Abstract

In vitro and in vivo lymphocyte function was studied in six patients with primary hypogammaglobulinaemia and nodular lymphoid hyperplasia (NLH) of the bowel. Lymphocyte transformation, numbers of circulating T and B lymphocytes, and delayed hypersensitivity skin tests did not significantly differ when compared with hypogammaglobulinaemic patients without NLH. However, patients with NLH had higher jejunal juice IgM concentrations and a tendency to higher serum IgM concentrations than those without NLH. The morphological features of NLH are similar to the germinal centres of lymph nodes but more closely resemble the follicle zone of Peyer's patches. These findings suggest that NLH represents a local immune response to antigens originating in the gut lumen.