類風濕關節炎患者接受生物製劑及口服小分子標靶藥物後產生之嗜酸性球增多症

The emergence of eosinophilia in patients with rheumatoid arthritis receiving therapy with biological agents or JAK inhibitor

目的：探討類風濕關節炎患者使用生物製劑及口服小分子標靶藥物後，是否會產生嗜酸性球增多症，並探討產生嗜酸性球增多症之風險因素。方法：蒐集2003年8月至2019年6月間，於中國醫藥大學附設醫院接受生物製劑及口服小分子標靶藥物治療之類風濕性關節炎患者，以回溯性方式分析在使用藥物前以及使用藥物後的第24週，臨床特性上的差異，以及出現嗜酸性球增多症（定義為血液中嗜酸性球數量≥500／μL）族群之特性。結果：本研究納入278例類風濕性關節炎患者用藥人次，平均年齡為54.5歲，其中有229位女性（82.4%）。有7位患者（2.52%）在用藥第24週出現嗜酸性球增多症，這7位患者都是接受生物製劑安挺樂（Tocilizumab）之治療。他們的特性是在用藥前的腎絲球過濾率較低（66.43 vs 97.6，p＜0.05）。在治療後，患者之平均紅血球沉降速率（ESR）及高敏感C-反應蛋白（hsCRP）改善、而平均之血液中嗜酸性球數量增加。結論：在本研究中顯示，部分使用生物製劑及口服小分子標靶藥物之類風濕關節炎患者會產生嗜酸性球增多症，尤其當使用生物製劑安挺樂（Tocilizumab）治療時更為顯著。

Introduction: This study was designed to investigate the occurrence of eosinophilia after the use of biological agents or JAK inhibitor therapies in patients with rheumatoid arthritis (RA); risk factors and associated events were analyzed. Methods: We retrospectively reviewed the medical records of RA patients treated with biological agents or JAK inhibitor between August 2003 and June 2019 at China Medical University Hospital. The presence of eosinophilia was defined as an absolute eosinophil count of ≥500/μL. Clinical characteristics and laboratory data at baseline and at week 24 after therapy with biological agents or JAK inhibitor were analyzed. Results: The mean age of the 278 patients (229 women, 82.4%) with RA was 54.5±11.85 years. Seven patients (2.52%) showed eosinophilia at week 24 after therapy with biological agents or JAK inhibitor. All 7 patients who developed eosinophilia received therapy with Tocilizumab compared with the other biologics (p<0.05). The occurrence of eosinophilia was associated with lower baseline eGFR compared with those with normal renal function (66.43 vs. 97.6, p<0.05). Both ESR and hsCRP declined and the absolute eosinophil count was elevated after treatment. Conclusions: A proportion of RA patients receiving biological agents resulted in eosinophilia, especially those treated with Tocilizumab.