Background: Autoreactive T lymphocytes participate in the development of type 1 diabetes mellitus. The migration of T cells is initiated by increased expression of L-selectin on the cellular membrane of lymphocyte. Recently, a correlation between the concentration of sL-selectin and the develop-ment of diabetic retinopathy, atherosclerosis and arterial hypertension was stated.
Objectives: The purpose of this study was to evaluate whether the expression of L-selectin on lymphocytes T alters in the course of the disease -- diabetes lasting less than 5 years and over 5 years; to assess a relationship between the percentage of L-selectin on T cells and the evolution of vascular complications; to elucidate whether the percentage of peripheral blood T lymphocytes expressing L-selectin could be an early marker of angiopathy in juvenile patients.
Material and methods: The study was carried out on 60 children and adolescents (aged 9-20) with diagnosed type 1 diabetes: a) (20 n) with the disease lasting <5 years, b) (20 n) with type 1 diabetes lasting >5 years without vascular complications, c) (20 n) with type 1 diabetes and vascular complications (microalbuminuria, arterial hypertension, diabetic retinopathy). The control group consisted of 20 healthy volunteers (aged 6-17). The expression of adhesion molecules has been evaluated by using three-color flow cytometry (Coulter EPICS XL). HbA1c concentration has been analysed by a liquid chromatography technique HPLC-Variant (Bio-Rad).
Results: The percentage of T lymphocytes expressing L-selectin was significantly increased in all groups of patients with type 1 diabetes versus healthy controls (p<0.005 and p<0.001, in groups without complications and with angiopathy, respectively). Moreover in patients with diagnosed arterial hypertension the percentage of T lymphocytes expressing L-selectin was higher than in patients in whom arterial hypertension was not developed (p<0.05).
Conclusions: In juvenile patients with type 1 diabetes the percentage of T lymphocytes expressing L-selectin was increased independently on the du-ration of the disease. In children with type 1 diabetes and diagnosed vascular complications the highest percentage of T lymphocytes expressing L-selectin was found.