IgG subclasses in smokers with chronic bronchitis and recurrent exacerbations

Abstract

Background-Tobaccosmokers have lower serum levels of IgG than nonsmokers. IgG subclass deficiency is common in patients with recurrent respiratory infections. Recurrent bronchial infections are common in smokers with chronic bronchitis (CB). We have investigated whether susceptibility to recurrent exacerbations in smokers with CB is associated with altered IgG subclass levels or IgG subclass deficiency. Methods-Serum levels of IgG, IgA, IgM, and IgG subclasses 1-4 were determined by radial immunodiVusion in 100 subjects: 33 smokers with stable CB and recurrent exacerbations, 24 asymptomatic smokers, and 43 healthy never smokers. Systemic tobacco exposure was verified and excluded using a serum cotinine ELISA. Immunoglobulin data were log transformed to enable use of parametric statistical methods. Results-Compared with never smokers, both patients with CB and asymptomatic smokers had significantly lower levels of IgG (median 9.7 g/l (range 5.6-15.2) and 9.9 (6.1-12.1) g/l v 12.0 (6.9-18.5) g/l) and IgG2 (2.8 (0.9-5.9) g/l and 2.5 (1.0-6.3) g/l v 4.0 (1.7-10.2) g/l). The estimated ratio of median values between the patients with CB and never smokers was 0.78 (95% confidence interval (CI) 0.69 to 0.89) for IgG and 0.65 (95% CI 0.50 to 0.83) for IgG2. The corresponding ratios between asymptomatic smokers and never smokers were 0.79 (95% CI 0.69 to 0.91) and 0.60 (95% CI 0.50 to 0.83), respectively. There were no significant diVerences between the smoking groups. Conclusions-Susceptibility to recurrent exacerbations in smokers with CB is not associated with lower levels of IgG subclasses than can be accounted for by smoking per se. (Thorax 2001;56:445-449)

Immunoglobulin G Levels before and after Lung Transplantation

“…Although previous studies have attributed lower IgG levels in patients with COPD to smoking, the use of corticosteroids, or older age, our findings effectively refute these hypotheses (8)(9)(10). All patients in our study with pretransplant HGG were current nonsmokers, confirmed by serial testing of urine nicotine metabolites.…”

Risk factors of chronic obstructive pulmonary disease exacerbations

“…Only a few articles have described the association between the IgG subclass deficiencies and COPD exacerbation risk . Using samples from two large COPD trials, Leitao Filho et al found that reduced total IgG levels are associated with increased risk of AECOPD and hospitalisations, with the greatest risk observed among participants with total IgG levels <7.0 g/L .…”

“…Only a few articles have described the association between the IgG subclass deficiencies and COPD exacerbation risk. [81][82][83] Using samples from two large COPD trials, 84,85 Leitao Filho et al found that reduced total IgG levels are associated with increased risk of AECOPD and hospitalisations, with the greatest risk observed among participants with total IgG levels <7.0 g/L. 82 Furthermore, they revealed that approximately 1 in 5 COPD patients had one or more IgG subclass deficiencies and reduced IgG1 or IgG2 levels were associated with increased risk of AECOPD, but only IgG2 remained as an independent predictor of hospitalisations.…”

Virale Atemwegsinfektionen bei Erwachsenen

“…B. bei Spitzenathleten nach langen intensiven Trainingseinheiten beobachtet wurde, ein Grund für gehäuftes Auftreten von respiratorischen Infekten im oberen Respirationstrakt sein [14]. Bei Patienten mit rekurrenten respiratorischen Infektionen, die sich auch auf die unteren Atemwege erstrecken, ist meist ein IgG-Subklassenmangel im Serum zu beobachten [15].Die Infektion der Nasen-Rachen-Schleimhaut mit Rhino-, Influenzaviren oder RSV stimuliert die Epithelzellen zur Zytokinproduktion. Besonders zu erwäh-nen sind Interleukin-8 (IL), das chemotaktisch den Anstieg neutrophiler Granulozyten aktiviert, RANTES, das für die Infiltration von eosinophilen Granulozyten verantwortlich ist, und IL-6.…”

“…Zudem geht aus Studien hervor, dass die durch Rauchen induzierte Entzündung bei latenter Adenovirusinfektion nicht durch Steroidbehandlung beeinflusst werden kann [34]. Rekurrente Infektionen sind bei Rauchern mit chronischer und chronisch obstruktiver Bronchitis häufig [15,35].…”