Lu Zhimin, Li Jing, Ji Juan, Gu Zhifeng, Da Zhanyun
Department of Rheumatology, Affiliated Hospital of Nantong University, Nantong, People's Republic of China.
Braz J Med Biol Res. 2019;52(4):e8131. doi: 10.1590/1414-431X20198131. Epub 2019 Apr 15.
The leading cause of death in systemic lupus erythematosus (SLE) patients is infection. The objective of this study was to evaluate the distribution of lymphocyte subsets in untreated SLE patients with infections. This was a cross-sectional study. Data from January 2017 to May 2018 were collected. Flow cytometry was used to measure the peripheral lymphocyte subsets including CD3+T cells, CD4+T cells, CD8+T cells, CD19+B cells, CD3-CD16+CD56NK cells, and CD3+CD16+CD56NKT cells in 25 healthy controls and 52 treatment-naive SLE patients, among whom 13 were complicated with infections. Association between the lymphocyte subsets and infections was further analyzed. SLE patients with infections (n=13) showed a significantly higher incidence rate of fever (84.6 vs 28.2%) and serositis (84.6 vs 23.1%), increased level of erythrocyte sedimentation rate (60.5±30.1 vs 37.4±27.1 mm/h), serum C-reactive protein (CRP) (102.7±94.9 vs 9.4±14.9 mg/L), procalcitonin (PCT) (1.07±0.08 vs 0.16±0.13 μg/L), and lower blood hemoglobin (Hb) (93.0±20.5 vs 110.4±16.0 g/L) level compared with non-infection patients (n=39) (all P<0.05). In comparison with non-infectious SLE patients (387.9±261.6/μL), CD4+T cells count decreased significantly in infectious SLE patients (217.8±150.4/μL) (P<0.05), and it was negatively correlated with infection-related indicators including PCT (r=-0.573, P=0.041) and CRP (r=-0.596, P=0.032) levels. Our findings suggested that abnormalities of peripheral lymphocyte subsets were related to the immune disorder of lupus itself, regardless of immunosuppressive treatment. Monitoring lymphocyte subsets, especially CD4+T cells, may be helpful for identifying the presence of infection in SLE patients.
系统性红斑狼疮（SLE）患者的主要死因是感染。本研究的目的是评估未治疗的合并感染的SLE患者淋巴细胞亚群的分布情况。这是一项横断面研究。收集了2017年1月至2018年5月的数据。采用流式细胞术检测25名健康对照者和52名未接受过治疗的SLE患者外周血淋巴细胞亚群，包括CD3⁺T细胞、CD4⁺T细胞、CD8⁺T细胞、CD19⁺B细胞、CD3⁻CD16⁺CD56NK细胞和CD3⁺CD16⁺CD56NKT细胞，其中13名SLE患者合并感染。进一步分析淋巴细胞亚群与感染之间的关联。合并感染的SLE患者（n = 13）发热（84.6% 对28.2%）和浆膜炎（84.6% 对23.1%）的发生率显著更高，红细胞沉降率（60.5±30.1对37.4±27.1 mm/h）、血清C反应蛋白（CRP）（102.7±94.9对9.4±14.9 mg/L）、降钙素原（PCT）（1.07±0.08对0.16±0.13 μg/L）水平升高，血红蛋白（Hb）水平降低（93.0±20.5对110.4±16.0 g/L），与未感染患者（n = 39）相比差异均有统计学意义（均P < 0.05）。与未感染的SLE患者（387.9±261.6/μL）相比，合并感染的SLE患者CD4⁺T细胞计数显著降低（217.8±150.4/μL）（P < 0.05），且与PCT（r = -0.573，P = 0.041）和CRP（r = -0.596，P = 0.032）水平等感染相关指标呈负相关。我们的研究结果表明，外周血淋巴细胞亚群异常与狼疮本身的免疫紊乱有关，与免疫抑制治疗无关。监测淋巴细胞亚群，尤其是CD4⁺T细胞，可能有助于识别SLE患者是否存在感染。
