Clinical And Experimental Study Of Recombinant Human-murine Chimeric Anti-TNF Monoclonal Antibody (Infliximab) In The Treatment Of Ankylosing Spondylitis

Part I: Clinical Study of Loading Regimen Infliximab in Active Ankylosing SpondylitisObjective: (1) To evaluate the efficacy and safety of a loading regimen of the anti-tumour necrosis factor (TNF)-a antibody infiiximab in ankylosing spondylitis (AS) of 10 weeks. (2) To investigate the parameters predicting the clinical response to infiiximab in AS. (3) To understand the change of AS disease activity after a loading regimen infiiximab therapy in another 8 months follow up study.Methods: This was an open-labeled, 2 center, phase III clinical trial. Patients eligible for this study were to be adults with a diagnosis of definite AS, as defined by the 1984 Modified New York Criteria. Active disease at the time of screening was a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥ 4 and a visual analogue scale (VAS) score for spinal pain of ≥ 4, each on a scale of 0 to 10. Infiiximab 5 mg/kg was infused at weeks 0,2,6. All patients were followed up to 10 weeks.To analyses parameters predicting the clinical response to infiiximab in AS: Logistic regression liklihood ratio tests (univariate and multivariate) were performed to investigate which of the following paremeters assessed before treatment were associated with BASDAI50 and ASAS40 response: sex, age, disease duration, spinal inflammatory (questions 5 and 6 of the BASDAI), HLA-B27, BASDAI, BASFI, night pain, patient global assessment, BASMI, chest expansion, enthesis index (EI), presence of peripheral arthritis, ESR, CRP, Bath Ankylosing Spondylitis radiology Index (BASRI).After week10, patients were treated with conventional therapies. Those patients who attained an improvement of ≥ ASAS20 at week 10 were followed up to relapse or another 8 months. Relapse definitated as BASDAI reaching 3.5 again.The statistical tools used were the Cox's Proportionate Hazard Model and the logrank method. These were also used to test if there were any parameters at weekO.Rusults:1.Efficacy Results: At week 10, 84.3% of patients reached the primary end point of ASAS20. The percent of patients reaching the secondary endpoints of ASAS40 and BASDAI50 were 74.6% and 69.8% respectively. The improvements at week 10 of BASDAI, BASFI, BASMI, ESR/CRP were statistically significant.2.Safety Results: 21(33.33%) patients reported 43 treatment related adverse events, the most frequently occurring were upper respiratory tract infection and skin and it's appendages abnormal. The secondary occuring was abnormal liver function tests. Most treatment-related adverse events were mild to moderate in severity. Most of them resolved after discontinuation of infliximab. 3(4.76%) female patients had delayed hypersensitivity reactions, and 2 of them accompanied alopical. All of them resolved after anti-histamine and immunosuppressive agent therapy.3.Predicting Parameters Analysis Results: Univariatitc and multivariatic Logistic regression analysis showed none of the 15 parameters evaluated at week 0 including CRP/ESR, disease duration etc were predictive of the degree of improvement.4.Follow Up Study Results: Those patients who attained an improvement of >ASAS20 at week 10 were followed using a definition of relapse of BASDAIreaching 3.5 again. 87% of these patients relapsed within 8 months afterwards. The percent of patients who relapsed within 2, 3and 6 months were 25, 50 and 75 respectively. The statistical tools used were the Cox's Proportionate Hazard Model and the logrank method. These were also used to test if there were any parameters at weekO, which could predict a faster relapse. Remarkably, the mean BASDAI values before treatment was highly predictive (X~2= 8.5, P=0.0035).Conclusions:1. This study confirms the remarkable efficacy of infliximab in our country.2. Infliximab was safe and well tolerated, with no changes in the overall patterns, incidences, and types of adverse events observed previously except delayed hypersensitivity reactions in 3 famale patients.3. In our study, all of demographic parameters and baseline AS activity parameters were not predictors of major clinical response to infliximab in active AS.4. Most of them would relapse within 8 months afterwards. The BASDAI values before treatment was highly predictive of the rate of relapse.Part IIChanges of serum cytokines and T cell cytokines in ankylosing spondylitis during treatment with infliximabObjective: (1) To compare the changes of 11 cytokines of serum of ankylosing spondylitis (AS) before and after therapy with anti TNF - α monoclonal antibody infliximab and to evaluate the potential AS related discriminating cytokines and explor their meaning in diseases activity and possible link to therapy response; (2) To compare the changes of TNF- α,,IFN- γ and IL-4 secreted of T cells of AS before and after therapy with infliximab and to investigate the the effects and possible functional mechanism of infliximab on T lymphocyte subset in peripheral blood in AS.Methods (1) Eleven different serum cytokines were detected by using protein chip technique, then, serum IL-6 level and TNF- γ level were measured by sandwich enzyme-linked immunosorbent assay(ELISA) and TNF- α bioactivity were measured by bioassay. (2) Three-color flow cytometric analysis was employed for intracellular cytokines (TNF- α , IFN- γ and IL-4 ) and surface antigens(CD3, CD8) of T cell in the peripheral blood of AS patients.Results1. Eleven serum cytokines were investigated before and after treatment in 10patients treated with infliximab by using biochip technique. Compared with baseline, IL-6 level decreased and TNF- a level increased obviously. Other cytokines has no statistical changes among different phase of theray.2. Serum level of IL-6 was detected by ELISA. Compared with healthy group, IL-6 level increased obviously in AS (P<0.01). After treatment with infliximab, IL-6 level decreased at week 2 and maintained until week 10. Baseline serum IL-6 level had positive correction with AS disease activity index(night pain scores, ESR and CRP).3. Serum level of TNF- α was detected by ELISA and bioassiay. After treatment...