Reduced natural killer cell activity in gluten-sensitive enteropathy

There is an increased risk of malignancy—particularly of lymphoma—associated with coeliac disease. Because natural killer (NK) cells are thought to play a role in immune surveillance against tumours, the activity of NK cells was studied in patients with coeliac disease who were being treated with a gluten-free diet. The 18 patients had a median age of 39 years (range: 13–75) and had been on the gluten-free diet for a median of 4 years (1 week-18 years). The NK cell activity of the peripheral blood mononuclear cells was assayed by measuring the ⁵¹Cr release from labelled K562 cells. The specific cytotoxicity of the cells from the patients were significantly lower than controls at effector: target cell ratios of 100: 1, 50: 1 and 25: 1. The experimental data were fitted to a mathematical model which described the relationship between effector: target cell ratio and specific cytotoxicity. Comparison showed that the maximum NK cytotoxicity by cells from treated patients was significantly less than from controls, and that the cytotoxicity was reduced over the whole range of effector: target cell ratios.