| Objective:Takayasu arteritis(TA)is a rare autoimmune disease characterized by inflammation of the aorta and its major branches.Genome-wide association studies(GWAS)showed novel genetic variants of IL12B,IL6,HLA-B/MICA,FCGR2A/FCGR3A,RSP9/LILRB3,MICA,EEFSEC,RIPPLY2 and MLX were associated with TA.Since TA was of ethnic difference,the present study aimed to investigate the linkage between these single nucleotide polymorphisms(SNP)and TA in a Chinese Han population.Methods:We performed a multicenter study involving four hundred and twelve patients and 597 healthy controls.Fourteen SNPs of following genes were genotyped using the Sequenom MassArray iPLEX platform,IL12B(rs6871626,rs4921492,rs60689680 and rs4921493),IL6(rs2069837),HLA-B/MICA(rs9366782 and rs12524487),MICA(rs3763288 and rs114202986),FCGR2A/FCGR3A(rs2099684),RSP9/LILRB3(rs11666543),EEFSEC(rs10934853),RIPPLY2(rs1570843)and MLX(rs665268).The association between these SNPs and TA early onset and TA companied with hypertension was also investigated.Results:We demonstrated a allele association between the four SNPs of IL12B and TA(rs6871626:OR 1.52,95%CI 1.26-1.83;rs4921492:OR 1.46,95%CI 1.21-1.75;rs60689680:OR 1.41,95%Cl 1.17-1.69;rs4921493:OR 1.45,95%CI 1.21-1.75).A genotype association between the four SNPs of IL12B and TA was also found(P=1.14×10-5,p=1.67×10-4,p=4.36×10-4 and P=1.91×10-4).The four SNPs were in strong linkage disequilibrium.The frequency of AATC haplotype in TA group was significantly higher than controls(P=4.61×10-4)while CCGT haplotype frequency of TA patient was less than healthy controls.SNP rs9366782 and rs12524487 of HLA-B/MICA were associated with TA(P =0.028 and P =0.01)while rs3763288 and rs114202986 of MICA showed negative association.ATGT haplotype consisted of rs9366782?rs12524487?rs3763288 and rs114202986 was more frequent in TA group compared to healthy controls(P=6.2×10-11),contrast with TTGT haplotype(P=0.026).Conditional analysis shows that rs12524487 were independent on other three SNPs factors.Both allele association and genotype association were found between rs2099684 of FCGR2A/FCGR3A and TA(P=3×10-9 and P=9.8×10-8).GG/AA+AG genotype of rs11666543(RSP9/LILRB3)were significantly different between TA and healthy group(P=0.033,OR=1.43,95%CI=1.10-2.0).Nevertheless,neither genotype nor allele frequencies of IL6(rs2069837),EEFSEC(rs10934853),RIPPLY2(rs1570843)and MLX(rs665268)showed significant between-group differences.Moreover rs2069837 of IL6 and rsl 1666543 of RSP9/LILRB3 were related to TA companied with hypertension(OR=2.12,95%CI=1.32-3.44;OR=1.74 95%CI=1.01-2.97).No association was found between these SNPs and TA early onset.Conclusions:Our findings indicated that IL12B,HLA-B/MICA,FCGR2A/FCGR3A and RSP9/LILRB3 might be susceptibility genes for TA in Chinese Han population.Besides polymorphism of IL6 and RSP9/LILRB3 were associated with TA companied with hypertension which provide further clues for reseairch into the pathogenesis of TA.Objective:Takayasu arteritis(TA)is an autoimmune disease characterized as chronic large vessel vasculitis.Because of an insidious onset and indistinct symptoms and a lack of effective autoantibody-based biomarkers for TA diagnosis,diagnosis of TA is often significantly delayed in the clinics.Thus we employed the HuProt arrays,comprised of 20,240 unique human proteins,to comprehensively screen for TA-specific serological biomarkers and help TA diagnosis.Methods:Here,we applied two-phase screening strategy,namely discovery and verification phases.In Phase I,an unbiased screen was performed on HuProt arrays with a relatively small cohort,comprised of 75 samples from TA,autoimmune disease controls and healthy controls.Bioinformatics analysis allowed us to identify 43 candidate autoantigens associated with TA.In Phase II,these 43 antigens were purified and used to fabricate TA focused arrays to validate these potential biomarkers in a large cohort of 315 subjects,comprised of 109 TA(78 active TA and 31 stable TA),110 autoimmune disease controls(50 RA,37ANCA and 23 SS)and 96 healthy controls.Finally,to provide further methodology validation,three of the eight proteins,SPATA7,QDPR and PRH2,were analyzed using Western blot analysis with representative serum samples from each groups.Results:Eight autoantigens,namely SPATA7,QDPR,SLC25A2,PRH2,DIXDC1,IL17RB,ZFAND4 and NOLC1,were validated as TA-specific biomarkers.The top two antigens,SPATA7 and QDPR,showed a high AUC of 0.803,and 0.801,respectively.SPATA7could distinguish TA from healthy controls and disease controls with 73.4%sensitivity at 85.4%specificity,while QDPR showed 71.6%sensitivity and 86.4%specificity.Among the eight validate biomarkers,SLC25A22 showed the highest sensitivity of 80.7%with somewhat lower specificity of 67.0%.On the other hand,PRH2,IL17RB and NOLC1 possessed a good specificity>85%with somewhat a lower sensitivity(e.g.,<50%).The left two biomarker DIXDC1 and ZFAND4 were of 67.0%and 50.5%sensitivity,with 65.5%and 77.7%specificity,respectively.However,combinations of these eight biomarkers could not outperform the single biomarkers of SPATA7 and QDPR.In addition,none of the eight biomarkers showed significant differences between the stable and active TA groups.Moreover,three of them,SPATA7,QDPR and PRH2,were successfully validated with Western blot analysis with representative samples.Conclusions:Using the two-phase strategy to screen a large cohort of 390 samples we discovered and validated eight novel serological biomarkers of TA diagnosis,three of which could be readily adopted to clinical settings. |
PDF Full Text Request