Clinical aggressiveness of incidental and non-incidental thyroid cancer

BACKGROUND

With the increasing use of thyroid ultrasound, the recognition of thyroid nodules in a large proportion of apparently healthy subjects has become common. Because also the papillary thyroid microcarcinomas (PTMC) are being increasingly discovered, it is important to ascertain whether PTMC may exhibit heterogenous clinical features, associated with different aggressiveness.

AIM

We retrospectively examined 122 subjects [98 female (80.3%), and 24 male (19.7%)] with thyroid cancer to find potential clinical and pathological findings that could be predictive of clinically aggressive behavior.

RESULTS

Twenty of the 31 patients with true incidental cancer (64.5%) in comparison to 20 of the 91 patients with non-incidental cancer (21.9%) had a diameter <10 mm, and this difference was statistically significant (p<0.0001). There was a statistically significant association between size and invasiveness because 19.3% of invasive cancers were <10 mm whereas 44.6% of non-invasive cancers were <10 mm (p=0.005). The relationship between incidental discovery and invasiveness was also evaluated, but the proportion of incidental invasive cancer (19.3%) was not significantly different from that of incidental non-invasive cancer (30.8%). In the multivariate analysis, only size <10 mm (odds ratio=0.35, p=0.013) and papillary vs other histotypes (odds ratio=0.35, p=0.04) were statistically significant protective factors against invasiveness.

CONCLUSIONS

a) Incidentally discovered thyroid cancers are more frequently microcarcinomas; b) there appears to be no difference in terms of invasive behavior between incidental and non-incidental thyroid cancer; c) smaller tumor size emerges as a protective factor.

Free triiodothyronine is associated with smoking habit, independently of obesity, body fat distribution, insulin, and metabolic parameters

BACKGROUND

The aim of this study was to examine the relationship between thyroid hormones and smoking and several other parameters like age, gender, insulin, and anthropometric and metabolic parameters in subjects with a wide range of body mass index (BMI).

PATIENTS AND METHODS

A total of 931 euthyroid normal weight (BMI<25.0 kg/m2), overweight and obese subjects (BMI ≥25.0 kg/m2), 663 women and 268 men, aged 18-68 yr, were investigated. Fasting TSH, free T3 (FT3), free T4 (FT4), insulin, glucose, and lipid serum levels were determined. Waist circumference was measured as an indirect parameter of central fat accumulation.

RESULTS

Smokers were younger (p<0.001) and showed higher FT3 (p<0.01), and triglyceride (p<0.01) levels and lower glucose (p<0.01) and HDL (p<0.001) concentrations than non smoking subjects. FT3 levels were directly associated with BMI (p<0.001), waist circumference (p<0.001), insulin (p<0.001), and triglyceride (p<0.01) levels and negatively correlated with age (p<0.001) and HDL-cholesterol levels (p<0.001). When a multiple regression analysis was performed with FT3 levels as the dependent variable, and smoking, age, gender, and TSH, insulin, triglyceride, and HDL-cholesterol serum concentrations as independent variables, FT3 levels maintained an independent positive association with smoking (p<0.05), age (p<0.001), male sex (p<0.001), waist circumference (p<0.05), and insulin levels (p<0.001).

CONCLUSIONS

Smoking increases FT3 levels independently of age, gender, obesity, body fat distribution and metabolic parameters.

LFA-1 and ICAM-1 Molecule Expression in Jejunal Mucosa from Children with Autoimmune Enteropathy

The expression of adhesion molecules by cells of the small intestinal mucosa was compared in gut biopsies from children with autoimmune small intestinal enteropathy and normal controls and related to HLA-DR expression by the same tissue. Jejunal biopsies were stained by IFL with monoclonal antibodies to LFA-1 (TS1/22 and CD11a/25.3.1) and ICAM-1 (RR1/1 and 84H10) molecules. LFA-1 and ICAM-1 positive cells were observed in the lamina propria in all cases and the counts were increased in autoimmune enteropathy compared with controls. In addition, in 4 of 7 cases of autoimmune enteropathy crypt enterocytes were positives for ICAM-1 when stained with RR1/1 and 3 of the 4 were also positive for LFA-1 when stained with both LFA-1 reagents. We speculate on the role of adhesion molecule expression in autoimmune enteropathy.

Free triiodothyronine and thyroid stimulating hormone are directly associated with waist circumference, independently of insulin resistance, metabolic parameters and blood pressure in overweight and obese women

OBJECTIVE

To examine whether obesity, body fat distribution and insulin resistance have an independent effect on serum TSH and free thyroid hormones (FT3 and FT4) in a cohort of euthyroid women, represented by overweight and obese patients.

DESIGN AND PATIENTS

A total of 201 women, aged 18-68 years, with body mass index (BMI) > or = 25.0 kg/m(2) and TSH levels < 4.0 mU/l were investigated.

MEASUREMENTS

Fasting TSH, FT3, FT4, insulin, glucose, and serum lipid concentrations, and the level of insulin resistance, estimated by the homeostasis model assessment for insulin resistance (HOMA-IR). Waist circumference was measured as an indirect parameter of central fat accumulation.

RESULTS

FT3 was directly associated with BMI (P < 0.01) and waist circumference (P < 0.01), and negatively correlated with age (P < 0.001). FT4 was negatively associated with HOMA-IR (P < 0.05) and fasting insulin levels (P < 0.05). TSH was positively correlated with waist circumference (P < 0.05) and negatively associated with age (P < 0.05). When multiple regression analysis was performed with FT3 as the dependent variable, and waist circumference, HOMA-IR, blood pressure levels and serum lipid concentrations as independent variables, FT3 maintained an independent association only with waist circumference (positive, P < 0.05) and age (negative, P < 0.001). When multiple regression analysis was performed with TSH as the dependent variable, and the above parameters as independent variables, TSH maintained an independent association only with waist circumference (positive, P < 0.05) and age (negative, P < 0.05). By contrast, when multiple regression analysis was performed with FT4 as the dependent variable, FT4 did not maintain an independent association with any of the independent parameters.

CONCLUSIONS

Progressive central fat accumulation is associated with an increase in both FT3 and TSH serum levels, independently of insulin sensitivity, metabolic parameters and blood pressure. These results suggest that (1) progressive central fat accumulation is associated with a parallel increase in FT3 levels, possibly as an adaptive thermogenic phenomenon, and (2) the control of TSH secretion by free thyroid hormones is possibly impaired in obesity.

The IGF-I axis in thyroid carcinoma

Insulin like-growth factor I (IGF-I) has been involved in the pathogenesis of a variety of human neoplasia due to the mitogenic and anti-apoptotic properties of its cognate receptor. In human thyroid carcinomas, we have previously documented an increased immunoreactivity of both IGF-I and the IGF-I receptor (IGF-I R) associated with up regulation of IGF-I mRNA . Immunoreactivity of IGF-I and cognate receptor positively correlated with tumor diameter and wide intrathyroidal extension but not with patient's gender and age or with the stage of the tumors and the occurrence of limph node metastases. Most experimental studies indicate that the effects of IGF-I on target cells are regulated in a complex fashion and depend on the simultaneous occurrence of IGF-IR and the binding proteins.

The IGF-I/IGF-I Receptor Pathway: Implications in the Pathophysiology of Thyroid Cancer

The biological actions of the insulin-like growth factor(IGF)-I are mediated by its activation of the IGF-I receptor (IGF-I R), a transmembrane tyrosine kinase linked to the Akt and ras-raf-MAPK cascades. A functional IGF-I R is required for the cell to progress through the cell cycle. Most importantly, cells lacking this receptor cannot be transformed by any of a number of dominant oncogenes, a finding that proves that the presence of the IGF-I R is important for the development of a malignant phenotype. Consistent with this role, it has been well established that IGF-I can protect cells from apoptosis under a variety of circumstances. For example, IGF-I prevents apoptosis induced by overexpression of c-myc in fibroblasts, by interleukin-3 withdrawal in interleukin-3-dependent hemopoietic cells, etoposide, a topoisomerase I inhibitor, anti-cancer drugs, UV-B irradiations, and serum deprivation. While the anti-apoptotic effect of IGF-I has been clearly demonstrated, the molecular mechanisms by which IGF-I inhibits apoptosis induced by these various stimuli remain unknown. We have previously documented increased IGF-I and IGF-I receptor immunoreactivity in human thyroid carcinomas with a corresponding up-regulation of IGF-I mRNA. Immunoreactivity for IGF-I and IGF-I receptor positively correlated with tumor diameter, but not with the occurrence of lymph node metastases. Several recent studies have identified new signaling pathways emanating from the IGF-I receptor that affect cancer cell proliferation, adhesion, migration and apoptosis, which represent critical functions for cancer cell survival and metastasizing capacity. In this review, various aspects of the IGF-I/IGF-I R pathway and its relationship to thyroid cancer are discussed.

Modifications of the immune responsiveness in patients with autoimmune thyroiditis: evidence for a systemic immune alteration

Hashimoto's thyroiditis, the most common form of autoimmune thyroid disease, is characterised by lymphocytic infiltration of the thyroid gland, gradual destruction of the organ and production of thyroid specific auto antibodies (antithyroid peroxidase and antithyroglobulin antibodies). There are evidences that cast doubt on the pathogenetic role of these antibodies in thyroid autoimmunity. It is very likely that cellular destruction is mediated by other cellular mechanisms, such as auto reactive T-lymphocytes, natural killer and cytokines. However, other studies performed in animal models have led to the conclusion that organ specific autoimmune thyroiditis should be regarded as a polygenic disease with a penetrance that is strongly influenced by environmental factors. According to our recent results, patients affected by autoimmune thyroiditis exhibited a decreased percentage of NK and CD25 + bearing cells significantly in comparison to normal controls. Altogether these data indicated that in the patients with autoimmune thyroid disease a certain degree of peripheral immune deficiency was present.

Breast cancer: biological characteristics in postmenopausal type 2 diabetic women. Identification of therapeutic targets

HYPOTHESIS

Epidemiological data have suggested a possible relationship between diabetes mellitus and cancer risk, particularly breast cancer. We set out to investigate the effect of diabetes mellitus on the expression of estrogen and progesteron receptors and on the proliferative activity of primary breast cancer.

METHODS

We selected 77 diabetic women and 578 control patients all in post-menopause and diagnosed with primary breast cancer. All patients underwent surgical excision of the tumor and on the specimens were performed an assessment of estrogen receptor and progesteron receptor and proliferative activity assay by (3)H-Thymidine incorporation.

RESULTS

Diabetic women showed a decreased proliferative activity, while having the same estrogen receptor and progesteron receptor status and mean cytoplasmic concentration of their receptors than control group. Insulin treated women had a lower proliferative activity than non-insulin treated ones.

CONCLUSION

Hyperinsulinemia and hyperglicemia influence in negative way the proliferative activity of diabetic women, likely inducing the expression of transforming growth factor beta, despite the high serum levels of Insulin-like growth factor and estrogen.

[Incidence of thyroid diseases in pregnant women with type I diabetes mellitus]

The interaction between pregnancy, Diabetes Mellitus and thyroid disturbance needs a particular attention. The antithyroid antibodies are more frequent in pregnant women with insulin-dependent diabetes mellitus (IDDM) than in normal pregnant women. Beside, an increased prevalence of subclinic ipotyroidism has been described in pregnant diabetic women. The object of this study is to verify if women with insulin-dependent diabetes mellitus have more probability than normal women to develop a thyroid pathology in pregnancy, in an area with sufficient iodine. Twenty-eight women have been studied: 15 with IDDM, with age 20-37 years, and 13 healthy women, with the same age. Patients were evaluated at the following time-intervals: 9-12 and 18-20 weeks' gestation, at delivery and six months after delivery. Diabetic women followed an insulinic therapy optimized for to reach a good metabolic control. All follow the patients had a thyroid ecography to evaluate thyroid volume and possible presence of nodular formation or others pathologic signs. A blood sample to assay FT3, FT4, TSH, of the antibodies Anti-Thyreoperoxidase (Anti-TPO) and Anti-Thyreoglobulin (Anti-TG). A urine specimen taken to evaluate the iodine excretion. No significant difference was observed between diabetic and normal women, for the values of TSH (p < 0.2), FT4(p < 0.7), FT3(p < 0.6). Instead a significant difference was found between the thyroid volume (p < 0.04), in the diabetic patients versus the normal women, at delivery and six months after delivery. The results of this study underline the importance of the screening of the thyroid function and morphology, in all the pregnant women and, particularly, in the diabetic patients, to find the presence of glandular alterations as early as possible.

Retrospective analysis of the association of nodular goiter with primary and secondary hyperparathyroidism

BACKGROUND

The association of hyperparathyroidism (HPT) with thyroid disease has long been known, but the mechanisms underlying such an association have not yet been clarified.

OBJECTIVE

To elucidate the main factors determining this combination of endocrine diseases, in a retrospective multicenter study.

METHODS

We retrospectively reviewed all patients referred for parathyroid scintigraphy in the period 1990-1999. A total of 487 patients in the age range 17-65 years were selected for the analysis (339 women and 148 men); group A included 241 patients with primary and group B 246 patients with secondary HPT.

RESULTS

A total of 124/241 patients in group A (51.5%), but only 92/246 patients in group B (38.2%) had thyroid disorders (notably nodular goiter) associated with HPT (P=0.0035). Thyroid disorders were evenly distributed throughout the entire 17-65 years age range in group A, but 17-40-year-old patients in group B had significantly fewer thyroid disorders than the older patients of the same group (15.5% compared with 43.3%, P<0.002), as expected in a general population. In patients with primary HPT there was no difference in the prevalence of thyroid disease between women and men, whereas the ratio of women to men in secondary HPT patients with thyroid disease was about 3:1.

CONCLUSIONS

These results demonstrate an increased prevalence of nodular goiter in patients with primary rather than secondary HPT, and are consistent with a possible role of increased endogenous calcium concentrations (a hallmark of primary, but not of secondary, HPT) as a goitrogenic factor in patients with HPT.

High frequency of incidental diagnosis of extrathyroidal neoplastic diseases at the fine-needle aspiration biopsy of laterocervical lymph nodes in patients with thyroid nodules

This study was undertaken to evaluate the frequency of the incidental diagnosis of extrathyroidal lymph node diseases at ultrasound-guided fine-needle aspiration biopsy/cytology (FNAB/C) being done to check the presence of metastatic thyroid cancer in 30 subjects with thyroid nodule (TN) and enlarged cervical lymph nodes (CLN). The patients in whom cytology suggested the presence of malignancy in the TN or in the CLN underwent surgical removal for histologic diagnosis. The spectrum of diseases revealed by this survey included: (1) 10 benign diseases including 1 case of Piringer-Kuchinka lymphadenitis with benign TN; (2) 10 metastatic thyroid cancers (2 anaplastic and 8 papillary cancers); (3) 3 benign TN associated with metastatic invasion of cervical lymph nodes from lung (2 cases) and breast (1 case) cancer; (4) 1 Hodgkin's lymphoma of the cervical lymph nodes with hyperplastic TN; (5) 3 nodal lymphomas with benign thyroid nodule and 2 cases of thyroid lymphoma with nodal invasion; and (6) 1 nodal sarcoidosis with benign TN. The results of this study demonstrate that important neoplastic and hematologic diseases affecting the cervical lymph nodes may frequently be incidentally detected using ultrasonography (US) and FNAB/C in the diagnostic procedure for thyroid nodule.

Large-cell variant of small cell carcinoma of the ovary with hypercalcaemia

A rare case of large-cell variant of hypercalcemic small cell carcinoma of the ovary diagnosed in a 17 year-old girl is presented and discussed. The patient died of disease progression and severe hypercalcemia within 25 months of diagnosis.

Insulin-like growth factor 1 expression in thyroid tumors

Insulin-like growth factor 1 (IGF-1) likely is involved in thyrocyte proliferation via autocrine mechanisms, but limited data are available on its in vivo expression in thyroid neoplasms. This prompted us to explore IGF-1 expression at the protein and mRNA levels and IGF-1 receptor (IGF-1rec) immunoreactivity in normal and neoplastic thyroids (50 adenomas and 53 carcinomas). We documented increased IGF-1 and IGF-1rec immunoreactivity in adenomas (31 of 50 and 40 of 50 cases, respectively) and carcinomas (38 of 53 and 42 of 53 cases) compared with normal thyroid, which only showed minimal immunoreactivity for the ligand and its receptor. A corresponding up-regulation of IGF-1 mRNA was documented in carcinomas, whereas adenomas exhibited down-regulated expression of IGF-1 mRNA. Immunoreactivity for IGF-1 and cognate receptor positively correlated with tumor diameter and wide intrathyroidal extension but not with patients' gender and age or with the stage of the tumors and the occurrence of lymph node metastases. These data emphasize a possible role of the IGF-1 system in thyroid tumorigenesis, as indicated by in vitro studies. In addition, the evaluation of IGF-1 and IGF-1rec immunoreactivity might have clinical implications, because it positively correlates with the aggressiveness of these tumors.

Insulin-like growth factor-1 and insulin-like growth factor receptor in thyroid tissues of patients with Graves' disease

Growth factors are frequently involved in the regulation of mitosis and differentiation of several cell types and insulin-like growth factor-1 (IGF-1) is actively involved in the thyroid stimulating hormone-mediated proliferation of thyrocytes. In view of the pivotal role of IGF-1 in thyrocyte proliferation and of the still unsettled role of this growth factor in the pathogenesis of hyperplastic thyroid lesions, we investigated the expression of IGF-1 and of its corresponding receptor, by means of immunohistochemistry, in the surgical specimens obtained from six patients with Graves' disease. Moreover, IGF-1 mRNA expression was analysed in one such case by means of Northern hybridisation. All samples showed consistent intracytoplasmic immunoreactivity for both IGF-1 and IGF-1 receptor; the vast majority of hyperplastic thyrocytes were strongly decorated by the two antibodies used in this study whereas stromal cells displayed IGF-1 immunoreactivity only. IGF-1 mRNA was markedly overexpressed in Graves' disease in comparison with normal thyroid tissues. The results of this study suggest that IGF-1 and IGF-1 receptor may be actively involved in the pathogenesis of Graves' disease; furthermore, IGF-1 and IGF-1 receptor apparently act by different mechanisms (paracrine vs. autocrine) as suggested by their differential expression in epithelial and stromal cells.

Assessment of cardiac vagal activity in patients with hyperthyroidism

Previous studies suggested that in patients with hyperthyroidism an autonomic imbalance and in particular a lower than normal vagal activity might be present. To verify this hypothesis we have evaluated the respiratory sinus arrhythmia (RSA, a measure of cardiac vagal activity) in ten hyperthyroid patients and in ten normal subjects. RSA was calculated from the power of the spectral component of the heart rate variability in high frequency band (HF-RR) during both spontaneous (supine and passive head-up tilt) and controlled breathing (supine). During controlled breathing the phase relation between heart rate and respiratory has been computed. The hyperthyroid patients showed a higher heart rate in all three conditions (P<0.001) and higher spontaneous respiratory rate in supine position (centered frequency of HF-RR: 0.342+/-0.015 vs 0.262+/-0.016 Hz; P<0.001). No difference was found in hyperthyroid patients compared to controls in terms of the HF-RR power in normalized units both during spontaneous breathing (supine, 43+/-8.3 vs 39.7+/-6.7%; tilt 18.8+/-5.9 vs 19.3 vs 4.1%; mean+/-SE) and controlled breathing (45.4+/-7.1 vs 48.9+/-6.9%). No difference was found also in terms of the phase relationship between the heart rate and the respiratory signals (77.5+/-32.3 vs 77.5+/-28.1, degrees). Hyperthyroid patients seem not to have an impaired cardiac vagal activity.

Increased expression of insulin-like growth factor 1 (IGF-1) in multinodular non toxic goiter

Thyroid cell growth and function both in vivo and in vitro, are mainly regulated by TSH. Recent studies have shown that growth factors including insulin-like growth factors (IGF-1) have an important role in the control of thyrocyte proliferation and differentiation. The aim of this study was to evaluate the expression of the IGF-1 gene by Northern analysis and the IGF-1 tissue protein by radioimmunoassay in multinodular euthyroid goiters. The study population consisted of 20 patients with multinodular goiter (14 females and 6 males) living in a non endemic geographic area. All patients were euthyroid at the time of surgery and submitted to total or subtotal thyroidectomy. Samples of normal thyroid tissue were obtained from three patients who were operated due to laryngeal carcinomas. The IGF-1 protein content was increased in non toxic multinodular goiter, 22 ng/g vs. 14 in controls (p<0.03), as was IGF-1 gene expression (p<0.05). The increase in the steady state mRNA content correlated with the increase in the protein content (r=0.665; p<0.005). These results suggest that IGF-1 may play a role in proliferation events involved in benign hyperplastic thyroid diseases.

34-day total fast in an adult man

The aim of this work was to investigate the changes of cardiac performance by both electrocardiography (ECG) and echocardiography (ECHOc), in addition to anthropometric and hormonal variables before, during and after prolonged total fasting (TF) and re-feeding in an overweight adult man. Physical examination, laboratory and hormonal measurements, ultrasonographic study of body fat distribution, ECG and ECHOc study were performed before during and after 34 days of TF and after 17 days of isocaloric re-feeding. The subject was a 52-year old Caucasian who was overweight with increased abdominal fat content (BMI: 28.6; W/H ratio: 0.95) and increased levels of arterial systolic and diastolic blood pressure (SBP, DBP). HPLC measurements of urinary catecholamine levels (HPLC), ECHOc study of cardiac performance, ultrasonographic study of body fat distribution were performed. The subject starved for 34 days losing 22kg, but after that time he was compelled to re-feed because of nausea and severe vomiting. A marked ketosis (ketonuria > 1200mg/day) was already present after 6 days of TF. After 17 days of TF norepinephrine (NE) and epinephrine (EPI) urinary levels showed a two-fold and nine-fold increase respectively, but they became undetectable at the end of TF. After 17 days of re-feeding catecholamine urinary levels were similar to those measured after 17 days of TF. After both TF and 17-day isocaloric re-feeding we found a decrease of visceral fat content and W/H ratio reached the normal values for age-matched subjects (W/H ratio after TF: 0.80, after re-feeding: 0.80).(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-like growth factor 1 (IGF-1) in multinodular goiters: a possible pathogenetic factor

In order to support previous in vitro studies which had stressed a possible autocrine role for Insulin-like Growth Factor 1 (IGF-1) in thyroid growth regulation, we have investigated the presence of IGF-1, as detected by means of radioimmuno assay and of immunocytochemistry, in thyrocytes from normal thyroid and from multinodular goiter. Our study revealed that IGF-1 is detectable in thyroid cells from multinodular goiter and, to a lesser extent, from normal thyroid. Both techniques used in this study demonstrated that thyrocytes are the site of accumulation of IGF-1 and that stromal cells contain lower amounts of this growth factor. The findings of the present study seem to suggest that thyrocytes could produce IGF-1 in vivo. This feature gives further support to the hypothesis that IGF-1 may regulate thyroid growth and therefore it might be involved in the pathogenesis of multinodular goiter.

Ttf1 gene-expression in human proliferating thyroid-diseases

TTF1 mRNA expression in the thyroid gland from 30 patients with thyroid proliferating diseases and 4 healthy donors used as normal controls was investigated using Northern blot analysis. Six patients affected by malignant thyroid carcinomas and six patients with adenoma were examined; moreover 18 patients with non malignant proliferating disease such as multinodular goiters were investigated. Determination of TTF1 mRNA revealed a significant decrease of the steady state mRNA levels in carcinomas and adenomas as compared to normal tissues. On the contrary, in patients affected by multinodular goiters variations were observed that seemed not to be directly associated with the pathological conditions.

[Clinical study of residual function and recurrences in patients after partial thyroidectomy for non-toxic nodular goiter]

The different surgical chances for the treatment of non toxic nodular goiter led the Authors to study the residual function after partial thyroidectomy. A variable rate of recurrences and hormone deficiency was shown in patients who underwent sub-total thyroidectomy, lobectomy and enucleation. It depended on the amount of residual gland and the different methods they used. Recurrences occurred more in patients studied by ultrasonography. After sub-total thyroidectomy the Authors noted a more reduced number of recurrences than after lobectomy and enucleation. There was a meaningless connection between high plasmatic levels of TSH and recurrences. Subclinical hypothyroidism was higher in patients who underwent subtotal thyroidectomy than in patients treated with lobectomy and enucleation. These clinical data show that recurrences could depend on growth factors (EGF, IGF) in thyroid tissues and not only on TSH action. Therefore the surgical attitude of the authors in the treatment of nodular goiter consists in total thyroidectomy.

Intercellular adhesion molecule-1 (ICAM-1) in Graves' disease: contrast between in vivo and in vitro results

We have reassessed the possible role of the adhesion molecule ICAM-1 in the pathogenesis of thyroid autoimmunity. In order to do that, we have investigated its expression in eight Graves' thyroids both in vivo (i.e. on cryostat sections and on cell suspensions), and in vitro (i.e. on cells cultured in monolayers for 3 days), and the results were compared with those obtained with similar preparations from four normal glands. On cryostat sections, the expression of ICAM-1, and for comparison that of HLA Class I and Class II molecules, was studied by immunofluorescence (IFL), but the former were also assessed by a distinct immunohistochemical technique. ICAM-1 was not detected in thyrocytes in vivo of both normal and Graves' glands, but solely in endothelial cells and antigen-presenting cells (APC). This selective reaction was confirmed by a four-layer technique using specific markers which identify endothelial cells and thyrocytes. HLA Class II molecules were confirmed to be inappropriately expressed in thyrocytes of Graves' glands, but there was no co-expression of these products and ICAM-1 in the same cells. In contrast, ICAM-1 appeared de novo in a proportion of Graves' and normal thyrocytes soon after the attachment and spreading of these cells in monolayer cultures (36-48 h). Graves' thyrocytes showed a quantitatively higher degree of expression compared with that detected on normal thyroid cells (40-70% versus 12-20%). Under these experimental conditions, the four-layer staining with thyroid microsomal antibodies confirmed that thyrocytes were indeed the positive cells which expressed ICAM-1. Blocking experiments with cultured thyrocytes from two Graves' glands and MoAbs to tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) did not prevent the occurrence of ICAM-1 expression. As a result of our study, we failed to demonstrate that Graves' thyrocytes express ICAM-1 in vivo. The unexpected case of inducing ICAM-1 on thyroid cells under certain in vitro conditions remains intriguing. The phenomenon could be the simple consequence of a mechanical effect rather than exerted by specific biological processes. Further investigations are, therefore, needed to establish whether ICAM-1 is really involved in the pathogenesis of Graves' disease.

In vitro secretion of interleukin-1 beta and interferon-gamma by peripheral blood lymphomononuclear cells in diabetic patients

There is evidence that cytokines, in particular interleukin-1 beta (IL-1 beta) and interferon-gamma (IFN-gamma) might mediate beta cell destruction in type 1 diabetes. Therefore the secretion of these cytokines by peripheral blood lymphomononuclear cells (PBMNC) was investigated in basal conditions and 48 h after stimulation with T-cell mitogen phytohaemagglutinin (PHA) in 33 diabetic patients and in 10 normal controls. The patients were divided in 4 groups (Group 1, 10 controls; Group 2, 13 newly diagnosed type 1 diabetics, the onset had occurred from 5 days to 3 months before the study; Group 3, 10 Long Standing (LS) type 1 diabetics with duration of the disease between 2 years and 10 years; and Group 4, 10 type 2 diabetics). No difference was found among the 4 groups considered in IL-1 beta secretion by unstimulated cultures, although the percentage of TAC+ cells was significantly higher in type 1 newly diagnosed diabetic patients with respect to the LS, the type 2 diabetics and the controls. After PHA stimulation a significant increase of IL-1 beta was found in newly diagnosed type 1 diabetic patients in comparison with the control subjects, the LS and type 2 diabetic patients (P < 0.001). The supernatants of newly diagnosed type 1 diabetics also showed a significant reduction in IFN-gamma production both in basal (P < 0.01) and in stimulated conditions (P < 0.001) in comparison with the controls, the LS (P < 0.002 in basal, and P < 0.001 in stimulated conditions) and the type 2 diabetic patients (P < 0.001 both in basal and stimulated conditions).(ABSTRACT TRUNCATED AT 250 WORDS)

In search of predictive markers of remission from insulin dependence in type 1 diabetes: a preliminary report

We studied 18 newly diagnosed diabetic patients (8 males and 10 females, aged 18-26 years, within 10-120 days from the onset of symptoms) who were submitted for 15 days to intensive insulin therapy performed via subcutaneous insulin infusion (CSII). We investigated some metabolic and immunological parameters in order to identify a possible marker to predict the selection of patients potentially more responsive to CSII treatment for the remission of type 1 diabetes. In accordance with the International Diabetes Immunology Group we considered clinical remission as being the withdrawal of insulin therapy for at least 3 months. In order to assess beta-cell function a fasting and post-prandial serum C-peptide, blood glucose and HbA1c were performed on all patients before, and 3 days after, the discontinuation of CSII. Islet cell antibodies were determined in all sera by indirect immunofluorescence. Analysis of T-lymphocyte subpopulations was carried out before starting the therapy. The following monoclonal antibodies were used: CD4, CD8, CD57, CD25, HLA-DR. The levels of C3 and C4 and serum IgG, IgA and IgM were also evaluated. After CSII, 11 of 18 patients showed remission. At the beginning of the study we observed no major difference in metabolic parameters between the two groups. Interestingly, the patients who exhibited remission presented a statistically higher percentage of positive cells for CD57, HLA-DR and CD25 surface antigens, significantly lower C4 levels and CD4/CD8 ratio and significantly higher IgG levels compared with patients who did not show any remission.(ABSTRACT TRUNCATED AT 250 WORDS)

Retrovirus-like sequences in Graves' disease: implications for human autoimmunity

On Southern blotting of DNA extracted from thyroid glands of five patients with Graves' disease, two probes (720 bp and 942 bp) for gag human immunodeficiency virus type 1 (HIV-1) gave a positive hybridisation signal in all samples tested. DNAs from peripheral blood mononuclear cells hybridised with the 720 bp gag HIV-1 probe in three of the five patients, none of whom had antibodies to HIV-1. Negative results were obtained with DNA from normal thyroid glands, thyroid neoplasms, various unrelated normal tissues, and virus-infected human cell lines. The intensity of the signal and the pattern of bands observed with the DNA of Graves' patients were heterogeneous and, in general, were not the same in the thyroid glands and peripheral blood mononuclear cells of individual patients. Similarly, no correlation was found between the positive hybridisation signals and other genetic and immunological indices or the duration of anti-thyroid drug treatment at the time the patients were investigated. The findings suggest the presence of a novel retrovirus, and the retrovirus-like sequences seem to be closely associated with thyroid autoimmunity.

Remission from insulin dependence induced by continuous subcutaneous insulin infusion (CSII) in type I, newly diagnosed diabetics: role of some hormonal and immunologic factors

Optimal and early control of recent onset, type I diabetes by intensive insulin therapy has been reported to allow insulin withdrawal in about two thirds of subjects treated. We used continuous s.c. insulin infusion (CSII) in the attempt to induce a temporary remission of insulin dependence in 18 newly diagnosed young adult diabetics. After 10 days of optimized glycometabolic control, insulin infusion was stopped and patients were switched to glibenclamide (15 mg/die) plus metformin (1 g/die). Diabetics were considered in remission of insulin dependence when their metabolic control fulfilled the following criteria for at least 3 months: absence of glycosuria, pre- and post-prandial blood glucose less than or equal to 120 and 180 mg/dl, respectively, HbA1c less than or equal to 7%. Insulin therapy could be discontinued for periods of over three months in 11 subjects (61%) and for as long as 18 months in one case. Insulin requirement during CSII was slightly higher in nonremitters (NR) than in remitters (R): 0.36-0.64 vs 0.26-0.41 U/kg/die. After 24 months from CSII, R still showed lower insulin requirement (0.35-0.42 U/kg/die) than NR (0.55-0.75 U/kg/die). Further, the role of some hormonal and immunologic factors was investigated. Plasma C-peptide and glucagon were measured, fasting and 2h after each meal, both on admission and immediately after CSII, when patients were switched to oral therapy. No difference in hormone levels could be detected on admission, whereas, after CSII, mean post-prandial increase of C-peptide over basal was significantly higher in R than in NR (1.18 +/- 0.37 vs 0.22 +/- 0.16 ng/ml, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of tsh binding inhibiting antibodies (TBI-ab) and thyroid adenylate cyclase stimulating antibodies (TS-ab) in sera of patients with Graves' disease

In the sera of patients with Graves' disease have been demonstrated the immunoglobulins able to inhibit the binding of TSH to the human thyroid membrane (TBI-Ab) and the immunoglobulins stimulating the thyroid adenylate cyclase (TS-Ab). The present study was performed in 75 hyperthyroid Graves' patients to ascertain the pathophysiological significance of these immunoglobulins. TS-Ab and TBI-Ab prevalence appeared to be much higher in the untreated and in relapsing patients than in subjects in remission. When the results of TBI-Ab and TS-Ab were compared in each group of patients no correlation was found between the two activities. We conclude that the TBI-Ab and the TS-Ab are the markers of hyperthyroidism in Graves' disease but the two activities are not equivalent and probably reflect a different phenomenon concomitantly produced.

Changes in circulating iodothyronines in diabetics with various degrees of metabolic control

Plasma TSH, total and free T3 and T4, reverse T3, blood pH, HbAlc, ketonuria and glycosuria were evaluated in 8 subjects with diabetic ketoacidosis, in 54 diabetics of group 1 and group 2 without severe metabolic derangement and in 10 control women. The diabetics with ketoacidosis showed before intensive therapy low T3, total and free, and high reverse T3 concentrations as compared to controls (unpaired t-test, p less than 0.001). After one day of intensive therapy the decrease of hyperglycemia and pH increase (p less than 0.001, paired t-test), glycosuria and ketonuria are not related to significant variations of iodothyronines and TSH. The significant variations (paired t-test, p less than 0.001) in total and free T3 and in reverse T3 concentrations were found only six days after remission of ketoacidosis. In diabetics (type 1 and 2) without recent history of ketoacidosis no differences were found in mean total and free T3 and T4, in reverse T3 and in plasma concentrations although mean blood glucose and HbAlc were statistically different (t-test, p less than 0.001). The changes in serum T3 (total and free) and reverse T3 are useful indicators of total metabolic control during the management of diabetic ketoacidosis.