Serum levels of 90K glycoprotein in type-1 diabetic patients

Purpose. The n-glycoprotein termed 90K was first identified in the serum of healthy individuals, and was found to be elevated in the serum of patients with various types of cancer and in patients infected by the human immunodeficiency virus (HIV). More recently, abnormal serum 90K levels were found in significant fractions of patient populations with autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). These findings suggest an important role for 90K in immune-related disorders and led us to evaluate whether diabetic patients could bear an alteration of its circulating values. Insuline-dependent diabetes mellitus (IDDM), better known as type-1 DM, is a relatively frequent systemic disease has a well known aumoimmune pathogenesis even if its etiology is certainly multifactorial. The aim of our study was to evaluate 90K serum levels in a group of IDDM patients with retinopathy at various stages of severity, in order to investigate the potential role of this glycoprotein as a further monitoring parameter for this category of patients. Methods. Blood samples of 8 ml were obtained from a group of 40 IDDM (mean age was 39.7) and from 40 age- and sex-matched healthy blood donors as controls. Excluded from the study were all patients with systemic diseases that could potentially bias 90K measurements (e.g., cancer, immunodepression, other immune-related diseases), and patients using immunomodulating or immuno-suppressive agents. 90K values were detected by a radioimmunological assay. Results showed significantly (p=0.0031) elevated 90K titles in IDDM patients (mean 6.4 U/ml) compared to normals (mean 3.4 U/ml). Patients with background retinopathy (BR, grades 1-4) showed, on average, higher 90K levels (6.77±4.66 U/ml) than diabetic subjects with no retinopathy (5.68±3.51 U/ml) while no statistically significant difference was seen between diabetics with no retinopathy and normals. Conclusions. We can consider that IDDM patients serum levels of this novel marker of immunological alterations may reflect different stages of the diseases and that immune system contributes to the retinal damage as monitored by 90K elevated values.