AB0470 EXPERIENCE WITH THE USE OF INTERLEUKIN 6 INHIBITOR IN SEVERE ANKYLOSING SPONDYLITIS

Abstract

Background:Inhibitors of interleukin 6 (IL6) have been found to be ineffective in ankylosing spondylitis (AS) based on the results of randomized clinical trials (RCTs) on tocilizumab (TCZ) and sarilimumab [1, 2]. However, there is evidence that IL6 is actively involved in the pathogenesis of the disease [3]. In addition, the efficacy of IL6 inhibitors has been shown in patients with secondary AA amyloidosis [4].Objectives:to analyze the effectiveness of IL6 inhibitor - TCZ in patients with AS with high disease activity and secondary AA-amyloidosis.Methods:The analysis included 10 patients with AS receiving TCZ therapy, of which 8 (80%) men, 2 (20%) women, and 100% HLA B27 positive. The average age of the patients was 40 ± 8.6 years, the average age of disease onset was 13.4 ± 7.5 years, the average duration of AS was 25.6 ± 6.5 years. 9 patients had histologically confirmed secondary AA-amyloidosis: 100% had kidney amyloidosis, 6 (66.6%) patients also had gastrointestinal amyloidosis and 3 (33.4%) patients had heart amyloidosis. All patients had arthritis and coxitis.Results:As the first biological drug, TCZ was prescribed to 2 patients due to the presence of manifestations of secondary AA-amyloidosis, and 8 patients had previous experience of treatment with one or more inhibitors of tumor necrosis factor-α (TNF-α). The average duration of TCZ treatment was 22.0 months [1.0; 36.0]. 8 (80%) patients continue to take TCZ therapy to date, and 2 (20%) - are transferred to TNF-α inhibitors. Table 1 shows the main clinical and laboratory characteristics of patients at the initiation of TCZ therapy and during the last hospitalization at the V.A. Nasonova Research Institute of Rheumatology. As you can see, against the background of TCZ therapy, both the level of CRP, proteinuria and the indices of AS activity (BASDAI, ASDAS CRP) significantly decreased. The number of patients with inflammatory back pain (IBP), arthritis and coxitis also decreased significantly.Table 1.The main clinical and laboratory characteristics of patients at the initiation and after of TCZ therapy.Before TCZAfter TCZрCRP, Ме [25‰; 75‰], mg/l95.2 [52.2; 189.0]10,8 [0.8; 8.0]р<0,05Proteinuria, Ме [25‰; 75‰], g/day.1,6 [1,0; 2,1]0,08 [0; 0,3]р<0,05BASDAI, Мean (SD)6,1 (1,6)3,3 (0,9)р<0,05ASDAS CRP, Мean (SD)4,3 (1,1)2,2 (0,7)р<0,05IBP, N (%)10 (100%)2 (20%)р<0,05Arthritis, N (%)10 (100%)2 (20%)р<0,05Cocxitis, N (%)10 (100%)5 (50%)р<0,05Enthesitis, N (%)7 (70%)6 (60%)р>0,05Conclusion:The above data showed that the method of treating AS with IL6 inhibitors, in certain clinical situations, primarily such as ineffectiveness of TNF-α inhibitors, high CRP level and the development of secondary AA-amyloidosis, can be highly effective. Therefore, it is advisable to continue the set of clinical observations on the treatment of especially severe patients with AS treated with non-standard methods.