High Prevalence of Common Human Viruses in Thyroid Tissue.

Introduction: Evidence points to viral infections as possible triggers of autoimmune thyroid disease (AITD), but little is known about the prevalence of common viruses in the thyroid gland. Using a novel approach based on virus enrichment in multiple cell lines followed by detection of the viral genome and visualization of viral proteins, we investigated the presence of multiple human viruses in thyroid tissue from AITD patients and controls. Methods: Thyroid tissue was collected by core needle biopsy or during thyroid surgery from 35 patients with AITD (20 Graves' disease and 15 Hashimoto's thyroiditis). Eighteen thyroid tissue specimens from patients undergoing neck surgery for reasons other than thyroid autoimmunity served as controls. Specimens were tested for the presence of ten different viruses. Enteroviruses and human herpesvirus 6 were enriched in cell culture before detection by PCR and immunofluorescence, while the remaining viruses were detected by PCR of biopsied tissue. Results: Forty of 53 cases (75%) carried an infectious virus. Notably, 43% of all cases had a single virus, whereas 32% were coinfected by two or more virus types. An enterovirus was found in 27/53 cases (51%), human herpesvirus 6 in 16/53 cases (30%) and parvovirus B19 in 12/53 cases (22%). Epstein-Barr virus and cytomegalovirus were found in a few cases only. Of five gastroenteric virus groups examined, only one was detected in a single specimen. Virus distribution was not statistically different between AITD cases and controls. Conclusion: Common human viruses are highly prevalent in the thyroid gland. This is the first study in which multiple viral agents have been explored in thyroid. It remains to be established whether the detected viruses represent causal agents, possible cofactors or simple bystanders.

Long-Term Efficacy of Ethanol Ablation as Treatment of Metastatic Lymph Nodes From Papillary Thyroid Carcinoma.

CONTEXT: Ethanol ablation (EA) is considered an alternative to surgery for metastatic lymph nodes from papillary thyroid carcinoma (PTC) in selected patients. OBJECTIVE: The aim of this study was to evaluate the long-term efficacy and safety of this treatment. DESIGN AND SETTING: Adult patients with PTC who had received EA in lymph node metastasis at a tertiary referral center, and were included in a published study from 2011, were invited to participate in this follow-up study. METHODS: Radiologic and medical history were reviewed. Ultrasound examination of the neck was performed by radiologists, and clinical examination was performed by an endocrine surgeon. Response was reported according to predefined criteria for satisfactory EA treatment. Adverse events associated with EA were evaluated. Cause of death was reported for deceased patients. RESULTS: From the 2011 study, 51 of 63 patients were included. Forty-four patients were reexamined (67/109 lesions) and 7 patients were deceased. Median follow-up time from primary surgery was 14.5 years. Median follow-up from the latest performed EA in the 2011 study was 11.3 years. Local control was permanently achieved in most patients (80%). Recurrence within an ablated node was registered in 13 metastases in 10 patients. Seven of these patients also had recurrent disease elsewhere in the neck. No major side effects were reported. CONCLUSION: EA is a minimally invasive procedure with a low risk of complications. Our data suggest that EA is a safe and efficient treatment, providing excellent results for a large group of patients in the long term.

HLA Class I Upregulation and Antiviral Immune Responses in Graves Disease.

CONTEXT: The origin of Graves disease (GD) remains elusive. However, evidence of an association between GD and viral infections is emerging. Human leukocyte antigen (HLA) class I presents viral antigens to circulating immune cells and plays a crucial role in the defense against viral infections. OBJECTIVE: This work aimed to investigate HLA class I expression, enterovirus presence, and the viral immune response proteins signal transducer and activation of transcription 1 (STAT1) and protein kinase R (PKR) in thyroid tissue from GD patients. METHODS: We collected thyroid tissue from core needle biopsies or surgical specimens from 48 GD patients and 24 controls. Standard immunohistochemistry was used to detect HLA class I and enteroviral capsid protein 1 (VP1) on formalin-fixed and paraffin-embedded tissue. STAT1 and PKR were examined by combined immunofluorescence staining. HLA class I expression score was the main outcome measure. RESULTS: The HLA class I expression score, which takes both proportion and intensity of immunostaining into account, was significantly higher in GD patients (3.1 ±â€…3.3) than in controls (0.5 ±â€…0.9) (P < .001). Significantly more VP1 positive thyroid cells were found GD samples (50.1 ±â€…30.5%) than in controls (14.9 ±â€…10.5%) (P < .001). STAT1 and HLA class I were found within the same thyroid cells and PKR and VP1 were also colocalized within thyroid cells. CONCLUSION: HLA class I is upregulated in GD and enterovirus protein is prevalent in thyroid tissue. The colocalization of HLA class I with STAT1 and VP1 with PKR indicates an antiviral tissue response. These findings support the concept of a link between viral infections and GD.

Thyroid nodules - investigation and follow-up. / Knuter i tyreoidea ­ utredning og oppfølging.

Thyroid nodules are common. As a result of increased use of diagnostic imaging, more nodules are detected as incidental findings. The great majority of them are benign and need no treatment. Systematic ultrasonography performed by a skilled doctor, possibly combined with cytology sampling, will to a large extent determine which nodules require follow-up.

Upregulation of HLA Class I and Antiviral Tissue Responses in Hashimoto's Thyroiditis.

Background: Hashimoto's thyroiditis (HT) is a common autoimmune disease of unknown origin. However, viral infections have been implicated as triggers for autoimmunity. Human leukocyte antigen (HLA) class I presents antigens to circulating immune cells and plays a crucial role in the defense against viral infections. This study aimed to investigate the presence of enterovirus and HLA class I expression in one of the largest HT thyroid tissue cohorts to date. In addition, viral receptors and viral immune response proteins were examined. Methods: Thyroid tissue samples from 46 HT patients were obtained using core needle biopsy. Thyroid tissue collected during neck surgery for other reasons than thyroid autoimmunity served as controls. Standard immunohistochemistry on formalin-fixed, paraffin-embedded tissue samples were used to detect HLA class I, enteroviral capsid protein 1 (VP1), and coxsackie and adenovirus receptor (CAR) in thyroid cells. A subset of the samples was examined with combined immunofluorescence staining for signal transducer and activator of transcription 1 (STAT1) and protein kinase R (PKR). Results: Significantly more HLA class I-positive samples were found in the HT group (31 out of 46 [67.4%]) than in the control group (5 out of 24 [20.8%]) (p < 0.001). Moreover, the semiquantitative score assessing the grade of HLA class I expression was significantly higher in the HT group (3.9 ± 3.1) than in the control group (0.5 ± 0.9) (p < 0.001). In addition, STAT1 was colocalized with HLA class I, and PKR and VP1 were also found and were colocalized together. VP1 was detected in both controls and the HT samples, with slightly more VP1+ thyroid cells in the HT samples (20.1% ± 16.4%) than in controls (14.9% ± 10.5%). Finally, the presence of CAR in thyroid cells was confirmed. Conclusion: The current study confirmed that HLA class I hyperexpression is a defining feature of HT. Thyroid cells express CAR, thus making them susceptible to enterovirus infection. The colocalization of HLA class I with STAT1 and VP1 with PKR indicates an intracellular, antiviral host response. These findings support the concept of a firm link between viral infection and autoimmune thyroid diseases.

Immunological changes and increased expression of myxovirus resistance protein a in thyroid tissue of patients with recent onset and untreated Graves' disease.

BACKGROUND: Few studies have systematically examined the immune cells that infiltrate thyroid tissue at the time of the onset of Graves' disease (GD). The role of viruses in the pathogenesis of autoimmune thyroid diseases is controversial. The present study analyzed inflammatory responses with respect to signs of virus infection. METHODS: Thyroid tissue was obtained from 22 patients with newly diagnosed and untreated GD, 24 patients with chronic GD, and 24 controls. Inflammation was assessed by immunostaining for CD4+ and CD8+ T cells, plasma cells (CD138+), and plasmacytoid dendritic cells (PDCs). The production of interferon-inducible myxovirus resistance protein A (MxA) was analyzed as a sign of virus infection. RESULTS: The degree of thyroid inflammation and fibrosis was significantly higher in both patient groups compared with that in controls. The number of CD4+ T cells and plasma cells (activated B cells) was significantly higher in both patient groups. CD8+ cells were only present in patients with chronic disease. MxA expression and the number of PDCs increased only in patients with newly diagnosed GD. There was a strong positive correlation between the number of PDCs and the number of MxA+ leucocytes. CONCLUSION: The increase in CD8+ T cells during the chronic stage of GD suggests that they may play a role in progression of the autoimmune process from early to chronic thyroiditis. Upregulation of MxA expression during the early stages of the disease, and the positive correlation between the number of PDCs and the number of MxA+ leucocytes, suggests that activated PDCs secrete type I IFNs at the lesion site, possibly in response to viral infection.

Detection of enterovirus in the thyroid tissue of patients with graves' disease.

The etiology and pathogenesis of Graves' disease (GD) are still unknown, although it is thought that both genetic and environmental factors are important. Some indirect evidence implies that a viral infection may be a possible etiologic factor in autoimmunity. The main objective of this study was to examine direct evidence of the presence of enteroviruses (EVs) in the thyroid tissue of patients with GD. Thyroid tissue from 22 patients with newly diagnosed GD was obtained by core needle biopsy, while tissue from 24 patients with chronic GD and 24 control subjects without any autoimmune thyroid diseases was collected during neck surgery. Formalin-fixed, paraffin-embedded thyroid tissue samples were examined for the presence of enterovirus capsid protein using immunohistochemistry and for enterovirus RNA using in situ hybridization. Enterovirus capsid protein was detected in 17 (37%) patients and in 4 (17%) control subjects (P = 0.103). Enterovirus RNA was identified in thyroid tissue from nine (20%) patients, but in none of the control subjects (P = 0.016). Eight (90%) of the nine virus RNA positive patients were also positive for enterovirus protein. This is the first study to analyze thyroid tissue for EVs, including patients with untreated, newly diagnosed GD. The results suggest that EVs are more frequently present in thyroid tissue of patients than controls. Further studies are indicated to explore this association to find out if a low-grade chronic enteroviral infection might be involved in the pathogenesis of GD and if this could offer new therapeutic and preventive opportunities.

Inflammation and increased myxovirus resistance protein A expression in thyroid tissue in the early stages of Hashimoto's thyroiditis.

BACKGROUND: The role of viruses as environmental triggers for Hashimoto's thyroiditis (HT) is controversial. Thyroid epithelial cells express a variety of molecules involved in antiviral responses. This study combined histological, immunological, and virological tests to describe changes in tissue from patients with newly diagnosed and untreated HT. To study the early events, patients with positive thyroid peroxidase antibodies (TPO-Ab) and normal thyroid function were also included. This stage was defined as "prethyroiditis." METHODS: Thyroid tissue was collected from 47 patients with high titers of TPO-Ab and from 24 controls. Seventeen patients had prethyroiditis, 17 had subclinical hypothyroidism, and 13 had overt hypothyroidism. The interferon (IFN)-α/ß-inducible myxovirus resistance protein 1 (myxovirus resistance protein A; MxA) was used as a surrogate marker for type I IFN expression. Inflammation, expression of MxA, and the presence of the enteroviralcapsid protein (VP1) were characterized by immunohistochemistry. The presence of enterovirus (EV) RNA was examined by in situ hybridization. RESULTS: The density of CD4+ T cells was increased in all three patient groups, while CD8+ T cells were increased only in patients with overt hypothyroidism. The density of plasma cells increased as the disease progressed. The density of plasmacytoid dendritic cells and the expression of MxA were significantly increased in all patient groups compared with controls (p<0.01). EV RNA was present in 11% of HT patients, but in none of the control subjects, whereas the enteroviral protein was detected in 19% and 16%, respectively. CONCLUSION: The inflammatory reaction in the thyroid gland is a very early event in the pathogenesis of HT. The increased expression of MxA in the inflamed tissue suggests that type I IFN plays a role in disease development. Whether this is virus-dependent needs to be explored in further studies.

Excessive decrease in serum magnesium after total thyroidectomy for Graves' disease is related to development of permanent hypocalcemia.

BACKGROUND: Transient postoperative hypocalcemia is one of the most common complications after thyroidectomy. Permanent hypocalcemia, however, is rare, but usually requires life-long treatment and follow-up. The risk of permanent hypocalcemia has been shown to be significantly higher in patients with Graves' disease. In the present study we evaluated short-term and long-term changes in serum calcium, phosphate, magnesium, and parathyroid hormone (PTH) levels in order to characterize subjects at risk of postoperative hypoparathyroidism. METHODS: Forty patients who underwent total thyroidectomy for Graves' disease were included in the study. Calcium, phosphate, magnesium, and PTH were measured before surgery and regularly during the year that followed. RESULTS: Postoperative hypocalcemia was seen in 21/40 (53 %) patients. Undetectable PTH (<0.6 pmol/L) was registered in 11/40 (27 %) patients. All patients with measurable PTH 6-48 h after operation regained normal calcium. Of those with undetectable PTH after 6-48 h, four developed permanent hypocalcemia. We found a significantly lower serum calcium level before operation in patients who developed permanent hypocalcemia compared to those who did not (p < 0.001). We also found a significant correlation between the decrease in serum magnesium from time 0 to 48 h after operation and permanent hypocalcemia (p = 0.015). CONCLUSIONS: Serum calcium prior to operation, serum PTH, and degree of decrease in magnesium levels in serum 48 h after operation may predict development of permanent hypocalcemia. Magnesium plays an important role in calcium homeostasis via stimulation of PTH secretion and modulation of PTH receptor sensitivity. Both mechanisms may have played a role for the findings reported in this article.