Subtyping of Type 1 Diabetes as Classified by Anti-GAD Antibody, IgE Levels, and Tyrosine kinase 2 (TYK2) Promoter Variant in the Japanese.

OBJECTIVE: Type 1 diabetes (T1D) is known to be caused by Th1 cell-dependent autoimmunity. Recently, we reported that TYK2 promoter variant serves as a putative virus-induced diabetes susceptibility gene associated with deteriorated interferon-dependent antiviral response. TYK2 is also related to HIES, that is, Th2 cell-dependent. Therefore, TYK2 promoter variant may be also associated with the pathogenesis of T1D, modulating Th1/Th2 balance. RESEARCH DESIGN AND METHODS: We assessed the association between anti- GAD Ab, IgE levels, and TYK2 promoter variant among 313 T1D patients, 184 T2D patients, and 264 YH controls in the Japanese. RESULTS: T1D patients had elevated IgE (median, 56.7U/ml; p<0.0001) compared with T2D patients (22.5U/ml) and controls (43.3U/ml). Contrary to our expectations, there was no correlation between TYK2 promoter variant and IgE levels. We found that T1D could be subtyped as four groups based on anti-GAD Ab and IgE profile: Subtype 1, anti-GAD Ab positive and non-elevated IgE (47.0%); Subtype 2, anti-GAD Ab negative and non-elevated IgE (35.1%); Subtype 3, anti-GAD Ab positive and elevated IgE (10.9%); and Subtype 4, anti-GAD Ab negative and elevated IgE (7.0%). In Subtype 2, a significantly higher incidence was observed in T1D cases carrying the TYK2 promoter variant (OR, 2.60; 95%CI, 1.03-6.97; p=0.032), and also showing a flu-like syndrome at diabetes onset (OR, 2.34; 95%CI, 1.27-4.35; p=0.003). INTERPRETATION: Anti-GAD Ab and IgE profiling helps classifying T1D into four groups that recognize variable pathogenic bases of T1D.

New Identification of Three or More Campylobacter Species on the Basis of a Degenerate PCR-RFLP Method Targeting gyrB Gene.

This method was aimed targeting more Campylobacter species than conventional PCR-based identifications. They generally use species-specific primers focusing on clinically common species like C. jejuni, resulting in failure to recognize other species. We made the PCR-based identification more flexible using degenerate primers and DdeI- and MboI-separately used RFLP assay, which were designed on the basis of gyrB nucleotide sequence data of 14 Campylobacter species including C. jejuni, C. coli, and C. fetus. Ninety-four clinical isolates from patients with Campylobacter gastroenteritis and 13 biochemically identified C. fetus were used for its evaluation. In consequence, this method succeeded in identifying C. jejuni, C. coli, and C. fetus with tentative sensitivity (93.4-98.0%) and specificity (89.0-99.0%). According to our data-based analysis, the primers can possibly target other related species including Helicobacter and Arcobacter. This method may be a universal identification for Campylobacter and related organisms and would provide an alternative identification in clinical microbiology.

TYK2 Promoter Variant and Diabetes Mellitus in the Japanese.

BACKGROUND: Recently, natural mutation of Tyrosine kinase 2 (Tyk2) gene has been shown to determine susceptibility to murine virus-induced diabetes. In addition, a previous human genome-wide study suggested the type 1 diabetes (T1D) susceptibility region to be 19p13, where the human TYK2 gene is located (19p13.2). METHODS: Polymorphisms of TYK2 gene at the promoter region and exons were studied among 331 healthy controls, and 302 patients with T1D and 314 with type 2 diabetes (T2D) in the Japanese. FINDINGS: A TYK2 promoter haplotype with multiple genetic polymorphisms, which are in complete linkage disequilibrium, named TYK2 promoter variant, presenting decreased promoter activity, is associated with an increased risk of not only T1D (odds ratio (OR), 2.4; 95% confidence interval (CI), 1.2 to 4.6; P = 0.01), but also T2D (OR, 2.1; 95% CI, 1.1 to 4.1; P = 0.03). The risk is high in patients with T1D associated with flu-like syndrome at diabetes onset and also those without anti-glutamic acid decarboxylase autoantibody. INTERPRETATION: The TYK2 promoter variant is associated with an overall risk for diabetes, serving a good candidate as a virus-induced diabetes susceptibility gene in humans. FUNDING: Ministry of Education, Culture, Sports, Science and Technology and of Health, Labor and Welfare of Japan.

Associations between vascular calcification, arterial stiffness and bone mineral density in chronic hemodialysis patients.

AIM: The aim of our study was to examine the associations between vascular calcification, arterial stiffness and bone mineral density (BMD) in chronic hemodialysis (HD) patients. METHODS: The study subjects were 83 (70 men and 13 women) HD patients. All patients had computed tomography (CT) to determine aortic calcification index (ACI), pulse wave velocity (PWV) using a volume-plethysmographic apparatus, and BMD estimated by digital image processing (DIP). RESULTS: Patients, 84.3% male, 38.6% diabetic, had a mean age of 59.3 +/- 11.2 years. In univariate linear regression analysis, ACI correlated positively with age (r = 0.586, P < 0.0001), dialysis vintage (r = 0.47, P = 0.002), pulse pressure (r = 0.311, P = 0.004), C-reactive protein (CRP) (r = 0.226, P = 0.0397) and PWV (r = 0.422, P < 0.0001). There was no significant association between ACI and serum markers of mineral metabolism. There was also a positive association between PWV and systolic blood pressure (P = 0.0004) or pulse pressure (P < 0.0001), and a trend towards greater PWV with increasing age (r = 0.494). In multivariate regression analysis only increasing age, pulse pressure, serum levels of albumin and CRP were significantly associated with ACI and PWV. Mean BMD on DIP was 2.7 +/- 0.4 mmAL. ACI was inversely correlated with BMD (r = -0.234, P = 0.0331). CONCLUSIONS: Vascular calcification is closely associated with arterial stiffness in HD patients. BMD is inversely correlated with ACI, suggesting that measurement of hand BMD by DIP is a useful tool for assessment of renal bone disease in these patients.

Plasma levels of fibroblast growth factor-23 and mineral metabolism in diabetic and non-diabetic patients on chronic hemodialysis.

OBJECTIVE: Fibroblast growth factor (FGF) 23 is a circulating factor that regulates phosphate (P) metabolism. Since higher P levels are associated with vascular calcification, we examined the role of serum FGF-23 levels in P metabolism and vascular calcification in hemodialysis (HD) patients with and without diabetes mellitus (DM). MATERIALS AND METHODS: Chronic HD patients with DM (n = 39) and without DM (n = 50) were enrolled. Serum samples were obtained before the start of dialysis sessions, and the FGF-23 levels were determined by enzyme-linked immunosorbent assay. Abdominal computed tomography (CT) scan was performed, and the aortic calcification index (ACI) was determined by one examiner, blinded to the patient characteristics. Measurements of bone mineral density (BMD) were performed at the time of ACI estimation. RESULTS: Log plasma FGF-23 levels were higher in non-DM (3.74 +/- 0.71 pg/ml) than in DM (3.35 +/- 0.74 pg/ml) patients. The log FGF-23 correlated positively with serum creatinine (r = 0.424, P < 0.0001), albumin (r = 0.225, P = 0.0337), Ca (r = 0.392, P = 0.0001), P (r = 0.735, P < 0.0001), and Ca x P product (r = 0.780, P < 0.0001). There were negative correlations between log FGF-23 and age (r = -0.208, P = 0.0497), glucose (r = -0.231, P = 0.0294), and CRP (r = -0.222, P = 0.0359). Multiple regression analyses were performed to explore the correlations between plasma FGF-23 and other factors associated with vascular calcification in all HD patients. Independent variables were selected based on the results of univariate analyses. The significant factors associated with FGF-23 in HD patients were age, serum levels of creatinine, albumin, glucose, Ca, P, and Ca x P product. Plasma FGF levels did not correlate significantly with either ACI or BMD in these patients. CONCLUSION: Our findings indicate that the plasma FGF-23 level is associated with calcium-phosphate metabolism disorders, but not with aortic calcification, in both non-DM and DM patients on chronic HD. In addition, plasma FGF-23 is associated with serum levels of creatinine and albumin. Therefore, the plasma FGF-23 level may provide a reliable marker for Ca and P imbalance and nutritional status in HD patients.

Penicillin susceptibility of non-serotypeable Streptococcus pneumoniae from ophthalmic specimens.

Nontypeable (NT) Streptococcus pneumoniae strains isolated from eyes were examined for both penicillin susceptibility by E-test and penicillin-binding protein (PBP) gene alterations using PCR. Of the 25 ophthalmic isolates, 15 proved to be sensitive (PSSP, MIC < or = 0.06 microg/ml) and 10 were shown as intermediately resistant to penicillin (PISP, MIC = 0.1-1 microg/ml). No penicillin-resistant S. pneumoniae (PRSP, MIC > or = 2 microg/ml) were found. PBP gene (pbp1a and pbp2b) alteration PCR indicated that 12 (80.0%) of the 15 ophthalmic PSSPs had unaltered pbp genes and that 3 (20.0%) had alterations in either pbp1a or pbp2b, whereas 8 (80.0%) of the 10 PISPs had unaltered pbp genes and 2 (20.0%) had alterations in both pbp1a and pbp2b. These data suggest that penicillin resistance is spread among NT pneumococci typically associated with ophthalmic infections.