Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
QJM. 2013 May;106(5):451-7. doi: 10.1093/qjmed/hct046. Epub 2013 Mar 4.
Hematological abnormalities, particularly lymphopenia, are common in patients with systemic lupus erythematosus (SLE), whether the disease is active or not. The aim of this study is to assess whether lymphopenia (blood counts ≤1000 K/µl) is a risk factor for severe infections in patients with SLE.
A retrospective case-control study was performed. We reviewed the clinical records of 167 SLE patients throughout a 5-year period. SLE patients with severe infections were compared with those without infection and the presence of lymphopenia was obtained from the blood count previous to the infection date. Also, other clinical and laboratory features as well as immunosuppressive therapy and SLE disease activity index (SLEDAI) were recorded.
Univariate analysis shows multiple risk factors for severe infections in SLE, such as lymphopenia, high SLEDAI index, prednisone (PDN) and mycophenolate mofetil treatment and low levels of C3 and C4. Moreover, hydroxychloroquine treatment conferred protection. However, after multivariate analysis, only lymphopenia [odds ratio (OR) 5.2, 95% confidence interval (CI) 2.39-11.3], PDN treatment (OR 4.8, 95% CI 2.1-11.9) and low levels of C3 (OR 2.97, 95% CI 1.1-7.9) remained as independent risk factors.
Our data suggest that lymphopenia, PDN treatment and low levels of C3 are independent risk factors for the development of severe infections in SLE patients, including diverse microorganisms, not only opportunistic infections.
无论系统性红斑狼疮（SLE）患者的疾病是否活跃，血液学异常，尤其是淋巴细胞减少症，都很常见。本研究旨在评估淋巴细胞减少症（血细胞计数≤1000 K/µl）是否是 SLE 患者发生严重感染的危险因素。
进行了一项回顾性病例对照研究。我们回顾了 5 年内 167 例 SLE 患者的临床记录。将 SLE 合并严重感染患者与无感染患者进行比较，并从感染前的血常规中获得淋巴细胞减少症的存在情况。此外，还记录了其他临床和实验室特征以及免疫抑制治疗和 SLE 疾病活动指数（SLEDAI）。
单因素分析显示，SLE 患者发生严重感染的多种危险因素，如淋巴细胞减少症、高 SLEDAI 指数、泼尼松（PDN）和霉酚酸酯治疗以及 C3 和 C4 水平降低。此外，羟氯喹治疗可提供保护。然而，多因素分析后，仅淋巴细胞减少症[比值比（OR）5.2，95%置信区间（CI）2.39-11.3]、PDN 治疗（OR 4.8，95%CI 2.1-11.9）和 C3 水平降低（OR 2.97，95%CI 1.1-7.9）仍然是独立的危险因素。
我们的数据表明，淋巴细胞减少症、PDN 治疗和 C3 水平降低是 SLE 患者发生严重感染的独立危险因素，包括多种微生物，而不仅仅是机会性感染。
