Primary intestinal lymphoma in South Africa.

All adult cases of primary intestinal lymphoma seen during the years 1953--77 at Groote Schuur Hospital, South Africa, were reviewed. Seventy percent of patients with solitary lymphoma and 80% with immunoproliferative small intestinal disease were mulatto. Patients in the latter group presented with malabsorption and those with a solitary lymphoma presented with intestinal obstruction. Four of 15 patients tested for the presence of alpha-heavy-chains were found to have alpha-heavy-chain disease. Family studies of potential genetic and immunologic factors showed some significant differences in IgA and IgG levels in the families of two patients with alpha-heavy-chain disease. Elevated alkaline phosphatase of intestinal origin was found in four of six patients with immunoproliferative small intestinal disease and in a high proportion of relatives. Fifty percent of the six patients were of blood group B. Minor blood groups, ABH secretor state and Pi phenotype distribution were similar to those of the control subjects. HLA gene frequency was particularly increased in the HLA-A9 antigen. These studies suggest that genetic factors may be relevant to the pathogenesis of immunoproliferative small intestinal disease.