Association of LncRNA-GAS5 gene polymorphisms and PBMC LncRNA-GAS5 level with risk of systemic lupus erythematosus in Chinese population.

Growth arrest-specific 5 (GAS5) is a kind of long non-coding RNAs (lncRNAs). Previous studies showed that down-regulation of LncRNA-GAS5 was involved in the development of systemic lupus erythematosus (SLE). However, the regulatory mechanism of down-expressed LncRNA-GAS5 in SLE remains obscure. In this study, we aimed to investigate the association of LncRNA-GAS5 polymorphism with SLE risk. And further explore how LncRNA-GAS5 is involved in the occurrence of SLE. Here, we evaluated the relationship between the risk for the development of SLE and the 5-base pair (AGGCA/-) insertion/deletion (I/D) polymorphism (rs145204276) in the LncRNA-GAS5 promoter region. A custom 36-Plex SNPscan kit was used for genotyping the LncRNA-GAS5 polymorphisms. The LncRNA-GAS5 and miR-21 target prediction was performed using bioinformatics software. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qRT-PCR) were performed to assess GAS5 and miR-21 mRNA expression and PTEN protein expression. The results revealed that rs145204276 resulted in a decreased risk of SLE (DD genotypes vs II genotypes: adjusted OR = 0.538, 95% CI, 0.30-0.97, P = .039; ID genotypes vs II genotypes: adjusted OR = 0.641, 95% CI, 0.46-0.89, P = .007; ID/DD genotypes vs II genotypes: adjusted OR = 0.621, 95% CI, 0.46-0.84, P = .002; D alleles vs I alleles: adjusted OR = 0.680, 95% CI, 0.53-0.87, P = .002). A reduced incidence of renal disorders in SLE was found to be related to ID/DD genotypes and D alleles (ID/DD genotypes vs II genotypes: OR = 0.57, 95% CI, 0.36-0.92, P = .020; D alleles vs I alleles: OR = 0.63, 95% CI, 0.43-0.93, P = .019). However, no significant association of rs2235095, rs6790, rs2067079 and rs1951625 polymorphisms with SLE risk was observed (P > .05). Additionally, haplotype analysis showed that a decreased SLE risk resulted from the A-A-C-G-D haplotype (OR = 0.67, 95% CI, 0.49-0.91, P = .010). Also, patients in the SLE group showed a down-regulated expression of LncRNA-GAS5 and PTEN than the healthy volunteers; however, patients with rs145204276 ID/DD genotypes showed up-regulated expression of LncRNA-GAS5 and PTEN compared with patients carrying the II genotype. Furthermore, the miR-21 levels were considerably up-regulated in the SLE group than the healthy volunteers, and patients with rs145204276 ID/DD genotype had lower miR-21 levels than the ones with the II genotype. Thus, we found that the LncRNA-GAS5/miR-21/PTEN signalling pathway was involved in the development of SLE, where LncRNA-GAS5 acted as an miR-21 target, and miR-21 regulated the expression of PTEN. These findings indicated that the rs145204276 ID/DD genotypes in the LncRNA-GAS5 gene promoter region may be protected against SLE by up-regulating the expression of LncRNA-GAS5, which consecutively regulated miR-21 and PTEN levels.

A genetic variant in the promoter of lncRNA MALAT1 is related to susceptibility of ischemic stroke.

BACKGROUND: Metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) was aberrantly expressed in diverse diseases. Particularly in ischemic stroke (IS), the abnormal expression of MALAT1 played important roles including promotion of angiogenesis, inhibition of apoptosis and inflammation and regulation of autophagy. However, the effects of genetic variation (single nucleotide polymorphisms, SNPs) of MALAT1 on IS have rarely been explored. This study aimed to investigate whether SNPs in promoter of MALAT1 were associated with the susceptibility to IS. METHODS: A total of 316 IS patients and 320 age-, gender-, and ethnicity-matched controls were enrolled in this study. Four polymorphisms in the promoter of MALAT1 (i.e., rs600231, rs1194338, rs4102217, and rs591291) were genotyped by using a custom-by-design 48-Plex SNPscan kit. RESULTS: The rs1194338 C > A variant in the promoter of MALAT1 was associated with the risk of IS (AC vs. CC: adjusted OR = 0.623, 95% CI, 0.417-0.932, P = 0.021; AA vs. CC: adjusted OR = 0.474, 95% CI, 0.226-0.991, P = 0.047; Dominant model: adjusted OR = 0.596, 95% CI, 0.406-0.874, P = 0.008; A vs. C adjusted OR = 0.658, 95% CI, 0.487-0.890, P = 0.007). The haplotype analysis showed that rs600231-rs1194338-rs4102217-rs591291 (A-C-G-C) had a 1.3-fold increased risk of IS (95% CI, 1.029-1.644, P = 0.027). Logistic regression analysis identified some independent impact factors for IS including rs1194338 AC/AA, TC, TG, HDL-C, LDL-C, Apo-A1, Apo-B and NEFA (P < 0.05). CONCLUSIONS: These results suggest that the rs1194338 AC/AA genotypes may be a protective factor for IS.

A Genetic Variant of miR-34a Contributes to Susceptibility of Ischemic Stroke Among Chinese Population.

miRNAs are small non-coding RNAs modulating gene expression, and variants in miRNA genes are involved in the pathogenesis of ischemic stroke (IS). However, the effect of miR-34a polymorphisms on IS susceptibility has rarely been reported. In the present study, we investigated the association between rs12128240, rs2666433, and rs6577555 of the miR-34a gene and IS susceptibility. Snapshot assay was used to detect miR-34a polymorphisms in 548 IS patients and 560 controls. Relative expression of miR-34a was measured by quantitative real-time PCR. We found that rs2666433 was associated with a significantly increased risk of IS (AA vs. GG: OR = 1.61, 95% CI = 1.05-2.52, P = 0.031; AA vs. GG+GA: OR = 1.58, 95% CI = 1.05-2.45, P = 0.026). For the IS subtypes, rs2666433 was associated with large artery atherosclerosis (AA vs. GG: OR = 2.09, 95% CI = 1.16-3.51, P = 0.007; AA vs. GG+GA: OR = 2.02, 95% CI = 1.15-3.33, P = 0.007; A vs. G: OR = 1.36, 95% CI = 1.07-1.81, P = 0.021). Additionally, the level of miR-34a was significantly up-regulated in IS patients compared to the controls (P < 0.001), and patients with rs2666433 AA genotype had a higher level of miR-34a than those with GG+GA genotypes (P < 0.001). Furthermore, increased level of homocysteine was observed in IS patients compared to the controls (P < 0.001), especially in patients carrying the rs2666433AA genotype compared to those carrying the rs2666433 GG+GA genotypes (P < 0.001). However, no significant association between rs12128240 or rs6577555 and IS was found. Collectively, our study found the association between miR-34a polymorphisms and the risk of IS among the Chinese population. The results may provide an explanation for etiology of IS and a potential biomarker or therapeutic target for IS. HIGHLIGHTS-MiR-34a rs2666433 polymorphism was associated with an increased risk of ischemic stroke.-The level of miR-34a was significantly up-regulated in ischemic stroke patients compared with controls, and patients with rs2666433 AA genotype had a higher level miR-34a than those with GG+GA genotypes.-Furthermore, increased level of homocysteine was showed in IS patients compared to controls, and in patients carrying the rs2666433AA compared to those carrying the rs2666433 GG+GA.

Association between polymorphisms in the promoter region of miR-17-92 cluster and systemic lupus erythematosus in a Chinese population.

The aim of this study was to investigate the association of genetic polymorphisms in the promoter region of miR-17-92 with systemic lupus erythematosus (SLE). The gene polymorphism was analysed using SNaPshot in 312 SLE patients and 396 controls. Relative expression of miR-17-92 was measured by quantitative real-time PCR. Association was found between rs9515692 and a decreased risk of SLE (CT vs CC: OR = 0.65, 95%CI, 0.46-0.92, P = .014; CT+TT vs CC: OR = 0.64, 95%CI, 0.46-0.90, P = .009; T vs C: OR = 0.69, 95%CI, 0.52-0.92, P = .010, respectively). Haplotype analysis showed that C-G-G, C-A-A haplotypes were associated with an increased SLE risk (OR=4.46, 95%CI, 2.17-9.17, P < 0.001; OR=2.33, 95%CI, 1.44-3.76, P < 0.001, respectively). T allele and CT+TT genotypes in rs9515692 were associated with decreased risk of anti-dsDNA in SLE (CT+TT vs CC: OR = 0.42, 95%CI = 0.24-0.72, P = .002; T vs A: OR = 0.49, 95%CI = 0.31-0.79, P = .003). Moreover, rs9515692 CT+TT genotypes had a higher level of miR-17 as compared to CC genotype (P = .017). These findings suggest that the rs9515692 CT+TT genotypes were a protective factor for the susceptibility of SLE, probably by increasing the expression of miR-17.

Association of S100B polymorphisms and serum S100B with risk of ischemic stroke in a Chinese population.

The levels of serum S100B were elevated in patients with ischemic stroke (IS), which may be a novel biomarker for diagnosing IS. The aim of this study was to investigate the association of S100B polymorphisms and serum S100B with IS risk. We genotyped the S100B polymorphisms rs9722, rs9984765, rs2839356, rs1051169 and rs2186358 in 396 IS patients and 398 controls using polymerase chain reaction-single base extension (SBE-PCR). Serum S100B levels were measured by enzyme-linked immunosorbent assay (ELISA). Rs9722 was associated with an increased risk of IS (AA vs. GG: adjusted OR = 2.172, 95% CI, 1.175-4.014, P = 0.013; dominant: adjusted OR = 1.507, 95% CI, 1.071-2.123, P = 0.019; recessive: adjusted OR = 1.846, 95% CI, 1.025-3.323, P = 0.041; additive: adjusted OR=1.371, 95% CI, 1.109-1.694, P = 0.003). The A-C-C-C-A haplotype was associated with an increased risk of IS (OR = 1.325, 95% CI, 1.035-1.696, P = 0.025). In addition, individuals carrying the rs9722 GA/AA genotypes had a higher serum S100B compared with the rs9722 GG genotype in IS patients (P = 0.018). Our results suggest that the S100B gene rs9722 polymorphism may contribute to the susceptibility of IS, probably by promoting the expression of serum S100B.

Association of interleukin 13 gene polymorphisms and plasma IL 13 level with risk of systemic lupus erythematosus.

Interleukin (IL) 13 plays a critical role in inflammatory diseases, including systemic lupus erythematosus (SLE). This study aims to explore the potential association of IL-13 polymorphisms with the risk of SLE. We genotyped IL-13 rs20541, rs848 and rs1295686 using Snapshot SNP genotyping assays. Plasma IL-13 level was determined by enzyme-linked immunosorbent assay (ELISA). We found that rs20541 was associated with increased risk of SLE (CT vs. CC: adjusted OR=1.43, 95%CI, 1.04-1.99, P=.030; TT vs. CC: adjusted OR=1.73, 95%CI, 1.10-2.73, P=.018; CT/TT vs. CC: adjusted OR=1.50, 95%CI, 1.10-2.04, P=.010; T vs. C adjusted OR=1.34, 95%CI, 1.08-1.93, P=.031). CT and TT genotypes in rs20541 were associated with increased risk of renal disorder in SLE (CT vs. CC: adjusted OR=1.97, 95%CI, 1.18-3.28, P=.009; TT vs. CC: adjusted OR=2.42, 95%CI, 1.22-4.77, P=.011). Moreover, The concentration of IL-13 was significantly elevated in rs20541 CT/TT genotypes compared with CC genotype (P<.001). These results suggest that rs20541 CT/TT genotypes may be a risk factor for SLE, probably by increasing the level of IL-13.

Association of miR-21, miR-126 and miR-605 gene polymorphisms with ischemic stroke risk.

We investigated whether three common microRNA polymorphisms (miR-21T>C [rs1292037], miR-126G>A [rs4636297] and miR-605T>C [rs2043556]) were associated with ischemic stroke (IS) risk in a Chinese population. The study population comprised 592 ischemic stroke patients and 456 normal controls. The polymorphisms were measured using Snapshot SNP genotyping assays and confirmed by sequencing. Relative expressions of miR-21, miR-126 and miR-605 were measured by quantitative real-time PCR. We found that miR-126 gene rs4636297 polymorphism was associated with decreased ischemic stroke risk (GA vs. GG: AOR=0.64, adjust P=0.025; AA vs. GG: AOR=0.32, adjust P=0.007; dominant model: AOR=0.58, adjust P=0.004). MiR-21 gene rs1292037 and miR-605 gene rs2043556 polymorphisms were not associated with ischemic stroke risk. In addition, compared with normal controls, serum miR-126 level was significantly decreased in ischemic stroke patients, while the miR-21 level was significantly increased. Importantly, patients carrying rs4636297 GA/AA genotypes had higher serum miR-126 level (P<0.05). MiR-126 gene rs4636297 polymorphism and serum miR-126/-21 levels are associated with ischemic stroke risk. Our data indicates that miR-126 and miR-21 play roles in the development of ischemic stroke.

The association of IL-17A polymorphisms with IL-17A serum levels and risk of ischemic stroke.

The aim of our study was to investigate the association of interleukin-17A (IL-17A) polymorphisms with IL-17A serum levels and risk of ischemic stroke (IS) in a Chinese population. 392 IS patients and 443 controls were included in this study. The polymorphisms of IL-17A gene were determined by Snapshot SNP genotyping assay and DNA sequencing. Serum IL-17A levels were measured by enzyme-linked immunosorbent assay (ELISA). We found that the G allele, GA and GG genotypes, and GA/GG vs. AA model of rs2275913 polymorphism were associated with increased risk of IS even after adjusted by clinical characters such as age, gender and diabetes (G vs. A: OR=1.27, 95% CI, 1.05∼1.54, P=0.014; GA vs. AA: OR=1.72, 95% CI, 1.05∼2.81, P=0.032; GG vs. AA: OR=1.99, 95% CI, 1.08∼3.67, P=0.028; GA/GG vs. AA: OR=1.78, 95% CI, 1.11∼2.86, P=0.017). Serum IL-17A levels were increased in IS patients compared with controls (P<0.01). Individuals carrying rs2275913 GA or GG genotype present higher serum IL-17A levels compared with the rs2275913AA genotype in the IS group (P<0.01). In conclusion, this is the first study reporting the rs2275913 polymorphism as a risk factor for IS, which may be partly explained by influencing the levels of IL-17A cytokine.

A SNP in 5' untranslated region of CD40 gene is associated with an increased risk of ischemic stroke in a Chinese population: a case-control study.

Cluster of differentiation 40 (CD40), the receptor for CD154, is a member of the tumor necrosis factor (TNF) receptor superfamily. Several studies have been conducted to investigate the effect of the CD40 rs1883832 polymorphism on atherosclerotic disease in different population; however, inconsistent results were obtained. In this study, we investigated the association of four polymorphisms (rs1883832, rs13040307, rs752118 and rs3765459) of CD40 gene and their effect on CD40 expression with the risk of ischemic stroke (IS) in a Chinese population. Three hundred and eighty patients with IS and 450 control subjects were included in the study. The CD40 polymorphisms were discriminated by Snapshot SNP genotyping assay. Serum soluble CD40 (sCD40) levels were detected by ELISA. We found that the rs1883832CT and rs1883832TT genotypes were associated with an increased risk of IS compared with the rs1883832CC genotype (OR = 1.42, 95% CI: 1.03-1.95, p = 0.030 and OR = 1.91, 95% CI: 1.29-2.82, P = 0.001, respectively), and the rs1883832T allele was associated with a significantly increased risk of IS compared with rs1883832C allele (OR = 1.40, 95% CI: 1.15-1.70, P = 0.001). Elevated serum sCD40 levels were observed in patients with IS compared with the control gropu (P < 0.01). Individuals carrying the rs1883832TT or rs1883832CT genotypes showed significantly higher sCD40 levels compared with the rs1883832CC genotype in the IS group [(64.8 ± 25.4 pg/mL, TT = 94); (63.9 ± 24.3 pg/mL, CT = 185) vs (53.3 ± 22.5 pg/mL, CC = 101), P < 0.01]. The TCCA haplotype was associated with an increased risk of IS compared with the control group (OR = 2.10, 95% CI: 1.23-3.58, p = 0.005). However, we did not find a significant association between the other three polymorphisms and IS risk. In conclusion, after a comprehensive comparison with other studies, we confirmed that the rs1883832T allele but not the rs1883832C allele is associated with an increased risk of IS. The rs1883832 polymorphism may exert influences on abnormal CD40 expression in IS patients among the Chinese population.

A SNP in 5′ untranslated region of CD40 gene is associated with an increased risk of ischemic stroke in a Chinese population: a case-control study

Abstract Cluster of differentiation 40 (CD40), the receptor for CD154, is a member of the tumor necrosis factor (TNF) receptor superfamily. Several studies have been conducted to investigate the effect of the CD40 rs1883832 polymorphism on atherosclerotic disease in different population; however, inconsistent results were obtained. In this study, we investigated the association of four polymorphisms (rs1883832, rs13040307, rs752118 and rs3765459) of CD40 gene and their effect on CD40 expression with the risk of ischemic stroke (IS) in a Chinese population. Three hundred and eighty patients with IS and 450 control subjects were included in the study. The CD40 polymorphisms were discriminated by Snapshot SNP genotyping assay. Serum soluble CD40 (sCD40) levels were detected by ELISA. We found that the rs1883832CT and rs1883832TT genotypes were associated with an increased risk of IS compared with the rs1883832CC genotype (OR = 1.42, 95% CI: 1.03-1.95, p = 0.030 and OR = 1.91, 95% CI: 1.29-2.82, P = 0.001, respectively), and the rs1883832T allele was associated with a significantly increased risk of IS compared with rs1883832C allele (OR = 1.40, 95% CI: 1.15-1.70, P = 0.001). Elevated serum sCD40 levels were observed in patients with IS compared with the control gropu (P < 0.01). Individuals carrying the rs1883832TT or rs1883832CT genotypes showed significantly higher sCD40 levels compared with the rs1883832CC genotype in the IS group [(64.8 ± 25.4 pg/mL, TT = 94); (63.9 ± 24.3 pg/mL, CT = 185) vs (53.3 ± 22.5 pg/mL, CC = 101), P < 0.01]. The TCCA haplotype was associated with an increased risk of IS compared with the control group (OR = 2.10, 95% CI: 1.23-3.58, p = 0.005). However, we did not find a significant association between the other three polymorphisms and IS risk. In conclusion, after a comprehensive comparison with other studies, we confirmed that the rs1883832T allele but not the rs1883832C allele is associated with an increased risk of IS. The rs1883832 polymorphism may exert influences on abnormal CD40 expression in IS patients among the Chinese population.

Association study of CD154 polymorphisms and serum CD154 level with systemic lupus erythematous in Chinese population.

The aim of this study was to investigate the association of three polymorphisms of CD154 with risk of SLE in Chinese population. The study population comprised 770 Chinese individuals, including 350 SLE patients and 420 healthy controls. The gene polymorphism was measured using Snapshot SNP genotyping assays and confirmed by sequencing. Serum CD154 (sCD154) level was measured by ELISA. Compared with control group, sCD154 levels were significantly increased in case group (P < 0.001). The minor C allele of rs1126535 was associated with a significantly increased risk of SLE as compared to the major T allele (P < 0.001). Furthermore, an increased frequency of C-G-A haplotype was also detected in case group which associated with an increased risk of SLE (P = 0.009). Notably, patients carrying rs1126535CT/CC genotypes had a higher sCD154 level compared with that carrying rs1126535TT genotype (P < 0.05). Unfortunately, analyses on the association between rs1126535 and several clinical manifestations of SLE failed to find any significant results. In conclusion, these results indicated that CD154 gene polymorphisms may associate with the risk of SLE and may play regulation role in the expression of sCD154 in SLE patients.

[Distribution of single nucleotide polymorphisms of arginine-vasopressin gene in Guangxi healthy population].

OBJECTIVE: To study the distribution of single nucleotide polymorphisms (SNP) of arginine-vasopressin (AVP) gene rs66818855 and rs1078152 in Chinese Guangxi healthy population in comparison with that in different ethnic populations. METHDOS: Polymerase chain reaction-single base extension (PCR-SBE) and DNA sequencing were used to detect the allele and genotype frequencies of AVP gene among 303 Chinese healthy individuals in Guangxi, China, and the results were compared with the reported frequencies in 4 other populations (HapMap-CEU, HapMap-YRI, HapMap-JPT, and HapMap-HCB) from Human Genome Project group (HapMap) data. RESULTS: We found significant AVP gene polymorphisms in this Guangxi healthy population. The frequencies of allele and genotype of AVP gene rs66818855 and rs1078152 polymorphisms in this Guangxi population differed significantly from those in HapMap-CEU population (P<0.01), and allele frequencies of AVP gene rs66818855 polymorphism differed significantly from those in HapMap-YRI populations (P<0.05). CONCLUSION: The distribution pattern of AVP gene polymorphisms in this Guangxi population is significantly different from that in other ethnic populations, which might account for the difference in the morbidity of AVP-related disease among different ethnic groups and may have important indications in the study of population genetics and anthropology.

[Distribution characteristics of rs1891385A/C and rs10975519C/T polymorphisms of interleukin-33 gene in Guangxi population].

OBJECTIVE: To explore the race- and gender-specific distribution characteristics of rs1891385A/C and rs10975519C/T polymorphism of interleukin-33 (IL-33) gene in Zhuang and Han populations. METHODS: The polymorphisms of rs1891385A/C and rs10975519C/T of IL-33 gene in 283 subjects from Guangxi Zhuang Autonomous Region were analyzed with single base extension (PCR-SEB) and DNA sequencing to analyze the differences in their distribution frequencies between genders and between Zhuang and Han populations. RESULTS: Three genotypes (AA, AC and CC) were found in rs1891385A/C with frequencies of 64.3%, 32.5% and 3.2%, respectively. The genotype and allele frequencies of rs1891385A/C in this Guangxi population showed no significant difference between Zhuang and Han subpopulations and between genders (P>0.05), but differed significantly from those in European and African black populations (P<0.01). Three genotypes (CC, CT and TT) were identified in rs10975519C/T with frequencies of 34.3%, 53.0%, and 12.7%, respectively, showing no significant ethnic or gender-specific differences in this population (P>0.05). The genotype frequency of rs10975519C/T in this population differed significantly from those in the European and Japanese populations (P<0.01), but the allele frequencies only showed significant differences from those in the European population (P<0.01). CONCLUSION: rs1891385A/C and rs10975519C/T polymorphisms of IL-33 gene show a race-specific difference.

The association of novel IL-33 polymorphisms with sIL-33 and risk of systemic lupus erythematosus.

The serum level of IL-33 was upregulated in systemic lupus erythematosus (SLE), which may be used as biomarkers and/or therapeutic targets for SLE. The aim of this study was to investigate the association of four novel polymorphisms of IL-33 with risk of SLE. The study population comprised 540 Chinese individuals, including 257subjects with SLE and 283 healthy controls. The gene polymorphism was measured using Snapshot SNP genotyping assays and confirmed by sequencing. Serum IL-33 (sIL-33) levels were measured by ELISA. The serum SLE levels were significantly higher in the group of patients with SLE than those in the control group (P<0.001). The rs1891385C allele was associated with a significantly increased risk of SLE as compared with the rs1891385 A allele (OR=1.405, 95% CI, 1.052-1.875, P=0.021). The C-T-T-G haplotype was significantly increased the risk of SLE (OR=1.411; 95% CI, 1.021-1.948; P=0.036). IL-33 gene rs1891385 polymorphism was significantly associated with the expression of sIL-33 in the SLE patients. Besides, in our study, we found that the unregulated sIL-33 level was significantly associated with the abnormal changed CRP and ESR. This is the first study reporting the IL-33 gene polymorphisms and SLE, which may help refine the SLE risk profile.

The association of interleukin-31 polymorphisms with interleukin-31 serum levels and risk of systemic lupus erythematosus.

Interleukin-31 (IL-31) is the most recently discovered member of the gp130/IL-6 cytokine family which is produced mainly by activated Th2 cells. IL-31 was proved to play a crucial role in autoimmune and inflammatory diseases such as atopic dermatitis, asthma, cutaneous T cell lymphomas, Kawasaki disease and allergic rhinitis. Previous studies have identified that IL-31 could significantly induce the release of proinflammatory cytokines IL-6. Moreover, a large number of studies have shown that IL-6 plays an important role in the pathogenesis of systemic lupus erythematosus (SLE). However, up to date, no study to data was reported on the relationship between IL-31 and SLE. Therefore, in the present study, we investigated the association between IL-31 polymorphisms and its serum levels with the risk of SLE in a Chinese population. We analyzed two single nucleotide polymorphisms of IL-31 gene rs7977932 C/G and rs4758680 G/T in 190 patients with SLE and 250 age- and sex-matched controls, using polymerase chain reaction-single base extension and DNA sequencing methods. Soluble IL-31 (sIL-31) levels were measured by ELISA. From this study, we found that there were significant differences in the genotype and allele frequencies of IL-31 gene rs7977932 C/G polymorphism between the group of patients with SLE and the control group (P < 0.05). sIL-31 levels were increased in patients with SLE compared with controls (P < 0.01). Moreover, genotypes carrying the IL-31 rs7977932 G variant allele were associated with increased IL-31 levels compared to the homozygous wild-type genotype in patients with SLE. The rs7977932 C/G polymorphism of IL-31 gene and its sIL-31 levels were associated with SLE in the Chinese population. Our data suggest that IL-31 gene may play a role in the development of SLE.