Chromosome X-linked Bruton agammaglobulinemia is classified as a primary immunodeficiency disorder. It is a genetic condition associated with a mutation in the BTK gene encoding tyrosine kinase. It is characterised by the lack or only trace amounts of B cells and immunoglobulins, which results in humoral immunodeficiency. Clinical signs of Bruton agammaglobulinemia include recurring bacterial respiratory tract infections, sinusitis and otitis media. Physical examination reveals hypoplastic palatine tonsils and peripheral lymph nodes. Patients are predisposed to severe, chronic and life-threatening infections, usually caused by polysaccharide encapsulated bacteria, such as: Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis and Moraxella catarrhalis. The diagnostic process of agammaglobulinemia is based on B cell and immunoglobulin counts. Its treatment consists in regular immunoglobulin supplementation. The paper presents a case of a patient admitted to hospital due to pneumonia. The interview revealed recurring infections, including severe pneumonia.

primary immunodeficiency disorder, agammaglobulinemia, tyrosine kinase, immunoglobulins, bacterial infections