Spondyloarthritis in China

Genetics of Ankylosing Spondylitis-Focusing on the Ethnic Difference Between East Asia and Europe

Ankylosing spondylitis (AS) is a common, highly heritable inflammatory arthritis affecting the mainly axial joints in both East Asia and Europe. To date, the pathogenesis of AS is still unknown, although we know that genetics play a vital role in it. The HLA-B27 allele is found in over 85% of AS patients. However, strong evidence suggests that other major histocompatibility complex (MHC) and non-MHC genes are also involved in the pathogenesis. In addition, current data showed that there were significant differences in both genomics and metagenomics among the different ethnic populations. The investigation of the key role of the microbiome in AS pathogenesis also highlighted the host–microbiome genetic interactions. Here, we systematically review current AS genetic research data and further compare genetic differences, especially between East Asian and European groups, which may highlight the challenge in future genetic studies.

Cross-cultural adaptation and validation of the Chinese version of the Health Assessment Questionnaire for the Spondyloarthropathies (HAQ-S)

The Health Assessment Questionnaire for Spondyloarthropathies (HAQ-S) is a commonly used questionnaire to evaluate function and health status of patients with ankylosing spondylitis (AS). The objective of this study was to cross-culturally adapt the HAQ-S into Chinese and then to evaluate its reliability and validity. The Chinese version of the HAQ-S was obtained with a five-step procedure of translation and cross-cultural adaptation. All invited patients met the New York criteria for AS, and a total of 103 patients finally participated in this study. Intraclass correlation coefficient (ICC) was used to evaluate the test-retest and inter-rater reliability of the HAQ-S. Internal consistency of the questionnaire was evaluated by Cronbach's alpha coefficient. Spearman's correlation coefficient was calculated to assess the construct validity between the HAQ-S and Bath AS Disease Activity Index (BASDAI), Bath AS Functional Index (BASFI), Bath AS Metrology Index (BASMI), and the laboratory parameters (erythrocyte sedimentation rate, ESR; C-reactive protein, CRP). Test-retest and inter-rater reliability were excellent with intraclass correlation coefficients of 0.987 (p < 0.05) and 0.982 (p < 0.05), respectively. The overall internal consistency of the HAQ-S was found satisfactory (Cronbach's alpha = 0.914). The Chinese version of the HAQ-S correlated good with the BASFI (r = 0.749, p < 0.01), and moderate with the BASDAI (r = 0.581, p < 0.01) and the BASMI (r = 0.425, p < 0.01). But, the adapted questionnaire correlated poorly with ESR (r = 0.298, p < 0.01) or CRP (r = 0.283, p < 0.01). The Chinese version of the HAQ-S is reliable and valid for the evaluation of Chinese-speaking patients with AS.

Kunxian capsules in the treatment of patients with ankylosing spondylitis: a randomized placebo-controlled clinical trial

Background

Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease. Kunxian capsule, a Chinese patent medicine which has been used in the treatment of immunologic diseases for many years in China, has anti-inflammatory and immunoregulatory effects. This study investigates the efficacy and safety of Kunxian capsules in the treatment of AS.

Method

This was a randomized, double-blind, parallel control clinical trial involving 80 patients with AS who fulfilled the modified New York criteria (1984) and had active disease defined by a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) ≥40 mm under background stable nonsteroidal anti-inflammatory drugs (NSAIDs) for more than 4 weeks. Patients were randomly divided into two groups, the Kunxian group and the placebo group, and Kunxian (0.6 g, three times per day) and the placebo were provided for 12 weeks. The primary endpoint was the Assessment of SpondyloArthritis international Society (ASAS) 20 response rate at week 12. The secondary endpoints were ASAS 40, BASDAI 50, the Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), and Ankylosing Spondylitis Disease Activity Score on the basis of C-reactive protein level (ASDAS-CRP) at weeks 2, 6, and 12.

Results

The primary endpoint of ASAS 20 at week 12 was achieved in 13 of 35 patients (37.1 %) among the Kunxian group, compared with 4 of 33 (12.1 %) in the placebo group (p < 0.05). Significant improvement (BASDAI 50) was also observed between the Kunxian group and the placebo group at week 6 (14 (40 %) and 5 (15.5 %), respectively, p < 0.05). At weeks 2, 6, and 12, the ASDAS-CRP level of the Kunxian group was significantly lower than that of the placebo group, especially at week 6 (p < 0.01). Kunxian obviously reduced CRP levels compared to placebo at weeks 2, 6, and 12 (p < 0.05). Compared with the placebo, Kunxian was associated with greater improvements in signs and symptoms of patients with AS from the baseline to week 12, and significant intergroup differences of additional composite indices of disease activity (i.e., erythrocyte sedimentation rate, patient global assessment of disease activity, total back pain, level of morning stiffness, tender joints, and BASFI scores) were also observed.

Conclusion

Kunxian capsule significantly decreased the disease activity of patients with AS.

Trial registration

NCT00953979. Registered on 5 August 2009.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1438-6) contains supplementary material, which is available to authorized users.