Silvia Martina Ferrari

Endocrine manifestations of hepatitis C virus infection

Chronic infection with hepatitis C virus (HCV) can result in both hepatic and extrahepatic disease and endocrine dysfunction represents an important class of HCV-related extrahepatic disease. The most frequently occurring—and clinically important—of these endocrine disorders are thyroid disease and type 2 diabetes mellitus. In this Review, we evaluate the evidence in support of a link between HCV infection and endocrine-system dysfunction, and discuss potential pathophysiological mechanisms. A meta-analysis of the literature has revealed significant associations between chronic HCV infection, thyroid autoimmunity and hypothyroidism. Furthermore, a high prevalence of thyroid cancer has been reported in HCV-positive patients. Several clinicoepidemiological studies have demonstrated that chronic HCV infection could lead to the development of type 2 diabetes mellitus, possibly as a result of HCV-induced metabolic disturbances. Some researchers have postulated that a type 1 T-helper -cell mediated immune response underpins the association of chronic HCV infection with endocrine disease. Indeed, the available data suggest that a common immunological, type 1 T-helper cell pattern of cytokine expression and activation (via interferon-γ) could provide the pathophysiological basis for this association. Nonetheless, additional studies will be necessary to elucidate fully all the mechanisms involved in HCV-related endocrine dysfunction.

Immunopathogenesis of HCV-related endocrine manifestations in chronic hepatitis and mixed cryoglobulinemia

Hepatitis C Virus (HCV) is known to be responsible for both hepatic and extrahepatic diseases (HCV-related extrahepatic diseases = HCV-EHDs). The most important systemic HCV-EHDs are mixed cryoglobulinemia and lymphoproliferative disorders, while the most frequent and clinically important endocrine HCV-EHDs are thyroid disorders and type 2 diabetes mellitus (T2D). From a meta-analysis of the literature a significant association between HCV infection and thyroid autoimmunity and hypothyroidism has been reported. A high prevalence of thyroid cancer has been reported, too. Furthermore, several clinical epidemiologic studies have reported that HCV infection is associated to T2D. Many studies have linked Th1 immune response with HCV infection, thyroid autoimmunity, or diabetes. These findings suggest that a possible common immunological Th1 pattern could be the pathophysiological base of the association of HCV-EHDs, with thyroid autoimmunity and T2D. In fact, HCV infection of thyrocytes or beta-cells may act by upregulating CXCL10 secretion in these cells that is responsible for Th1 lymphocyte recruitment. Th1 response leads to increased IFNgamma and TNFalpha production that in turn stimulates CXCL10 secretion by the target cells, thus perpetuating the immune cascade. This process may lead to the appearance of thyroid autoimmune disorders or T2D in genetically predisposed subjects.

Dedifferentiated thyroid cancer: a therapeutic challenge.

Human papillary dedifferentiated thyroid cancer (HPDTC) represents a therapeutic dilemma. Targeted therapy (RET proto-oncogene or BRAF-targeting drugs) are promising treatments for HPDTC. Also PPARg agonists are another exciting field for redifferentiating therapy of HPDTC. However, even if many new approaches for the therapy of HPDTC are emerging, until now a significant clinical impact on survival by the use of these drugs is still lacking. In the future, the identification of patients who are likely to benefit from each therapeutic option will be important. In this view particular importance should be given to development of primary cells from the single patient by fine needle aspiration samples, as recently observed in anaplastic thyroid cancer. In fact, chemosensitivity tests in primary tumoral cells may help in detecting responsive patients and in preventing the administration of inactive drugs to those unresponsive.

Increase of interferon-gamma-inducible CXC chemokine CXCL10 serum levels in patients with active Graves' disease, and modulation by methimazole therapy.

Background  CXCL10 plays an important role in the initial phases of Graves’ disease (GD) and autoimmune thyroiditis (AT); however, until now, CXCL10 serum levels (sCXCL10) in patients with GD have never been evaluated in relation to thyroid function and treatment.

High Values of CXCL10 Serum Levels in Mixed Cryoglobulinemia Associated With Hepatitis C Infection

OBJECTIVES:No study has evaluated circulating CXCL10 in patients with mixed cryoglobulinemia (MC) and hepatitis C virus (HCV) chronic infection. The aim of this study is to measure inteferon-inducible protein 10 (CXCL10/IP-10), interferon-gamma (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) (Th1 cytokines) in a series of cryoglobulinemic patients and to correlate this parameter to the clinical phenotype.METHODS:Serum CXCL10, IFN-gamma, and TNF-alpha were assayed in 102 patients with hepatitis C-associated cryoglobulinemia (MC + HCV), in 102 sex- and age-matched patients with type C chronic hepatitis without cryoglobulinemia (HCV+), and in 102 sex- and age-matched controls.RESULTS:Cryoglobulinemic patients showed significantly higher mean CXCL10 serum levels than controls (P < 0.0001) or HCV+ patients (P < 0.0001) (397 ± 132 pg/mL, 92 ± 53 pg/mL, 280 ± 149 pg/mL, respectively). Moreover, CXCL10 was significantly increased in 30 cryoglobulinemic patients with active vasculitis compared to those without it (460 ± 104 pg/mL vs 369 ± 139 pg/mL, respectively; P < 0.001). Both groups of MC + HCV patients with or without active vasculitis had serum CXCL10 significantly higher than HCV+ patients (P < 0.001, P= 0.02, respectively). IFN-gamma levels were not significantly different in MC + HCV than in HCV+ patients or controls. Serum TNF-alpha levels were significantly higher in MC + HCV than in HCV+ patients or controls (median [interquartile range]: 12.0 [9.8], 5.7 [5.4], 1.3 [2.1] pg/mL, respectively; P < 0.0001).CONCLUSIONS:The study demonstrates high CXCL10 and TNF-alpha serum levels in patients with hepatitis C-associated cryoglobulinemia. Moreover, in MC + HCV patients, increased CXCL10 levels were significantly associated with the presence of active vasculitis.

Novel Pyrazolopyrimidine Derivatives as Tyrosine Kinase Inhibitors with Antitumoral Activity in Vitro and in Vivo in Papillary Dedifferentiated Thyroid Cancer

AIM We have studied the antitumoral activity of two new pyrazolo[3,4-d]pyrimidine compounds (CLM3 and CLM29) in primary papillary dedifferentiated thyroid cancer (DePTC) cells. METHODS The antiproliferative effect was tested in DePTC cells obtained at reoperation from patients with recurrence of the tumor. The concentrations of CLM3 and CLM29 used in the in vitro experiments were 1, 10, 30, and 50 μm. RESULTS Proliferation assays in DePTC cells showed a significant reduction of proliferation by CLM3 and CLM29, which was by 12% with CLM3 (the most potent compound) 10 μm, 43% with CLM3 30 μm, and 60% with CLM3 50 μm. CLM3 and CLM29 increased the percentage of apoptotic cells in DePTC cells dose dependently (P < 0.001) and inhibited migration (P < 0.001). A DePTC cell line (AL) was injected sc in CD nu/nu mice, and tumor masses became detectable 10 d after xenotransplantation. CLM3 (40 mg/kg · die) significantly inhibited tumor growth and weight, and the therapeutic effect was significant starting on the 19th day after cell implantation (4 d after the beginning of treatment). The CLM3-treated group of animals did not show any appreciable toxicity. CLM3 and CLM29 increased thrombospondin-1 expression in the AL cell line. A significant reduction of microvessels and in the percentage of antivascular endothelial growth factor antibody immunoreactivity was observed in the CLM3 treated tumors, with a simultaneous increase of the percentage of necrosis. CONCLUSION The antitumoral activity of two new pyrazolo[3,4-d]pyrimidine compounds (CLM3, CLM29) in vitro and CLM3 in vivo in DePTC has been shown, opening the way to a future clinical evaluation.

Thiazolidinediones and antiblastics in primary human anaplastic thyroid cancer cells.

Objective  No study has evaluated the antiproliferative effects of thiazolidinediones and antiblastics in ‘primary cultured human anaplastic thyroid cancer cells’.

High values of CXCL10 serum levels in patients with hepatitis C associated mixed cryoglobulinemia in presence or absence of autoimmune thyroiditis.

The aim of this study was to evaluate CXCL10 serum levels in patients with hepatitis C virus chronic infection (HCV) associated mixed cyoglobulinemia (MC), in the presence or absence of autoimmune thyroiditis (AT). CXCL10 was assayed in 50 MC patients without AT, in 40 MC patients with AT (MC+AT), in 2 gender- and age-matched control groups [50 healthy controls (without HCV or AT; control); 40 controls with AT (without HCV and MC; control+AT)]. CXCL10 was significantly higher: (1) in control+AT than in control (p<0.001); (2) in MC patients than in control (p<0.001); (3) in MC+AT patients than in control (p<0.001), control+AT (p<0.001), or in MC (p=0.002). CXCL10 was significantly increased in MC+AT patients with thyroid hypoechogenicity (388+/-147 vs 302+/-112; p=0.03), or hypothyroidism (391+/-142 vs 307+/-118; p=0.04), compared to those without. By defining a high CXCL10 level as a value at least 2 SD above the mean value of the control (>167 pg/ml), 8% of control, 22% of control+AT, 47% of MC and 80% of MC+AT had high CXCL10 (p<0.0001). In conclusion, our study is the first to demonstrate high serum levels of CXCL10 in MC and that CXCL10 in MC+AT patients are significantly higher compared to MC patients.

CXCR3, CXCL10 and type 1 diabetes

Type 1 diabetes (T1D) is due to antigen-specific assaults on the insulin producing pancreatic β-cells by diabetogenic T-helper (Th)1 cells. (C-X-C motif) ligand (CXCL)10, an interferon-γ inducible Th1 chemokine, and its receptor, (C-X-C motif) receptor (CXCR)3, have an important role in different autoimmune diseases. High circulating CXCL10 levels were detected in new onset T1D patients, in association with a Th1 autoimmune response. Furthermore β-cells produce CXCL10, under the influence of Th1 cytokines, that suppresses their proliferation. Viral β-cells infections induce cytokines and CXCL10 expression, inducing insulin-producing cell failure in T1D. CXCL10/CXCR3 system plays a critical role in the autoimmune process and in β-cells destruction in T1D. Blocking CXCL10 in new onset diabetes seems a possible approach for T1D treatment.

Dysregulation of secretion of CXC α-chemokine CXCL10 in papillary thyroid cancer: modulation by peroxisome proliferator-activated receptor-γ agonists

In papillary thyroid carcinomas (PTCs), oncogenes activate a transcriptional program including the upregulation of CXCL10 chemokine, which stimulates proliferation and invasion. Furthermore, peroxisome proliferator-activated receptor-gamma (PPARgamma) activators thiazolidinediones (TZDs) modulate CXCL10 secretion in normal thyroid follicular cells (TFC), and inhibit PTC growth. Until now, no study has evaluated the effect of cytokines on CXCL10 secretion in PTCs, nor the effect of PPARgamma activation. The combined effects of interferon gamma (IFNgamma) and tumor necrosis factor alpha (TNFalpha) stimulation on CXCL10 secretion in primary cells from PTCs and TFC were tested. Furthermore, the effect of PPARgamma activation by TZDs, on CXCL10 secretion and proliferation in these cell types was studied. In primary cultures of TFC and PTCs CXCL10 production was absent under basal conditions; a similar dose-dependent secretion of CXCL10 was induced by IFNgamma in both cell types. TNFalpha alone induced a slight but significant CXCL10 secretion only in PTCs. The stimulation with IFNgamma+TNFalpha induced a synergistic CXCL10 release in both cell types; however, a secretion more than ten times higher was induced in PTCs. Treatment of TFC with TZDs dose-dependently suppressed IFNgamma+TNFalpha-induced CXCL10 release, while TZDs stimulated CXCL10 secretion in PTCs. A significant antiproliferative effect by TZDs was observed only in PTCs. In conclusion, a dysregulation of CXCL10 secretion has been shown in PTCs. In fact, a CXCL10 secretion more than ten times higher has been induced by IFNgamma+TNFalpha in PTCs with respect to TFC. Moreover, TZDs inhibited CXCL10 secretion in TFC and stimulated it in PTCs. The effect of TZDs on CXCL10 was unrelated to the significant antiproliferative effect in PTCs.