在末期腎病變中免疫發炎與心血管疾病之關聯

The relationship between Immune - inflammation and cardiovascular disease in End-Stage Renal Disease

楊豐榮(Feng-Jung Yang)

指導教授 ： 楊偉勛

共同指導教授 ： 黃瑞仁(Juey-Jen Hwang)

國立臺灣大學/醫學院/臨床醫學研究所/博士(2020年)

https://doi.org/10.6342/NTU202002204

摘要

背景：
末期腎病常伴隨許多生理病理改變，如感染、發炎、動脈粥狀硬化、及過早的死亡。傳統風險和非傳統風險如發炎據信為產生末期腎病患者心血管風險中非常重要的角色。在透析的發炎微觀環境常來自尿毒毒素、感染及組織缺氧。吾等嘗試建立一個長期的末期腎病世代，來討論慢性病毒感染及發炎相關的副作用。
方法：
本研究是建立一個以免疫研究的末期腎病世代。我們收集病患每週透析前的血液，血色素、白血球計數，血中生化指數包括尿素氮、肌肝酸、白蛋白、總膽固醇、三酸甘油脂，鈣、磷，並計算透析廓清率（簡稱Kt/V）標準化蛋白質異化速率（簡稱nPCR）來評估透析適量及蛋日質攝取狀況。周邊血單核細胞也同時收集並染色並由流式胞儀分類判讀。血漿中發炎胞激素（TNF-α 和 IL-6）亦會測定。周邊血單核細胞經由細胞表抗體分不同細胞種類。本研究將T細胞分為四大類：初始T細胞(Tnaive), 中央記憶型T細胞 (TCM), 作用記憶型T細胞 T cell (TEM) 和再表現CD45RA之終端作用型T 細胞 (TEMRA)。各式免疫細胞資料的判讀是由多色相流式細胞儀協助。
結果：
收集412位末期病患加入本研究，408位病患是曾經被巨細胞病毒（Cytomegalovirus, HCMV）感染，經由和57位健康測試者比對，透析患者有較高的巨细胞病毒免疫球蛋白(anti-HCMV IgG)。在多重迴歸分析下且調整年紀、性別、血色素、糖尿病、鈣磷乘積和高敏感反應蛋白(hs-CRP)，既存心血管疾病和取對數的巨细胞病毒免疫球蛋白(anti-HCMV IgG)的血中濃度有獨立相關性(OR = 1.93, 95% CI = 1.2~ 3.2, p = 0.01)。巨细胞病毒的免疫球蛋白(anti-HCMV IgG)的值和終端分化的CD8+ and CD4+中再表現CD45RA之終端作用型T 細胞 (TEMRA)的細胞比例及絕對細胞數有顯著的的正相關，意味著免疫老化在心血管疾病的發展扮演重要角色。而我們前導實驗，發現由IL-1β誘導的3T3-L1 脂肪細胞，模仿PFY著胰島素阻抗，可發現發炎反應中Plasma leucine-Rich α 2-glycoprotein 1 (LRG1)有上昇的反應。在本研究中血中LRG-1和IL-6, hsCRP呈正相關，而在單一變項迴歸分析，LRG1和心血管疾病及週邊動脈血管疾病中有顯著的的相關。在多重迴歸分析下且調整年紀、性別、血色素、糖尿病、鈣磷乘積和高敏感反應蛋白(hs-CRP)，LRG1分三組後愈高的組別和週邊動脈疾病 (odds ratio = 3.49) 和心血管疾病(odds ratio = 1.65) 有顯著的風險增加。
結論：
本研究是第一個在末期腎病中發現巨細胞病毒的免疫球蛋白的量是增加的，可能是持續性的巨細胞病毒感染，並和心血管疾病有相關，這個作用是明顯且獨立於傳統及非傳統的心血管風險因子。巨细胞病毒的免疫球蛋白(anti-HCMV IgG)的量和T細胞往末端分化有正相關，可能正是心血管風險相關的媒介。LRG1也獨立地和心血管疾病及週邊動脈血管疾病有顯著的相關。LRG1的量也和造成心血管病理的發炎反應中IL-6和hsCRP呈正相關。
進一步研究末期腎病中巨細胞病毒的活化及血中LRG1和心血管風險的研究，可以進一步闡釋感染及發炎在易感族中可能的機轉。

關鍵字

末期腎病 ； 巨細胞病毒感染 ； 心血管疾病 ； 動脈硬化 ； 發炎 ； 週邊動脈疾病

並列摘要

Background: Many adverse pathophysiological changes including infection, inflammation, atherosclerosis, and premature mortality is associated with End-stage renal disease (ESRD). Traditional risk factors as well as non-traditional risk factors, such as inflammation, are believed to contribute to the excessively heavy burden of cardiovascular disease in ESRD patients. The pro-inflammatory microenvironment is collectively caused by uremic milieu, infection, and tissue ischemia even before the initiation of dialysis. We established a cohort-base study to explore virus infection and inflammation -related adverse outcome.
Method: This analysis is based on the subjects enrolled in the Immunity in ESRD. We collected peripheral blood samples at the beginning of hemodialysis during the first session of the week. Hemoglobin level, white blood cell counts, blood biochemistry including blood urea nitrogen (BUN), creatinine, albumin, total cholesterol, triglyceride, calcium, and phosphate were measured. Kt/V and normalized protein catabolic rate (nPCR) were calculated to represent dialysis adequacy and dietary protein intake.　Peripheral blood mononuclear cells (PBMCs) were isolated and submitted for flow cytometry analysis. LRG1 was measured by ELISA. The plasma levels of inflammatory cytokines, TNF-α and IL-6, were assayed respectively. We obtained peripheral blood mononuclear cell (PBMC) to identify distinct cell types based on surface marker. The expression patterns of specific T cell subsets in progressive differentiation status are as the following: Naïve T cells (Tnaive), central memory T cells (TCM), effector memory T cell (TEM) and terminal effector T cells with CD45RA re-expression(TEMRA). Data acquisition was performed using a multicolor flow cytometer.
Result: Among 412 of the immunity in ESRD study (iESRD study) participants, 408 were HCMV seropositive and were analyzed. Compared to 57 healthy individuals, ESRD patients had higher levels of anti-HCMV IgG. In a multivariate-adjusted logistic regression model, the log level of anti-HCMV IgG was independently associated with prevalent coronary artery disease (OR = 1.93, 95% CI = 1.2~ 3.2, p = 0.01) after adjusting for age, sex, hemoglobin, diabetes, calcium phosphate product and high sensitivity C-reactive protein. Levels of anti-HCMV IgG also positively correlated with both the percentage and absolute number of terminally differentiated CD8+ and CD4+ T EMRA cells, indicating that immunosenescence may participate in the development of coronary artery disease. Our pilot study found that Plasma leucine-Rich α 2-glycoprotein 1 (LRG1) is linked with inflammatory response via an IL-1β-treated 3T3-L1 adipocyte model. The level of LRG1 had a positive correlation with IL-6, hsCRP in our cohort . In the univariate analysis, a higher level of LRG1 was associated with the presence of cardiovascular disease (CVD) and peripheral arterial occlusive disease (PAOD). In multivariate logistic regression models, higher LRG1 tertile was significantly associated with PAOD (odds ratio = 3.49) and CVD (odds ratio = 1.65), but not with coronary artery disease, history of myocardial infarction, or stroke after adjusting for gender, diabetes, hemoglobin, albumin, calcium-phosphate product, and level of hsCRP.
Conclusion:
Our current study is the first to demonstrate that anti-HCMV IgG titer is elevated in ESRD patients with persistent HCMV infection and associates with coronary artery disease. The effect is significant and independent of traditional and non-traditional cardiovascular risk factors. Level of HCMV IgG also positively correlates with T cell terminal differentiation, which could serve as the mediator for this association.
LRG1 level is independently associated with higher prevalence of peripheral arterial occlusive disease(PAOD) and cardiovascular disease (CVD) in ESRD patients treated with hemodialysis. The level of plasma LRG1 is also significantly correlated with inflammation, represented by IL-6 and hsCRP levels, which contributes to the development of cardiovascular pathology.
Further investigation about HCMV reactivation and LRG1 with cardiovascular risk should be considered and the possible mechanism about infection and inflammation is warranted to explorer in this susceptible population.

並列關鍵字

end-stage renal disease ； human cytomegalovirus ； cardiovascular disease ； Leucine-rich α-2-glycoprotein 1 ； inflammation ； peripheral arterial disease

參考文獻

References

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