Clinical findings:
(1) absence of tonsillar tissue
(2) failure to thrive in an infant or young child
(3) frequent infections, especially with encapsulated organisms
(4) infections with greater-than-expected severity
(5) failure of infections to respond as expected to appropriate therapy
(6) chronic infections that never quite resolve
(7) fever of unknown origin (FUO)
(8) immune thrombocytopenic purpura (ITP), seronegative arthropathy or other autoimmune disease
(9) splenomegaly
Common sites of chronic or recurrent infection:
(1) sinopulmonary
(2) gastrointestinal tract
(3) joints (as an inflammatory arthropathy)
Laboratory findings:
(1) depressed gamma globulins on evaluation of total serum proteins
(2) absence of an antibody response following vaccination
(3) granulomatous inflammatory response to bacteria
A primary antibody deficiency can appear at almost any age after 3 to 6 months of age (when maternal antibodies disappear).
