Association analysis of IL-4 VNTR polymorphism with rheumatoid arthritis in Iranian patients

Rheumatoid arthritis (RA) is an autoimmune disease characterized by movement disability and pain in the joints. The affected individuals are susceptible to other subsequent diseases, exacerbating the condition. To find out the genetic variability of this disease at the genomic level for the first time in the Iranian population, we carried out an investigation on the VNTR of IL-4 gene within its third intron. For this goal we isolated the genomic DNA from blood samples of 576 rheumatoid arthritis patients and 546 healthy controls and investigated the presence or absence of specific amplicons via polymerase chain reaction (PCR). The size of each amplicon on a 1.5% agarose gel corresponded to a certain number of tandem repeats which indicated a specific allele. Statistical test of χ² Fisher’s exact test and odds ratio (OR) was used to analyze the data. The results showed that RA1/RA1 genotype was the dominant genotype in both healthy controls and patients and the heterozygote genotype of RA1/RA2 was observed more in the healthy controls than patients (108 vs. 66) with significant difference with P value < 0.005 and odds ratio of 0.214. However two genotypes of RA2/RA2 and RA2/RA3 were exclusively observed in the patients’ samples with P value = 0.023 and odds ratio of 0.988. We concluded that IL-4 VNTR polymorphism has a strong association with rheumatoid arthritis and might be a high risk factor for development of rheumatoid arthritis in the investigated Iranian population.     

Selective IgA deficiency in autoimmune diseases

Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.     

CTLA4 is differentially associated with autoimmune diseases in the Dutch population

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) is an important negative regulator of T-cell response and its genetic association with type 1 diabetes (T1D) has recently been demonstrated. The frequent co-association of autoimmune diseases (AID) and the implication from multiple genome scans that the CTLA4 gene region is a general autoimmune region, led us to study the role of CTLA4 in independent cohorts of T1D, coeliac disease (CD) and rheumatoid arthritis (RA) patients. We present independent data that confirm the association of CTLA4 in Dutch patients with juvenile onset T1D and show differential association of CTLA4 with CD and RA. The CTLA4 gene polymorphisms were tested for association in 350 T1D, 310 CD, 520 RA patients and 900 controls. In addition, 218 families were tested by the transmission disequilibrium test (TDT). T1D patients showed the highest association with the MH30*G: −1147*C: +49*G: CT60*G: JO37_3*G (haplotype 2) in both a case/control cohort (P=0.002, OR=1.42) and by TDT (P=0.02, OR=1.43). In contrast, this haplotype showed no association in the RA and CD cohorts. However, we observed an increased frequency of the MH30*G: −1147*T: +49*A: CT60*G: JO37_3*A (haplotype 3) in the CD patients diagnosed at a young age (OR=1.6, P=0.026, P _c=0.052). Furthermore, when T1D and CD patients were stratified based on the HLA risk, the T1D susceptible CTLA4 haplotype 2 was over-represented in the high HLA-risk T1D and CD groups. In conclusion, we confirmed association between CTLA4 haplotype 2 and T1D in the Dutch population. Association with another CTLA4 haplotype (haplotype 3) was confirmed for CD, but only in those patients who had an early age of expression. No effect was found between RA and CTLA4. The association of the CTLA4 haplotype 2 with the high-risk HLA genotype in T1D and CD, which share DQ2 as the one of high-risk alleles, might provide a clue to understanding the common genetic background of AID.Electronic Supplementary Material Supplementary material is available for this article at An erratum to this article can be found at     

The polymorphisms of Tim-1 promoter region are associated with rheumatoid arthritis in a Korean population

It has been determined that the family of T-cell immunoglobulin domain and mucin domain (TIM) proteins is expressed on T cells. A member of the TIM family, TIM-1, is considered to be a membrane protein associated with the development of Th2-biased immune responses and selectively expressed on Th2 cells. We previously showed that the exon 4 variations of Tim-1 are associated with susceptibility to allergic diseases, as well as autoimmune diseases such as rheumatoid arthritis (RA). In this study, we assessed the association between genotype and allele frequencies of the Tim-1 gene promoter region, in both RA patients and the controls without RA, using polymerase chain reaction-restriction fragment length polymorphism and single-base extension methods. We further investigated the relationships among the genotypes of each polymorphism and C-reactive protein or rheumatoid factor levels in RA patients. The genotype and allele frequencies of the –1637A>G polymorphism in RA patients are significantly different from those in the non-RA controls (P=0.0004 and P=0.001, respectively). Our results strongly suggest that polymorphism in the Tim-1 promoter region might be associated with susceptibility to RA.     

A Combination of CD28 (rs1980422) and IRF5 (rs10488631) Polymorphisms Is Associated with Seropositivity in Rheumatoid Arthritis: A Case Control Study

IntroductionThe aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA).MethodsA total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti–citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA.ResultsHLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA.ConclusionsThe association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA.     

Identification of the gene variations in human CD22

 CD22, a member of the immunoglobulin superfamily, is a B-cell transmembrane glycoprotein that acts as an accessory-signaling component of the B-cell antigen receptor (BCR). Recent evidence indicating the role of CD22 as a negative regulator of BCR signal transduction prompted us to test the possibility that genetic variations of human CD22 may be associated with autoimmune diseases. In this study, variation screening of the entire CD22 coding region was performed, and possible association with rheumatic diseases was tested, using the genomic DNA from 207 healthy Japanese individuals, 68 patients with systemic lupus erythematosus (SLE), and 119 patients with rheumatoid arthritis (RA). Through the variation screening, seven non-synonymous and four synonymous substitutions were identified. In addition, single base substitutions were found in two introns flanking exon-intron junctions. Among these variations, Q152E substitution within the second extracellular domain was observed with a marginally higher frequency in the patients with SLE (3/68, 4.4%) than that in healthy individuals (1/207, 0.5%) (P=0.048. SLE vs healthy individuals), although this difference was no longer significant after correction for the number of comparisons (Pc=0.62). No significant association was observed between any of the variations and RA. These findings indicate that a number of genetic variants are present in CD22, and suggest that CD22 could be considered a candidate for the susceptibility genes to autoimmune diseases. Received: 14 July 1998 / Revised: 7 September 1998     

Overlapping genetic susceptibility variants between three autoimmune disorders: rheumatoid arthritis, type 1 diabetes and coeliac disease

Introduction

Genome wide association studies, replicated by numerous well powered validation studies, have revealed a large number of loci likely to play a role in susceptibility to many multifactorial diseases. It is now well established that some of these loci are shared between diseases with similar aetiology. For example, a number of autoimmune diseases have been associated with variants in the PTPN22, TNFAIP3 and CTLA4 genes. Here we have attempted to define overlapping genetic variants between rheumatoid arthritis (RA), type 1 diabetes (T1D) and coeliac disease (CeD).

Methods

We selected eight SNPs previously identified as being associated with CeD and six T1D-associated SNPs for validation in a sample of 3,962 RA patients and 3,531 controls. Genotyping was performed using the Sequenom MassArray platform and comparison of genotype and allele frequencies between cases and controls was undertaken. A trend test P-value < 0.004 was regarded as significant.

Results

We found statistically significant evidence for association of the TAGAP locus with RA (P = 5.0 × 10^-4). A marker at one other locus, C1QTNF6, previously associated with T1D, showed nominal association with RA in the current study but did not remain statistically significant at the corrected threshold.

Conclusions

In exploring the overlap between T1D, CeD and RA, there is strong evidence that variation within the TAGAP gene is associated with all three autoimmune diseases. Interestingly a number of loci appear to be specific to one of the three diseases currently studied suggesting that they may play a role in determining the particular autoimmune phenotype at presentation.     

The contact-mediated response of peripheral-blood monocytes to preactivated T cells is suppressed by serum factors in rheumatoid arthritis

Stimulation of monocytes/macrophages after cell contact with preactivated T cells has been suggested to contribute to the excessive TNF-α production in rheumatoid arthritis (RA). In this study, T cell-contact-dependent TNF-α production by peripheral-blood monocytes in vitro was investigated and found to be significantly lower in treated and untreated patients with RA than in healthy controls. This suppression was not due to a general deficiency of monocytes to respond, because responses to lipopolysaccharide were comparable in patients and controls. In agreement with the pivotal role of TNF-α in RA, T cell-dependent induction of TNF-α in synovial macrophages was fivefold to tenfold higher than in peripheral-blood monocytes from either patients or controls. The decreased response of peripheral-blood monocytes from patients with RA was found to be mediated by inhibitory serum factors, because the addition of patient sera to monocytes from healthy controls suppressed TNF-α response in the co-culture assay. Preincubation of monocytes from healthy controls with RA serum was sufficient to suppress the subsequent TNF-α response in T cell co-cultures, indicating that inhibitory factors do indeed bind to monocyte surfaces, which might represent a regulatory counter-action of the immune system to the long-standing and consuming autoimmune process in RA. There are some indications that apolipoprotein A-1 might be part of this regulatory system.     

PTPN22 polymorphism and anti-cyclic citrullinated peptide antibodies in combination strongly predicts future onset of rheumatoid arthritis and has a specificity of 100% for the disease

We analysed relationships between the PTPN22 1858 polymorphism and antibodies to cyclic citrullinated peptide (CCP), rheumatoid factors (RFs) and the shared epitope (SE) gene (HLA-DRB1*0404 or 0401) and determined their combined predictive value for rheumatoid arthritis (RA) in individuals who subsequently developed RA. This case-control study was nested within the Medical Biobank of Northern Sweden. Patients with RA (n = 92) were identified from amongst blood donors antedating onset of disease by a median of 2.4 (interquartile range 1.2 to 4.9) years. Matched controls were selected randomly from the same cohorts (n = 368). Anti-CCP antibodies and RFs were determined using enzyme-linked immunoassays. Genotyping was performed using an ABI PRISM 7900HT instrument and HLA-SE genes were identified using PCR sequence-specific primers. The 1858T allele and also carriage of T were associated with future onset of RA (odds ratio (OR) = 2.29, 95% confidence interval (CI) 1.45–3.61 and OR = 2.64, 95% CI 1.56–4.47, respectively). The combination of the 1858T variant and anti-CCP antibodies gave 100% specificity for the disease. None of the 368 controls expressed this combination. The PTPN22 1858T variant and anti-CCP antibodies were clearly associated (OR = 3.80, 95% CI 1.51–9.57). A combination of the PTPN22 1858T variant and anti-CCP antibodies gave a much higher relative risk (>132.03) for developing RA than the combination of the T variant and HLA-SE (OR = 7.85). The PTPN22 1858T variant was associated with future development of RA. There was an association between the T variant and anti-CCP antibodies and their combination, found only among pre-patients, gives a very high relative risk for development of RA. The combination gave a specificity of 100% for diagnosing RA.     

Gene polymorphisms and serum levels of TL1A in patients with rheumatoid arthritis

Recent findings showed elevated expression of tumor necrosis factor (TNF)-like ligand 1A (TL1A) in rheumatoid arthritis (RA) patients and arthritis mice. However, whether TL1A gene polymorphisms may correlate with RA susceptibility needs to be discussed. This case-control study was performed on 350 RA patients and 556 healthy subjects to identify TL1A genetic variants (rs3810936, rs6478109, and rs7848647) and their possible association with TL1A levels, susceptibility to and severity of RA. Odds ratio and 95% confidence interval were calculated to represent the correlation between TL1A polymorphisms and RA. The TL1A serum levels were evaluated. Results showed that frequencies of TC, TT + TC genotypes of rs3810936, rs7848647 in RA patients were significantly lower in RA patients compared with controls. Patients with C allele showed more severe disease course (disease activity index: erythrocyte sedimentation rate, rheumatoid factor) than in carriers of T allele. However, the allele or genotype frequencies of rs6478109 were not associated with RA. In addition, TL1A genetic variants conferred higher TL1A levels in RA patients compared with controls. In conclusion, these findings indicated an association between TL1A rs3810936, rs7848647 variation and the susceptibility of RA in a sample of Chinese individuals, and TL1A may correlate with severity of RA.     

Association of common polymorphisms in known susceptibility genes with rheumatoid arthritis in a Slovak population using osteoarthritis patients as controls

Introduction  

Both genetic and environmental factors contribute to rheumatoid arthritis (RA), a common and complex autoimmune disease. As well as the major susceptibility gene HLA-DRB1, recent genome-wide and candidate-gene studies reported additional evidence for association of single nucleotide polymorphism (SNP) markers in the PTPN22, STAT4, OLIG3/TNFAIP3 and TRAF1/C5 loci with RA. This study was initiated to investigate the association between defined genetic markers and RA in a Slovak population. In contrast to recent studies, we included intensively-characterized osteoarthritis (OA) patients as controls.     

The <Emphasis Type="Italic">PTPN22</Emphasis>1858C/T polymorphism is associated with anti-cyclic citrullinated peptide antibody-positive early rheumatoid arthritis in northern Sweden

The PTPN22 1858C/T polymorphism has been associated with several autoimmune diseases including rheumatoid arthritis (RA). We have shown that carriage of the T variant (CT or TT) of PTPN22 in combination with anti-cyclic citrullinated peptide (anti-CCP) antibodies highly increases the odds ratio for developing RA. In the present study we analysed the association between the PTPN22 1858C/T polymorphism and early RA in patients from northern Sweden, related the polymorphism to autoantibodies and the HLA-DR shared epitope, and analysed their association with markers for disease activity and progression. The inception cohort includes individuals who also donated samples before disease onset. A case–control study was performed in patients (n = 505; 342 females and 163 males) with early RA (mean duration of symptoms = 6.3 months) and in population-based matched controls (n = 970) from northern Sweden. Genotyping of the PTPN22 1858C/T polymorphism was performed using a TaqMan instrument. HLA-shared epitope alleles were identified using PCR sequence-specific primers. Anti-CCP2 antibodies were determined using enzyme-linked immunoassays. Disease activity (that is, the number of swollen and tender joints, the global visual analogue scale, and the erythrocyte sedimentation rate) was followed on a regular basis (that is, at baseline and after 6, 12, 18 and 24 months). Both the 1858T allele and the carriage of T were associated with RA (χ² = 23.84, P = 0.000001, odds ratio = 1.69, 95% confidence interval = 1.36–2.11; and χ² = 22.68, P = 0.000002, odds ratio = 1.79, 95% confidence interval = 1.40–2.29, respectively). Association of the 1858T variant with RA was confined to seropositive disease. Carriage of 1858T and the presence of anti-CCP antibodies was independently associated with disease onset at an earlier age (P < 0.05 and P < 0.01, respectively), while the combination of both resulted in an even earlier age at onset. Smoking was identified as a risk factor independent of the 1858T variant and anti-CCP antibodies.     

Expression and functional properties of antibodies to tissue inhibitors of metalloproteinases (TIMPs) in rheumatoid arthritis

Tissue inhibitors of matrix metalloproteinases (TIMPs) regulate the breakdown of extracellular matrix components and play an important role in tissue remodelling and growth, in both physiological and pathological conditions. We studied the autoimmune response to TIMPs in patients with rheumatoid arthritis (RA). Eighty-nine paired blood and synovial fluid samples from patients with RA were assessed for their reactivity with recombinant tissue inhibitors of metalloproteinases (TIMPs) 1 to 4 by an ELISA and were compared with blood from 62 healthy controls and 21 synovial fluid samples from patients with degenerative joint diseases. Presence of antibodies was established as the absorbance of the sample more than 2 standard deviations above the mean of the controls. In addition, immunoglobulin G (IgG) from blood samples of RA patients possessing TIMP antibodies was isolated on protein A–sepharose and tested for the in vitro ability to neutralize TIMP-2-dependent effects on metalloproteinase 9 (MMP9). Anti-TIMP antibodies were found in 56% of RA samples but in only 5% of the controls (P < 0.005). RA patients had high frequencies of antibodies against all TIMPs except TIMP-3. TIMP-2 antibodies were most frequently found (33%), being significantly more prevalent (P = 0.024) in patients with nonerosive than erosive RA. TIMP-1 antibodies were significantly more often found in synovial fluid samples than in the matched blood samples (P < 0.025). Importantly, the IgG fraction containing TIMP antibodies down-regulated the TIMP-2 inhibitory effect, thereby supporting MMP9 activity in vitro. In the present study, we show that RA patients frequently develop autoimmune response to TIMPs that may act as a functionally significant regulator of MMP activity and thereby of joint destruction.     

Association of the CTLA-4 +49A/G polymorphism with rheumatoid arthritis in Chinese Han population

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is an important molecule in the regulation of T cells, so the CTLA-4 gene has been considered as a strong candidate associated with T cell-mediated autoimmune diseases such as rheumatoid arthritis (RA). CTLA-4 has many variants and polymorphic forms, among which the +49A/G polymorphism, causing a non-synonymous substitution, has been studied most. However, previous studies of the association between the +49A/G polymorphism of the CTLA-4 gene and RA have provided conflicting results. The aim of this study was to determine the potential relationship of the CTLA-4 +49A/G polymorphism and the risk of RA in Chinese Han population. TaqMan assay was used to genotype the +49A/G polymorphism in 1,489 RA patients and 1,200 healthy controls. Furthermore, a meta-analysis of all studies relating this polymorphism in Chinese population to the risk of RA was performed. The genotype and allele frequencies of the CTLA-4 +49A/G in patients with RA differed significantly from those of controls (P = 0.03 and P = 0.007, respectively). The meta-analysis also revealed that the CTLA-4 +49G allele was associated with an increased risk of RA in Chinese population. Our results suggested that the CTLA-4 gene might contribute to the pathogenesis of RA, and the +49A/G polymorphism of this gene was a risk factor associated with increased RA susceptibility in Chinese Han population.     

A promoter haplotype of the interleukin-18 gene is associated with juvenile idiopathic arthritis in the Japanese population

Recently, we reported that genetic polymorphisms within the human IL18 gene were associated with disease susceptibility to adult-onset Still's disease (AOSD), which is characterized by extraordinarily high serum levels of IL-18. Because high serum IL-18 induction has also been observed in the systemic type of juvenile idiopathic arthritis (JIA), we investigated whether similar genetic skewing is present in this disease. Three haplotypes, S01, S02, and S03, composed of 13 genetic polymorphisms covering two distinct promoter regions, were determined for 33 JIA patients, including 17 with systemic JIA, 10 with polyarthritis, and 6 with oligoarthritis. Haplotypes were also analyzed for 28 AOSD patients, 164 rheumatoid arthritis (RA) patients, 102 patients with collagen diseases, and 173 healthy control subjects. The frequency of individuals carrying a diplotype configuration (a combination of two haplotypes) of S01/S01 was significantly higher in the JIA patients, including all subgroups, than in the healthy controls (P = 0.0045, Fischer exact probability test; odds ratio (OR) = 3.55, 95% confidence interval (CI) = 1.55–8.14). In patients with systemic JIA, its frequency did not differ statistically from that of normal controls. Nevertheless, it is possible that haplotype S01 is associated with the phenotype of high IL-18 production in systemic JIA because the patients carrying S01/S01 showed significantly higher serum IL-18 levels compared with patients with other diplotype configurations (P = 0.017, Mann-Whitney U test). We confirmed that the frequency of the diplotype configuration of S01/S01 was significantly higher in AOSD patients than in healthy control subjects (P = 0.011, OR = 3.45, 95% CI = 1.42–8.36). Furthermore, the RA patients were also more predisposed to have S01/S01 (P = 0.018, OR = 2.00, 95% CI = 1.14–3.50) than the healthy control subjects, whereas the patients with collagen diseases did not. In summary, the diplotype configuration of S01/S01 was associated with susceptibility to JIA as well as AOSD and RA, and linked to significantly higher IL-18 production in systemic JIA. Possession of the diplotype configuration of S01/S01 would be one of the genetic risk factors for susceptibility to arthritis in the Japanese population.     

Novel insights into systemic autoimmune rheumatic diseases using shared molecular signatures and an integrative analysis

We undertook this study to identify DNA methylation signatures of three systemic autoimmune rheumatic diseases (SARDs), namely rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis, compared to healthy controls. Using a careful design to minimize confounding, we restricted our study to subjects with incident disease and performed our analyses on purified CD4⁺ T cells, key effector cells in SARD. We identified differentially methylated (using the Illumina Infinium HumanMethylation450 BeadChip array) and expressed (using the Illumina TruSeq stranded RNA-seq protocol) sites between cases and controls, and investigated the biological significance of this SARD signature using gene annotation databases. We recruited 13 seropositive rheumatoid arthritis, 19 systemic sclerosis, 12 systemic lupus erythematosus subjects, and 8 healthy controls. We identified 33 genes that were both differentially methylated and expressed (26 over- and 7 under-expressed) in SARD cases versus controls. The most highly overexpressed gene was CD1C (log fold change in expression = 1.85, adjusted P value = 0.009). In functional analysis (Ingenuity Pathway Analysis), the top network identified was lipid metabolism, molecular transport, small molecule biochemistry. The top canonical pathways included the mitochondrial L-carnitine shuttle pathway (P = 5E-03) and PTEN signaling (P = 8E-03). The top upstream regulator was HNF4A (P = 3E-05). This novel SARD signature contributes to ongoing work to further our understanding of the molecular mechanisms underlying SARD and provides novel targets of interest.     

腺苷脱氨酶及同工酶对自身免疫病诊断和病情监测的作用

摘要 目的：检测腺苷脱氨酶(ADA)及其同工酶在自身免疫病患者血清中的变化,探讨其诊断和病情监测作用。方法：收集70例系统性红斑狼疮（SLE）、114例类风湿性关节炎(RA)、55例强直性脊柱炎(AS)、及其年龄性别对应的健康血清标本。测定血清总ADA（tADA）、ADA1及ADA2活性。ROC曲线分析其诊断价值。结果：与健康对照相比,ADA活性在SLE患者血清中显著升高[tADA：15（12,20）vs 8（7,10）U/L;ADA1：3.5（2,5）vs 3（2,3）U/L;ADA2：11（8,15）vs 6（5,7）U/L;P<0.01）]。与健康对照相比,RA患者血清中tADA和ADA1活性无显著变化(P>0.05),ADA2活性水平升高[8（5.25,10）vs 7（5,9）U/L,P<0.05）];与健康对照相比,AS患者血清中tADA和ADA1活性无显著变化(P>0.05),ADA2活性升高[7（5,9）vs 6（5,7）U/L,P<0.05）]。ROC分析显示tADA及ADA2对SLE具有较好诊断价值（tADA：88.6%特异性、77.1%敏感性;ADA2：92.9%特异性、68.6%敏感性）。ADA活性对RA及AS患者无诊断价值。spearman相关性分析显示,tADA活性与SLE患者疾病活动度有一定正相关性（r=0.303,P=0.011)。结论：血清tADA活性检测可作为SLE辅助诊断和病情监测指标。     

PTPN22 genetic variation: evidence for multiple variants associated with rheumatoid arthritis

The minor allele of the R620W missense single-nucleotide polymorphism (SNP) (rs2476601) in the hematopoietic-specific protein tyrosine phosphatase gene, PTPN22, has been associated with multiple autoimmune diseases, including rheumatoid arthritis (RA). These genetic data, combined with biochemical evidence that this SNP affects PTPN22 function, suggest that this phosphatase is a key regulator of autoimmunity. To determine whether other genetic variants in PTPN22 contribute to the development of RA, we sequenced the coding regions of this gene in 48 white North American patients with RA and identified 15 previously unreported SNPs, including 2 coding SNPs in the catalytic domain. We then genotyped 37 SNPs in or near PTPN22 in 475 patients with RA and 475 individually matched controls (sample set 1) and selected a subset of markers for replication in an additional 661 patients with RA and 1,322 individually matched controls (sample set 2). Analyses of these results predict 10 common (frequency >1%) PTPN22 haplotypes in white North Americans. The sole haplotype found to carry the previously identified W620 risk allele was strongly associated with disease in both sample sets, whereas another haplotype, identical at all other SNPs but carrying the R620 allele, showed no association. R620W, however, does not fully explain the association between PTPN22 and RA, since significant differences between cases and controls persisted in both sample sets after the haplotype data were stratified by R620W. Additional analyses identified two SNPs on a single common haplotype that are associated with RA independent of R620W, suggesting that R620W and at least one additional variant in the PTPN22 gene region influence RA susceptibility.     

PTPN22 polymorphism and anti-cyclic citrullinated peptide antibodies in combination strongly predicts future onset of rheumatoid arthritis and has a specificity of 100% for the disease

We analysed relationships between the PTPN22 1858 polymorphism and antibodies to cyclic citrullinated peptide (CCP), rheumatoid factors (RFs) and the shared epitope (SE) gene (HLA-DRB1*0404 or 0401) and determined their combined predictive value for rheumatoid arthritis (RA) in individuals who subsequently developed RA. This case-control study was nested within the Medical Biobank of Northern Sweden. Patients with RA (n = 92) were identified from amongst blood donors antedating onset of disease by a median of 2.4 (interquartile range 1.2 to 4.9) years. Matched controls were selected randomly from the same cohorts (n = 368). Anti-CCP antibodies and RFs were determined using enzyme-linked immunoassays. Genotyping was performed using an ABI PRISM 7900HT instrument and HLA-SE genes were identified using PCR sequence-specific primers. The 1858T allele and also carriage of T were associated with future onset of RA (odds ratio (OR) = 2.29, 95% confidence interval (CI) 1.45-3.61 and OR = 2.64, 95% CI 1.56-4.47, respectively). The combination of the 1858T variant and anti-CCP antibodies gave 100% specificity for the disease. None of the 368 controls expressed this combination. The PTPN22 1858T variant and anti-CCP antibodies were clearly associated (OR = 3.80, 95% CI 1.51-9.57). A combination of the PTPN22 1858T variant and anti-CCP antibodies gave a much higher relative risk (>132.03) for developing RA than the combination of the T variant and HLA-SE (OR = 7.85). The PTPN22 1858T variant was associated with future development of RA. There was an association between the T variant and anti-CCP antibodies and their combination, found only among pre-patients, gives a very high relative risk for development of RA. The combination gave a specificity of 100% for diagnosing RA.     

Follistatin-like protein 1 is elevated in systemic autoimmune diseases and correlated with disease activity in patients with rheumatoid arthritis

Introduction

Follistatin-like protein 1 (FSTL1) is a proinflammation mediator implicated in arthritis in rodent animal models. The present study is aimed at assessing FSTL1 levels in systemic autoimmune diseases and correlating them with disease activity in patients with rheumatoid arthritis (RA).

Methods

Serum FSTL1 levels from 487 patients with systemic autoimmune diseases and 69 healthy individuals were measured by enzyme-linked immunosorbent assay (ELISA). FSTL1 expression in synovial fluid (SF) and synovial tissues (STs) was determined by ELISA, immunohistochemistry, real-time polymerase chain reaction (RT-PCR) and western blot analysis in RA patients and trauma controls. FSTL1 levels in fibroblast-like synoviocytes (FLSs) from RA patients were determined by real-time PCR and western blot analysis.

Results

Serum FSTL1 levels were significantly elevated in patients with RA, ulcerative colitis, systemic lupus erythematosus, Sjögren's syndrome (SS), systemic sclerosis and polymyositis/dermatomyositis. Serum FSTL1 levels in the RA and secondary SS patients were substantially higher than those in other patients. Serum FSTL1 levels were increased in early RA, rheumatoid factor (RF)- and anti-cyclic citrullinated peptide antibody (ACPA)-negative patients compared to healthy controls. Moreover, serum FSTL1 concentrations were significantly higher in long-standing RA patients than in early RA patients and in the RF- and ACPA-positive RA patients than in RF- and ACPA-negative RA patients. Elevated FSTL1 levels in the STs and SF of RA patients were also observed. FSTL1 levels in serum were markedly higher than those in SF in RA patients. The strongest FSTL1 staining was detected in the cytoplasm of synovial and capillary endothelial cells from RA synovium. Furthermore, FSTL1 was induced in FLSs by inflammatory mediators. Importantly, serum FSTL1 levels were correlated with several important biologic and clinical markers of disease activity, including erythrocyte sedimentation rate, C-reactive protein, RF, ACPA, swollen joint count, patient global visual analogue scale score and Disease Activity Score 28 in the adult RA patient population. Notably, serum FSTL1 levels were significantly diminished following successful treatment and clinical improvement.

Conclusions

Elevated FSTL1 levels reflect not only joint diseases but also inflammation and tissue degradation in systemic autoimmune diseases. Serum FSTL1 levels may thus serve as a serological inflammatory marker of disease activity in RA patients.