Analysis of eluted peptides from type 1 diabetes-susceptible HLA class II molecules identified novel islet protein, heparin/heparan sulfate-interacting protein

Prognosis for residual islet β-cell secretion function in young patients with newly diagnosed type 1 diabetes

BACKGROUND

This study investigated possible predictors of residual islet β-cell function (RBF) in young patients with newly diagnosed type 1 diabetes (T1D).

METHODS

After analyzing RBF in 443 patients with T1D according to age at diagnosis and disease duration, 110 were followed-up over 18-60 months. A nomogram was developed by logistic regression to explore factors associated with long-term RBF.

RESULTS

Of the 443 T1D patients (mean [±SD] age 20.28 ± 5.50 years; mean [±SD] diabetes duration 28.5 ± 14.6 months), RBF was preserved in 64.3%. Independent predictors for poor RBF outcome among the 110 patients in the follow-up cohort were age at onset (odds ratio [OR] 0.82; 95% confidence interval [CI] 0.73-0.92; P < 0.001), high-risk human leukocyte antigen (HLA) status (OR 4.73; CI 1.28-17.52; P = 0.020), female sex (OR 3.39; CI 1.03-11.22; P = 0.045), and a history of diabetic ketoacidosis (DKA; OR 8.71; CI 2.31-32.83; P < 0.001). Baseline glutamic acid decarboxylase (GAD) antibody, family history of diabetes, body mass index, insulin dosage, and C-peptide and HbA1c levels were not associated with poor RBF outcome. Intensive glycemic control after T1D diagnosis may improve RBF within a mean (±SD) follow-up of 35.1 ± 13.8 months. The calibration plot for the probability of 2-, 3-, and 4-year RBF showed optimal agreement between nomogram-predicted and actual observed probabilities.

CONCLUSIONS

Younger age of onset, female sex, higher HLA risk status, and a history of DKA were the main factors predicting long-term poor preserved β-cell function. Glycemic control could improve RBF during the course of diabetes. The nomogram provides an individualized risk estimate of RBF in patients with newly diagnosed T1D within Chinese Han populations.

Antigen Presentation, Autoantigens, and Immune Regulation in Multiple Sclerosis and Other Autoimmune Diseases

Antigen presentation is in the center of the immune system, both in host defense against pathogens, but also when the system is unbalanced and autoimmune diseases like multiple sclerosis (MS) develop. It is not just by chance that a major histocompatibility complex gene is the major genetic susceptibility locus in MS; a feature that MS shares with other autoimmune diseases. The exact etiology of the disease, however, has not been fully understood yet. T cells are regarded as the major players in the disease, but most probably a complex interplay of altered central and peripheral tolerance mechanisms, T-cell and B-cell functions, characteristics of putative autoantigens, and a possible interference of environmental factors like microorganisms are at work. In this review, new data on all these different aspects of antigen presentation and their role in MS will be discussed, probable autoantigens will be summarized, and comparisons to other autoimmune diseases will be drawn.

Combination of HLA-A24, -DQA1*03, and -DR9 contributes to acute-onset and early complete beta-cell destruction in type 1 diabetes: longitudinal study of residual beta-cell function

To elucidate the genetic factors contributing to heterogeneity of the rate of beta-cell destruction in type 1 diabetes, we investigated the relationship between the time course of complete beta-cell loss and HLA class I and II alleles. HLA allele frequencies were also examined among subgroups classified by the mode of onset. The subjects were 266 type 1 diabetic patients (among whom 196 patients were studied longitudinally) and 136 normal control subjects. Earlier complete loss of beta-cell function was observed in patients who possessed both HLA-A24 and HLA-DQA1*03 and in patients who had HLA-DR9, compared with those without these HLA alleles (P=0.0057 and 0.0093, respectively). Much earlier complete beta-cell loss was observed in the patients who possessed all of HLA-A24, -DQA1*03, and -DR9 compared with the remaining patients (P=0.0011). The combination of HLA-A24, -DQA1*03, and -DR9 showed a higher frequency in acute-onset than slow-onset type 1 diabetes (P=0.0002). In contrast, HLA-DR2 was associated with a slower rate of progression to complete beta-cell loss. These results indicate that the combination of HLA-A24, -DQA1*03, and -DR9 contributes to the acute-onset and early complete beta-cell destruction, whereas HLA-DR2 has a protective effect against complete beta-cell loss in type 1 diabetes.