisadas amostras de DNA de 204 pacientes com LES, e um subgrupo com JA (n=24). Um grupo de controle (n=133) da mesma cidade também foi incluído. Os polimorfismos de nucleotídeos únicos TLR9 (SNPs) (−1237 C>T e +2848 G>A) foram identificados pela análise de sequenciamento. A frequência do genótipo genético TLR9 foi semelhante tanto em pacientes com LES quanto no grupo controle. Em toda a população de LES, foi encontrada associação entre a homozigose do alelo C na posição −1237 com psicose e anemia (p < 0,01). Da mesma forma, a homozigose do alelo G na posição +2848 foi associada a uma erupção cutânea discoide (p < 0,05). Não houve associação entre polimorfismos JA e TLR9. Esses dados mostram que os polimorfismos TLR9 não parecem ser um fator predisponível para o LES na população brasileira, e que os SNPs não estão associados ao JA.

Deficiency of two-pore segment channel 2 contributes to systemic lupus erythematosus via regulation of apoptosis and cell cycle / 中华医学杂志(英文版)

BACKGROUND@#Systemic lupus erythematosus (SLE) is a complex autoimmune disease, and the mechanism of SLE is yet to be fully elucidated. The aim of this study was to explore the role of two-pore segment channel 2 (TPCN2) in SLE pathogenesis.@*METHODS@#Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression of TPCN2 in SLE. We performed a loss-of-function assay by lentiviral construct in Jurkat and THP-1 cell. Knockdown of TPCN2 were confirmed at the RNA level by qRT-PCR and protein level by Western blotting. Cell Count Kit-8 and flow cytometry were used to analyze the cell proliferation, apoptosis, and cell cycle of TPCN2-deficient cells. In addition, gene expression profile of TPCN2-deficient cells was analyzed by RNA sequencing (RNA-seq).@*RESULTS@#TPCN2 knockdown with short hairpin RNA (shRNA)-mediated lentiviruses inhibited cell proliferation, and induced apoptosis and cell-cycle arrest of G2/M phase in both Jurkat and THP-1 cells. We analyzed the transcriptome of knockdown-TPCN2-Jurkat cells, and screened the differential genes, which were enriched for the G2/M checkpoint, complement, and interleukin-6-Janus kinase-signal transducer and activator of transcription pathways, as well as changes in levels of forkhead box O, phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin, and T cell receptor pathways; moreover, TPCN2 significantly influenced cellular processes and biological regulation.@*CONCLUSION@#TPCN2 might be a potential protective factor against SLE.

Exosomal microRNAs: an emerging player in systemic lupus erythematosus / 生理学报

Exosomes are nanometer-sized membranous extracellular vesicles that can be secreted by almost all types of cells in the body. Exosomes are involved in cell-to-cell communication through autocrine and paracrine forms. Exosomal microRNAs (miRNAs) are stable in plasma, urine and other body fluids, and have various biological functions. They play an irreplaceable role in the occurrence, development, immune regulation of systemic lupus erythematosus (SLE). Recent studies have proposed that exosomal miRNAs have promising application prospects in the pathogenesis, early diagnosis, and treatment of SLE. Therefore, this review aims to introduce the current research progress on exosomal miRNAs in SLE and analyze their potential application value.

Identification and functional analysis of a novel phospholipase D2 gene mutation associated with familial systemic lupus erythematosus / 中南大学学报(医学版)

OBJECTIVES@#Systemic lupus erythematosus (SLE) is a kind of autoimmune inflammatory connective tissue disease which seriously endangers human health. Genetic factors play a key role in the pathogenesis of SLE. This study aims to investigate a novel phospholipase D2 (PLD2) mutation associated with familial SLE, and further explore the underlying mechanism of the mutation in SLE.@*METHODS@#The blood samples from a SLE patient, the patient's parents, and 147 normal controls were collected and DNA was extracted. Whole genome high-throughput sequencing was performed in the patient and her parents and the results were further analyzed by various bioinformatics methods. The wild type (wt), mutant type (mu), and negative control PLD2 plasmids were further constructed and transfected into 293 cells. The expression level of HRAS protein in 293 cells was detected by Western blotting.@*RESULTS@#In this SLE family, the female SLE patient and her mother, 1 in generation II and 1 in generation III had typical clinical manifestations of SLE, and all of them had lupus nephritis at early stage. The genetic characteristics are consistent with autosomal dominant inheritance. A novel PLD2 heterozygous mutation (c.2722C>T) was found in the patient and her mother, but not in her father and other normal controls. Compared with wtPLD2 plasmid and negative control PLD2 plasmid, the expression of HRAS in 293 cells transfected with muPLD2 plasmid was significantly up-regulated (both @*CONCLUSIONS@#PLD2 c.2722C>T mutation may be one of the pathogeny of SLE in this family.

Susceptibilidad genética y enfermedad autoinmune reumática: Revisión narrativa / Genetic susceptibility and autoimmune rheumatic disease: Narrative review

La autoinmunidad es la consecuencia de la pérdida de control y regulación de la respuesta inmune. Se re-porta que ocurre entre 5 y 9% de patologías a nivel mundial. A las enfermedades con esta anomalía se les denomina autoinmunes y se clasifican de acuerdo con el órgano o sistema afectado. Las reumáticas involucran al tejido conectivo y las articulaciones. Los factores asociados a su aparición incluyen: edad, género, medioam-biente y genéticos. La susceptibilidad genética indica la presencia de uno o varios genes asociados al desarrollo de determinada enfermedad, cuya expresión podría ser el producto de la migración, selección, recombinación y adaptación de genes entre las poblaciones, lo que explica la variación fenotípica y la expresión clínica resultan-te. Los estudios de asociación del genoma completo (GWAS por sus siglas en inglés) han permitido identificar múltiples genes involucrados con enfermedades reumáticas, destacan el lupus eritematoso sistémico y artritis reumatoide, asociadas con más de 60 alelos, y otras como la espondilitis anquilosante, en donde la asociación ha sido primordialmente con un gen y sus polimorfismos. Esta revisión tiene como objetivo informar el estado de la susceptibilidad determinada genéticamente para estas enfermedades y el impacto que tiene sobre la expresión clínica. Se realizó una búsqueda en PubMed y la base de datos de la biblioteca Cochrane, se incluyeron artículos relacionados con las palabras clave propuestas desde el 2000. La revisión identifica genes y la asociación con estas enfermedades, expone la diversidad existente y justifica continuar la búsqueda de genes en todas las poblaciones.

Autoimmunity is the consequence of the loss of control and regulation of the immune response. It is reported that between 5 and 9% of pathologies occur worldwide. Diseases with this abnormality are called autoimmune and are classified according to the organ or system affected. Rheumatic diseases involve connective tissue and joints. Factors associated with its appearance include age, gender, environment, and genetics. Genetic suscepti-bility indicates the presence of one or more genes associated with the development of a certain disease, whose expression could be the product of migration, selection, recombination and adaptation of genes between popu-lations, which explains the phenotypic variation and the resulting clinical expression. Genome wide association studies (GWAS) have allowed the identification of multiple genes involved with rheumatic diseases, including systemic lupus erythematosus and rheumatoid arthritis, associated with more than 60 alleles, and others such as ankylosing spondylitis, where the association has been primarily with a gene and its polymorphisms. This review aims to report the status of genetically determined susceptibility to these diseases and the impact it has on clinical expression. A search was carried out in PubMed and the Cochrane library database, articles related to the proposed keywords from the year 2000 were included. The review identifies genes and the association with these diseases, exposes the existing diversity and justifies continuing the search for genes in all populations.

Circulating exosomal micrornas as biomarkers of systemic lupus erythematosus

OBJECTIVES: Many studies indicate that microRNAs (miRNAs) could be potential biomarkers for various diseases. The purpose of this study was to investigate the clinical value of serum exosomal miRNAs in systemic lupus erythematosus (SLE). METHODS: Serum exosomes were isolated from 38 patients with SLE and 18 healthy controls (HCs). The expression of miR-21, miR-146a and miR-155 within exosomes was examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Using receiver operating characteristic (ROC) curves, we evaluated the diagnostic value of exosomal miRNAs. RESULTS: Exosomal miR-21 and miR-155 were upregulated (p<0.01), whereas miR-146a expression (p<0.05) was downregulated in patients with SLE, compared to that in HCs. The expression of miR-21 (p<0.01) and miR-155 (p<0.05) was higher in SLE patients with lupus nephritis (LN) than in those without LN (non-LN). The analysis of ROC curves revealed that the expression of miR-21 and miR-155 showed a potential diagnostic value for LN. Furthermore, miR-21 (R=0.44, p<0.05) and miR-155 (R=0.33, p<0.05) were positively correlated with proteinuria. The expression of miR-21 was negatively associated with anti-SSA/Ro antibodies (R=−0.38, p<0.05), and that of miR-146a was negatively associated with anti-dsDNA antibodies (R=−0.39, p<0.05). CONCLUSIONS: These findings suggested that exosomal miR-21 and miR-155 expression levels may serve as potential biomarkers for the diagnosis of SLE and LN.

Impact of C4, C4A and C4B gene copy number variation in the susceptibility, phenotype and progression of systemic lupus erythematosus

Abstract Background Complement component 4 (C4) gene copy number (GCN) affects the susceptibility to systemic lupus erythematosus (SLE) in different populations, however the possible phenotype significance remains to be determined. This study aimed to associate C4A , C4B and total C4 GCN and SLE, focusing on the clinical phenotype and disease progression. Methods C4 , C4A and C4B GCN were determined by real-time PCR in 427 SLE patients and 301 healthy controls, which underwent a detailed clinical evaluation according to a pre-established protocol. Results The risk of developing SLE was 2.62 times higher in subjects with low total C4 GCN (< 4 copies, OR = 2.62, CI = 1.77 to 3.87, p < 0.001) and 3.59 times higher in subjects with low C4A GCN (< 2 copies; OR = 3.59, CI = 2.15 to 5.99, p < 0.001) compared to those subjects with normal or high GCN of total C4 (≥4) and C4A (≥2), respectively. An increased risk was also observed regarding low C4B GCN, albeit to a lesser degree (OR = 1.46, CI = 1.03 to 2.08, p = 0.03). Furthermore, subjects with low C4A GCN had higher permanent disease damage as assessed by the Systemic Lupus International Collaborating Clinics - Damage Index (SLICC-DI; median = 1.5, 95% CI = 1.2-1.9) than patients with normal or high copy number of C4A (median = 1.0, 95% CI = 0.8-1.1; p = 0.004). There was a negative association between low C4A GCN and serositis ( p = 0.02) as well as between low C4B GCN and arthritis ( p = 0.02). Conclusions This study confirms the association between low C4 GCN and SLE susceptibility, and originally demonstrates an association between low C4A GCN and disease severity.

Association between tumor necrosis factor polymorphisms and rheumatoid arthritis as well as systemic lupus erythematosus: a meta-analysis

Tumor necrosis factor-alpha (TNF-α) plays an important role in autoimmune diseases. Previous studies have investigated the association of TNF-α-238G/A (rs361525) and -308G/A (rs1800629) polymorphisms with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, no agreed conclusion had been made. Therefore, this meta-analysis was conducted to assess the associations of TNF-α-238G/A and -308G/A polymorphisms with RA and SLE risk. A systematic search was conducted in commonly used databases. Meta-analysis was performed by STATA12.0. A total of 43 studies were included. In the overall population, the TNF-α-238A allele was observed to be a protective factor for RA (A vs G: OR=0.75, 95%CI=0.57-0.99, P=0.040) and the TNF-α-308A allele was found to be a risk factor for SLE (A vs G: OR=1.78, 95%CI=1.45-2.19, P<0.001). However, no evidence of association was found between TNF-α-238 G/A polymorphism and SLE nor between -308G/A and RA. In the subgroup analysis, TNF-α-308A allele played a pathogenic role for RA in Latin Americans (A vs G: OR=1.46, 95%CI=1.15-1.84, P=0.002) and for SLE in Latin Americans (A vs G: OR=2.12, 95%CI=1.32-3.41, P=0.002) and Europeans (A vs G: OR=2.03, 95%CI=1.56-2.63, P<0.001), while it played a protective role for RA in Asians (A vs G: OR=0.54, 95%CI=0.32-0.90, P=0.017). No significant association was found between TNF-α-308G/A and SLE susceptibility in Africans and Asians. This meta-analysis demonstrated that TNF-α-238A was associated with decreased risk of RA rather than SLE, while -308G/A polymorphism was associated with SLE rather than RA. Stratification analysis indicated that different ethnicities would have different risk alleles.

Asociación de variantes polimorfas de los genes PTPN22 , TNF y VDR en niños con nefritis lúpica: un estudio de tríos en familias colombianas / Association of polymorphic variants of PTPN22 , TNF and VDR genes in children with lupus nephritis: A study in Colombian family triads

RESUMEN Introducción. El lupus eritematoso sistémico es una enfermedad autoinmunitaria cuya gravedad varía según la raza, el sexo y la edad de aparición. Esta disparidad también se observa en los marcadores genéticos asociados con la enfermedad presentes en los genes PTPN22, VDR y TNF. La estratificación genética que presentan las diferentes poblaciones en el mundo puede influir en dicha variabilidad. Objetivo. Analizar la asociación de variantes genéticas de los genes PTPN22, VDR y TNF con nefritis lúpica en niños y su caracter de hereditarias en familias colombianas. Materiales y métodos. Se llevó a cabo un estudio basado en familias con 46 tríos (caso, padre y madre). Se hizo la genotipificación de las variantes rs2476601 de PTPN22, rs361525 y rs1800629 del TNF, y TaqI [rs731236], ApaI [rs7975232], BsmI [rs1544410] y FokI [rs2228570] del VDR, mediante reacción en cadena de la polimerasa cuantitativa (quantitative Polymerase Chain Reaction, qPCR). Se estimó el efecto de la transmisión del alelo de riesgo de padres a hijos y el desequilibrio de ligamiento de los loci VDR y TNF. Resultados. Se observó que el alelo A de rs2476601 en PTPN22 se distribuyó en 8,69 % (n=16) de los padres y en 19,5 % (n=18) de los casos, y que su transmisión de padres a hijos fue 17 veces mayor con relación al alelo G (p=0,028). Los polimorfismos de TNF y VDR no presentaron desequilibrio de transmisión. Las variantes TaqI, ApaI y BsmI del VDR presentaron desequilibrio de ligamiento. Conclusión. Estos hallazgos evidenciaron una asociación del polimorfismo rs2476601 de PTPN22 con la nefritis lúpica en niños, determinada por su transmisión en el grupo de familias estudiadas.

ABSTRACT Introduction: Systemic lupus erythematosus is an autoimmune disease in which the severity varies according to race, sex and age of onset. This variation is also observed in the genetic markers associated with the disease, including PTPN22, VDR and TNF genes. The genetic stratification in different populations worldwide can influence the variability. Objective: To analyze the heritability of PTPN22, VDR and TNF genetic variants and their association with pediatric lupus nephritis in Colombian families. Materials and methods: We conducted a family-based study including 46 triads (case, father and mother). The variants rs2476601 of PTPN22; rs361525 and rs1800629 of TNF, and TaqI [rs731236], ApaI [rs7975232], BsmI [rs1544410] and FokI [rs2228570] of VDR were genotyped by qPCR. The effects of overtransmission of the risk allele from parents to children and linkage disequilibrium at the VDR and TNF loci were estimated. Results: We found that allele A of rs2476601 in PTPN22 was distributed among 8.69 % (n=16) of the parents and 19.5 % (n=18) of the cases; this allele was overtransmitted from parents to children 17 times more often than the G allele (p=0.028). TNF and VDR polymorphisms did not exhibit transmission disequilibrium. VDR TaqI, ApaI and BsmI variants exhibited linkage disequilibrium. Conclusion: These findings showed an association between the PTPN22 rs2476601 polymorphism and pediatric lupus nephritis due to its overtransmission in the group of families studied.

Association of PDCD1 polymorphism to systemic lupus erythematosus and rheumatoid arthritis susceptibility / Associação entre o polimorfismo do gene PDCD1 e a susceptibilidade ao lúpus eritematoso sistêmico e à artrite reumatoide

ABSTRACT Objective: This study aims to analyze the relationship of programmed cell death 1 (PDCD1) gene polymorphism (PD1.3G/A - rs11568821) with features of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) in a Southern Brazilian population. Methods: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed in 95 SLE and 87 RA patients and 128 control group individuals from Santa Catarina, Southern Brazil. The Hardy-Weinberg equilibrium (HWE) test, and odds ratio (OR) were analyzed, considering CI 95% and p ≤ 0.05. Results: The PD1.3A allele frequencies were 0.095 (SLE), 0.115 (RA) and 0.078 (controls). The genotypes of the control group were in HWE, while those of SLE and RA patients were not. However, we found no association between PD1.3 polymorphism and the SLE or RA susceptibility, nor clinical or epidemiological data. Conclusion: There was no significant association between PD1.3 polymorphism and SLE or RA susceptibility in this Southern Brazilian population.

RESUMO Objetivo: Este estudo teve como objetivo analisar a relação entre o polimorfismo do gene PDCD1 (programmed cell death 1) (PD1.3G/A - rs11568821) com características do lúpus eritematoso sistêmico (LES) e da artrite reumatoide (AR) em uma população do sul do Brasil. Métodos: A técnica de PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Lenght Polymorphism) foi utilizada para analisar amostras de 95 pacientes com LES e 87 com AR, assim como em 128 indivíduos do grupo controle de Santa Catarina, sul do Brasil. Foi analisada a probabilidade de equilíbrio de Hardy-Weinberg (EHW) e a odds ratio (OR), considerando um IC 95% e p ≤ 0,05. Resultados: As frequências alélicas PD1.3 A foram de 0,095 (LES), 0,115 (AR) e 0,078 (controles). Os genótipos do grupo controle estavam em EHW, enquanto aqueles dos pacientes com LES e AR não estavam. No entanto, não foi encontrada associação entre o polimorfismo PD1.3 e a suscetibilidade ao LES ou à AR, nem com dados clínicos ou epidemiológicos. Conclusão: Não foi encontrada associação significativa entre o polimorfismo PD1.3 e a susceptibilidade ao LES ou à AR nessa população do sul do Brasil.

Polymorphisms in NAT2 (N-acetyltransferase 2) gene in patients with systemic lupus erythematosus / Polimorfismos no gene NAT2 (N-acetiltransferase 2) em pacientes com lúpus eritematoso sistêmico

ABSTRACT Objective: To investigate potential associations of four substitutions in NAT2 gene and of acetylator phenotype of NAT2 with systemic lupus erythematosus (SLE) and clinical phenotypes. Methods: Molecular analysis of 481C>T, 590G>A, 857G>A, and 191G>A substitutions in the NAT2 gene was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, from DNA extracted from peripheral blood samples obtained from patients with SLE (n = 91) and controls (n = 97). Results and conclusions: The 857GA genotype was more prevalent among nonwhite SLE patients (OR = 4.01, 95% CI = 1.18-13.59). The 481T allele showed a positive association with hematological disorders that involve autoimmune mechanisms, specifically autoimmune hemolytic anemia or autoimmune thrombocytopenia (OR = 1.97; 95% CI = 1.01-3.81).

RESUMO Objetivo: Investigar potenciais associações de quatro substituições do gene NAT2 (N-acetiltransferase 2) e do fenótipo acetilador de NAT2 com o lúpus eritematoso sistêmico (LES) e os fenótipos clínicos. Métodos: A análise molecular das substituições 481C > T, 590G > A, 857G > A e 191G > A do gene NAT2 foi feita com a técnica de PCR-RFLP, usando DNA extraído de amostras de sangue periférico obtidas de pacientes com LES (n = 91) e controles (n = 97). Resultados e conclusões: O genótipo 857GA foi mais prevalente entre pacientes com LES não brancas (OR = 4,01, IC 95% = 1,18-13,59). O alelo 481 T apresentou associação positiva com as alterações hematológicas que envolvem mecanismos autoimunes, especificamente anemia hemolítica autoimune ou trombocitopenia autoimune (OR = 1,97; IC 95% = 1,01-3,81).

Fc gamma receptor IIIa polymorphism is not associated with susceptibility to systemic lupus erythematosus in Brazilian patients / Polimorfismo do receptor Fc gama IIIa não está associado à susceptibilidade ao lúpus eritematoso sistêmico em pacientes brasileiros

ABSTRACT We evaluated the possible association between FCGR3A V/F (158) polymorphism and SLE susceptibility and clinical phenotype in 305 sequentially retrieved SLE patients and 300 healthy controls from the southeastern part of Brazil by allele-specific polymerase chain reaction. Our results showed no association between FCGR3A 158V/F alleles and susceptibility to SLE in this series of patients albeit the heterozygous genotype was strongly associated with the disease.

RESUMO Avaliou-se a possível associação entre o polimorfismo FCGR3A V/F (158) e a suscetibilidade e o fenótipo clínico do lúpus eritematoso sistêmico (LES) em 305 pacientes com LES admitidos sequencialmente e 300 controles saudáveis da Região Sudeste do Brasil por reação em cadeia da polimerase alelo-específica. Os resultados do presente estudo mostraram não haver associação entre os alelos FCGR3A 158 V/F e a suscetibilidade ao LES nessa série de pacientes, ainda que o genótipo heterozigoto tenha sido fortemente associado à doença.

Lúpus Eritematoso Sistêmico: Revisão das Manifestações Cardiovasculares / Systemic Lupus Erythematosus: Review of Cardiovascular Aspects

Lúpus eritematoso sistêmico (LES) é uma condição autoimune com processo fisiopatológico complexo, no qual sua atividade inflamatória é potencializadora da doença coronariana através de inflamação sistêmica, disfunção endotelial e predisposição à trombose. O acometimento cardiovascular no LES não é critério diagnóstico, sendo considerado somente como dano já estabelecido em longo prazo de doença. O objetivodeste artigo é destacar a importância da visão clínica para a identificação precoce do acometimento cardiovascular no LES. É feita uma análise crítica da abordagem cardiológica no LES, com ênfase nos aspectos clínicos, biomarcadores cardiovasculares e genética e solicitação racional dos exames complementares. Aparticularidade dos pacientes com nefrite lúpica e síndrome do anticorpo antifosfolipídeo também é destacada.A percepção do dano cardíaco subclínico é fundamental para interromper o ciclo de agressão miocárdica e evitar progressão de doença cardíaca.

Systemic lupus erythematosus (SLE) is an autoimmune condition with a complex pathophysiological process in which its inflammatory activity is an enhancer of coronary disease by systemic inflammation, endothelial dysfunction and predisposition to thrombosis. Thecardiovascular involvement in SLE is not a diagnostic criterion and is considered only as damage established in the long-term of the disease. The objective of this study is to highlight the importance of clinical vision for the early identification of cardiovascular involvement in SLE. A critical analysis of the cardiac approach in SLE, with emphasis on clinical aspects, cardiovascular biomarkers and genetics and rational request of additional tests. The particularity of patients with lupus nephritis and antiphospholipid antibodysyndrome is also highlighted. The perception of subclinical cardiac damage is critical for interrupting the cycle of myocardial injury and to avoid progression of heart disease.

Mannose binding lectin (MBL) 2 gene polymorphism & its association with clinical manifestations in systemic lupus erythematosus (SLE) patients from western India.

Background & objectives: systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by production of autoantibodies. Mannose binding lectin (MBL) is an important element of the innate defense system. the present study was undertaken to determine whether variant alleles in MBL2 gene were associated with disease severity in SLE patients. Methods: The MBL alleles [-550, -221, +4, Codon 52, Codon 54 and Codon 57] were studied by PCR- RFLP (restriction fragment length polymorphism) method in 100 SLE patients fulfilling ACR (American College of Rheumatology) criteria along with 100 healthy controls. SLE disease activity was evaluated using SLE Disease Activity Index (SLEDAI) score. Results: Homozygosity for MBL variant allele (O/O) was observed in 24 per cent of the SLE patients compared to 16 per cent of the normal controls, while no difference was found for heterozygosity (A/O) (37 vs 35%). A significant difference was reported in incidence of double heterozygosity for mutant allele B and D (B/D) among SLE patients as against control group (p = 0.015). MBL genotypes did not show any association with renal involvement. Interpretation & conclusions: In this study from western India, MBL gene polymorphism showed an influence as a possible risk factor for susceptibility to SLE, but had no direct effect on disease characteristics. Further studies need to be done on a larger number of SLE patients in different regions of the country.

Global DNA methylation pattern and correlation with complement system proteins in Brazilian patients with systemic lupus erythematosus / Padrão global de metilação do DNA e correlação com proteínas do sistema complemento em pacientes brasileiros com lúpus eritematoso sistêmico

Introduction: Nucleic acid methylation may have major effects on gene expression patterns and, by consequence, on the development of autoimmunity, like Systemic Lupus Erythematosus (SLE). Objective: To investigate the pattern of global DNA methylation in SLE patients and compare this pattern with laboratory parameters. Methods: Genomic DNA was isolated from SLE patients with non-active disease (SLEDAI<6), SLE patients with active disease (SLEDAI>6), and healthy individuals. Global DNA methylation was evaluated by digestion of genomic DNA with Hpa II and Msp I and compared with laboratory parameters. Results and conclusion: A statistical difference in DNA global methylation was observed when SLE patients were compared to healthy individuals. A positive correlation was observed between the frequency of global methylation and C3 and C4 serum levels for SLE patients with SLEDAI<6. These results suggest that the relative amount of DNA methylation is increased in SLE patients, and differential methylation of genes related to the complement pathway alters gene expression involved in autoimmune response in SLE patients.

Introdução: Metilação do ácido nucleico pode alterar a expressão gênica e favorecer o desenvolvimento de autoimunidade, como lúpus eritematoso sistêmico (LES). Objetivo: Investigar o padrão de metilação global do DNA em pacientes com LES e comparar com parâmetros laboratoriais. Métodos: DNA genômico foi isolado de pacientes com LES com doença não ativa (SLEDAI <6), pacientes com doença ativa (SLEDAI> 6) e indivíduos saudáveis. Metilação do DNA global foi avaliada por digestão do DNA genômico com Hpall e MspI e comparados com parâmetros laboratoriais. Resultados e conclusão: Foi observada diferença estatística na metilação global do DNA em pacientes com LES. Verificou-se correlação positiva entre a frequência de metilação global e níveis séricos C3 e C4 em pacientes com SLEDAI <6. Estes resultados sugerem que a quantidade relativa de metilação do DNA está aumentada em pacientes com LES, e a metilação de diferentes genes relacionados com o sistema complemento podem alterar a expressão de genes envolvidos no LES.

Association of genetic variants of xenobiotic metabolic pathway with systemic lupus erythematosus.

In view of documented evidence that catechol estrogen-DNA adducts serve as epitopes for binding of anti-nuclear antibodies, genetic polymorphisms of the xenobiotic metabolic pathway involved in estrogen metabolism might contribute towards pathophysiology of systemic lupus erythematosus (SLE). To test this hypothesis, a case-control study was conducted. Cytochrome P 450 1A1 (CYP1A1) m4 (OR: 4.93, 95% CI: 1.31-18.49), catecholamine-o-methyl transferase (COMT) H108L (OR: 1.39, 95% CI: 1.03-1.88) and glutathione-S-transferase (GST) T1 null (OR: 1.83, 95% CI: 1.11- 3.01) variants showed association with SLE risk. SHEsis web-based platform analysis showed mild to moderate linkage disequilibrium between the CYP1A1 m1, m2 and m4 variants (D’: 0.19-0.37). Among the different haplotypes of CYP1A1, CAC-haplotype harboring CYP1A1 m1 variant showed association with SLE risk (OR: 1.46, 95% CI: 1.11-1.92). Multifactor dimensionality reduction analysis (MDR) showed potential gene-gene interactions between the phase II variants i.e. COMT H108L × GSTT1 null × GSTM1 null (p<0.0001) and also between the phase II and I variants i.e. COMT H108L × GSTT1 null × CYP1A1 m1 × CYP1A1 m2 in inflating the risk of SLE by 3.33-folds (95% CI: 2.30-4.82) and 4.00-folds (95% CI: 2.77-5.78), respectively. To conclude, hyperinducibility of CYP1A1 due to m1 and m4 variants and defective phase-II detoxification due to COMT H108L and GSTT1 null variants increase the susceptibility to SLE.