依那西普血清水平与强直性脊柱炎患者疗效无相关性

De Vries MK, Wolbink GJ, et al. EULAR 2007. Present ID: FRI0382.

背景：我们最近的一研究显示AS的Infliximab无效者与Infliximab外周血水平低以及和出现Infliximab抗体有关。

目的：评价AS的Etanercept疗效是否也与Etanercept水平以及出现Etanercept抗体有关。

方法： 用Etanercept 25mg x2/周治疗AS患者。基线时、治疗第3和6月时，随机挑选患者采集血清。 ASAS疗效的定义：BASDAI分数出现50%相对变化或绝对改变超过2 cm。用ELISA测定Etanercept血清水平。用经典的抗原结合试验检测Etanercept抗体。将临床疾病活动度数据与血清 Etanercept水平进行相关分析。

结果：共纳入72例患者。治疗后有50例(69.4%)出现ASAS应答。第3、6 月时，Etanercept中位数水平为2.4 mg/l (范围：0～7.5, N=63)、2.9 mg/l (范围：0.8～5.4, N=57)。应对组与非应答组Etanercept水平无显著差异。BMI、ESR、CRP水平与Etanercept水平之间无相关性。未发现 Etanercept抗体。

结论：Etanercept治疗3月后，69% AS患者被判为治疗有效。应答组与非应答组之间的Etanercept血清水平相似。而且与之前研究发现Infliximab抗体明显不同的是，本研究未发现Etanercept抗体。

[FRI0382] NO DIFFERENCE IN ETANERCEPT LEVELS BETWEEN RESPONDERS AND NON-RESPONDERS IN PATIENTS WITH ANKYLOSING SPONDYLITIS TREATED WITH 25 MG ETANERCEPT TWICE A WEEK

M.K. de Vries ¹, G.J. Wolbink ², M.T. Nurmohamed ³, L.A. Aarden ⁴, S.O. Stapel ⁴, M.J.L. Peters ³, J.C. van Denderen ³, B.A.C. Dijkmans ¹, I.E. van der Horst-Bruinsma ¹. ¹Rheumatology, VU University Medical Center, ²Rheumatology, Sanquin Research, ³Rheumatology, Jan van Breemen Institute, ⁴Immunopathology, Sanquin Research, Amsterdam, Netherlands

Background: Recently we showed in patients with Ankylosing Spondylitis (AS), who were treated with infliximab, that non-response was correlated with undetectable infliximab levels and presence of antibodies to infliximab.
Objectives: To evaluate whether clinical response of AS to etanercept also correlates with etanercept levels, and the presence of antibodies to etanercept.
Methods: AS patients were treated with etanercept 25 mg twice weekly. Sera were collected randomly at baseline, after 3 and 6 months of treatment.
ASAS response was defined as 50% relative change of the BASDAI score or absolute change of 2cm.
Etanercept levels were measured by a newly developed ELISA, measuring binding of etanercept to TNFalpha. Antibodies to etanercept were measured with an antigen binding test and a classical two side assay. Clinical data were used to correlate disease activity with serum etanercept levels.
Results: 72 patients were included. After 3 months of treatment 50 patients (69.4%) were ASAS responders. Median etanercept levels were 2.4 mg/l (range 0-7.5, N=63) and 2.9 mg/l (range 0.8-5.4, N=57), after 3 and 6 months resp. No significant differences were found between the etanercept levels of responders and non-responders. No correlation was found between BMI, ESR, CRP levels and etanercept levels. No antibodies to etanercept were detected with any of the assays used.

Fig. 1. Mean etanercept levels (mg/l) and SD for ASA non-responders and responders after 3 months of treatment of AS with etanercept.

Conclusion: 69% of the patients was classified as responder after 3 months of treatment. Serum etanercept levels of responders and non-responders were similar. Moreover, no antibody formation against etanercept was detected in these patients which is in contrast with our prior study of infliximab in AS.

Citation: Ann Rheum Dis 2007;66(Suppl II):395
Session: Spondylarthropathies