INCREASED LYMPHOCYTE INFILTRATION IN DUODENAL MUCOSA FROM PATIENTS WITH PSORIASIS AND SERUM IGA ANTIBODIES TO GLIADIN

In a screening study concerning IgA and IgG antibodies to gliadin (IgA AGA and IgG AGA, respectively) in psoriasis, raised levels of IgA and AGA were found to be more common than in a reference group. To determ ine whether elevated AGA levels were associated with an increased numb er of intraepithelial lymphocytes, 33 patients with IgA AGA (n = 28) o r IgG AGA (n = 5) values above 90% of the reference values (>50 units/ ml IgA AGA and <12 units/ml IgG AGA) underwent gastroduodenoscopy and duodenal biopsy in a prospective study. For comparison, six patients w ith low levels of both IgA AGA and IgG AGA were included. Five biopsy specimens were taken in each patient. Paraffin-embedded specimens were examined with regard to the degree of intraepithelial lymphocyte infi ltration, and scored from 0 to 3. Biopsy specimens with a score of 0 h ad one mononuclear cell or less per four epithelial cells. The specime ns were also examined with regard to the presence of intraepithelial C D3(+) T lymphocytes and gamma/delta(+) T lymphocytes. In the six patie nts with low IgA AGA and low IgG AGA, the biopsy score was 0. Fourteen of the 33 patients with raised AGA had a score of greater than or equ al to 1; of these, 12 had raised IgA AGA and two had slightly raised I gG AGA. Two of the patients with raised IgA AGA had partial villous at rophy, but the majority had normal villous architecture. There was a s ignificant correlation both between the biopsy score and the number of intraepithelial CD3(+) cells and between the score and the number of intraepithelial gamma/delta(+) positive T lymphocytes. The serum IgA A GA levels were significantly correlated with the duodenal biopsy score , the number of intraepithelial gamma/delta(+) T lymphocytes, and the number of CD3(+) intraepithelial T lymphocytes. Most patients had no, or only mild, gastrointestinal symptoms. Of the 14 patients with biops y scores greater than or equal to 1, seven had severe psoriasis and fi ve moderately severe psoriasis, whereas only two had mild psoriasis. T here was no relationship between the duodenal score and haemoglobin, f olate, whole blood selenium or serum zinc levels. Some of these patien ts improve on a gluten-free diet, but it is still too early to draw an y definite conclusions concerning the type of relationship between the skin lesions, the increased number of intraepithelial lymphocytes in the duodenal mucosa and gluten hypersensitivity.