Specific antibody response against the 23-valent pneumococcal vaccine in patients with alpha(1)-antitrypsin deficiency with and without bronchiectasis

Objective: To assess the specific antibody response against polyvalent pneu mococcal vaccine in patients with alpha(1)-antitrypsin deficiency (AATD) an d respiratory infections. Design and participants: We investigated specific IgG, IgG1, and IgG2 antib ody responses against the 23-valent antipneumococcal vaccine in 18 patients with AATD phenotype PiZZ, 9 of whom had bronchiectasis and 4 a history of recurrent pneumonia, and compared them with a control group of 40 healthy v olunteers. Interventions: Blood samples were drawn just prior to and 3 weeks after imm unization. Measurements and results: Quantification of specific IgG and its subclasses was performed by an enzyme-linked immunosorbent assay. For patients with A ATD, mean increases in specific antipneumococcal titers were 4.7-fold (25 t o 75% quartiles, 2.5- to 6.8-fold) for total IgG, 3.2-fold (1.2- to 4.9-fol d) for IgG1, and 2.1-fold (1.8- to 3.7-fold) for IgG2, For the control grou p, the values were 3.3-fold (1.8- to 5.8-fold) for total IgG, 2.5-fold (1.9 - to 3.4-fold) for IgG1, and 3.1-fold (1.9- to 4.5-fold) for IgG2; differen ces were not significant, Patients with bronchiectasis showed a tendency to ward higher levels of IgG subclasses than both control subjects and patient s without bronchiectasis; however, there was a tendency toward lower postva ccination serum levels of specific antipneumococcal IgG, IgG1, and IgG2 in patients with bronchiectasis compared with patients without bronchiectasis, but this trend did not reach statistical significance. Three of the four p atients with recurrent pneumonia did not show an appropriate IgG2 response. Conclusions: These results suggest that, as a group, patients with AATD hav e a preserved antibody response against pneumococcal polysaccharides. Patie nts with bronchiectasis show a tendency toward a decreased antibody respons e, even with increased serum levels of most Ig types. Individuals with an i mpaired IgG2 response seem to be at increased risk of recurrent pneumonia, Considering the pernicious effect of pulmonary infections on these patients and the preserved antibody response in a majority of them, pneumococcal va ccination should be recommended to patients with AATD.