A simple method for removing low-density granulocytes to purify T lymphocytes from peripheral blood mononuclear cells.

OBJECTIVE: Low-density granulocytes (LDGs) can form neutrophil extracellular traps (NETs) spontaneously and excessively. When peripheral blood mononuclear cells (PBMCs) are used for studying T lymphocytes, LDGs contained in the PBMCs may decrease the threshold of activating T lymphocytes by forming NETs. This study focused on the profiles of LDGs in common autoimmune diseases and methods for removing LDGs from PBMCs. METHODS: The percentages of LDGs in PBMCs from 55 patients with dermatomyositis (DM), 15 with polymyositis (PM), 42 with rheumatoid arthritis (RA), 25 with systemic lupus erythematosus (SLE), and 19 healthy controls were determined by flow cytometry. Three methods of removing LDGs were explored and compared. After removal, PBMCs from six patients with positive T-SPOT.TB were tested again to find out if LDGs contained in the PBMCs could influence T lymphocyte reactions. RESULTS: Significantly higher LDG percentages were found in PBMCs from patients with DM ((8.41±10.87)%, P<0.0001), PM ((8.41±10.39)%, P<0.0001), RA ((4.05±6.97)%, P=0.0249), and SLE ((7.53±11.52)%, P=0.0006), compared with the controls ((1.28±0.73)%). The T-SPOT.TB values significantly decreased after LDGs were removed. Increasing relative centrifugal force (RCF) within a limited range can decrease the LDG percentage from an initial high level, but not markedly increase the LDG clearance rate. Compared with the whole blood sediment method, the PBMC adherence method can significantly remove LDGs yet scarcely influence the T lymphocyte percentage in PBMCs. CONCLUSIONS: The LDG percentage in PBMCs is significantly increased in patients with SLE, DM, PM, and RA. The influence of LDGs on T lymphocytes cannot be ignored in PBMC cultures. The adherence method is a simple and easy-to-use method for removing LDGs and purifying T lymphocytes from PBMCs.

[Progress on rheumatoid arthritis in elderly].

During choosing non-steroidal anti-inflammatory drugs(NSAIDs), risk factors should be evaluated in elder patients with rheumatoid arthritis. The present study focused on biological therapies, and elderly patients should be more concerned about the risk of infection when used it. Traditional Chinese medicine has advantages of obvious curative effect, especially for tripterygium wilfordii, large clinical trial on western and Chinese medical accurate drug strategies for old patients with rheumatoid arthritis. Old patients are easier to suffer from cardiac diseases and interstitial lung disease, rheumatoid arthritis could be controlled along with the treatment for coexistent disease. The incidence of rheumatoid arthritis in old patients is the same with other RA, and need to treat to target based on the aim of relieve pain and reduce activity of diseases, while the clinical charteristic and treatment target in elder patients with rheumatoid arthritis were not similar with other aged patient, so treatment standard target would vary with aging. Resent clinical studies excluded old patients, lead to lack of evidence-based medicine data. Clinical study for elder patients with rheumatoid arthritis are energetically carrying out, and could provide base and guide for clinical treatment.

[Correlation of DNase I in serum and synovial fluid with inflammatory activity in patients with rheumatoid arthritis].

OBJECTIVE: To investigate the potential role of deoxyribonuclease I (DNase I) in the pathogenesis of rheumatoid arthritis (RA). METHODS: DNase I activity was measured by radial enzyme-diffusion method in serum samples from 83 RA patients and 60 healthy volunteers and in the synovial fluid (SF) from 27 RA patients and 38 patients with other inflammatory arthritis. SF cfDNA level was measured with Pico Green Kit, and the correlation among DNase I activity, cfDNA level and clinical parameters of RA patients was analyzed. RESULTS: Serum DNase I activity was significantly lower in RA patients than in the healthy control subjects (0.3065∓0.1436 vs 0.4289∓0.1976 U/mL, P<0.001), and was negatively correlated with ESR (r=-0.2862, P=0.0122), CRP (r=-0.2790, P=0.0184) and neutrophil cell counts (r=-0.287, P=0.011). SF DNase I activity was almost negative in patients with RA, ankylosing spondylitis (AS) and gouty arthritis (GA). SF cfDNA level in RA patients was significantly higher than that in patients with osteoarthritis (100.81∓142.98 vs 18.98∓31.40 µg/mL, P=0.002), but similar to that in patients with AS (45.85∓47.67 µg/mL, P=0.428) and GA (162.95∓97.49 µg/mL, P=0.132). In patients with inflammatory arthritis, SF cfDNA level was positively correlated with ESR (r=0.4106, P=0.0116) and CRP (r=0.5747, P=0.0002). CONCLUSION: Impairment of DNase I activity may be responsible for the enhanced NETs generation and plays a role in the pathogenesis of RA.