Cytopathology-histopathology correlation and the effect of nodule diameter on diagnostic performance in patients undergoing thyroid fine-needle aspiration biopsy

Introduction

Although thyroid fine-needle aspiration biopsy (FNAB) is established to have a good overall sensitivity and specificity, various outcomes have been reported on its performance in large nodules. The aim of the study was to evaluate the diagnostic performance of FNAB and the effect of the nodule diameter on its diagnostic performance.

Materials and Methods

The outcomes of a total of 7319 patients who underwent FNAB over the course of 5 years were analyzed retrospectively and 648 patients who had undergone post-FNAB thyroidectomy or lobectomy were included in the study. FNAB results were classified according to the Bethesda system. After evaluating the compatibility between cytology and pathology results, all-nodules and diameter-based (<4 cm and ≥4 cm) sensitivity, specificity, false positivity, false negativity, and accuracy rates of FNAB were calculated.

Results

Sensitivity of FNAB was 85.4% for all nodules, 88.3% for nodules <4 cm, and 75.8% for nodules >4 cm (P < 0.001). Specificity was 58.4% for all nodules, 49.3% for nodules <4 cm, and 75.1% for nodules >4cm (P < 0.001). While false positivity was 41.6% for all nodules, it was 50.7% for nodules smaller than 4 cm and was 24.9% for nodules larger than 4 cm (P < 0.001). False negativity was 14.6% for all nodules and was 11.7% for nodules smaller than 4 cm and 24.2% for nodules larger than 4 cm (P < 0.001). Finally, among the entire set of nodules, the accuracy was 64.4%, which was 59.2% in nodules smaller than 4 cm, and 75.2% in nodules larger than 4 cm (P < 0.001).

Conclusion

Despite a higher rate of false negativity, FNAB has higher specificity and accuracy in large nodules than those in the small nodules. Nodule diameter should not be used alone as a criterion to recommend thyroidectomy to the patient.

TRAIL induces proliferation in rodent pancreatic beta cells via AKT activation

Strategies to increase functional pancreatic beta cell mass is of great interest in diabetes-related research. TNF-related apoptosis-inducing ligand (TRAIL) is well known to promote proliferation and survival in various cell types, including vascular smooth muscle and endothelial cells. Correlation between the protective nature of TRAIL on these cells and its proliferative effect is noteworthy. TRAIL's seemingly protective/therapeutic effect in diabetes prompted us to question whether it may act as an inducer of proliferation in pancreatic beta cells. We used rat primary islet cells and MIN6 mouse beta cell line to investigate TRAIL-induced proliferation. Cell viability and/or death was analyzed by MTT, WST-1, and Annexin-V/PI assays, while proliferation rates and pathways were assessed via immunocytochemical and Western blot analyses. Receptor neutralization antibodies identified the mediator receptors. Recombinant soluble TRAIL (sTRAIL) treatment led to 1.6-fold increased proliferation in insulin-positive cells in dispersed rat islets compared to the untreated group, while adenovirus-mediated overexpression of TRAIL increased the number of proliferating beta cells up to more than six-fold. sTRAIL or adenoviral vector-mediated TRAIL overexpression induced proliferation in MIN6 cells also. TRAIL's proliferative effect was mediated via AKT activation, which was suppressed upon specific inhibition. Neutralization of each TRAIL receptor reversed the proliferative effect to some degree, with the highest level of inhibition in death receptor 5 (DR5) blockage in MIN6 cells and in decoy receptor 1 (DcR1) blockage in primary rat beta cells. Thus, TRAIL induces proliferation in rodent pancreatic beta cells through activation of the AKT pathway.

Bone metastases without primary tumor: A well-differentiated follicular thyroid carcinoma case

Metastases to the bone are the most common malignant bone tumors. Prostate, breast, and lung carcinomas are the most common primaries of bone metastases. Bone metastases show poor prognosis in means of median survival; however, some patients with highly curable tumors such as thyroid carcinoma may benefit from treatment. We report and discuss a unique case of a 70-year-old female patient presenting with arm pain, diagnosed with metastatic well-differentiated follicular carcinoma without a primary tumor in the thyroid.

Diagnostic value of the late-night salivary cortisol in the diagnosis of clinical and subclinical Cushing’s syndrome: results of a single-center 7-year experience

Late-night salivary cortisol (LNSaC) is an easy-to-use test reflecting the free cortisol level in the serum and does not require hospitalization. Controlled studies reported that LNSaC has a high sensitivity and specificity, but have not set a clearly defined cut-off value to be used in the diagnosis of Cushing’s syndrome. In this study, we aimed to evaluate the diagnostic performance of LNSaC in patients with clinical Cushing’s syndrome (CCS) and subclinical Cushing’s syndrome (SCS). The data of 543 patients, whose LNSaC levels were assessed using electrochemiluminescence immunoassay method, were retrospectively evaluated. The study included a total of 324 patients: 58 patients with CCS, 53 patients with SCS, and 213 patients without Cushing’s syndrome (NoCS). The cause of the Cushing’s syndrome was hypophyseal in 26 patients (45%), adrenal in 24 patients (41%), and ectopic in 8 patients (14%) in the CCS group. Median LNSaC levels were 0.724 (0.107–33) µg/dL in CCS group, 0.398 (0.16–1.02) µg/dL in SCS group, and 0.18 (0.043–0.481) µg/dL in NoCS group (p=0.001). Accordingly, LNSaC had 89.6% sensitivity and 81.6% specificity at a cut-off value of 0.288 µg/dL in the diagnosis of CCS; and had 80.7% sensitivity and 85.1% specificity at a cut-off value of 0.273 µg/dL in the diagnosis of SCS. In the present study, a lower sensitivity and specificity than previously reported was found for LNSaC in the diagnosis of CCS. Moreover, the diagnostic performance of LNSaC in patients with SCS was close to its diagnostic performance in patients with CCS. Each center should determine its own cut-off value based on the method adopted for LNSaC measurement, and apply that cut-off value in the diagnosis of Cushing’s syndrome.

Therapeutic Potential of Lentivirus-Mediated Glucagon-Like Peptide-1 Gene Therapy for Diabetes

Postprandial glucose-induced insulin secretion from the islets of Langerhans is facilitated by glucagon-like peptide-1 (GLP-1)-a metabolic hormone with insulinotropic properties. Among the variety of effects it mediates, GLP-1 induces delta cell secretion of somatostatin, inhibits alpha cell release of glucagon, reduces gastric emptying, and slows food intake. These events collectively contribute to weight loss over time. During type 2 diabetes (T2DM), however, the incretin response to glucose is reduced and accompanied by a moderate reduction in GLP-1 secretion. To compensate for the reduced incretin effect, a human immunodeficiency virus-based lentiviral vector was generated to deliver DNA encoding human GLP-1 (LentiGLP-1), and the anti-diabetic efficacy of LentiGLP-1 was tested in a high-fat diet/streptozotocin-induced model of T2DM. Therapeutic administration of LentiGLP-1 reduced blood glucose levels in obese diabetic Sprague Dawley rats, along with improving insulin sensitivity and glucose tolerance. Normoglycemia was correlated with increased blood GLP-1 and pancreatic beta cell regeneration in LentiGLP-1-treated rats. Plasma triglyceride levels were also normalized after LentiGLP-1 injection. Collectively, these data suggest the clinical potential of GLP-1 gene transfer therapy for the treatment of T2DM.

Using plasma exchange to successfully manage thyrotoxicosis in a patient with possible antithyroid drug-related thrombotic thrombocytopenic purpura

OBJECTIVE

Thrombotic thrombocytopenic purpura (TTP) is a rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenic purpura, neurologic abnormalities, fever, and renal insufficiency. The association or co-existence of thyrotoxicosis or antithyroid drugs with TTP has not been previously reported. Subject and Results. Herein, we present a 54-year-old female patient newly diagnosed with toxic multinodular goiter accompanying with TTP, possibly triggered by either thyrotoxicosis or antithyroid drugs.

CONCLUSIONS

The present report is the first in the literature to demonstrate the co-existence of these two diseases and the use of plasma exchange as a modality to treat both conditions.

Incretins: their physiology and application in the treatment of diabetes mellitus

Therapies targeting the action of incretin hormones have been under close scrutiny in recent years. The incretin effect has been defined as postprandial enhancement of insulin secretion by gut-derived factors. Likewise, incretin mimetics and incretin effect amplifiers are the two different incretin-based treatment strategies developed for the treatment of diabetes. Although, incretin mimetics produce effects very similar to those of natural incretin hormones, incretin effect amplifiers act by inhibiting dipeptidyl peptidase-4 (DPP-4) enzyme to increase plasma concentration of incretins and their biologic effects. Because glucagon-like peptide-1 (GLP-1) is an incretin hormone with various anti-diabetic actions including stimulation of glucose-induced insulin secretion, inhibition of glucagon secretion, hepatic glucose production and gastric emptying, it has been evaluated as a novel therapeutic agent for the treatment of type 2 diabetes mellitus (T2DM). GLP-1 also manifests trophic effects on pancreas such as pancreatic beta cell growth and differentiation. Because DPP-4 is the enzyme responsible for the inactivation of GLP-1, DPP-4 inhibition represents another potential strategy to increase plasma concentration of GLP-1 to enhance the incretin effect. Thus, anti-diabetic properties of these two classes of drugs have stimulated substantial clinical interest in the potential of incretin-based therapeutic agents as a means to control glucose homeostasis in T2DM patients. Despite this fact, clinical use of GLP-1 mimetics and DPP-4 inhibitors have raised substantial concerns owing to possible side effects of the treatments involving increased risk for pancreatitis, and C-cell adenoma/carcinoma. Thus, controversial issues in incretin-based therapies under development are reviewed and discussed in this manuscript.

Clinical utility of insulin and insulin analogs

Diabetes is a pandemic disease characterized by autoimmune, genetic and metabolic abnormalities. While insulin deficiency manifested as hyperglycemia is a common sequel of both Type-1 and Type-2 diabetes (T1DM and T2DM), it does not result from a single genetic defect--rather insulin deficiency results from the functional loss of pancreatic β cells due to multifactorial mechanisms. Since pancreatic β cells of patients with T1DM are destroyed by autoimmune reaction, these patients require daily insulin injections. Insulin resistance followed by β cell dysfunction and β cell loss is the characteristics of T2DM. Therefore, most patients with T2DM will require insulin treatment due to eventual loss of insulin secretion. Despite the evidence of early insulin treatment lowering macrovascular (coronary artery disease, peripheral arterial disease and stroke) and microvascular (diabetic nephropathy, neuropathy and retinopathy) complications of T2DM, controversy exists among physicians on how to initiate and intensify insulin therapy. The slow acting nature of regular human insulin makes its use ineffective in counteracting postprandial hyperglycemia. Instead, recombinant insulin analogs have been generated with a variable degree of specificity and action. Due to the metabolic variability among individuals, optimum blood glucose management is a formidable task to accomplish despite the presence of novel insulin analogs. In this article, we present a recent update on insulin analog structure and function with an overview of the evidence on the various insulin regimens clinically used to treat diabetes.

Molecular mechanisms of death ligand-mediated immune modulation: a gene therapy model to prolong islet survival in type 1 diabetes

Type 1 diabetes results from the T cell-mediated destruction of pancreatic beta cells. Islet transplantation has recently become a potential therapeutic approach for patients with type 1 diabetes. However, islet-graft failure appears to be a challenging issue to overcome. Thus, complementary gene therapy strategies are needed to improve the islet-graft survival following transplantation. Immune modulation through gene therapy represents a novel way of attacking cytotoxic T cells targeting pancreatic islets. Various death ligands of the TNF family such as FasL, TNF, and TNF-Related Apoptosis-Inducing Ligand (TRAIL) have been studied for this purpose. The over-expression of TNF or FasL in pancreatic islets exacerbates the onset of type 1 diabetes generating lymphocyte infiltrates responsible for the inflammation. Conversely, the lack of TRAIL expression results in higher degree of islet inflammation in the pancreas. In addition, blocking of TRAIL function using soluble TRAIL receptors facilitates the onset of diabetes. These results suggested that contrary to what was observed with TNF or FasL, adenovirus mediated TRAIL gene delivery into pancreatic islets is expected to be therapeutically beneficial in the setting of experimental models of type 1 diabetes. In conclusion; this study mainly reveals the fundamental principles of death ligand-mediated immune evasion in diabetes mellitus.