Screening disease-associated proteins from sera of patients with rheumatoid arthritis: a comparative proteomic study.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation at the synovial membrane. Although great progress has been made recently in exploring the etiology and pathogenesis of RA, its molecular pathological mechanism remains to be further defined and it is still a great challenge in determining the diagnosis and in choosing the appropriate therapy in early patients. This study was performed to screen candidate RA-associated serum proteins by comparative proteomics to provide research clues to early diagnosis and treatment of RA. METHODS: Sera isolated from 6 RA patients and 6 healthy volunteers were pooled respectively and high-abundance proteins were depleted by Plasma 7 Multiple Affinity Removal System. The protein expression profiles between the two groups were then compared by two-dimensional gel electrophoresis (2-DE) and the proteins over/under-expressed by more than 3-fold were identified by mass spectrometry analysis. To validate the differential expression levels of the identified proteins between the two groups, ELISA was performed in two of the identified proteins in individual sera from 32 RA patients and 32 volunteers. RESULTS: Eight proteins which over/under-expressed in sera of RA patients were identified. Among them, chain A of transthyretin (TTR) was under-expressed, while serum amyloid A protein, apolipoprotein A (ApoA)-IV, ApoA-IV precursor, haptoglobin 2, ceruloplasmin (Cp), immunoglobulin superfamily 22 and HT016 were over-expressed. ELISA test confirmed that Cp expressed remarkably higher while TTR obviously lower in RA group compared with volunteer group. CONCLUSION: There were 8 identified proteins differentially expressed between RA group and volunteer group, which might be candidate RA-associated proteins and might be promising diagnostic indicators or therapeutic targets for RA.

[Expressions of CD147 in peripheral monocytes and T lymphocytes of patients with ankylosing spondylitis].

OBJECTIVE: To investigate the roles of CD147 in the pathogenesis and development of ankylosing spondylitis (AS). METHODS: Flow cytometry was used to detect the expression levels of CD147 in peripheral monocytes and T lymphocytes of 30 AS patients, 30 rheumatoid arthritis (RA) patients and 30 healthy controls (HC). reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the expression levels of CD147 mRNA in peripheral blood mononuclear cells (PBMC). Then the expression levels of CD147 were compared among the groups. And a correlation analysis was conducted between CD147 levels and disease activity indices of AS patients. RESULTS: The mean fluorescence intensities of CD147 in monocytes of AS, RA and HC group were 213.5 ± 37.8, 228.7 ± 49.7 and 163.6 ± 44.8, and in T lymphocytes 36.8 ± 10.1, 40.2 ± 10.5 and 28.3 ± 10.6 respectively. Both the expression levels of CD147 in monocytes and T lymphocytes of AS patients were slightly lower than those of RA patients. But the differences was not statistically significant (P > 0.05). Both the CD147 levels in monocytes and T lymphocytes of AS and RA group were significantly higher than those of HC group (P < 0.05). The expression levels of CD147 mRNA in PBMC of AS and RA group were significantly higher than those of HC group (P < 0.05) while no significant difference was found between AS and RA group (P > 0.05). Both the expression levels of CD147 in monocytes and T lymphocytes of AS patients were positively correlated with the patients' erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). CONCLUSION: The expressions of CD147 in peripheral monocytes and T lymphocytes of AS patients are up-regulated and their levels are positively correlated with patients' ESR and CRP. It implies that CD147 plays critical roles in the pathogenesis and development of AS.

[Study on expressions of CD25 and CD127 in CD4+ peripheral T lymphocytes of patients with rheumatoid arthritis].

OBJECTIVE: To study the proportion of regulatory T cells (Tregs) in peripheral blood of patients with rheumatoid arthritis (RA) and investigate the significance of Tregs change in the incidence and inflammatory activity of RA. METHODS: Three-color fluorescence flow cytometry was used to detect the CD4, CD25 and CD127 markers in the peripheral blood lymphocytes of 25 RA patients and 31 healthy volunteers (HVs). The proportions of CD4(+)CD25(+), CD4(+)CD25(high), CD4(+)CD25(+)CD127(-) and CD4(+)CD25(high)CD127(-) cells were compared between the two groups and correlation analysis was conducted between Tregs and disease activity indices which including disease activity score (DAS28-4), tender joint count (TJC), swollen joint count (SJC), time of morning stiffness, patient's global assessment of disease activity on a 100 mm VAS by doctor and patients, erythrocyte sedimentation rate and C-reactive protein. RESULTS: The proportions of CD4(+)CD25(+)CD127(-) and CD4(+)CD25(high)CD127(-) cells in CD4(+) peripheral T lymphocytes were (2.53 +/- 0.85)% and (0.91 +/- 0.32)% respectively in RA group, while they were (3.22 +/- 0.97)% and (1.25 +/- 0.41)% in HV group. Both of the proportions of CD4(+)CD25(+)CD127(-) and CD4(+)CD25(high)CD127(-) cells were lower in RA group comparing with HV group, and both were significantly different between the two groups (P < 0.05). Correlation analysis indicated significant negative correlations of the proportions of CD4(+)CD25(+)CD127(-) and CD4(+)CD25(high)CD127(-) cells with DAS28-4 and TJC (P < 0.05), furthermore, CD4(+)CD25(high)CD127(-) T cells still showed significant negative correlation with the SJC and patient's global assessment of disease activity on a 100 mm VAS by patients (P < 0.05). CONCLUSION: The proportion of Tregs decreased in peripheral blood lymphocytes of patients with RA and the abnormality of Tregs may play an important role in the incidence and inflammatory activity of RA.