Production of islet cell antibodies from Epstein-Barr virus-transformed peripheral blood lymphocytes in type 1 (insulin-dependent) diabetic patients

An efficient method for routine Epstein-Barr virus immortalization of human B lymphocytes

A variety of methods exist for the immortalization of B lymphocytes by Epstein-Barr virus due to the simplicity of such techniques to establish cell lines with stable genomic DNA. Two different methods for immortalizing lymphoblastoid cell lines were compared for differences in techniques and materials, time between initiation and immortalization, and success rate of immortalization. An incubation period in Epstein-Barr virus and the use of conditioned media improved immortalization efficiency from 86 to 98% and decreased the time (usually weeks) from culture initiation to cryopreservation. The resulting cell bank was used to produce DNA for genetic studies focusing on the genes involved in non-insulin-dependent diabetes mellitus.

Immunogenetic heterogeneity in type 1 (insulin-dependent) diabetes among Japanese--class II antigen and autoimmune thyroid disease

HLA-DQA1 and DPB1 alleles were examined in relation to autoimmune thyroid disease (AITD) in the Japanese type 1 diabetic patients. The subjects consisted of 14 type 1 diabetic patients with Graves' disease, 12 patients with Hashimoto's thyroiditis and 32 type 1 diabetic patients without AITD. Comparisons were made with 35 normal controls. Among the type 1 diabetic patients with Graves' disease, the age at onset of diabetes was 31.8 +/- 14.6 years old, which was later than that of those without AITD (P < 0.01). DR9 was increased (57.1% vs. 25.9%, P < 0.05, RR: 3.85, chi 2:4.36) in the patients with Graves' disease. DQA1*0301 was increased and DQA1*0103 was decreased in the patients with Graves' disease and those without AITD. HLA-DPB1*0501 was increased (92.9% vs. 54.3%, P < 0.05, RR: 11.0, chi 2:6.57) in the patients with Graves' disease. These findings suggest the existence of a Graves' complicated subgroup characterized by the increasing association of DPB1*0501 and late onset of diabetes in Japanese type 1 diabetic patients. There exists a heterogeneity in Japanese type 1 diabetes.

Autoantibodies to glutamic acid decarboxylase (GAD), 64,000-Mr islet cell protein (64K) antibodies and islet cell antibodies (ICA) in insulin-dependent diabetes mellitus with and without autoimmune diseases in Japan

IDDM is known to be a heterogeneous disease which is frequently complicated with other autoimmune diseases (AID). We previously reported that IDDM patients with AID were characterized by late onset of diabetes, persistent ICA-positivity and increased association with DR9, while those without AID were characterized by rapid decline of ICA with duration of diabetes and increased association with DR4. The present study was performed to investigate the prevalence of autoantibodies to glutamic acid decarboxylase (GAD), autoantibodies to 64KDa islet cell protein (64K antibodies) and islet cell antibodies (ICA) in Japanese IDDM patients with and without AID. In short-duration diabetes (< 1 year), the prevalence of GAD antibodies, 64K antibodies and ICA were 100%, 100%, and 100%, respectively, in IDDM patients with AID, and 82%, 64% and 82%, respectively, in patients without AID. In long-standing diabetes (3-28 years), the prevalence of GAD antibodies were 76%, 48% and 33%, respectively, in IDDM patients with AID, and 48%, 28% and 16%, respectively, in patients without AID. The mean levels of GAD antibodies, 64K antibodies and ICA in IDDM patients with AID was significantly higher than in those without AID. Furthermore, the prevalence of GAD antibodies were detected more frequently than ICA and 64K antibodies in long standing IDDM patients. Our results demonstrate that the prevalence of GAD antibodies in IDDM patients were as high as those reported in Caucasians, and high levels of GAD antibodies were observed in IDDM patients with AID.

Autoantibodies to 64,000-M(r) islet cell protein in long-term type 1 (insulin-dependent) diabetic patients

Autoantibodies to the 64,000-M(r) (64K) islet cell protein, identified as glutamic acid decarboxylase, were assayed in 46 Type 1 (insulin-dependent) diabetic patients with a disease duration of more than 5 years. Of 46 Type 1 diabetic patients, 18 (39.1%) were found to be positive for 64K antibodies and 12 of these patients had been diagnosed with autoimmune thyroid disease. Serum C-peptide levels were not detectable in 15 of 18 patients positive for 64K antibodies. The samples were also tested for titres of islet cell antibodies. Islet cell antibodies were detected in 15 (32.6%) of the 46 patients and all the islet cell antibody positive patients were also found to be positive for 64K antibodies. Furthermore, of these 15 patients 12 had previously been diagnosed with autoimmune thyroid disease. A correlation between levels of 64K antibodies and islet cell antibody titre revealed that higher levels of 64K antibodies were observed in patients who had higher islet cell antibody titre. These results demonstrate that most long-term Type 1 diabetic patients with 64K antibodies were also positive for islet cell antibodies complicated by autoimmune thyroid disease.