Serum IgG Levels and Risk of COPD Hospitalization: A Pooled Meta-analysis.

Abstract

BACKGROUND:

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.

RESEARCH QUESTION:

To determine the relationship between hypogammaglobulinemia and the risk of hospitalization in patients with COPD.

STUDY DESIGN AND METHODS:

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.

RESULTS:

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.

INTERPRETATION:

Hypogammaglobulinemia is associated with a higher risk of COPD hospital admissions.

• Authors: Fernando Sergio Leitao Filho, Andre Mattman, Robert Schellenberg, Gerard J Criner, Prescott Woodruff, Stephen C Lazarus, Richard K Albert, John Connett, Meilan K Han, Steven E Gay, Fernando J Martinez, Anne L Fuhlbrigge, James K Stoller, Neil R MacIntyre, Richard Casaburi, Philip Diaz, Ralph J Panos, J Allen Cooper Jr, William C Bailey, David C LaFon, Frank C Sciurba, Richard E Kanner, Roger D Yusen, David H Au, Kenneth C Pike, Vincent S Fan, Janice M Leung, Shu-Fan Paul Man, Shawn D Aaron, Robert M Reed, Don D Sin
• Journal: Chest (Chest) Vol. 158 Issue 4 Pg. 1420-1430 (10 2020) ISSN: 1931-3543 [Electronic] United States
• PMID: 32439504 (Publication Type: Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Chemical References

• Immunoglobulin G

Topics

• Agammaglobulinemia (blood, complications)
• Aged
• Female
• Hospitalization (statistics & numerical data)
• Humans
• Immunoglobulin G (blood)
• Incidence
• Male
• Middle Aged
• Pulmonary Disease, Chronic Obstructive (blood, complications, epidemiology)
• Risk Assessment