Therapeutic approach for type 1 diabetes mellitus using the novel immunomodulator FTY720 (fingolimod) in combination with once-daily injection of insulin glargine in non-obese diabetic mice.

UNLABELLED: Aims/Introduction: The therapeutic effectiveness against type 1 diabetes mellitus (DM) of the novel immunomodulator FTY720 (fingolimod), alone and in combination with insulin glargine, was examined in the non-obese diabetic (NOD) mouse model. MATERIALS AND METHODS: Female NOD mice that had developed DM spontaneously were divided into four groups: (i) an FTY720 (0.1 mg/kg, p.o., twice weekly)-treated group; (ii) an insulin glargine (1.0 IU, s.c., once daily)-treated group; (iii) a combination FTY720 + insulin glargine (0.1-1.0 IU, s.c., once daily)-treated group; and (iv) a placebo (vehicle)-treated group. Treatment was initiated at the time of onset of DM and continued for 70 days or until death. The therapeutic efficacy of FTY720, insulin glargine and FTY720 + insulin glargine was evaluated by measuring the ratio of insulin-positive ß-cells/total islet area, the extent of islet inflammation (insulitis score), blood glucose levels, and serum C-peptide levels. RESULTS: Therapeutic administration of FTY720 to NOD mice with hyperglycemia (i.e. overt DM) significantly prolonged survival (P < 0.05 vs placebo). In the placebo group, all mice died within 63 days on the onset of DM; in contrast, 45% of FTY720-treated mice survived during the observation period (up to 70 days after the onset of DM). Therapeutic administration of FTY720 in combination with insulin glargine to NOD mice with hyperglycemia further improved survival (P < 0.05) compared with either FTY720 or insulin glargine alone (i.e. 85% of FTY720 + insulin glargine-treated mice survived to the end of the observation period). The efficacy of FTY720 in combination with insulin glargine was confirmed by histochemical, immunohistochemical and endocrinologic observations. CONCLUSIONS: Combination therapy with FTY720 plus insulin glargine is a promising candidate for the treatment of DM and may allow for a reduction in the frequency of insulin self-injections. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00160.x, 2011).

Differences in the contribution of HLA-DR and -DQ haplotypes to susceptibility to adult- and childhood-onset type 1 diabetes in Japanese patients.

To clarify heterogeneity in Japanese adult-onset type 1 diabetes, we analyzed the HLA-DR and -DQ haplotypes, depending on the clinical phenotype, and compared them with those in childhood-onset type 1 diabetes (CO). The patients in a previously reported Ehime Study were divided into subgroups by the mode of onset of diabetes: 68 acute-onset type 1 diabetic patients (AO) and 28 slowly progressive type 1 diabetic patients (SO). HLA haplotypes were compared with those of 80 CO patients and 190 control subjects. Two major susceptible HLA haplotypes in the Japanese, DRB1*0405-DQB1*0401 (DR4) and DRB1*0901-DQB1*0303 (DR9), were significantly increased in the AO and CO groups, but only DR9 was increased in the SO group. AO subjects had a higher frequency of DR9 than CO subjects. Accordingly, the DR9:DR4 frequency increased with increasing age of onset. Another susceptible haplotype, DRB1*0802-DQB1*0302 (DR8), was involved only in the CO group. Analysis of haplotype combinations revealed that DR4 and DR9 had significant dosage effects on the AO and CO groups (P < 0.0001), but only DR9 had such an effect in the SO group (P < 0.03). These results suggest differences in the contribution of HLA class II haplotypes to susceptibility of type 1 diabetes depending on the clinical phenotype and also indicate that HLA class II haplotypes may be associated with the onset age of type 1 diabetes.

Early detection of infantile pre-type 1 diabetes case with transient hyperglycemia.

The patient was an infant with transient hyperglycemia and decreased endogenous insulin secretion on intravenous glucose tolerance test (IVGTT) with the appearance of IA-2 autoantibodies (IA-2Ab), and we speculated that he was in the prediabetes stage. To our knowledge, this is the first case reported to be diagnosed as type 1 diabetes prior to clinical onset in Japan.

Clinical, autoimmune, and genetic characteristics of adult-onset diabetic patients with GAD autoantibodies in Japan (Ehime Study).

OBJECTIVE: To characterize the clinical, autoimmune, and genetic features in Japanese adult-onset diabetic patients with GAD autoantibodies. RESEARCH DESIGN AND METHODS: GAD autoantibodies (GADab) were screened in 4,980 diabetic patients with age of onset >20 years in the hospital-based Ehime Study, and the GADab-positive (GADab(+)) patients were then divided into two groups according to their insulin secretion and compared with nondiabetic subjects. The insulin-deficient state was defined as <0.33 nmol/l serum C-peptide (CPR) at 2 h postprandial or 6 min after a 1-mg glucagon load. RESULTS: GADab was detected in 188 (3.8%) of the 4,980 diabetic patients tested. Of these patients, 72 (38.3%) were classified as insulin deficient, 97 (51.6%) were classified as non-insulin deficient, and 19 (10.1%) were unclassified. The GADab(+) insulin-deficient patients were characterized by young age at onset of diabetes, low BMI, low maximum BMI, and high levels of HbA(1c). The prevalence of IA-2 autoantibodies and thyrogastric autoantibodies in the GADab(+) insulin-deficient patients were significantly higher than those in the GADab(+) non-insulin-deficient patients (P < 0.05). GADab(+) patients with insulin deficiency had increased frequencies of HLA DRB1*0405-DQB1*0401, *0802-*0302, and *0901-*0303 haplotypes, whereas the frequency of only HLA DRB1*0405-DQB1*0401 was increased in the case of GADab(+) non-insulin-deficient patients. Of note is the fact that the GADab(+) non-insulin-deficient group did not differ from healthy control subjects with respect to type 1 diabetes protective haplotype HLA DRB1*1502-DQB1*0601. A total of 13% of the GADab(+) patients with diabetes had genotypes comprising the DRB1*1501-DQB1*0602 or *1502-*0601 and were characterized by old age at onset of diabetes, high BMI, resistance to the insulin-deficient state, low titer of GADab, and low frequency of other organ-specific autoantibodies. CONCLUSIONS: We conclude that GADab(+) non-insulin-deficient patients differ from GADab(+) patients with insulin deficiency with respect to clinical characteristics, humoral autoimmunity to other organ-specific autoantibodies, as well as HLA class II genes.

Antibodies to food antigens in Japanese patients with type 1 diabetes mellitus.

To examine humoral and mucosal immune responses to food antigens and their relation to the pathophysiology of type 1 diabetes mellitus, IgA and IgG antibodies to cow's milk antigens (bovine serum albumin (BSA) and beta-lactoglobulin (BLG)) and another food antigen (ovalbumin, (OVA)) in human serum were assessed by enzyme-linked immunosorbent assay (ELISA). If anti-idiotype antibodies to the antibodies were present in serum, they might interfere with the ELISA assay, so suitable microtiter plates were employed to minimize such interference. The levels of IgA and IgG antibodies to the above antigens (P<0.001-P<0.01) and the prevalence of positive sera (P<0.001-P<0.05) in the patient group (n=52, aged 14.5+/-4.1 (S.D.) years) were significantly higher than those in the control group (n=41, aged 13.3+/-6.8 (S.D.) years). Interestingly, the levels of IgA antibodies to all the food antigens examined were elevated in 26 (50%) patients, while the elevation was seen in 3 (7%) healthy controls. The elevation of IgA antibodies in the patients was well correlated with increased concentrations of IgA and transforming growth factor (TGF)-beta, which induces IgA-producing B-cells, in serum. Although the cytokine TGF-beta is secreted from regulatory T-cells (Th3), and is related to oral tolerance, the interleukin-2 (IL-2, Th1)/IL-4 (Th2) ratio in the patient group was significantly elevated (P<0.001), which might indicate that the oral tolerance is impaired in patients. Thus, we demonstrated that both IgA and IgG antibodies to several food antigens are elevated in patients. We suggest that impairment of oral tolerance might be related to the pathogenesis of type 1 diabetes mellitus.