僵直性脊椎炎病人發炎性細胞激素的表現及細胞內鈣鎂濃度之研究

The expression of proinflammatory cytokines and intracellular minerals in patients with ankylosing spondylitis

目的：本研究目的為探討僵直性脊椎炎病人發炎性細胞激素的表現及細胞內鈣鎂濃度。方法：我們收集了40位僵直性脊椎炎病人及19位正常人血清。分別利用流式細胞儀 （flow cytometry） 來偵測發炎性細胞激素 （IL-1β, TNF-α, IFN-γ） 的表現及光譜儀 （spectroflurometer） 來測定細胞內鈣鎂濃度。臨床指標紀錄了包括紅血球沉降速率 （ESR）、發炎指數 （CRP）、BASDAI、BASFI、發病年齡、家族病史及虹彩炎有無，並且分別作進一步分析。結果：T細胞刺激後發炎性細胞激素 （IL-1β, TNF-α, IFN-γ） 的表現，在僵直性脊椎炎病人比正常人有顯著的增加 （p<0.05）。僵直性脊椎炎病人細胞內鈣離子濃度和CD8+ T 細胞內TNF-α 表現有顯著相關性 （r=0.439, p<0.05）。IFN-γ在CD3+ T細胞刺激後表現增加幅度在BASFI分數較低的病人較少 （BASFI <20 和 BASFI ≧20比較, p<0.05）；在有虹彩炎病史的病人增加較多。IL-1β在CD4+ T細胞刺激後表現增加幅度在發病年齡較晚的病人較少 （>30歲, p<0.05）。結論：發炎性細胞激素 （IL-1β, TNF-α, IFN-γ） 在T細胞刺激後的表現增加程度在僵直性脊椎炎病人顯著升高。細胞內鈣離子濃度和TNF-α表現在僵直性脊椎炎病人有顯著相關性，至於細胞內鈣離子濃度是否會增加TNF-α 表現, 則有待進一步研究。

Objective: Our study aimed to investigate the expression of intracellular proinflammatory cytokines and mineral contents in patients with ankylosing spondylitis (AS). Methods: Serum samples from 40 patients with AS and 19 healthy individuals were collected for this study. Flow cytometry was used to determine the intracellular concentration of interleukin (IL)-1β, interferon (IFN)-γ and tumor necrosis factor (TNF)-α in the CD3–, CD4–, and CD8– bearing T cells. The mass fraction of calcium (Ca2+) and magnesium (Mg2+) in phytohemagglutin (PHA)-stimulated lymphocytes were measured using a spectrofluorometer. Clinical variables, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), age at onset, uveitis and family history were recorded. Results: Intracellular proinflammatory cytokine (IL-1β, TNF-α, & IFN-γ) expression in CD3+ and CD4+ T cells after phorbol myristate acetate (PMA) stimulation was more significantly increased in AS patients than in healthy controls (p<0.05). Intracellular Ca2+ exhibited a significant correlation to the TNF-α level in stimulated CD8+ T cells in AS patients (r=0.439, p<0.05), but not in healthy controls. Comparison between an increase in cytokine expression and clinical variables showed that the increase in IFN-γ was significantly less prominent in patients with a lower BASFI score (BASFI <20 vs. ≧20, p<0.05) and more prominent in patients with uveitis. The IL-1β increase after stimulation was less prominent in patients with a higher age of onset (>30 years of age, p<0.05). Conclusion: The increased expression of intracellular proinflammatory cytokines, including IL-1β, TNF-α and IFN-γ after PMA-stimulation was more pronounced in AS patients than in normal individuals. A significant correlation between intracellular TNF-α level and Ca2+ was found in AS patients. Whether the elevation of intracellular Ca2+ can enhance intracellular TNF-α expression in AS patients requires further study.