[Preliminary study on differential expression of plasma proteins of patients with Takayasu's arteritis in different stage].

Objectives: To investigate differential expression of plasma proteins of patients with Takayasu's arteritis to screen disease-related or phase-related proteins or biomarkers.

Methods: From March, 2005 to January, 2006, Plasma of 20 patients with acute Takayasu's arteritis, 20 patients with chronic Takayasu's arteritis, and 20 healthy people as control were collected. Plasma proteins were profiled by two-dimensional electrophoresis. Spots of differential expression were screened by computerized map analysis and identified by matrix assisted laser desorption/ionization time of flight-mass spectrometry. Circulation levels of parts of differential expression proteins were investigated by Elisa in each subject.

Results: Fourteen differential expression proteins were identified, including serum amyloid A, serum amyloid P, fibrinogen, complement C3c, C7, C4 binding protein, factor H related protein-1, immunoglobin, alpha-acid glycoprotein, RAG1 protein, alpha1-microglobin, apolipoprotein A-I, A-IV, transthyretin, haptoglobin. Proteins related to acute and chronic phase were serum amyloid A, fibrinogen, transthyretin, haptoglobin; Circulation levels of Serum amyloid A (SAA) and Complement C4 binding protein (C4BP) were significantly increased in active TA patients comparing to that in inactive TA patients and in controls (SAA: 95.9 vs 49.2, P = 0.009 and 23.9 mg/L, P = 0.001, respectively; C4BP: 88.5 vs 61.7, P = 0.023 and 32.6 mg/L, P < 0.001, respectively).

Conclusions: Acute phase proteins and immune proteins may possible be markers for diagnosis and activity of Takayasu's arteritis, Complement activity, complement modulation protein and antibody production may be involved in immune mechanism of Takayasu's arteritis. Further study of these proteins may be helpful to elucidate the pathologic mechanism of Takayasu's arteritis.