In the human inflammatory myopathies (polymyositis and dermatomyositis), the early, widespread appearance of MHC class I on the surface of muscle cells and the occurrence of certain myositisspecific autoantibodies are striking features. We have used a controllable muscle-specific promoter system to up-regulate MHC class I in the skeletal muscles of young mice. These mice develop clinical, biochemical, histological, and immunological features very similar to human myositis. The disease is inflammatory, limited to skeletal muscles, self-sustaining, more severe in females, and often accompanied by autoantibodies, including, in some mice, autoantibodies to histidyl-tRNA synthetase, the most common specificity found in the spontaneous human disease, anti-Jo-1. This model suggests that an autoimmune disease may unfold in a highly specific pattern as the consequence of an apparently nonspecific event-the sustained up-regulation of MHC class I in a tissue-and that the specificity of the autoantibodies derives not from the specificity of the stimulus, but from the context, location, and probably the duration of the stimulus. This model further suggests that the presumed order of events as an autoimmune disease develops needs to be reconsidered.

Both osteoporosis and cardiovascular disease (CVD) are major public health problems leading to increased morbidity and mortality. Although traditionally viewed as separate disease entities that increase in prevalence with aging, accumulating evidence indicates that there are similar pathophysiological mechanisms underlying both diseases. In addition to menopause and advanced age, other risk factors for CVD such as dyslipidemia, oxidative stress, inflammation, hyperhomocystinemia, hypertension, and diabetes have also been associated with increased risk of low bone mineral density (LBMD). Elevated LDL and low HDL cholesterol are associated with LBMD, altered lipid metabolism is associated with both bone remodeling and the atherosclerotic process, which might explain, in part, the co-existence of osteoporosis and atherosclerosis in patients with dyslipidemia. Similarly, inflammation plays a pivotal role in both atherosclerosis and osteoporosis. Elevated plasma homocysteine levels are associated with both CVD and osteoporosis. Nitric oxide (NO), in addition to its known atheroprotective effects, appears to also play a role in osteoblast function and bone turnover. Supporting this notion, in a small randomized controlled trial, nitroglycerine (an NO donor) was found to be as effective as estrogen in preventing bone loss in women with surgical menopause. Statins, agents that reduce atherogenesis, also stimulate bone formation. Furthermore, bis- phosphonates, used in the treatment of osteoporosis, have been shown to inhibit atherogenesis. Intravenous bisphosphonate therapy significantly decreases serum LDL and increases HDL in postmenopausal women The exciting possibilities of newer pharmacological agents that effectively treat both osteoporosis and CVD hold considerable promise. However, it is important to emphasize that the current evidence linking both of these diseases is far from conclusive. Therefore, additional research is necessary to further characterize the relationship between these two common illnesses.

MRL/MpJ-Tnfrsf6lpr (MRL/MpJ-Faslpr; MRL-Faslpr) mice develop a spontaneous lupus syndrome closely resembling human systemic lupus erythematosus. To define the role of IL-10 in the regulation of murine lupus, IL-10 gene-deficient (IL-10−/−) MRL-Faslpr (MRL-Faslpr IL-10−/−) mice were generated and their disease phenotype was compared with littermates with one or two copies of an intact IL-10 locus (MRL-Faslpr IL-10+/− and MRL-Faslpr IL-10+/+ mice, respectively). MRL-Faslpr IL-10−/− mice developed severe lupus, with earlier appearance of skin lesions, increased lymphadenopathy, more severe glomerulonephritis, and higher mortality than their IL-10-intact littermate controls. The increased severity of lupus in MRL-Faslpr IL-10−/− mice was closely associated with enhanced IFN-γ production by both CD4+ and CD8+ cells and increased serum concentration of IgG2a anti-dsDNA autoantibodies. The protective effect of IL-10 in this lupus model was further supported by the observation that administration of rIL-10 reduced IgG2a anti-dsDNA autoantibody production in wild-type MRL-Faslpr animals. In summary, our results provide evidence that IL-10 can down-modulate murine lupus through inhibition of pathogenic Th1 cytokine responses. Modulation of the level of IL-10 may be of potential therapeutic benefit for human lupus.

γδ T cells secrete Th1- and Th2-like cytokines that help mediate innate and acquired immunity. We have addressed the mechanism whereby murine γδ T cells acquire the capacity to differentially produce such cytokines. Splenic γδ T cells could be polarized into IFN-γ- or IL-4-secreting cells in vitro; however, in contrast to CD4+ αβ T cells, γδ T cells predominantly produced IFN-γ, even in the presence of IL-4, a finding independent of genetic background. Like CD4+ Th1 cells, IFN-γ-producing cells expressed the IL-12 receptor β2-chain after activation in the presence of IL-12; however, unlike Th2 cells, IL-4-primed γδ T cells also expressed this receptor, even in the absence of IFN-γ and despite the presence of the transcription factor GATA-3. IL-12 also induced IL-4-primed γδ T cells to proliferate and to translocate Stat3/Stat4, indicating signaling through the IL-12 receptor. These molecular events can account for the predominant production of IFN-γ by γδ T cells in the presence of IL-12, despite the availability of IL-4. Early and predominant production of IFN-γ by γδ T cells likely is critical for the roles that these cells play in protection against intracellular pathogens and in tumor immunity.

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Up to one third of patients with chronic hepatitis C virus (HCV) develop type 2 diabetes mellitus (DM). This prevalence is much higher than that observed in the general population, and in patients with other chronic liver diseases such as hepatitis B virus, alcoholic liver disease, and primary biliary cirrhosis. Further, HCV seropositivity in patients with DM appears to be higher than in the general population. Post- liver transplantation DM also appears to be higher among patients with HCV. In this article, we review the epidemiologic association between HCV and DM, highlighting the most recent pathophysiologic insights into the mechanisms underlying this association.

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Thyroid cancer can be largely classified as well-differentiated, poorly differentiated, medullary and anaplastic. Differentiated thyroid cancer (DTC) includes follicular and papillary subtypes, with the incidence of papillary thyroid cancer (PTC) on the rise. The mainstay of treatment for DTC includes a combination of surgery, radioactive iodine (RAI) and levothyroxine suppression. DTC portends a favorable prognosis, even in the presence of distant metastases, with a 50% rate of 5-year survival largely due to tumor cell’s sensitivity to RAI therapy influencing disease outcome. In radioactive iodine refractory differentiated thyroid cancer (RAI-refractory DTC) there is a lower survival rate prompting the use of other therapeutic options available. RAI refractoriness is more common in older patients (age >40), large metastases and lesions that are fluorodeoxyglucose (FDG) avid on position emission tomography (PET). Over the past decade, Identification of genetic mutations in the signaling pathway involved in thyroid tumorigenesis has led to the approval of tyrosine kinase inhibitors (TKIs); Sorafenib and Lenvatinib in RAI-refractory DTC. Similarly, metastatic medullary thyroid cancer (MTC) implies an unfavorable 10-year survival rate of only 20% as the principal treatment options focuses on loco regional control via surgical and/or non-surgical options. The approval of TKIs such as Cabozantinib and Vandetanib has introduced an encouraging, novel, systemic therapeutic option for metastatic MTC. Lastly, anaplastic thyroid cancer (ATC) carries the worst prognosis with high recurrence rates. Treatment includes surgery, chemotherapy and external beam radiation. The FDA recently approved Dabrafenib plus trametinib for BRAF V600E mutated ATC. Considering the modality of chemotherapy and the expanding field of targeted therapies, the role of the oncologist and interaction with endocrinologist in the management of thyroid cancer needs further clarification aiming at collaborative management plans more than ever. This review summarizes the key phase III trials that led to the approval of TKIs in the treatment of DTC and metastatic MTC. Additionally, the review aims to clarify the patient selection criteria for initiation of TKIs and examine the implications, considerations and adverse effects prior to utilizing targeted therapy. Clinical trials are ongoing with promising results and may contribute to the addition of several targeted molecules and immune check point inhibitors to the therapeutic armamentarium for RAI-refractory DTC, medullary and anaplastic thyroid cancer.