Objective. To determine whether there were differences in the circulating T lymphocyte subsets or clinical features of patients with primary Sjogren's syndrome (SS) who were positive for different HLA alleles.Methods. Two-and three-color flow cytometry analyses were performed, using a whole blood lysing method.Results Submitted for publication Octoher 4, 1995; accepted in revised form April 16, 1996. autoimmune disorders in patients with the HLA-DR3 haplotype.

SUMMARY Increased proportions of circulating antigen-primed CD45ROþ TCR gd cells have been found in untreated CoD patients. As certain immunological features are now found in both CoD and healthy persons carrying the HLA DQ2 heterodimer, we sought to establish whether healthy members of the families of CoD patients who are positive for HLA DQ2 and also have increased densities of TCR gd intraepithelial lymphocytes (IEL) in their small bowel mucosa have elevated levels of circulating TCR gd memory cells. Peripheral blood T cells were analysed by flow cytometry in 22 patients with CoD and 16 healthy family members. Untreated CoD patients had higher percentages of circulating CD45RO þ TCR gd cells and CD45ROþ Vd1 þ cells than healthy family members. On the other hand, the amount of circulating Vd1 þ lymphocytes was lower in patients with CoD compared with healthy family members. In contrast, no differences were found between HLA DQ2 þ and HLA DQ2 ¹ healthy family members in respect of circulating TCR gd cell subsets. The change in circulating TCR gd cell subsets found in patients with CoD is thus a consequence of an ongoing immunological process which diminishes on a gluten-free diet rather than a phenomenon directly caused by DQ2. These changes in peripheral blood are not found in healthy individuals who have the same HLA alleles DQA1*0501 and DQB1*0201 encoding the HLA DQ2 and who also have increased densities of TCR gd IEL in their otherwise normal jejunal mucosa.