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, 56.7 U/ml; p < 0.0001) compared with T2D patients (22.5 U/ml) and controls (43.3 U/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

Immunohistochemical identification of Propionibacterium acnes in granuloma and inflammatory cells of myocardial tissues obtained from cardiac sarcoidosis patients.

BACKGROUND:Although rare, cardiac sarcoidosis (CS) is potentially fatal. Early diagnosis and intervention are essential, but histopathologic diagnosis is limited. We aimed to detect Propionibacterium acnes, a commonly implicated etiologic agent of sarcoidosis, in myocardial tissues obtained from CS patients. METHODS AND RESULTS:We examined formalin-fixed paraffin-embedded myocardial tissues obtained by surgery or autopsy and endomyocardial biopsy from patients with CS (n = 26; CS-group), myocarditis (n = 15; M-group), or other cardiomyopathies (n = 39; CM-group) using immunohistochemistry (IHC) with a P. acnes-specific monoclonal antibody. We found granulomas in 16 (62%) CS-group samples. Massive (≥14 inflammatory cells) and minimal (<14 inflammatory cells) inflammatory foci, respectively, were detected in 16 (62%) and 11 (42%) of the CS-group samples, 10 (67%) and 10 (67%) of the M-group samples, and 1 (3%) and 18 (46%) of the CM-group samples. P. acnes-positive reactivity in granulomas, massive inflammatory foci, and minimal inflammatory foci were detected in 10 (63%), 10 (63%), and 8 (73%) of the CS-group samples, respectively, and in none of the M-group and CM-group samples. CONCLUSIONS:Frequent identification of P. acnes in sarcoid granulomas of originally aseptic myocardial tissues suggests that this indigenous bacterium causes granuloma in many CS patients. IHC detection of P. acnes in massive or minimal inflammatory foci of myocardial biopsy samples without granulomas may be useful for differentiating sarcoidosis from myocarditis or other cardiomyopathies

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

Clinical profiles of the patients providing EMB samples.

<p>Clinical profiles of the patients providing EMB samples.</p

Immunohistochemical identification of <i>Propionibacterium acnes</i> in granuloma and inflammatory cells of myocardial tissues obtained from cardiac sarcoidosis patients

<div><p>Background</p><p>Although rare, cardiac sarcoidosis (CS) is potentially fatal. Early diagnosis and intervention are essential, but histopathologic diagnosis is limited. We aimed to detect <i>Propionibacterium acnes</i>, a commonly implicated etiologic agent of sarcoidosis, in myocardial tissues obtained from CS patients.</p><p>Methods and results</p><p>We examined formalin-fixed paraffin-embedded myocardial tissues obtained by surgery or autopsy and endomyocardial biopsy from patients with CS (n = 26; CS-group), myocarditis (n = 15; M-group), or other cardiomyopathies (n = 39; CM-group) using immunohistochemistry (IHC) with a <i>P</i>. <i>acnes</i>-specific monoclonal antibody. We found granulomas in 16 (62%) CS-group samples. Massive (≥14 inflammatory cells) and minimal (<14 inflammatory cells) inflammatory foci, respectively, were detected in 16 (62%) and 11 (42%) of the CS-group samples, 10 (67%) and 10 (67%) of the M-group samples, and 1 (3%) and 18 (46%) of the CM-group samples. <i>P</i>. <i>acnes</i>-positive reactivity in granulomas, massive inflammatory foci, and minimal inflammatory foci were detected in 10 (63%), 10 (63%), and 8 (73%) of the CS-group samples, respectively, and in none of the M-group and CM-group samples.</p><p>Conclusions</p><p>Frequent identification of <i>P</i>. <i>acnes</i> in sarcoid granulomas of originally aseptic myocardial tissues suggests that this indigenous bacterium causes granuloma in many CS patients. IHC detection of <i>P</i>. <i>acnes</i> in massive or minimal inflammatory foci of myocardial biopsy samples without granulomas may be useful for differentiating sarcoidosis from myocarditis or other cardiomyopathies.</p></div

Representative samples with sarcoid granulomas.

<p>An autopsy sample (<b>A–C</b>) and an EMB sample (<b>D–F</b>) from patients with sarcoidosis were stained with haematoxylin and eosin and immunostained with anti-<i>P</i>. <i>acnes</i> antibody. Many sarcoid granulomas were observed at the lower magnification (<b>A, D</b>). Small round bodies indicated by the black arrows (<b>C, F</b>) were found in some of epithelioid cells and multinucleated giant cells of these sarcoid granulomas by immunohistochemistry with anti-<i>P</i>. <i>acnes</i> antibody. Original magnification; ×200 (left), ×1000 (middle and right).</p

Summary of histologic and immunohistochemical findings.

<p>Summary of histologic and immunohistochemical findings.</p