| 摘要: | 生物指標於全身性紅斑狼瘡與修格連氏症之研發與臨床運用:
測量紅血球上C4d及CR1(complement receptor 1)的比值，是一相當有潛能的生物標(Biomarker)來預估狼瘡病情活躍程度，並且能提供臨床醫師作出適當的治療決策，並且也有提早診斷紅斑性狼瘡的潛能及評估患者接受治療後的療效；我們研發出一新的單株抗體(CR1-2B11)具有正確估算紅血球上CR1的能力(Clin Exp
Immunol. 2007 Jun;148(3):546-54)，這是我們研發此一生物指標的第一個步驟，第二個步驟乃運用此抗體來研究紅斑性瘡病患紅血球上C4d及CR1（E-C4d/CR1 ratio）的實際比值，並以此數值來比對狼瘡患者病程，以了解此一生物指標於臨床運用之潛能：我們初步完成的研究，包括已確定診斷為紅斑性狼瘡的患者，其它自體免疫疾病患者、相關發炎性疾病及健康受試者，我們使用流式細胞儀分別運用
CR1-2B1及 anti-C4d抗體來研究病患紅血上C4d及CR1的消長並計算出此一生物指標的實際數值（E-C4d/CR1 ratio），並且分析與臨床病程之關聯性。我們使用流式細胞儀分別運用CR1-2B1及 anti-C4d抗體來研究病患紅球上C4d及CR1的消長並計算出此一生物指標的實際數值，初步研究報告顯示從紅斑性狼瘡病患所獲的比值與其它疾病患者及健康受試者的比值別為(4.63 ± 5.10 versus 0.29 ± 2.23 and 0.12 ±0.10, respectively; P < 0.0001 for both) ；此一結論顯示此生物指標具有診斷狼瘡之潛能，另外我們也追蹤了同數位狼瘡患者生物指標的變化，當病程活躍時其比值明顯上升，當治療病程明顯得到控制時比值明顯下降；另外從三位活躍紅斑性狼瘡患者我們也追蹤其類固醇脈衝治療前（3-day of methylprednisolone pulse therapy）
與治療後之指標變化 (19.23 to1.01, 5.47 to 1.25, and 13.16 to 2.40). (APLAR Journalof Rheumatology. Suppl.1:A14-A15,July 2006)。以上結果說明了運用此一新發展出
的單株抗體(CR1-2B11)用來計算紅血球上C4d及CR1比值（E-C4d/CR1 ratio）所獲得的生物指標具有評估臨床療效之能力及具有預估狼瘡的病情活躍程度的能力。
我們研發此一新的生物指標的第三個步驟乃在於驗證生物指標於臨床狼瘡病患的運用，是否具有正確評估狼瘡活性、預期治療效果與早期診斷狼瘡的潛能。首先我們將同時比較同一位患者以其他不同之生物指標與E-C4d/CR1比值與紅斑性狼瘡疾病活動指數 (SLE disease activity index)之相關性加以比較以確認此生物指標是否具有正確評估狼瘡活性之潛能，收集因病程活躍之狼瘡患者其治療前與治療
後之指標變化以評估其預期治療紅斑性狼瘡效果，同時我們也運用此生物指標用來評估疑似紅斑性狼瘡患者以輔助判斷是否有早期診斷紅斑性狼瘡的潛能。另外我們也計算出此生物指標的切點值 (cut-off value)並由統計學方法評估其診斷全身性紅斑狼瘡之敏感度及專一性;其次再以此生物指標之評估運用於狼瘡復發與合併感染之鑑別診斷，期望此生物指標能成為臨床醫師照護狼瘡患者之一實用之監測
模式。
我們於另一自體免疫疾病修格連氏症(Sjögren syndrome)患者身上也試圖研發可行之生物指標，目前由病因學方面指出與患者腺體細胞異常之自我凋亡(apoptosis)有關，在自體免疫疾病細胞異常之自我凋亡研究上，Growth arrest-specific 6 (Gas6)可能與相關慢性腺體發炎有關，然而直到今日，我們還不清楚Gas6對修格連氏症
的臨床重要性。因此我們設計了一個臨床實驗去探討血中Gas6蛋白質於修格連氏症全身發炎反應及唾液腺腺體發炎中所扮演之角色。我們的研究發現修格連氏症患者血中Gas6蛋白質濃度與正常健康受試者相比較是偏低的，特別是原發性修格連氏症的患者，但在合併其他如紅斑性狼瘡或類風濕性關節炎等次發性修格連氏症患者則無差異；在患者唾液腺腺體切片的研究上，Gas6蛋白質於腺體上的表現與正常健康受試者相比較是亦是偏低的。綜合我們的臨床研究結果與過去細胞、
動物實驗發現，Gas6蛋白質於原發性修格連氏症扮演非常重要的角色，或許調控Gas6系統的活性將成為未來另一種診斷或是新的治療方式。
Biomarkers development and its clinical application in systemic lupus
Erythematosus
Objective: Fever in systemic lupus erythematosus (SLE) can be caused by a number of
reasons, with infection and flare-up of the disease being the most common. This study
aimed at determining whether the ratio of the level of erythrocyte-bound C4d to that of
complement receptor 1 (C4d/CR1) can serve as a useful biomarker in the differentiation
between infection and flare-up in febrile SLE patients.
Materials and Methods: We enrolled febrile SLE patients and determined the
C4d/CR1 ratio on the day of admission. The patients were divided into 2 groups
according to the subsequent clinical course: 22 SLE patients with infection and 25 SLE
patients with flare-up and without infection. In addition, we enrolled 20 febrile patients
without SLE and 30 healthy controls.
Results: Among the febrile SLE patients, those with flare-up had higher C4d/CR1 ratios
and lower C-reactive protein (CRP) levels (range, 0.68–8.80 vs. 0.03–3.51; average,
3.34 ± 2.17 vs. 0.80 ± 0.91; p < 0.001 and range, 0.10–4.21 vs. 0.10–13.12; average,
0.85 ± 1.16 vs. 4.71 ± 3.40; p < 0.001, respectively) than those with infection. Cut-off
values of <1.2447 and >4.67 for C4d/CR1 ratio and CRP, respectively, were 40.91%
sensitive and 100.0% specific for the presence of infection in febrile SLE patients;
similarly, cut-off values of >1.2447 and <2.2, respectively, were 80% sensitive and
100% specific for the absence of infection in febrile SLE patients.
Conclusion: The C4d/CR1 ratio is a simple and quickly determinable biomarker that
enables the differentiation between infection and flare-up in febrile SLE patients at
initial evaluation. Further, when combined with the CRP level, it is useful to evaluate
disease activity in SLE patients with infection.
Study II: Biomarkers development and its clinical application in Sjögren Syndrome
Objective: Growth arrest-specific protein 6 (Gas6) is a vitamin K-dependent protein
expressed by endothelial cells and leukocytes that are involved in cell survival,
migration, and proliferation in response to inflammatory processes. The aim of this
study was to assess the implications of Gas6 in Sjögren syndrome (SS) and its
expression in the labial salivary gland.
Methods and Results: A total of 254 adults, including 159 with primary Sjögren
syndrome (pSS), 34 with secondary Sjögren syndrome (sSS), and 61 normal controls,
were recruited. Plasma Gas6 concentrations were determined, and Gas6 expressions in
labial salivary gland (LSG) tissues from controls and pSS and sSS patients were also
evaluated. Plasma Gas6 concentrations were significantly lower among patients with
pSS than normal controls (13.5 ± 8.6 vs. 19.9 ± 13.4 ng/ml, p < 0.001). There were,
however, no significant differences in plasma Gas6 levels between pSS and sSS patients
(13.5 ± 8.6 vs. 16.9 ± 11.2 ng/ml, p = 0.068). In multivariate logistic regression analysis,
after adjustment for white blood cell count, hemoglobin level, platelet count,
lymphocyte count, and C3 and C4 levels, lower plasma Gas6 concentrations were
significantly associated with an increased risk of SS. Moreover, by using a
semi-quantitative scale to evaluate Gas6 expression in LSG tissues, Gas6 expression
was found to be markedly lower in LSG tissues from pSS patients than in tissues from
normal controls.
Conclusion: Decreased plasma Gas6 concentration and LSG expression were
associated with pSS. As such, Gas6 may represent a novel independent risk factor for
pSS, with a potential role in salivary gland inflammation and dysfunction. |
