Nephrology Department, Centro Hospitalar de VilaNova de Gaia/Espinho, Vila Nova de Gaia, Portugal.
Nephrology Department, Christian Medical College Vellore, Vellore, Tamilnadu, India.
Nephrol Dial Transplant. 2018 Sep 1;33(9):1604-1610. doi: 10.1093/ndt/gfx318.
Hydroxychloroquine (HCQ) is a recommended drug in systemic lupus erythematosus (SLE). It has a long terminal half-life, making it an attractive target for therapeutic drug monitoring. The aim of this study was to establish a relationship between blood HCQ concentration and lupus nephritis activity.
We conducted a retrospective observational study with data collected from clinical and laboratory records. Inclusion criteria were patients followed in the lupus clinic with biopsy-proven International Society of Nephrology/Renal Pathology Society Classes III, IV or V lupus nephritis on HCQ for at least 3 months (200-400 mg daily) and with HCQ levels measured during treatment. Exclusion criteria were patients on renal replacement therapy at baseline or patients lost to follow-up.
In 171 patients, the HCQ level was measured in 1282 samples. The mean HCQ blood level was 0.75±0.54mg/L and it was bimodally distributed. An HCQ level <0.20 mg/L [232 samples (18.1%)] appeared to define a distinct group of abnormally low HCQ levels. For patients in complete or partial remission at baseline compared with those remaining in remission, patients with renal flare during follow-up had a significantly lower average HCQ level (0.59 versus 0.81 mg/L; P= 0.005). Our data suggest an HCQ target level to reduce the likelihood of renal flares >0.6 mg/L (600 ng/mL) in those patients with lupus nephritis.
HCQ level monitoring may offer a new approach to identify non-adherent patients and support them appropriately. We propose an HCQ minimum target level of at least 0.6 mg/L to reduce the renal flare rate, but this will require a prospective study for validation.
羟氯喹 (HCQ) 是系统性红斑狼疮 (SLE) 的推荐药物。它具有较长的终端半衰期，因此成为治疗药物监测的有吸引力的目标。本研究的目的是建立血液 HCQ 浓度与狼疮肾炎活动之间的关系。
我们进行了一项回顾性观察性研究，数据来自临床和实验室记录。纳入标准为在狼疮诊所接受至少 3 个月（每日 200-400mg）HCQ 治疗且治疗期间测量 HCQ 水平的活检证实为国际肾脏病学会/肾脏病理学会 III、IV 或 V 级狼疮肾炎的患者。排除标准为基线时接受肾脏替代治疗或失访的患者。
在 171 名患者中，共测量了 1282 个 HCQ 水平样本。HCQ 血药浓度的平均值为 0.75±0.54mg/L，呈双峰分布。HCQ 水平<0.20mg/L（232 个样本[18.1%]）似乎定义了一组明显异常低的 HCQ 水平。与基线时仍处于缓解期的患者相比，在随访期间出现肾脏复发的患者平均 HCQ 水平显著较低（0.59 与 0.81mg/L；P=0.005）。我们的数据表明，对于狼疮肾炎患者，HCQ 目标水平为>0.6mg/L（600ng/mL）可降低肾脏复发的可能性。
HCQ 水平监测可能为识别不依从患者并提供适当支持提供一种新方法。我们建议 HCQ 的最低目标水平至少为 0.6mg/L，以降低肾脏复发率，但这需要前瞻性研究验证。
