Leitao Filho Fernando Sergio, Mattman Andre, Schellenberg Robert, Criner Gerard J, Woodruff Prescott, Lazarus Stephen C, Albert Richard K, Connett John, Han Meilan K, Gay Steven E, Martinez Fernando J, Fuhlbrigge Anne L, Stoller James K, MacIntyre Neil R, Casaburi Richard, Diaz Philip, Panos Ralph J, Cooper J Allen, Bailey William C, LaFon David C, Sciurba Frank C, Kanner Richard E, Yusen Roger D, Au David H, Pike Kenneth C, Fan Vincent S, Leung Janice M, Man Shu-Fan Paul, Aaron Shawn D, Reed Robert M, Sin Don D
Centre for Heart Lung Innovation, St. Paul's Hospital & Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
Chest. 2020 Oct;158(4):1420-1430. doi: 10.1016/j.chest.2020.04.058. Epub 2020 May 19.
Hypogammaglobulinemia (serum IgG levels < 7.0 g/L) has been associated with increased risk of COPD exacerbations but has not yet been shown to predict hospitalizations.
To determine the relationship between hypogammaglobulinemia and the risk of hospitalization in patients with COPD.
Serum IgG levels were measured on baseline samples from four COPD cohorts (n = 2,259): Azithromycin for Prevention of AECOPD (MACRO, n = 976); Simvastatin in the Prevention of AECOPD (STATCOPE, n = 653), Long-Term Oxygen Treatment Trial (LOTT, n = 354), and COPD Activity: Serotonin Transporter, Cytokines and Depression (CASCADE, n = 276). IgG levels were determined by immunonephelometry (MACRO; STATCOPE) or mass spectrometry (LOTT; CASCADE). The effect of hypogammaglobulinemia on COPD hospitalization risk was evaluated using cumulative incidence functions for this outcome and deaths (competing risk). Fine-Gray models were performed to obtain adjusted subdistribution hazard ratios (SHR) related to IgG levels for each study and then combined using a meta-analysis. Rates of COPD hospitalizations per person-year were compared according to IgG status.
The overall frequency of hypogammaglobulinemia was 28.4%. Higher incidence estimates of COPD hospitalizations were observed among participants with low IgG levels compared with those with normal levels (Gray's test, P < .001); pooled SHR (meta-analysis) was 1.29 (95% CI, 1.06-1.56, P = .01). Among patients with prior COPD admissions (n = 757), the pooled SHR increased to 1.58 (95% CI, 1.20-2.07, P < .01). The risk of COPD admissions, however, was similar between IgG groups in patients with no prior hospitalizations: pooled SHR = 1.15 (95% CI, 0.86-1.52, P =.34). The hypogammaglobulinemia group also showed significantly higher rates of COPD hospitalizations per person-year: 0.48 ± 2.01 vs 0.29 ± 0.83, P < .001.
Hypogammaglobulinemia is associated with a higher risk of COPD hospital admissions.
低丙种球蛋白血症（血清IgG水平<7.0g/L）与慢性阻塞性肺疾病（COPD）急性加重风险增加相关，但尚未证实其可预测住院情况。
确定低丙种球蛋白血症与COPD患者住院风险之间的关系。
对来自四个COPD队列（n = 2259）的基线样本测定血清IgG水平：阿奇霉素预防慢性阻塞性肺疾病急性加重（MACRO，n = 976）；辛伐他汀预防慢性阻塞性肺疾病急性加重（STATCOPE，n = 653），长期氧疗试验（LOTT，n = 354），以及COPD活动：血清素转运体、细胞因子与抑郁（CASCADE，n = 276）。IgG水平通过免疫比浊法（MACRO；STATCOPE）或质谱法（LOTT；CASCADE）测定。采用该结局和死亡的累积发病率函数（竞争风险）评估低丙种球蛋白血症对COPD住院风险的影响。进行Fine-Gray模型以获得各研究中与IgG水平相关的调整后亚分布风险比（SHR），然后使用荟萃分析进行合并。根据IgG状态比较每人年的COPD住院率。
低丙种球蛋白血症的总体发生率为28.4%。与IgG水平正常的参与者相比，IgG水平低的参与者中观察到更高的COPD住院发病率估计值（Gray检验，P <.001）；合并的SHR（荟萃分析）为1.29（95%CI，1.06 - 1.56，P =.01）。在既往有COPD住院史的患者（n = 757）中，合并的SHR增至1.58（95%CI，1.20 - 2.07，P <.01）。然而，在无既往住院史的患者中，各IgG组之间的COPD住院风险相似：合并的SHR = 1.15（95%CI，0.86 - 1.52，P =.34）。低丙种球蛋白血症组的每人年COPD住院率也显著更高：0.48±2.01对0.29±0.83，P <.001。
低丙种球蛋白血症与COPD住院风险较高相关。
