血液羥氯奎寧濃度與全身性紅斑狼瘡復發率的相關性：台灣單一醫學中心的前導研究

Correlation of hydroxychloroquine blood levels and flare risk in patients with systemic lupus erythematosus in Taiwan: a pilot study in a tertiary medical center

目的：研究羥氯奎寧血液濃度和單位體重劑量之間的關聯性，並評估其對長期治療患者全身性紅斑狼瘡復發風險的影響。
方法：我們以回顧性研究的方式收集了接受羥氯奎寧血液檢測的全身性紅斑狼瘡患者的數據。使用修改版的SELENA-SLEDAI復發指數（modified SELENA-SLEDAI flare index, mSFI）記錄臨床特徵和復發事件。最後，我們分析了這些復發事件與羥氯奎寧血液濃度或單位體重劑量之間的相關性。
結果：共有39名全身性紅斑狼瘡患者被納入分析，我們收集了這些病人自疾病初診斷至2020年12月的病歷資料。單位體重劑量和血液濃度之間的相關係數為0.24。根據單位體重劑量分組的患者，在復發事件（p=0.6）、嚴重復發事件（p=0.6）、全因素住院（p>0.9）或感染（p=0.6）方面沒有顯著差異。根據血液濃度分組的患者，相較於血液濃度低的組（<1,200 ng/mL），血液濃度高的組（≥1,200 ng/mL）的復發事件（p<0.001）和嚴重復發事件（p<0.001）明顯減少。兩組在全因素住院（p=0.7）和感染（p=0.2）方面相似。
結論：在台灣人口中，測量全身性紅斑狼瘡患者的羥氯奎寧血液濃度可能在改善疾病控制方面扮演著一定的角色。

Objective: Investigate the link between hydroxychloroquine (HCQ) blood levels and weight-based dosing and assess its impact on systemic lupus erythematosus (SLE) flare risk in long-term treated patients.
Methods: We retrospectively gathered data on patients with SLE who underwent testing for HCQ blood levels. Clinical characteristics and flare events were recorded using the modified Safety of Estrogens in Lupus National Assessment (SELENA)-Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) flare index (mSFI). Finally, we analyzed the correlation between these flare events and the HCQ blood levels or weight-based dosing.
Results: Thirty-nine patients with SLE were included in the analysis. Clinical data were collected from the time of diagnosis until 31th December, 2020. Correlation coefficient between weight-based dosing and blood levels was 0.24. There were no significant differences observed in flare events (p=0.6), severe flare events (p=0.6), hospitalizations due to any cause (p>0.9), or infections (p=0.6) among patients grouped by weight-based dosing. If grouped by blood levels, there was a significant decrease in flare events (p<0.001) and severe flare events (p<0.001) in the high blood level group (≥1,200 ng/mL), compared to the group with low blood levels (<1,200 ng/mL). Hospitalizations due to any cause (p=0.7) and infections (p=0.2) were similar in both groups.
Conclusions: This study represents the first investigation of HCQ blood levels in the Taiwanese population, and it suggests that higher levels of HCQ in the blood may provide protection against disease flare-ups. Therefore, monitoring HCQ blood levels in patients with SLE could potentially improve disease management.