Serum interleukin-23 (IL-23) is increased in Hashimoto's thyroiditis

Recent studies have demonstrated that T-helper 17 lymphocytes (Th17), which produce mostly IL-17, play a major role in several autoimmune diseases commonly thought to be Th1-related, including Hashimoto's thyroiditis (HT). IL-23, a member of the IL-12 cytokine family, is known to guide T cells toward the Th17 phenotype and its serum levels are increased in several autoimmune disease. Few data are available in the literature on IL-23 in HT. Using IL-23 Quantikine ELISA Kit (lower limit of detection 2.7 pg/mL) we analyzed the serum levels of IL-23 in 81 HT patients (75 females and 6 males, aged 14-70; mean age 39±17 years), and an age- and sex-matched group of 80 healthy persons. Both patients and controls did not receive any treatment. The positive detection rates of serum IL-23 were significantly higher in patients with HT: 56% of HT patients had detectable IL-23 in serum compared to 36% of healthy subjects (Chi χ² test, p=0.014). Moreover, HT patients had significantly higher serum concentrations of IL-23 (157.38 ± 17.92 pg/mL) in comparison with healthy controls (21.46 ± 5.4 pg/mL; p <0.0001). No significant correlation was found between serum levels of IL-23 and Tg-Ab or TPO-Ab levels, as well as with TSH values, in HT patients. In conclusion, serum IL-23 is increased in euthyroid and untreated HT patients, as compared to healthy subjects. Our data suggest that IL-23 would play a role in the pathogenesis of HT.

HGF/c-met system targeting PI3K/AKT and STAT3/phosphorylated-STAT3 pathways in pituitary adenomas: an immunohistochemical characterization in view of targeted therapies

The ligand/receptor hepatocyte growth factor (HGF)/c-met signaling system promotes cellular growth and angiogenesis through PI3K/phosphor-Akt and STAT3/phosphor-STAT3 downstream effectors. In this study, we have evaluated the expression of molecules of the HGF/c-met pathway in pituitary adenomas (PA). The expression of HGF, c-met, PI3K (p85αsubunit) pAkt, STAT3, and pSTAT3 was analyzed by immunohistochemistry in an archival series of 30 PA (12 non-functioning and 18 functioning; 25 macroadenomas and 5 microadenomas). PAs expressed all six proteins in tumor epithelial cells. The proportion of c-met(+ve) cells was greater than HGF(+ve) cells (49 ± 19 vs 34 ± 17 %, P < 0.01), the pAkt(+ve) cells greater than PI3K(+ve) cells (39 ± 16.0 vs 1.3 ± 0.5 %, P < 0.001), and the STAT3(+ve) cells greater than active pSTAT3(+ve) cells (14 ± 8 vs 7 ± 6 %, P < 0.01). Furthermore, endothelial Akt immunostaining was detected on the vascular surface area of 17 PAs, in macroadenomas more frequently than in microadenomas (82 vs 18 %). The percentage of immunostained endothelial cells was greater in macro than in microadenomas (19 ± 7 and 7 ± 3 %; P < 0.05). In conclusion, HGF and c-met are widely expressed in PA, and correlate with pAkt expression. These data, together with the finding of pAkt immunostaining on microvascular areas related to tumor size, suggest a major role of the pAKT signaling in tumor growth and angiogenesis. There might be practical implications for the targeted therapy of PA.

The unusual association of Graves' disease, chronic spontaneous urticaria, and premature ovarian failure: report of a case and HLA haplotype characterization

Chronic spontaneous urticaria (CSU), defined as the occurrence of spontaneous wheals for more than six weeks, has been associated with autoimmune diseases. Herein, we report the unusual association of CSU, Graves' disease, and premature ovarian failure. Human leukocyte antigen (HLA) studies were performed. A 36-year-old woman presented symptoms and signs of hyperthyroidism for three months. In the same period, the patient complained of widespread urticarial wheals, intensely itchy, and poorly responsive to therapy with antihistaminic agents. Hyperthyroidism was confirmed biochemically, and treatment with methimazole was started. As hyperthyroidism improved, a marked improvement in her urticaria was also observed. However, the patient continued to complain of amenorrhea. Endocrine evaluation, at the age 38, was consistent with premature ovarian failure. This is the first report of coexistence of GD, CSU, and POF. The genetic background of such unusual association is a specific combination of HLA.

Chronic idiopathic urticaria and Graves' disease

Chronic urticaria is a common condition characterized by recurrent episodes of mast cell-driven wheal and flare-type skin reactions lasting for more than 6 weeks. In about 75% of cases, the underlying causes remain unknown, and the term chronic idiopathic urticaria (CIU) is used to emphasize that wheals develop independently of identified external stimuli. Although CIU affects about 1.0% of the general population, its etiopathogenesis is not yet well understood. It is now widely accepted that in many cases CIU should be regarded as an autoimmune disorder caused by circulating and functionally active IgG autoantibodies specific for the IgE receptor (FceRI) present on mast cells and basophils or for IgE itself. The well-known association of CIU with other autoimmune processes/diseases represents further indirect evidence of its autoimmune origin. Autoimmune thyroid diseases, especially autoimmune thyroiditis, represent the most frequently investigated diseases in association with CIU. Here we review this topic with particular regard to the association between Graves' disease and CIU. The possible pathogenetic mechanisms and the clinical implications of such an association are discussed.

Follicular variant of papillary thyroid carcinoma presenting as toxic nodule in an adolescent: coexistent polymorphism of the TSHR and Gsα genes

BACKGROUND

Autonomously functioning, "hot", thyroid nodules are not common in children and adolescents. Such nodules are not considered alarming because they are assumed to be benign adenomas. Herein, we present a 15-year-old girl with a papillary thyroid carcinoma of 3.5 cm in diameter, which was functionally autonomous and scintigraphically hot.

PATIENT FINDINGS

The patient, initially referred to our Endocrine Unit because of a thyroid nodule, returned 6 months later for symptoms of hyperthyroidism. Hyperthyroidism was confirmed biochemically. Radioactive iodine ((131)I) thyroid scintigraphy was consistent with an autonomous thyroid nodule. As per guidelines, the patient underwent surgery and a pathological examination revealed papillary carcinoma, follicular variant. The excised nodule was examined for activating mutations of the thyrotropin receptor (TSHR), Gsα (GNAS1), H-RAS, N-RAS, K-RAS, and BRAF genes by direct sequencing. No mutations were found. Nevertheless, two combined nonfunctioning mutations were detected: a single-nucleotide polymorphism (SNP) of the TSHR gene, in exon 7, at codon 187 (AAT→AAC, both encoding asparagine), and a SNP within exon 8 of the Gsα gene at codon 185 (ATC→ATT, both encoding isoleucine). Both SNPs were also identified in the germline DNA of the patient. The same SNPs were sought in the parents and brother of our patient. Her father was heterozygous for the TSHR SNP, her mother heterozygous for the Gsα SNP, and her brother was wild type.

CONCLUSIONS

This case demonstrates that the presence of hyperfunctioning thyroid nodule(s) does not rule out cancer and warrants careful evaluation, especially in childhood and adolescence to overlook malignancy.

Parathyroid carcinoma as a challenging diagnosis: report of three cases

Parathyroid carcinoma (PC) is a rare malignancy with an indolent but progressive course. This rare tumour is often difficult to diagnose preoperatively, thus limiting the efficacy of surgery. As long-term survival is largely dependent on the extent of the primary surgical resection, it is of great importance to consider PC in the differential diagnosis of hyperparathyroidism. We herein report three PC patients with different clinical histories who were followed up at our hospital for over a 5-year period, emphasizing the variability in clinical presentation of this rare tumour. Moreover, NORA (Nucleolar Organizer Regions, a standardised silver-stain, marker of proliferation rate) values encountered in these PC patients confirm that AgNOR analysis may be regarded as an additional tool when the pathologist encounters difficulties in defining parathyroid lesions which are not clearly benign.

Cell proliferation parameters and apoptosis indices in pituitary macroadenomas

BACKGROUND

Pituitary adenomas are usually well-differentiated tumors but may show locally aggressive behavior.

AIM

To investigate the relationship between proliferation and apoptosis parameters and tumor recurrence in a series of 20 radically resected pituitary macroadenomas (11 functioning, 9 non-functioning).

MATERIALS AND METHODS

Proliferative activity and DNA ploidy were analyzed by flow cytometry (FCM) on fresh surgical specimens. Immunohistochemistry for Ki-67/MIB-1 and for the anti-apoptotic protein Bcl-2 was performed on paraffin-embedded specimens from the same tumors. Tumor regrowth was evaluated by magnetic resonance imaging (MRI).

RESULTS

Six adenomas recurred after surgery, regardless of hormonal hypersecretion. Pre-surgical tumor size was significantly higher in recurrent than in non-recurrent adenomas (p=0.003). Pre-surgical MRI demonstrated cavernous sinus (CS) invasiveness in all recurrent tumors, while none of the non-invasive adenomas recurred (p=0.042, by Fisher's exact test). The DNA content was aneuploid in 5/20 adenomas, one of which recurred. Cell percentages in the S (%SPF) and G2+M (%G2-M) phases and proliferative index (PI) (PI=%SPF+%G2-M) were significantly higher in aneuploid than in diploid adenomas (p<0.05), but no significant differences concerning all FCM parameters were observed between recurrent and non-recurrent adenomas. Similarly, MIB-1 did not show a significant difference of expression between recurrent and non-recurrent adenomas (p=0.33). Bcl-2 immunoreactivity was detected in 12/15 pituitary adenomas, involving 63±35% of tumor cells, regardless of tumor recurrence.

CONCLUSIONS

In this group of radically resected pituitary macroadenomas, neuroradiological finding of CS invasiveness--but not FCM parameters nor MIB-1 and Bcl-2 expression--is useful for predicting tumor recurrence.

HGF/C-MET system pathways in benign and malignant histotypes of thyroid nodules: an immunohistochemical characterization

OBJECTIVE

Upon binding with HGF, the thyrosine-kinase receptor c-met induces cell growth, scattering and morphogenic effects via the trasducers STAT3 and phosphorylated-STAT3, PI3K/Akt, Rho. HGF, c-met and STAT3 are expressed with very high frequency in papillary thyroid carcinomas (PTC), suggesting a role in PTC. Herein we first investigate the simultaneous expression of HGF, c-met, STAT3, phosphor-STAT3, PI3K, Akt and Rho in thyroid nodules.

DESIGN AND METHODS

Using immunohistochemistry, we studied: 30 colloid nodules (CN), 18 hyperplastic nodules (HN), 20 follicular adenomas (FA), 15 oncocytic adenomas (OA), 20 PTC, 16 follicular carcinomas (FTC) and 6 anaplastic carcinomas (ATC).

RESULTS

All 7 proteins were expressed in 15% of FA (with HGF, PI3K and Rho stromal reactivity) and 25% of PTC, and the combination HGF/c-met/STAT3/ pSTAT3/PI3K was expressed by all PTC, each protein being expressed by tumor cells. In contrast, 13/16 FTC (81%) exhibited immunoreactivity for PI3K (both epithelial and stromal), and 100% of ATC was PI3K+ (both epithelial and stromal) and Rho+ (epithelial). Epithelial expression of PI3K correlated with the clinical behavior of histotypes and, within FTC, the proportion of PI3K+ cells correlated with both the clinical and pathological stage (r=0.95; p<0.001). As for the shared epithelial expression of PI3K, this concerned approximately one-fourth of tumor cells in FTC and ATC vs one-thirtieth in PTC.

CONCLUSIONS

Our data may have practical implications for the targeted medical therapy of thyroid cancer arising from the follicular epithelium.

Association of autonomously functioning thyroid nodules with Hashimoto's thyroiditis: study on a large series of patients

OBJECTIVE

Autonomously functioning thyroid nodules (AFTNs) associated with Hashimoto's thyroiditis (HT) are rarely reported. This study evaluates the magnitude of such association, elaborating the clinical and biochemical characteristics of HT and AFTN.

MATERIALS AND METHODS

We reviewed the records of our patients with thyroid nodules, including serum TSH, free T4 and T3, Tg-Ab, TPO-Ab, ultrasonography, Tc-99m Sodium Pertechnetate scintigraphy (performed in overt or subclinical hyperthyroid patients). HT patients with coexisting AFTN(s) (group A) were compared with patients with AFTNs alone (group B, n=267).

RESULTS

80 patients (65 women and 15 men; F:M ratio 4.3:1; age 57±15 years) had AFTN(s) and coexisting HT. Except 9 patients who were under methimazole, all had suppressed (<0.01 mU/L) or low (<0.4 mU/L) TSH; 17/71 (24%) had increased FT4 and/or FT3. Subclinical hyperthyroidism prevailed over frank hyperthyroidism in group A (76 vs. 24%), but not in group B (56 vs. 44%) ( P=0.005). Group A patients had lower serum FT3 (∼0.6 pmol/L or 9%) and FT4 (∼0.9 pmol/L or 4%) as compared to group B. The maximum diameter of the AFTN(s) was 8% smaller in group A as compared with group B, thus matching the said difference in FT3. A positive correlation between nodule size and age was found only in group B ( P=0.015).

CONCLUSION

Even if difference in the size of nodules between groups A and B does not reach statistical significance, the chronic intrathyroid lymphocytic infiltration of HT may decrease the tendency of the AFTNs to grow and diminish their degree of functioning.

An analytical model for improving absorbed dose calculation accuracy in non spherical autonomous functioning thyroid nodule

AIM

Patients candidate to radioiodine treatment of autonomous functioning thyroid nodule (AFTN) are characterized by a wide range of nodule volumes with different shapes. To optimize the treatment, pretherapeutic dosimetry should account also for the dependence of deposited energy on the nodule geometry.

METHODS

We developed a Monte Carlo code in Geant4 to simulate the interaction of beta and gamma radiations emitted by Na-131I into ellipsoidal volumes of soft tissue homogeneously uptaking the radionuclide, surrounded by a simplified antropomorphic phantom. We simulated 9 volumes between 0.1 and 50 cm3, each one with 8 different ellipsoidal shapes. We considered the data of 10 patients affected by AFTN, whose nodule volumes were in the range 1-40 cm3, who underwent radioiodine therapy following the traditional dosimetric approach. The patients underwent ultrasonographic (US) study, in order to determine the nodule volume, and radioiodine thyroid uptake measurements between 3 and 168 hours after radioiodine tracer dose administration.

RESULTS

We found an analytical relationship between the average deposited energy and the ellipsoid's semiaxes and we included it in the formula for the calculation of activity to be administered, A0. For the 10 patients studied, A0 calculated with our approach ranges from +9% to -2% with respect to the one calculated with the traditional formula.

CONCLUSION

The proposed model, accounting for the dependence of beta and gamma absorbed fractions from nodule volume and shape, can lead to a more accurate estimation of A0 during AFTN therapy. Since the measurement of nodule axes is routinely obtained from pretherapeutic US, our approach can be introduced in the clinical practice without changing the diagnostic pre-therapeutic protocol.

The tyrosine kinase receptor c-met, its cognate ligand HGF and the tyrosine kinase receptor trasducers STAT3, PI3K and RHO in thyroid nodules associated with Hashimoto's thyroiditis: an immunohistochemical characterization

Hepatocyte growth factor (HGF) exerts proliferative activities in thyrocytes upon binding to its tyrosine kinase receptor c-met and is also expressed in benign thyroid nodules as well as in Hashimoto's thyroiditis (HT). The simultaneous expression of HGF/c-met and three trasducers of tyrosine kinase receptors (STAT3, PI3K, RHO) in both the nodular and extranodular tissues were studied by immunohistochemistry in 50 benign thyroid nodules (NGs), 25 of which associated with HT. The ligand/tyrosine kinase receptor pair HGF/c-met and the two trasducers PI3K and RHO were expressed in NGs, regardless of association with HT, with a higher positive cases percentage in HT-associated NGs compared to not HT-associated NGs (25/25 or 100% vs 7/25 or 28%; P<0.001). HGF, PI3K and RHO expression was only stromal (fibroblasts and endothelial cells), in all 32 reactive NGs, while c-met localization was consistently epithelial (thyrocyes). Immunoreactions for HGF, c-met, PI3K and RHO were also apparent in the extra-nodular tissue of HT specimens, where HGF and PI3K were expressed not only in stromal cells but also in thyrocyes along with the c-met. Finally, a positive correlation was observed between the proportion of HGF, c-met, PI3K follicular cells and the grade of lymphoid aggregates in HT. In conclusion, HGF, c-met, PI3K are much more frequently and highly expressed in HT compared to NGs, and among all NGs in those present in the context of HT. A paracrine effect of HFG/c-met on nodule development, based on the prevalent stromal expression, may be suggested along with a major role of HGF/c-met and PI3K in HT. Finally, the expression of such molecules in HT may be regulated by lymphoid infiltrate.

Serum hepatocyte growth factor is increased in Hashimoto's thyroiditis whether or not it is associated with nodular goiter as compared with healthy non-goitrous individuals

BACKGROUND

Some growth factors and cytokines are known to cooperate with TSH in thyroid nodular growth, but few data are available on their circulating levels in Hashimoto's thyroiditis (HT).

AIM

To evaluate in HT patients whether thyroid nodules are associated with variations in serum levels of hepatocyte growth factor (HGF) and interleukin-6 (IL-6).

SUBJECTS AND METHODS

Serum levels of HGF and IL-6 were measured by enzyme-linked immunosorbent assay in 176 euthyroid subjects, subdivided into 4 groups: A) HT patients with nodular goiter (no.=42); B) non-goitrous HT patients (no.=36); C) non-HT patients with nodular goiter (no.=48), and D) healthy subjects without thyroid disease (no.=50).

RESULTS

The highest concentrations of serumHGF were found in patients with nodular goiter, irrespective of the presence of associated HT (groups A and C). Nevertheless, in group A serum HGF levels were significantly higher than in group C (860.8+/-333.6 pg/ml vs 691.5+/-156 pg/ml, p<0.01). Moreover, though serum HGF levels in group B (578.3+/-217 pg/ml) were lower than in group A, they were significantly higher than in healthy controls (group D, 512.7+/-170.4 pg/ml, p<0.001). Serum IL-6 levels were similar in the two HT groups (A and B), and increased with respect to groups C and D.

CONCLUSIONS

Serum HGF is increased in HT, especially associated to thyroid nodules, as compared with healthy non-goitrous individuals.

Immunohistochemical localization and functional characterization of somatostatin receptor subtypes in a corticotropin releasing hormone-secreting adrenal phaeochromocytoma: review of the literature and report of a case

Somastostatin receptors are frequently expressed in phaeochromocytoma but data on somatostatin receptor subtyping are scanty and the functional response to the somatostatin analogue octretide is still debated.We report an unusual case of pheochromocytoma, causing ectopic Cushing’s syndrome due to CRH production by the tumour cells, in a 50-yr-old woman. Abdominal computed tomography revealed an inhomogeneous, 9-cm mass in the right adrenal gland, and [¹¹¹In-DTPA⁰] octreotide scintigraphy showed an abnormal uptake of the radiotracer in the right perirenal region, corresponding to the adrenal mass. The patient underwent laparoscopic surgery and formalin-fixed and paraffin-embedded samples were studied. The tumour was extensively characterized by immunohistochemistry and somatostatin receptor (SSTRs) subtypes expression was analyzed. Histological and immunohistochemical examination of the surgical specimens displayed a typical pheochromocytoma, which was found to be immunoreative to S-100, chromogranin A and neurofilaments. Immunostaining for SSTR subtypes showed a positive reaction for SSTR₁, SSTR_2A, SSTR_2B, antisera on tumour cells. The intense and diffuse immunostaining for corticotropin releasing hormone (CRH) antiserum indicated that Cushing’s disease was dependent on CRH overproduction by the pheochromocytoma, in which no immunostaining for adrenocorticotropic hormone was found. Our report confirms the heterogeneity of the pattern of SSTR expression in pheochromocytomas, and provide further evidence for functional SSTR subtype SSTR_2a in a subgroup of pheochromocytomas, suggesting that these tumours may represent potential target for octreotide treatment.

Non-functioning pituitary adenomas infrequently harbor G-protein gene mutations

BACKGROUND

Mutations of the genes encoding the alpha subunit of the stimulatory G protein (Gs) and of the inhibiting Gi2 protein (GNAS1 and GNAI2 genes, respectively) have been described in various endocrine neoplasias, including pituitary tumors.

AIM

To search for mutations of GNAS1 and GNAI2 in a continuous series of non-functioning pituitary adenoma (NFPA) patients neurosurgically treated.

SUBJECTS AND METHODS

The surgical samples of 22 patients who have been defined and characterized on a clinical, biochemical, histological, and immunohistochemical point of view have been processed for investigating the presence of the above mutations by PCR amplification of the hot spots exons 8 and 9 of GNAS1, and exons 5 and 6 of GNAI2, followed by direct sequencing. Moreover, the promoter region of GNAI2, in order to assess the prevalence of single nucleotide polymorphisms (SNP), was investigated in the same series.

RESULTS

A CGT>TGT mutation at codon 201 of GNAS1 gene in a single case of NFPA was found, but no mutation of GNAI2A was demonstrated.

CONCLUSIONS

This finding suggests and confirms that G-protein mutations are rare and not crucial in NFPA development. Additionally, we found a silent SNP at codon 318 in the promoter of the Gi2alpha gene in one out of the 22 NFPA.

Expression of hepatocyte growth factor in Hashimoto's thyroiditis with nodular lesions

Hashimoto's thyroiditis (HT) is an autoimmune thyroid disease frequently associated with hyperplastic nodules (HN)s. Hepatocyte growth factor (HGF) is expressed in benign thyroid nodules and over-expressed in malignant thyroid nodules, particularly in papillary thyroid carcinomas. To elucidate the role of HGF in the development of HNs in association with HT we evaluated, by immunohistochemistry, the expression of HGF in both nodular and extranodular tissues, obtained from 30 HTs and 15 goiter samples. Six normal thyroid glands were used as controls. All normal control tissue samples exhibited no evidence of HGF immunoreaction. HNs showed weak to moderate HGF immunoreaction, which was located exclusively in the cytoplasm of stromal cells (fibroblasts and endothelial cells). However, the percentage of positive cases was higher in HNs arisen in the context of HT, compared to HNs not associated with HT (30/30 or 100% vs 4/15 or 40%; p<0.001). HGF immunoreactivity was also detected in all extranodular tissues from HT specimens (30/30 or 100%), but we found some significant differences. In fact, while in HNs observed in the context of HT lesions HGF was expressed only in stromal cells, in the extranodular tissues from the same thyroid gland affected by HT it was also detected in the cytoplasm of the epithelial follicular cells. Furthermore, HTs showed a much higher HGF staining grade in the extranodular tissue compared to HNs. Finally, a clear positive correlation was observed in HT between the proportion of HGF expressing follicular cells and the grade of lymphoid aggregates of the thyroid gland. In conclusion, HGF is much more frequently and highly expressed in thyroid tissue with HT, compared to goiter. In HT glands HGF can be detected in both follicular thyroid cells and stromal cells, while in HNs, either from goiters or associated with HT, its expression is restricted only to the stromal cells. These data indicate that HGF may play a role in cell proliferation processes occurring in thyroid glands affected by HT, probably under the regulation of the lymphoid infiltrate.

Immunoexpression of multidrug-resistance protein 2 and cyclooxygenase 2 in medullary thyroid carcinomas

CONTEXT

Chemoresistance is due to the expression of multidrug-resistance proteins (MRPs). Cyclooxygenase 2 (COX2), a key enzyme in prostaglandins synthesis, upregulates MRP1. MRP1 is overexpressed in medullary thyroid carcinomas (MTCs), but it is not involved in resistance to doxorubicin and cisplatin, which are commonly used in MTC treatment. MRP2 is specifically involved in resistance to both chemotherapeutic agents, but no data exist on the expression of MRP2 and COX2 in MTC.

OBJECTIVE

To evaluate MRP2 and COX2 expressions in MTC.

DESIGN

We analyzed immunohistochemical expression of MRP2 and COX2 in 12 MTCs and in 6 lymph node metastases. Results were correlated with pTNM and clinical stage.

RESULTS

MRP2 and COX2 expressions were observed only in tumor samples and metastases. Nine MTCs, all pTNM stage T4, were positive for MRP2, whereas 3 MTCs, pTNM stages T2 and T3, were unreactive for MRP2. Six metastatic MTCs at stage T4 showed higher proportion of MRP2+ cells, compared with primary tumors. All 12 MTCs were positive for COX2. Three MTCs, pTNM stage T2 and T3, showed COX2 positivity in all cells. The proportion of COX2+ cells decreased with increased pTNM stage. Four out of 6 metastatic MTCs, stage T4, showed a lower proportion of COX2+ cells, compared with primary tumors. The proportion of MRP2+ cells was inversely related to the proportion of COX2+ cells.

CONCLUSIONS

MRP2 and COX2 expression correlated with pTNM stage. High MRP2 and low COX2 expression may explain resistance to doxorubicin and cisplatin, which is observed in advanced stage MTC. Evaluation of the expression pattern of these 2 proteins may be useful to predict chemosensitivity of these types of tumors.

Immunoexpression of the CD30 ligand/CD30 and IL-6/IL-6R signals in thyroid autoimmune diseases

To elucidate the role of Th2 cytokines in autoimmune thyroid diseases, we have studied by immunohistochemistry the expression of two Th2 ligand/receptor systems (CD30-L/CD30 and IL-6/IL-6R) in goitrous Graves' disease (GD) and Hashimoto's thyroiditis (HT). A total number of 50 nodular goiters (NG), including 10 GD showing a lymphoid aggregate grade I, 30 HT 8 of which had a lymphoid aggregate of grade I, 12 of grade II and 10 grade III, and 10 colloid goiters have been evaluated. In addition, 5 normal thyroids were included in the study as controls. Reactivity of ligand and cognate receptor of both CD30-L/CD30 and IL-6/IL-6R pathways was observed in a greater proportion of GD, compared to HT (P<0.005). In HT, the expression of CD30-L/CD30 system was detected more frequently than IL-6/IL-6R (P<0.05) and showed an inverse correlation with the grade of lymphoid aggregate, whereas IL-6/IL-6R correlated positively with lymphocyte infiltration (P<0.05). Based on our results concerning a dominance of Th2 cytokines in GD, we postulate that CD30-L/CD30 and IL-6/IL-6R systems could play a major role in the pathogenesis of GD. However, the expression of CD30L/CD30 and IL-6/IL-6R in HT suggests that Th2 mechanisms are involved also in tissue damage of HT. The two systems could contribute to drive the autoimmune response skewing toward a Th2 phenotype and this appears to be correlated with the lymphoid aggregate grade.

Clinico-pathological significance of cell-type-specific loss of heterozygosity on chromosome 7q21: analysis of 318 microdissected thyroid lesions

A careful pathological examination often reveals the presence of different lesions at various stages of tumor progression and invasion, even in those thyroid glands presenting with solitary nodules. Each thyroid lesion is composed of many different cell types, reflecting the marked heterogeneity of normal thyroid tissue. Among the different chromosome regions altered in thyroid tumors, 7q21 appears to be specifically involved in malignant tumors, especially of the follicular type. This study was conducted to analyze the loss of heterozygosity (LOH) pattern at 7q21 in pure populations of cells from each single lesion harbored in surgically removed thyroid glands, and to evaluate its clinical significance. One hundred and forty-two thyroid glands were examined, all showing, as a common trait, a goitrous appearance associated with one single lesion in 114 cases and with more than one in the remaining 28 cases. A total number of 318 lesions was analyzed, consisting of 142 goiters (TG), 48 hyperplasias (TH), 80 adenomas (TA) and 48 carcinomas (TC). Five different types of cells were isolated by laser capture microdissection from each lesion. DNA was analyzed by PCR and polyacrylamide gel electrophoresis in search of LOH affecting five microsatellite markers, D7S660, D7S630, D7S492, D7S657, and D7S689. We detected LOH at 7q21 not only in thyroid malignant tumors but also in benign lesions. Allelic loss occurred exclusively in dark nucleus and eosinophilic cytoplasm cells, commonly observed in the follicular type of lesions. In these types of lesions allelic loss frequency increases along with neoplastic transformation (9% in TG, 41% in TH, 68% in TA and 100% in TC), and is directly correlated with thyroid gland volume as well as with the presence of multiple lesions. The highest LOH rate was observed for D7S492, indicating that the recurrent region of deletion was localized at the corresponding genetic locus at 7q21.2, in the same position where the common fragile site FRA7E was previously mapped. LOH at this locus represents an early event in the development of follicular TC and is associated with intense growth of thyroid glands.

Distinctive expression of STAT3 in papillary thyroid carcinomas and a subset of follicular adenomas

Hepatocyte growth factor (HGF), HGF receptor (c-met) and the interleukin 6 (IL-6) are expressed in thyroid nodules. In extra-thyroidal tissues, the HGF/c-met and IL-6/IL-6 receptor (IL-6R) systems activate STAT3, a member of the signal transducers and activators of transcription (STATs) family. To evaluate whether either system utilizes STAT3 in thyroid nodules, we examined the immunohistochemical expression of HGF, c-met, IL-6, IL-6R, STAT3 in 6 normal thyroids and in 68 thyroid nodules. STAT3 expression was observed in 12/12 (100%) papillary thyroid carcinomas (PTC) but in none of the follicular tumors. Among benign thyroid nodules, only 2/10 (20%) follicular adenomas (FA) were STAT3+. All these 14 STAT3+ cases expressed both HGF and c-met, but only 5 PTC co-expressed IL-6 and IL-6R and the 2 FA were IL-6+ but IL-6R-. The remaining 8 FA were all HGF/c-met-, but IL-6+; of these 8, only 2 were also IL-6R+. In conclusion, in thyroid nodules STAT3 is expressed only in PTC and a number of FA. Since these cases are consistently HGF+/c-met+ and only one-third of them co-express IL-6/IL-6R, STAT3 expression correlates with the HGF/c-met expression, not with the IL-6/IL-6R expression. The 100% rate of expression of the HGF/c-met/STAT3 signaling in PTC could be relevant for the establishment of the papillary phenotype. Because of the communeness of a HGF/c-met/STAT3 pattern between all PTC and a subset of FA, we speculate that a fraction of FA may progress to PTC.

Co-expression of interleukin-6 (IL-6) and interleukin-6 receptor (IL-6R) in thyroid nodules is associated with co-expression of CD30 ligand/CD30 receptor

Data on the expression of interleukin 6 (IL-6)/interleukin 6 receptor (IL-6R) in thyroid nodules is scarce. Based on our recent data of CD30 ligand (CD30L)/CD30 receptor (CD30) in these nodules and on the knowledge that this signal stimulates IL-6 production in non-thyroid neoplasms, we wanted to evaluate the immunocytochemical expression of these 2 ligand/receptor systems in a large archival series of paraffin-embedded specimens. These specimens included 6 normal thyroids and 130 thyroid nodules. Co-expression of IL-6 and IL-6R in the epithelial (follicular) cells was observed solely in CD30L/CD30 positive nodules: 5/15 (33%) oncocytic adenomas; 6/30 (20%) follicular adenomas which belonged to 2 variants (4/4 microfollicular toxic and 2/2 hyalinizing trabecular); 9/30 (30%) papillary thyroid cancers (PTC), all belonging to the conventional variant. In PTC the proportion of tumor epithelial cells that were IL6 positive was inversely correlated with the pTNM staging (r=-0.549, p=0.01). All 15 follicular cancers (FTC), all 6 anaplastic cancers (ATC) were IL-6/lL-6R negative; 14/15 FTC and 5/6 ATC were CD30L/CD30 negative. In another oncocytic adenoma, another 4 conventional PTC and another 7 non-conventional PTC CD30L/CD30 expression was associated to expression of IL-6 only. IL-6 staining associated to absent expression of CD30L and CD30 was observed in 7 follicular adenomas (all belonging to variants different from toxic and hyalinizing trabecular), 2 oncocytic adenomas, 5 of the 30 colloid nodules and 2 normal thyroids. Of the 6 tumors arising from the parafollicular C cells (medullary thyroid cancer, MTC), all 3 that had metastasized were CD30L/CD30/IL-6 positive and IL-6R negative; only IL-6 expression was lost in both the local and distant metastases. This finding matched the loss of IL-6 expression in one PTC metastasis. All 3 non-metastasized MTC were IL-6/IL-6R negative, and 1/3 was CD30L positive/CD30 negative. We conclude that only in a subset of both benign and malignant thyroid nodules the IL-6/IL-6R signal could be induced by the CD30L/CD30. IL-6 expression is related with aggressiveness in both PTC and MTC. In the normal thyroid tissue, colloid nodules, and another subset of benign and malignant thyroid nodules, IL-6 expression is under control of signals other than CD30L/CD30.

Thyroid hormone autoantibodies in primary Sjögren syndrome and rheumatoid arthritis are more prevalent than in autoimmune thyroid disease, becoming progressively more frequent in these diseases

To verify the greater prevalence of circulating thyroid hormone autoantibodies (THAb) in primary Sjogren syndrome (SS) vs Hashimoto's thyroiditis (HT) and Graves' disease (GD), we measured THAb in the serum of patients with these 3 diseases who were sampled from 1998-1999 (no.=20, 88, 25) and 1990-1992 (no.=13, 75, 31). Patients with rheumatoid arthritis (RA) (no.=23 and 16) and other collagenoses (no.=20 and 16) were also studied. A third series of patients with these 5 diseases was studied from 1975-1982, and data have been taken into account. THAb were detected using a specific radioimmunoprecipitation method, and their presence was correlated with the presence of TG antibodies (TGAb). We found that IgG antibodies against T3, T4 or both were present with these prevalences in the 1975-1982, 1990-1992 and 1998-1999 series: HT=1, 4, 20%; GD=2, 6, 32%; SS=20, 31, 50%; RA=0, 12, 26%; other collagenoses=0, 0, 0%. The majority of the Sjogren or arthritis cases positive for THAb were negative for TGAb, while the opposite was true for the 2 autoimmune thyroid diseases. We conclude that prevalence of THAb in the 2 non-thyroid autoimmune diseases is greater than in the 2 thyroid autoimmune diseases. In addition, prevalence of THAb is increasing over time regardless of disease. Molecular similarity between extra-thyroid connective proteins (specifically associated to primary SS and RA) and iodinated regions of TG, and an increased preponderance of environmental factors as triggers of autoimmune diseases might account for our findings.

Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial

Old studies in animals and unblinded studies in a few hyperthyroid patients suggested that L -carnitine is a periferal antagonist of thyroid hormone action at least in some tissues. This conclusion was substantiated by our recent observation that carnitine inhibits thyroid hormone entry into the nucleus of hepatocytes, neurons, and fibroblasts. In the randomized, double-blind, placebo-controlled 6-month trial reported here, we assessed whether 2 or 4 g/d oral L-carnitine were able to both reverse and prevent/minimize nine hyperthyroidism- related symptoms. We also evaluated changes on nine thyroid hormone-sensitive biochemical parameters and on vertebral and hip mineral density (bone mineral density). Fifty women under a fixed TSH-suppressive dose of L -T(4) for all 6 months were randomly allocated to five groups of 10 subjects each. Group 0 associated placebo for 6 months; groups A2 and A4 started associating placebo (first bimester), substituted placebo with 2 or 4 g/d carnitine (second bimester), and then returned to the association with placebo. Groups B2 and B4 started associating 2 and 4 g/d carnitine for the first two bimesters, and then substituted carnitine with placebo (third bimester). Symptoms and biochemical parameters worsened in group 0. In group A, symptoms and biochemical parameters worsened during the first bimester, returned to baseline or increased minimally during the second bimester (except osteocalcin and urinary OH-proline), and worsened again in the third bimester. In group B, symptoms and biochemical parameters (except osteocalcin and urinary OH-proline) did not worsen or even improved over the first 4 months; they tended to worsen in the third bimester. In both the A and B groups, the two doses of carnitine were similarly effective. At the end of the trial, bone mineral density tended to increase in groups B and A (B > A). In conclusion, L-carnitine is effective in both reversing and preventing symptoms of hyperthyroidism and has a beneficial effect on bone mineralization. Because hyperthyroidism depletes the body deposits of carnitine and since carnitine has no toxicity, teratogenicity, contraindications and interactions with drugs, carnitine can be of clinical use.

Expression of CD30 ligand and CD30 receptor in normal thyroid and benign and malignant thyroid nodules

Because the CD30 ligand (CD30L)/CD30 receptor (CD30) system is expressed in certain malignancies, but has not been studied in thyroid nodules, we investigated its immunohistochemical expression in 6 normal thyroids (NT) and 131 thyroid nodules: 28 colloid nodules (CN), 45 adenomas (15 oncocytic [OA], 30 follicular [FA]) and 58 carcinomas (15 follicular [FTC], 1 insular [ITC], 6 anaplastic [ATC], 30 papillary [PTC], and 6 medullary [MTC]). NT and CN expressed neither CD30L nor CD30 (CD30L-/CD30-). Forty percent of OA and 20% of FA showed epithelial coexpression of CD30L and CD30, and interstitial expression of CD30L, which was also observed in the surrounding normal tissue. Within malignancies, epithelial coexpression of CD30L and CD30 was observed in 7% of FTC, 33% of ATC, 67% of PTC, and 67% of MTC. Only PTC and MTC showed epithelial expression of CD30L in the perinodular tissue with similar frequency (80% PTC, 75% MTC). PTC and MTC had the highest proportion of CD30L+ or CD30+ cells, and together with OA, a thus far unreported nuclear location of CD30L. In PTC, the proportion of CD30L+ cells and the prevalence of nuclear location of CD30L correlated inversely and directly, respectively, with aggressiveness. In conclusion, CD30L/CD30 signaling is activated only past the colloid nodule stage, most frequently in an autocrine fashion.