Soluble L‐selectin levels in type I diabetes mellitus: a surrogate marker fordisease activity?

Summary L‐selectin (CD62L) is a cell adhesion molecule which plays a key role in the initiation of leucocyte migration from blood vessels to sites of local inflammation. The aim of this study was to investigate T‐lymphocyte expression of CD62L antigen and serum levels of soluble L‐selectin (sL‐selectin) in subjects with clinical and preclinical type I diabetes to determine whether they could provide surrogate markers for disease activity. CD62L selectin expression on memory T lymphocytes was studied by cytometric analysis in 22 patients with newly diagnosed type I diabetes, 20 first‐degree relatives of patients with type I diabetes, 14 patients with Graves’ disease, and 22 healthy controls. sL‐selectin levels were measured by enzyme‐linked immunosorbent assay (ELISA) in enlarged groups of subjects in these categories, as well as in patients with long‐standing type I diabetes, treated Graves’ disease and type II (non‐insulin dependent) diabetes. L‐selectin levels were also related to islet autoantibodies, human leucocyte antigen (HLA) genotype and L‐selectin T668C gene polymorphisms. L‐selectin expression on memory T lymphocytes was reduced in newly diagnosed diabetes and islet autoantibody positive siblings compared with controls. sL‐selectin levels were significantly raised in newly diagnosed type I diabetes compared with controls, with intermediate levels in family members, both with and without islet autoantibodies, and in long‐standing type I diabetes. Levels were also raised in patients with untreated Graves’ disease. Patients with type II diabetes had sL‐selectin levels which did not differ from controls. sL‐selectin levels correlated with the presence of diabetes‐associated HLA alleles in both family members and controls; levels also fell with increasing age in family members. Multiple regression analysis showed that... [ABSTRACT FROM AUTHOR]