The types of recurrent infections in a particular patient offer a clue to the underlying PID syndrome. Which microorganisms are responsible for recurrent infections in B cell immunodeficiency syndromes?
Microbial cultures are important to determine if a patient truly has recurring infections, and if so, with which organism(s). More often than not, symptoms of frequent upper respiratory tract infections in adults may be due to uncontrolled allergic rhinosinusitis, asthma, or chronic aspiration rather than true infections. The risk of infection is also elevated in patients with these more common illnesses. In B-cell immunodeficiency, such as X-linked (Bruton’s) agammaglobulinemia (XLA), inadequate immunoglobulin production leads to recurrent infection with extracellular, encapsulated, pyogenic bacteria, particularly Streptococcus pneumoniae , Haemophilus influenzae, and Moraxella catharralis . These organisms typically cause acute and chronic infections of the upper (sinusitis, otitis, bronchitis) and lower (pneumonias) respiratory tracts, meningitis, and bacteremia. GI infections ( Giardia, Cryptosporidium, C. difficile, and norovirus) are also increased.
