High prevalence of TSHR/Gsα mutation-negative clonal hot thyroid nodules (HNs) in a Turkish cohort.

Whereas the majority of hot thyroid nodules are caused by somatic TSH-receptor mutations, the percentage of TSH-receptor mutation negative clonal hot nodules (HN) and thus the percentage of hot nodules likely caused by other somatic mutations are still debated. This is especially the case for toxic multinodular goiter (TMNG). 35 HNs [12 solitary hot nodules (SHN), 23 TMNG] were screened for somatic TSHR mutations in the exons 9 and 10 and for Gsα mutations in the exons 7 and 8 using DGGE. Determination of X-chromosome inactivation was used for clonality analysis. Overall TSHR mutations were detected in 14 out of 35 (40%) HNs. A nonrandom X-chromosome inactivation pattern was detected in 18 out of 25 (72%) HNs suggesting a clonal origin. Of 15 TSHR or Gsα mutation negative cases 13 (86.6%) showed nonrandom X-chromosome inactivation, indicating clonal origin. The frequency of activating TSHR and/or Gsα mutations was higher in SHNs (9 of 12) than in TMNGs (6 of 23). There was no significant difference for the incidence of clonality for HNs between TMNGs or SHNs (p: 0.6396). Activating TSHR and/or Gsα mutations were more frequent in SHNs than in TMNG. However, the frequency of clonality is similar for SHN and TMNG and there is no significant difference for the presence or absence of TSHR and/or Gsα mutations of clonal or polyclonal HNs. The high percentage of clonal mutation-negative HNs in SHN and TMNG suggests alternative molecular aberrations leading to the development of TSHR mutation negative nodules.

Comparison of Color Flow Doppler Sonography (CFDS) and immunohistologic detection of microvessels for the assessment of the malignancy of thyroid nodules.

The assessment of tumor vascularization by color flow Doppler sonography (CFDS) has been suggested for the distinction between benign and malignant thyroid nodules. Our objective was to investigate if the CFDS results reflect the percentage of histologically determined microvessels in adenomas (As), adenomatous nodules (ANs), and papillary carcinomas (PCs). Tissue sections from 10 adenomas, 8 ANs and 13 PC and surrounding tissue of 10 PCs and 2 benign nodules were immunostained for CD34. A computerized image analysis was used to determine the microvessel density in four hot spots and ten systematically selected fields. Preoperatively CFDS was performed and classified according to Frates et al. We found a consistent percentage increase of CD34 stained microvessels in PCs (83 and 96%) as compared to adenomas and ANs (38 and 49%) determined by the hot spot analysis and systematic field analysis. A ROC analysis on the basis of the histologically determined number of microvessels demonstrated 70% microvessels as an optimal cut point for the diagnosis of PC with the highest sensitivity of 92% and highest specificity of 89%. The analysis of the CFDS-classification IV for the distinction between PCs and adenomas and ANs showed a sensitivity of 62% with a specificity of 100%. The lower sensitivity of the CFDS classification as compared with the immunohistologic determination of the microvessel density indicates that the CFDS classification detects the pathognomonic intranodular microvessels only incompletely. The higher CFDS specificity is most likely due to the detection of other vascular aspects of malignancy in addition to intranodular microvessels.

Increased percentage of microvessels but decreased density of large vessels in papillary carcinomas as compared to hot and cold thyroid nodules.

OBJECTIVE: For thyroid tumors increased as well as decreased vessel densities have been reported. Because of different morphometric methods and specificities of previously used antibodies for small and large vessels our objective was to investigate and compare the density of large vessels and microvessels by different morphometric methods and antibodies in hot nodules(HN), cold nodules (CN), papillary carcinoma (PC) and Graves' disease (GD) to try to clarify some of these discrepancies. DESIGN: Tissue sections from 29 HN, 22 CN, 19 PC and 8 GD thyroids were stained with the antibodies for CD34 and alpha-SMA. A computerized image analysis was used to calculate the mean area of endothelium (mEA) and the mean endothelium to tumor epithelial nucleus area ratio (mE/N) in four hot spots and ten systematically selected fields. MAIN OUTCOME: We found a consistent increase of the CD34 stained percentage of microvessels in PC as compared to HN and CN determined by the hot spot analysis and systematic field analysis. This increased microvessel density in PC is of a similar magnitude as in GD, which is characterised by a prominent increase of vascularisation during its active disease stage. Our SMA staining results reveal a kind of mirror image of the CD34 staining results with higher vessel counts in the normal surrounding tissues as compared to HN, CN and PC. CONCLUSIONS: The specific immunohistologic detection of microvessels with the CD34 antibody combined with their specific evaluation is able to clearly differentiate PCs from normal tissue, HN and CN.

Neutrophil adhesion to endothelial cells and factors affecting adhesion in patients with Behçet's disease.

OBJECTIVES: To study the in vitro adhesion of polymorphonuclear leucocytes (PMNLs) to endothelial cells in patients with Behçet's disease (BD), and the humoral and cellular factors which may contribute to adhesion. METHODS: A total of 118 patients with BD and 60 healthy controls were studied. In vitro adhesion of chromium-51 labelled normal neutrophils to human umbilical vascular endothelial cell (HUVEC) monolayers were studied in the presence of normal serum or serum obtained from patients with BD. Adhesion of neutrophils from patients with BD to HUVEC stimulated with tumour necrosis factor (TNF), interleukin-1 (IL-1), and lipopolysaccharide (LPS) and adhesion molecule (CD11a, CD11b, CD18 and L-selectin) expression on the patient's neutrophils and lymphocytes were determined, and the serum concentration of IL-8 was measured. RESULTS: Sera from patients with BD were found to enhance the adherence of normal PMNLs to HUVEC monolayers in vitro. Patients' sera induced an increase in surface expression of CD11a and CD18 on normal neutrophils and intercellular adhesion molecule-1 (ICAM-1) expression on HUVECs. The number of CD11a positive neutrophils was greater in the blood of patients with BD than in that of healthy controls (89.4% v 71%; p < 0.001). Pretreatment of HUVECs with IL-1 alpha, TNF alpha or LPS resulted in an increased adhesion of patients' PMNLs greater than that observed for normal PMNLs. Monoclonal antibodies to CD11a, CD11b, CD18, and ICAM-1 caused varying degrees of inhibition of neutrophil adhesion. The concentration of IL-8 was also found to be significantly increased in sera of patients with BD (490 (SD 470) pg/ml) compared with normal controls (97.5 (56.3) pg/ml). CONCLUSION: Abnormalities of neutrophils, endothelial cells, or both, have been suggested to be responsible for many of the clinical manifestations of BD. Our findings may explain the underlying mechanism of neutrophil accumulation in Behçet's lesions.