Authors: Naoto Umeda Isao Matsumoto Hoshimi Kawaguchi Yuko Kurashima Yuya Kondo Hiroto Tsuboi Hiroshi Ogishima Takeshi Suzuki Yayoi Kagami Takuya Sakyu Akihito Ishigami Naoki Maruyama Takayuki Sumida
Publish Date: 2015/09/29
Volume: 35, Issue: 5, Pages: 1181-1188
Abstract
The objectives of this study are to investigate the prevalence of PAD4 and antiPAD4 antibodies Abs in autoimmune diseases and to clarify their association with anticitrullinated protein antibodies ACPAs and shared epitope SE in patients with rheumatoid arthritis RA Levels of human PAD4 and antiPAD4 Abs in serum or plasma were measured using sandwich ELISA Samples were obtained from patients with RA n = 148 SLE n = 36 or SS n = 37 and from healthy controls HCs n = 40 Antibodies against cyclic citrullinated glucose6phosphate isomerase GPI CCG2 CCG7 antiCEP1 and antiCCP Abs were also measured using ELISA Patients with RA were genotyped for HLADRB1 The human PAD4 and antiPAD4 Ab levels were compared with the ACPA and SE in patients with RA The PAD4 levels were 1119 U/ml in the RA 304 U/ml in the SLE 819 U/ml in the SS patients and 466 U/ml in the HCs The PAD4 levels were significantly higher in the RA than in the SLE patients or the HCs AntiPAD4 Abs were detected in 297 of the patients with RA but not in the patients with SLE or SS nor in the HCs In the RA patients the PAD4 levels in the antiPAD4 Abnegative group were significantly higher than those in the antiPAD4 Abpositive group Moreover antiCCG2 CCG7 CEP1 and antiCCP Ab levels were significantly higher in the antiPAD4 Abpositive group than in the antiPAD4 Abnegative group In the RA patients the PAD4 levels were not correlated with ACPAs Neither PAD4 nor antiPAD4 Abs were significantly correlated with the presence of SE alleles The PAD4 levels were higher in RA than in SLE or HC AntiPAD4 Abs appeared specifically in patients with RA Moreover antiPAD4 Abs were associated with ACPAs
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