Common variable immunodeficiency disorder (CVID) is the most common form of primary antibody immunodeficiency. Due to low antibody levels, CVID patients receive intravenous or subcutaneous immunoglobulin replacement therapy as treatment. CVID is associated with the chronic activation of granulocytes, including an increased percentage of low-density neutrophils (LDNs). In this study, we examined changes in the percentage of LDNs and the expression of their surface markers in 25 patients with CVID and 27 healthy donors (HD) after in vitro stimulation of whole blood using IVIg. An oxidative burst assay was used to assess the functionality of LDNs. CVID patients had increased both relative and absolute LDN counts with a higher proportion of mLDNs compared to iLDNs, distinguished based on the expression of CD10 and CD16. Immature LDNs in the CVID and HD groups had significantly reduced oxidative burst capacity compared to mature LDNs. Interestingly we observed reduced oxidative burst capacity, reduced expression of CD10 after stimulation of WB, and higher expression of PD-L1 in mature LDNs in CVID patients compared to HD cells. Our data indicate that that the functional characteristics of LDNs are closely linked to their developmental stage. The observed reduction in oxidative burst capacity in mLDNs in CVID patients could contribute to an increased susceptibility to recurrent bacterial infections among CVID patients.

中文翻译：

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常见变异型免疫缺陷患者低密度中性粒细胞亚群的表型和氧化爆发发生改变

常见变异型免疫缺陷病 (CVID) 是原发性抗体免疫缺陷最常见的形式。由于抗体水平较低，CVID患者接受静脉或皮下免疫球蛋白替代疗法作为治疗。 CVID 与粒细胞的慢性激活有关，包括低密度中性粒细胞 (LDN) 百分比增加。在这项研究中，我们检查了 25 名 CVID 患者和 27 名健康供体 (HD) 在使用 IVIg 体外刺激全血后 LDN 百分比及其表面标志物表达的变化。使用氧化爆发测定来评估 LDN 的功能。 CVID 患者的相对和绝对 LDN 计数均增加，与 iLDN 相比，mLDN 的比例更高，根据 CD10 和 CD16 的表达进行区分。与成熟的 LDN 相比，CVID 和 HD 组中未成熟的 LDN 的氧化爆发能力显着降低。有趣的是，与 HD 细胞相比，我们观察到 CVID 患者成熟 LDN 中氧化爆发能力降低、WB 刺激后 CD10 表达降低以及 PD-L1 表达升高。我们的数据表明，LDN 的功能特征与其发育阶段密切相关。观察到的 CVID 患者 mLDN 氧化爆发能力降低可能导致 CVID 患者对复发性细菌感染的易感性增加。