Immunoproliferative small intestinal disease and primary small intestinal lymphoma. Relation to alpha chain protein.

Forty-three patients with immunoproliferative small intestinal disease and primary small intestinal lymphoma were studied prospectively. Eighteen patients in whom alpha-chain protein was detected in the serum had significantly more features of malabsorption, and disease was localized more commonly in the jejunum. In all of these patients, a diffuse lymphoplasmacytic infiltrate was found in the intestine; in three patients lymphoma was found only in mesenteric lymph nodes. Twenty-five patients with lymphoma in whom alpha-chain protein failed to be detected had significantly more features of intestinal obstruction, and disease was found more commonly in the ileum. Five of these patients had lymphoma associated with a diffuse mucosal infiltrate that was indistinguishable from the first group. In patients available for follow-up, no difference was found in cumulative survival over 30 months in the two groups, with approximately 40% mortality at 6 months.