Gastrointestinal complications of immunodeficiency syndromes.

Patients with B cell deficiency have a high incidence of prolonged Giardia lamblia infection of the gastrointestinal tract that causes symptoms of malabsorption with villus flattening. The changes are reversible with therapy directed against Giardia. There is a high incidence of pernicious anaemia in patients with agammaglobulinaemia. Those with abnormal B lymphocytes tend to develop lymphoid nodular hyperplasia. Gastrointestinal disease is rare in boys with X-linked agammaglobulinaemia when compared with adults with the 'acquired' or common variable form of the disease. T cell deficiency results in intractable diarrhoea and monilial infection of the gastrointestinal tract.