Reduced quantity and function of pneumococcal antibodies are associated with exacerbations of COPD in SPIROMICS

While hypogammaglobulinemia is associated with COPD exacerbations, it is unknown whether frequent exac-erbators have specific defects in antibody production/function. We hypothesized that reduced quantity/function of serum pneumococcal antibodies correlate with exacerbation risk in the SPIROMICS cohort.We measured total pneumococcal IgG in n = 764 previously vaccinated participants with COPD. In a propensity-matched subset of n = 200 with vaccination within five years (n = 50 without exacerbations in the previous year; n = 75 with one, n = 75 with >= 2), we measured pneumococcal IgG for 23 individual serotypes, and pneumococcal antibody function for 4 serotypes.Higher total pneumococcal IgG, serotype-specific IgG (17/23 serotypes), and antibody function (3/4 sero-types) were independently associated with fewer prior exacerbations. Higher pneumococcal IgG (5/23 serotypes) predicted lower exacerbation risk in the following year. Pneumococcal antibodies are inversely associated with exacerbations, supporting the presence of immune defects in frequent exacerbators. With further study, pneumococcal antibodies may be useful biomarkers for immune dysfunction in COPD.

Automated summary

This study found that reduced quantity/function of serum pneumococcal antibodies are associated with higher risk of COPD exacerbations. Higher levels of pneumococcal antibodies, especially for certain serotypes, are associated with lower exacerbation risk. These findings suggest immune defects in frequent exacerbators and pneumococcal antibodies may serve as biomarkers for immune dysfunction in COPD.