Defective pneumococcal antibody response in patients with recurrent respiratory tract infections

Area of Science:

• Immunology
• Infectious Diseases
• Clinical Medicine

Background:

• Streptococcus pneumoniae causes pulmonary infections and is a leading cause of mortality in B cell immunodeficiencies.
• Antibody production is the primary defense against S. pneumoniae; measuring antipolysaccharide antibodies is key for evaluating B cell deficiencies.

Purpose of the Study:

• To quantify serotype-specific immunoglobulin G (IgG) antibody responses to pneumococcal vaccine in patients with recurrent respiratory tract infections.
• To identify the prevalence of impaired antibody responses and associated B cell immunodeficiencies.

Main Methods:

• 416 patients with recurrent respiratory tract infections received an unconjugated pneumococcal vaccine.
• Serotype-specific IgG antibodies were measured before and three weeks after vaccination.
• Clinical features of 55 patients with impaired antibody response were evaluated.

Main Results:

• 13% (55 of 416) of patients showed an impaired antibody response.
• Specific antibody deficiency was diagnosed in 10 patients, common variable immunodeficiency in 18, ataxia telangiectasia in 10, and other antibody deficiencies in 7.
• Impaired antibody response was linked to various B cell immunodeficiencies.

Conclusions:

• Evaluating antibody response to polysaccharide antigens should be an early consideration in patients with recurrent respiratory infections.
• This evaluation is vital for diagnosing specific antibody deficiency and informing treatment strategies.
• Prompt diagnosis and appropriate management are essential for patients with B cell immunodeficiencies.