Corrêa Raquel da Silva, Rodrigues Luciana Silva, Pereira Leticia Hagge Lima, Nogueira Otto Castro, Leung Janaína, Sousa Marcela da S, Hacker Mariana de Andrea, Siqueira Helio Ribeiro de, Capone Domênico, Alves Rogério Lopes Rufino, Pessolani Maria Cristina Vidal, Schmitz Veronica, Pereira Geraldo Moura Batista
Universidade do Estado do Rio de Janeiro, Faculdade de Ciências Médicas, Laboratório de Imunopatologia, Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Microbiologia Celular, Rio de Janeiro, RJ, Brasil.
Mem Inst Oswaldo Cruz. 2019;114:e180579. doi: 10.1590/0074-02760180579. Epub 2019 Apr 8.
CD64 (FcγR1) is a high-affinity receptor for monomeric IgG1 and IgG3. Circulating neutrophils express very low amounts of CD64 on their surface.
Our primary aim was to investigate the utility of neutrophil CD64 surface expression as a biomarker of active pulmonary tuberculosis (TB). We hypothesised that elevated neutrophil CD64 expression in TB infection would be associated with interferon gamma (IFN-γ) as an inducer of CD64 expression.
The expression level of CD64 per neutrophil (PMN CD64 index) was quantitatively measured with flow cytometry using a Leuko64 kit in samples from patients with TB and latent TB infection (LTBI) as well as healthy controls, as part of a prospective cohort study in Brazil.
The PMN CD64 index in patients with TB was higher than that in healthy controls and LTBI. Receiver operating characteristic curve analyses determined that the PMN CD64 index could discriminate patients with TB from those with LTBI and healthy individuals. PMN CD64 index levels returned to baseline levels after treatment.
The positive regulation of CD64 expression in circulating neutrophils of patients with active TB could represent an additional biomarker for diagnosis of active TB and could be used for monitoring individuals with LTBI before progression of TB disease.
CD64（FcγR1）是单体IgG1和IgG3的高亲和力受体。循环中的中性粒细胞在其表面表达非常少量的CD64。
我们的主要目的是研究中性粒细胞CD64表面表达作为活动性肺结核（TB）生物标志物的效用。我们假设TB感染中中性粒细胞CD64表达升高与作为CD64表达诱导剂的干扰素γ（IFN-γ）有关。
作为巴西一项前瞻性队列研究的一部分，使用Leuko64试剂盒通过流式细胞术对来自TB患者、潜伏性TB感染（LTBI）患者以及健康对照的样本中每个中性粒细胞的CD64表达水平（PMN CD64指数）进行定量测量。
TB患者的PMN CD64指数高于健康对照和LTBI患者。受试者工作特征曲线分析确定，PMN CD64指数可区分TB患者与LTBI患者及健康个体。治疗后PMN CD64指数水平恢复到基线水平。
活动性TB患者循环中性粒细胞中CD64表达的正向调节可能代表活动性TB诊断的另一种生物标志物，并且可用于在TB疾病进展之前监测LTBI个体。
