TTuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Autoantibodies to angiotensin-converting enzyme 2 in patients with connective tissue diseases. | Takahashi et al. Arthritis Research Therapy 2010 12 R85 http content 12 3 R85 RESEARCH ARTICLE Open Access Aufolantibodies to angiotensin-converting enzyme 2 in patients with connective tissue diseases Yuko Takahashi21 Shiori Haga22 Yukihito Ishizaka2 and Akio Mimori 1 Abstract Introduction Angiotensin-converting enzyme ACE 2 a homolog of ACE converts angiotensin Ang II into Ang 1-7 and the vasoprotective effects of Ang 1-7 have been documented. We explored the hypothesis that serum autoantibodies to ACE2 predispose patients with connective tissue diseases to constrictive vasculopathy pulmonary arterial hypertension PAH or persistent digital ischemia. Methods Serum was examined from 42 patients with systemic lupus erythematosus SLE scleroderma or mixed connective tissue disease. Eighteen vasculopathy patients with PAH five cases and or persistent digital ischemia 16 cases were compared with 24 patients without these vasculopathies control patients for serum reactivity to purified recombinant human ACE2 using an ELISA. Results The sera from 17 of the 18 94 vasculopathy patients had ELISA scores above the baseline level determined using control sera from 28 healthy subjects and the mean ELISA score in the vasculopathy patients was significantly higher than that in the control patients P . The relative activity of serum ACE2 which was defined using a reference serum correlated inversely with the ELISA scores for serum anti-ACE2 antibodies in the 18 vasculopathy patients R2 . The IgG fraction from vasculopathy patients but not from healthy subjects inhibited ACE2 activities in vitro. Consistent with this immunosuppressive therapy given to one SLE patient with digital necrosis markedly decreased the anti-ACE2 antibody titer and restored serum ACE2 activity. Conclusions Autoantibodies to ACE2 may be associated with constrictive vasculopathies. Introduction Angiotensin-converting enzyme ACE 2 a homolog of ACE is a carboxypeptidase that
