Supplementary Material for: Leukocyte Profile in Peripheral Blood and Neutrophil-Lymphocyte Ratio in Hidradenitis Suppurativa: A Comparative Cross-Sectional Study of 462 Cases

Background: Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease. Increasing evidence suggests that HS involves dysfunctional immune responses in both the adaptive and the innate immune system. The recently proposed association of HS with metabolic syndrome may further add to the inflammatory state in HS. Objective: To investigate the status of inflammation and leukocyte profile in the peripheral blood of HS patients. Materials and Methods: Using a comparative cross-sectional study design, we investigated blood samples of high-sensitivity C-reactive protein (hs-CRP) and leukocyte profile in hospital-treated HS patients (HS-HOSP), self-reported population-based HS patients (HS-POP) and population controls. Results: Our study comprised 32 individuals in the HS-HOSP group, 430 in the HS-POP group, and 20,780 controls. The median hs-CRP for the HS-HOSP group was 5.1 mg/l (quartile range 2.6-8.2), 2.2 mg/l (1.0-4.3) for the HS-POP group and 1.3 mg/l (0.7-2.9) for the controls. An age-sex-adjusted analysis revealed a significantly higher hs-CRP for both HS groups compared to controls (p < 0.0001). When performing age-sex-adjusted analysis, both HS groups had significantly higher odds of leukocytosis when compared to controls with an odds ratio for the HS-HOSP group of 4.38 (95% CI = 2.18-8.80; p < 0.0001) and 1.95 (95% CI = 1.58-2.42; p < 0.0001) for the HS-POP group. The age-sex-adjusted leukocyte differential count yielded significantly higher neutrophil (p < 0.0001) and monocyte (p = 0.0014, p = 0.0004) levels in the HS groups compared with controls. Conclusion: The hs-CRP levels associated with HS appear to be intermediate (2.2-5.1 mg/l), implying systemic inflammation rather than infection. The peripheral blood leukocytosis in HS was dominated by neutrophils and monocytes.

背景：化脓性汗腺炎（Hidradenitis suppurativa, HS）是一种慢性炎症性皮肤病。越来越多的研究证据表明，HS的发病与适应性免疫系统及先天免疫系统的功能异常密切相关。近期提出的HS与代谢综合征的关联，可能进一步加剧HS患者的炎症状态。
目的：探讨HS患者外周血的炎症指标与白细胞谱特征。
材料与方法：本研究采用对比横断面研究设计，对医院收治的HS患者（HS-HOSP）、自我报告的人群队列HS患者（HS-POP）及人群对照的血液样本，开展高敏C反应蛋白（high-sensitivity C-reactive protein, hs-CRP）与白细胞谱检测。
结果：本研究共纳入HS-HOSP组32例、HS-POP组430例，以及对照人群20780例。HS-HOSP组的hs-CRP中位数为5.1 mg/l（四分位间距2.6~8.2），HS-POP组为2.2 mg/l（1.0~4.3），对照组为1.3 mg/l（0.7~2.9）。经年龄-性别校正后的分析显示，两个HS组的hs-CRP水平均显著高于对照组（p < 0.0001）。经年龄-性别校正分析后发现，两个HS组出现白细胞增多的比值比均显著高于对照组：HS-HOSP组的比值比为4.38（95%置信区间：2.18~8.80；p < 0.0001），HS-POP组为1.95（95%置信区间：1.58~2.42；p < 0.0001）。年龄-性别校正后的白细胞分类计数结果显示，HS组的中性粒细胞与单核细胞水平均显著高于对照组（中性粒细胞p < 0.0001，单核细胞p=0.0014、p=0.0004）。
结论：与HS相关的hs-CRP水平处于2.2~5.1 mg/l的中间区间，提示机体存在系统性炎症而非感染。HS患者外周血白细胞增多以中性粒细胞与单核细胞为主。