Idiopathic late-onset immunoglobulin deficiency with associated defect in cell-mediated immunity

An 8-year-old boy presented with idiopathic late-onset immunoglobulin deficiency manifested principally by recurrent suppurative chest infections and chronic diarrhoea with malabsorption. Nodular lymphoid hyperplasia and giardiasis were shown on small bowel biopsy. Investigation of the immune system showed low serum levels of IgG, IgM, and IgA, negative skin tests to four recall antigens, absent mixed lymphocyte reactivity, and impared lymphocyte responses to mitogens in vitro. Serum complement and granulocyte function studies were normal. Maintenance therapy with gammaglobulin and antibiotics gave a good response.