肽精氨酸脱亚胺基酶Ⅳ基因表达与抗环瓜氨酸肽抗体的相关性研究

Association of peptidylarginine deiminase IV gene expression with anti-cycfic citrullinated peptide antibody levels in rheumatoid arthritis

目的探讨类风湿性关节炎（RA）中四型肽精氨酸脱亚胺基酶（peptidylarginine deiminaseIV，PAD14）基因表达与白细胞抗原共同表位（shared epitope，SE）、抗环瓜氨酸肽（CCP）抗体、类风湿因子（RF）的相关性，编码RA易感。方法用实时荧光定量逆转录（FQ—RT）-PCR检测70例RA患者、38例疾病对照患者和91名健康体检者外周血单个核细胞中PAD14基因的表达水平，巢氏PCR分析HLA-DRB1＊01、＊04、＊10基因型，ELISA测定血清抗CCP抗体含量，免疫比浊法测定血清RF含量。结果RA组PADl4基因相对表达量为3．43±1．97，分别高于健康对照组的1．524-0．95（t=-8．259，P=0．000）和疾病对照组的1．41±0．79（t=-8．357，P=0．000）。RA患者抗CCP抗体阳性组（3．40±1．97）与阴性组PAD14表达量差异无统计学意义（3．78±2．15，t=0．453，P=0．688），疾病对照患者抗CCP抗体阳性组（1．34±0．93）与阴性组PAD14表达差异也无统计学意义（1．25±0．79，t=0．568，P=0．476）；RA组和健康对照组中SE等位基因阳性与阴性者PAD14表达量（RA组：3．88±1．81，1．02±0．47；健康对照组：1．52±0．95，1．07±0．70）比较，差异有统计学意义（RA组t=-10．382，P=0．000；健康对照组t=-2．457，P=0．016）；RA组内RF阳性者与RF阴性者中PAD14表达差异有统计学意义（t=-3．521，P=0．001），但疾病对照组与健康对照组比较，差异无统计学意义（t值分别为0．385和-1．144，P均〉0．05）。RA组中PAD14表达量与抗CCP抗体含量间的差异无相关性（r=0．083，P=0．640），在抗CCP抗体阳性状况下SE表型（t=-0．690，P=0．493）、RF变化（t=1．330，P=0．189）不影响RA患者血清中抗CCP抗体浓度。结论RA患者体内存在PAD14过量表达，PAD14基因表达量与SE等位有显著相关性，且与RF也有一定相关性，抗CCP抗体含量与PAD14表达量无相关性。

Objective To explore the relationship between the gene expression of peptidylarginine deiminase 1V and human leukocyte antigen （HLA）-DRB1 shared epitope （SE）, anti-eyeli citrullinated peptide antibody （anti-CCP）, rheumatoid factor （RF） in rheumatoid arthritis （RA）. Methods PADI4 expression was examined using real-time quantitative reverse transcription （RT）-PCR in 70 patients with RA, 38 patients with non-RA and 91 healthy controls. And their HLA-DRB1 ＊ 01, ＊ 04, ＊ 10 subtypes were determined by polymerase chain reaction with sequence-specific primers. Serum anti-CCP levels were measured with ELISA, serum RF levels were measured by turbidimetric immunoassay. Results The level of PADI4 expression was significantly higher in RA patients （ 3.43 ± 1.97 ） than healthy controls （ 1.52 ± 0. 95, t = -8. 259, P =0. 000） and non-RA patients （1.41 ±0. 79, t = -8. 357, P =0. 000）. There was no significantly difference for PAD14 expression between anti-CCP positive and anti-CCP negative in RA （ 3.40 ± 1.97, 3.78 ± 2. 15, t = 0. 453, P = 0. 688） and non-RA patients （ 1.34 ± 0. 93, 1.25_± 0. 79, t = 0. 568, P = 0. 476）. SE alleles carriers had significantly higher level of PADI4 expression than SE alleles noncarriers among RA （3.88 ± 1.81,1.02 ±0.47, t = - 10. 382,P =0. 000） and healthy controls （ 1.52 ± 0. 95, 1. 07±0. 70, t = -2.457, P = 0. 016）. PADI4 expression was higher in RF positive group than RF negative group in RA patients （ t = - 3. 521, P =0. 001 ）, but there was no significant difference between healthy group and disease control group. There was no correlation（ r =0. 083, P = 0. 640）between the level of PADI4 expression and the content of anti-CCP in RA patients. For RA patients with anti-CCP positive, SE alleles （t = - 0. 690, P = 0. 493 ） and RF （ t = 1. 330, P = 0. 189） did not affect serum level of anti- CCP. Conclusions PADI4 is overexpressed in RA patients. There is significant correlation between PADI4 expression and HLA-DRB1 SE alleles, and there is also certain correlation between PADI4 expression and RF. The correlation between the PADI4 expression levels and anti-CCP could not be proved in our study.