Ruiz-Irastorza Guillermo, Olivares Nerea, Ruiz-Arruza Ioana, Martinez-Berriotxoa Agustin, Egurbide Maria-Victoria, Aguirre Ciriaco
Department of Internal Medicine, Hospital de Cruces, University of the Basque Country, Pza Cruces s/n, Barakaldo, Bizkaia, Spain.
Arthritis Res Ther. 2009;11(4):R109. doi: 10.1186/ar2764. Epub 2009 Jul 15.
Infections commonly complicate the course of systemic lupus erythematosus (SLE). Our aim is to investigate the clinical predictors of major infections in patients with SLE.
A nested case-control study design was used within the prospective Lupus-Cruces cohort. The endpoints of the study were major infections. Cases were defined as patients with a major infection. Two controls (SLE patients without major infections), matched for time of follow-up until the event and age at diagnosis, were selected for each case. Univariate analysis and logistic regression models were used for the analysis of data.
Two hundred and forty-nine patients (83 cases, 166 controls) were selected. Eighty-three episodes of major infections were analyzed; E. coli, S. aureus, M. tuberculosis and S. pneumoniae being the most frequent isolates. Univariate analysis identified several variables related with infection: lung and renal involvement, at or previous to the study point; leukopenia at the study point; antiphospholipid antibody-positivity and treatment with prednisone within 3 months previous to the study point, and the dose of prednisone received. Treatment with antimalarials, on the other hand, showed a strong inverse association with major infections. Logistic regression models identified treatment with antimalarials (odds ratio (OR) = 0.06, 95% confidence interval (CI) = 0.02 to 0.18), prednisone dose (OR = 1.12, 95% CI = 1.04 to 1.19) and lung involvement (OR = 4.41, 95% CI = 1.06 to 18.36) as significant and independent predictors of major infections. No significant interactions among these three variables were found. Further adjustment for potential confounders related with antimalarial treatment did not change the results.
The risk of major infections in patients with SLE is mostly influenced by treatment. Prednisone treatment, even at moderate doses, increases the risk, whilst antimalarials have a protective effect.
感染常使系统性红斑狼疮（SLE）病情复杂化。我们的目的是研究SLE患者发生严重感染的临床预测因素。
在前瞻性的狼疮-克鲁塞斯队列中采用巢式病例对照研究设计。研究终点为严重感染。病例定义为发生严重感染的患者。为每个病例选择两名对照（无严重感染的SLE患者），根据事件发生前的随访时间和诊断时的年龄进行匹配。采用单因素分析和逻辑回归模型进行数据分析。
共选取249例患者（83例病例，166例对照）。分析了83次严重感染发作；最常见的分离菌株为大肠杆菌、金黄色葡萄球菌、结核分枝杆菌和肺炎链球菌。单因素分析确定了几个与感染相关的变量：在研究时间点或之前出现的肺部和肾脏受累；研究时间点的白细胞减少；抗磷脂抗体阳性以及在研究时间点前3个月内使用泼尼松治疗，以及泼尼松的剂量。另一方面，抗疟药治疗与严重感染呈强烈负相关。逻辑回归模型确定抗疟药治疗（比值比（OR）=0.06，95%置信区间（CI）=0.02至0.18）、泼尼松剂量（OR = 1.12，95% CI = 1.04至1.19）和肺部受累（OR = 4.41，95% CI = 1.06至18.36）是严重感染的显著且独立预测因素。未发现这三个变量之间有显著的相互作用。对与抗疟药治疗相关的潜在混杂因素进行进一步调整后，结果未改变。
SLE患者发生严重感染的风险主要受治疗影响。泼尼松治疗，即使是中等剂量，也会增加风险，而抗疟药具有保护作用。
