Non-clinical sciences/Immunology · Immunodeficiencylow yield

Bruton's agammaglobulinaemia

What it means

X-linked (BTK mutation) → arrest of B-cell maturation → no mature B cells, all immunoglobulin classes very low. Boys present after ~6 months (maternal IgG wanes) with recurrent encapsulated-bacteria infection (pneumococcus, Hib). Treat with immunoglobulin replacement.

Worked example

Recurrent sinopulmonary infection in a boy with absent tonsils and undetectable immunoglobulins.

In the exam

After 6 months of age a boy gets recurrent infections with encapsulated bacteria; he has no detectable B cells and all antibody classes are absent.

What settles it

Bruton's = antibody/B-cell defect (T cells normal); SCID = combined T-cell defect from birth.

Classically confused with

SCID

Source: StatPearls