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。越来越多的证据表明，HS 涉及适应性免疫系统与固有免疫系统的免疫功能异常。近期提出的 HS 与代谢综合征的关联，可能进一步加重 HS 患者的炎症状态。

研究目标：本研究旨在探讨 HS 患者外周血的炎症状态与白细胞谱特征。

材料与方法：本研究采用对比性横断面研究设计，对住院治疗的 HS 患者（HS-HOSP 组）、自我报告的人群队列 HS 患者（HS-POP 组）以及人群对照者的血液样本，开展了高敏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 20780 名对照者。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）。同样经年龄-性别校正后，两个 HS 组出现白细胞增多症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，与对照组相比，两个 HS 组的中性粒细胞（p < 0.0001）与单核细胞水平均显著升高（单核细胞：p = 0.0014，p = 0.0004）。

结论：与 HS 相关的 hs-CRP 水平处于中等区间（2.2~5.1 mg/L），提示其为全身性炎症而非感染。HS 患者外周血白细胞增多症以中性粒细胞与单核细胞升高为主。