Department of Rheumatology and Immunology, The Second Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China.
Department of Medical Research, Chung Shan Medical University Hospital, Taichung City, Taiwan, Taiwan.
Ann Rheum Dis. 2020 Jun;79(6):793-799. doi: 10.1136/annrheumdis-2020-217013. Epub 2020 Apr 2.
Idiopathic thrombocytopenic purpura (ITP) may play a role in early-stage systemic lupus erythematosus (SLE). The incidence of SLE in patients with ITP and the potential relationship between them is still unclear. This study was performed to provide epidemiological evidence regarding the relationship between ITP and SLE occurrence.
In this population-based retrospective cohort study, the risk of SLE was analysed in a cohort of patients newly diagnosed with ITP between 2000 and 2013. Controls were selected at a 1:2 ratio through propensity score matching (PSM) using the greedy algorithm. The Cox proportional hazard model was used to analyse the association between ITP and SLE incidence. There were four different Cox regression models, and the sensitivity analyses were implemented to evaluate the HR of SLE after exposure with ITP.
In the age-matched and sex-matched ITP and non-ITP cohort, the average follow-up time was about 80 months in this study. There were 34 (4.70%) and 27 (0.19%) incident cases of SLE in ITP and non-ITP group. The incidence rates were 62.0 (95% CI 44.3 to 86.8) and 2.10 (95% CI 1.44 to 3.06), respectively. The adjusted HR of incidental SLE in the ITP group was 25.1 (95% CI 13.7 to 46.0). The other risk factors for SLE were female sex and Sjogren's syndrome. After PSM, the incidence rate and Kaplan-Meir curves of SLE were consistent with the results for the age-matched and sex-matched population, the HR 17.4 (95% CI 5.28 to 57.4) was estimated by conditional Cox model.
This cohort study demonstrated that patients with ITP have a higher risk of SLE. Clinically, patients with ITP should be monitored for incidental lupus.
特发性血小板减少性紫癜（ITP）可能在早期系统性红斑狼疮（SLE）中起作用。ITP 患者中 SLE 的发病率以及它们之间的潜在关系尚不清楚。本研究旨在为 ITP 与 SLE 发生之间的关系提供流行病学证据。
在这项基于人群的回顾性队列研究中，分析了 2000 年至 2013 年间新诊断为 ITP 的患者队列中 SLE 的发病风险。通过使用贪婪算法进行倾向评分匹配（PSM），以 1:2 的比例选择对照。使用 Cox 比例风险模型分析 ITP 与 SLE 发生率之间的关联。有四个不同的 Cox 回归模型，进行了敏感性分析以评估暴露于 ITP 后 SLE 的 HR。
在年龄匹配和性别匹配的 ITP 和非 ITP 队列中，本研究的平均随访时间约为 80 个月。ITP 和非 ITP 组分别有 34 例（4.70%）和 27 例（0.19%）SLE 发病病例。发病率分别为 62.0（95%CI 44.3 至 86.8）和 2.10（95%CI 1.44 至 3.06）。ITP 组意外 SLE 的调整后 HR 为 25.1（95%CI 13.7 至 46.0）。SLE 的其他危险因素为女性和干燥综合征。PSM 后，SLE 的发病率和 Kaplan-Meier 曲线与年龄匹配和性别匹配人群的结果一致，条件 Cox 模型估计 HR 为 17.4（95%CI 5.28 至 57.4）。
本队列研究表明，ITP 患者发生 SLE 的风险更高。临床上，应监测 ITP 患者的狼疮意外发作。
