| Abstract: | 前言
僵直性脊椎炎，好發於16至40歲的成年人，男女比例約為3：1。估算台灣僵直性脊椎炎的盛行率則約為0.2~0.4 %。一般醫師普遍缺乏早期診斷此病與正確治療的能力，病人常被延誤診斷與治療。因此，目前重要的課題是促進民眾的認識，並提昇醫師診斷的警覺，同時加強致病機轉與遺傳免疫學的了解，突破診斷與治療的盲點，這些任務，相當程度地有賴於建立一個「僵直性脊椎炎病人資料庫」。
研究目的
1.建立台灣「僵直性脊椎炎病人資料庫」。
2.建立台灣版「僵直性脊椎炎臨床評估問卷」之信效度。
3.分析台灣僵直性脊椎炎病人資料庫之臨床流行病學、血中發炎指標及HLA基因型分析。
材料與方法
1.病人來源：取得人體試驗委員會核可及受試者同意書，自民國93年1月至95年12月至中山醫學大學附設醫院就診之871位僵直性脊椎炎病患及60位年齡性別相符之健康成人為對照組。僵直性脊椎炎之診斷定義依1984年之Modified New York criteria。
2.資料庫內容：所有僵直性脊椎炎初診病患皆需建立初診問卷，複診病患於抽血追蹤疾病病程之同時填寫複診問卷，含僵直性脊椎炎臨床評估量表BASDAI、BASFI及BAS-G。同時抽取周邊靜脈血液後2小時內需分離血清及周邊血液單核球，血清立刻保存於攝氏-80℃之冰箱內；周邊血液單核球保存於液態氮內；DNA、RNA保存於攝氏-20℃之冰箱內。部分病人之關節滑膜、關節液及肌腱附著點保存於攝氏-80℃之冰箱內。
3.血中發炎指數及細胞激素分析：ESR 以Westergren毛細管法測量，IgA、CRP及HS-CRP皆以Nephelometry測量；血清細胞激素檢驗TNF-α、IL-8及MMP-3以commercial ELISA kits分析。
4.HLA基因型及亞型鑑定：分析國內41名 HLA-B27 陰性的僵直性脊椎炎患者，以淋巴細胞毒殺法鑑定HLA-ABC之全基因，比對捐血中心11383名正常捐血者的基因。部份HLA-B27陽性之病患以聚合脢連鎖反應法-序列特異性核
Backgrounds.
Ankylosing Spondylitis (AS) is a chronic inflammatory autoimmune disease involving spine, peripheral joints, enthesis, and sometimes visceral organs. The prevalence of AS is estimated about 0.2~0.4%. Unfortunately, most AS Patients were mis-diagnosed and under-treated due to their unrecognized disease conditions.
Genetics of AS is highly related to a human leukocyte antigen, HLA-B27. The frequency of HLA-B27 in the Chinese population is 4%-9%. Basic science of AS was not well understood, but the immunology and treatment of AS have achieved great advances in the past few years. There are still many unmet needs in the pathogenesis and management of AS.
There are still no useful or specific biomarkers for AS. For clinical evaluation, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Bath Ankylosing Spondylitis Global Score (BAS-G) have been well accepted for evaluating function and disability in patients with ankylosing spondylitis (AS). However, there is no validated Chinese version of these instruments yet.
Hence, a comprehensive AS database including clinical parameters and tissue samples is crucial and essential for future researches in Taiwan.
Purposes.
1.To establish a database of clinical information as well as tissue samples in patients with AS in Taiwan.
2.To validate the Chinese version of BASDAI, BASFI and BAS-G indices.
3.To analyze epidemiological, genetic and serological parameters using this database.
Methods.
During Jan 2002 to Dec 2006, we created and performed a comprehensive questionnaire for every first visit AS patients in Chung Shan medical university. Serum were separated within 2 hours and stocked into -80 degree. Peripheral blood mononuclear cells (PBMC) were separated and stored in liquid nitrogen. DNA and RNA were extracted and stocked into -20 degree refrigerators.
Psochometric validation of the Chinese version of Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Bath Ankylosing Spondylitis Global Index (BAS-G) were performed. The Bath indices and physical examination parameters were evaluated simultaneously when blood samples were obtained.
For AS patients with positive HLA-B27, subtyping for 12 subtypes was done by PCR-SSO methods. For AS patients with negative HLA-B27, complete HLA-ABC typing was done by lymphocytotoxicity assay. Erythrocyte sedimentation rate (ESR), Hypersensitive C-reactive protein (HS-CRP) and Immunoglobulin A (IgA) were measured and compared the Bath clinical indices.
Statistics: SAS for Windows was used for the statistical analyses. Comparisons were made using Student’s t-test for continuous variables and the c2 test for discrete variables. Reliability of our Chinese versions of the BASDI, BASFI, and BAS-G was tested by internal consistency and test-retest reliability. Internal consistency of the instrument was given as Cronbach’s alpha. Test-retest reliability was assessed by intraclass correlation coefficient. Correlations between BASDAI, BASFI, and BAS-G with laboratory and clinical assessments were also evaluated with Spearman’s rank correlation coefficient. For the case-control study, phenotype frequencies between patients and controls were assessed by the uncorrected c2 test. Haplotype frequencies in the control samples were determined using the program ‘Phase’. Only haplotypes with >90% probability were considered in linkage disequilibrium calculations. The presence of significant linkage disequilibrium was tested using Fisher’s exact test. Significance was set at p<0.05.
Results.
Since Jan 2002, an Taiwan AS database with 2647 samples from AS patients, including 982 first-visit patients, 130 Peripheral mononuclear cell samples with RNA and 932 DNA samples were collected.
The reliability of three Bath instruments—the BASDAI, BASFI, and BAS-G—for a 24-hours test-retest showed acceptable intraclass correlation coefficients (0.92-0.94). Our Chinese versions of the BASDAI, BASFI, and BAS-G also showed 0.87, 0.94, and 0.90, respectively, with Cronbach’s alpha coefficient, indicating good reliability.
In this AS database, mean age was 34.41 ± 11.23 and delay diagnosis time lag was 5.17 ± 7.39 years. Sex ratio (M:F) was around 3:1. Average BASDAI was 3.92 ± 2.23, BASFI 2.12 ± 2.19 and BAS-G 4.17 ± 2.81 cm in 10-cm scale. Less than 40% of AS patients were regularly treated.
Peripheral arthritis was found in 65.75％ of patients, uveitis in 23.03％ and psoriasis in 14.82.
61.38% of AS patients are disease-active and 27.67% are functional disabled. Less than 40% of first visit AS patients were under regular treatment.
Significant correlations were demonstrated between BASDAI and BASFI, BASDAI and BAS-G, and BASFI and BAS-G, respectively. When comparing the scores of BASDAI (4.1 v 3.9), BASFI (2.5 v 1.9), and BAS-G (4.5 v 3.9), higher scores of BASDAI, BASFI, and BAS-G were observed in the juvenile onset disease (JAS) group than in the adult onset disease (AAS) group.
Major HLA-B27 subtype of AS patients in Taiwan was B2704 (89%) and B2705 (11%), different from B2705 in the Caucasians. For HLA-B27 negative AS, we found significant high ratio of HLA-B60 (68.3% vs 38.0%, OR=3.5, 95% CI 1.8 to 6.8, p<0.001) and B61 gene (OR 19.2 , 95% CI 9.5 to 38.9, p<0.001)
ESR, CRP, HS-CRP and IgA all correlate well with BASDAI, BASFI and BAS-G index. MMP-3 is a potential useful biomarker to predict AS activity. Plasma Hcy level increased significantly in AS patients under sulfasalazine (10.4 ±3.8 mmol/L, p<0.05), MTX (11.9 ±4.7, p<0.05) and sulfasalazine/MTX combination treatment (11.2 ±2.6, p<0.05) when compared with normal controls (8.6 ±1.2 mmol/L) and AS patients without DMARD(9.4 ± 2.6 mmol/L). No correlation between disease activity and plasma Hcy level was found. Daily supplement of vitamin B-12 0.5 mg, B-6 50 mg and folic acid 5 mg can lower Hcy level in 2 weeks (32.3 ± 24.0 vs. 15.6 ± 11.1 mmol/L, p=0.007 ).
Conclusions.
Our Chinese versions of the BASDAI, BASFI, and BAS-G showed adequate reliability, validity, and responsiveness to clinical change. Among this 2592 AS patients’ database, male to female ratio was around 3:1.Average duration of delayed diagnosis was 5.17 years. Peripheral arthritis was found in 65.75％ of patients, uveitis in 23.03％ and psoriasis in 14.82. In this database, 61.38% of AS patients are disease-active and 27.67% are functional disabled. Less than 40% of first visit AS patients were under regular treatment. ESR, HS-CRP, IgA and MMP-3 were all useful biomarkers in AS. Plasma homocysteine level increased significantly in AS patients because of sulfasalazine and methotrexate treatment. Daily supplement of vitamin can lower homocysteine level in 2 weeks. We had established a comprehensive clinical and tissue database of AS in Taiwan. This database can be used for further researches, medical practice and education. |
