Quantitative analysis of Tr1 lymphocytes in patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is usually accompanied by a low-grade inflammatory phenomenon, which participates in the pathogenesis of different complications of this condition. The inflammatory response is under the regulation of different mechanisms, including T regulatory (Treg) lymphocytes. However, the possible role of type 1 T regulatory (Tr1) cells in T2DM has not been explored so far.

AIM

To carry out a quantitative analysis of Tr1 lymphocytes and other immune cell subsets in patients with T2DM and correlate these results with clinical findings and treatments.

MATERIALS AND METHODS

Sixty patients with T2DM and twenty-three healthy controls were included in the study. Biochemical and anthropometric variables were evaluated, and Tr1 lymphocytes (CD4+CD49+LAG-3+IL-10+) and other cell subsets (Th17, Th22 and Foxp3 + Treg cells) were analyzed in peripheral blood samples by multiparametric flow cytometry.

RESULTS

Significant increased levels of Tr1 cells were detected in patients with severe and mild disease, compared to healthy controls. In addition, CD4+IL-10+ lymphocytes were also increased in patients with T2DM. In contrast, similar levels of Foxp3+ Treg cells, Th17 and Th22 lymphocytes were observed in patients and controls. Likewise, no significant associations were detected between Tr1 cell levels and different clinical and laboratory parameters. However, those patients receiving glucagon-like peptide-1 receptor agonists (GLP-1-RA) showed similar levels of Tr1 cells than healthy controls, and significant lower numbers than untreated patients.

CONCLUSION

We observed an increase in Tr1 and CD4+IL10+ lymphocyte levels in T2DM. Moreover, GLP1-RA treatment was significantly associated with normalization of the Tr1 levels. This highlights another potential immune dysfunction in patients with T2DM, which could participate in the pathogenesis of this condition.

Association of remnant cholesterol with glycemic control and presence of microvascular complications in individuals with type 1 diabetes mellitus

INTRODUCTION

This study examines the relationship between remnant cholesterol, glucose metrics, and chronic complications of type 1 diabetes in users of glucose monitoring systems.

MATERIAL AND METHODS

Clinical variables and glucose metrics were collected from individuals using glucose sensors. Statistical models were employed to investigate the association of remnant cholesterol with glucose metrics, diabetic retinopathy, and diabetic nephropathy.

RESULTS

A total of 383 individuals, aged 48.3 ± 16.2 years, with 54.1% women, and a remnant cholesterol level of 16 ± 10 mg/dL, were included. The results demonstrated that remnant cholesterol was associated with less time within the target range (p = 0.015) and more time above the target range (p = 0.003). Diabetic nephropathy was the only complication associated with remnant cholesterol levels exceeding 30 mg/dL, OR 8.93, 95% CI (2.99-26.62), p < 0.001.

CONCLUSION

Remnant cholesterol is independently associated with hyperglycemia and diabetic nephropathy in individuals with type 1 diabetes.

Finding answers in lipid profile in COVID-19 patients

INTRODUCTION

A small percentage of patients will develop a severe form of COVID-19 caused by SARS-CoV-2 infection. Thus, it is important to predict the potential outcomes identifying early markers of poor prognosis. In this context, we evaluated the association of SARS-CoV-2 infection with lipid abnormalities and their role in prognosis.

METHODS

Single-center, retrospective, observational study of COVID-19 patients admitted from March to October 2020. Clinical and laboratory data, comorbidities, and treatments for COVID-19 were evaluated. Main outcomes including intensive care unit (ICU) admission and mortality were analyzed with a multivariable Cox proportional hazards regression model.

RESULTS

We selected 1489 from a total of 2038 consecutive patients with confirmed COVID-19, who had a complete lipid profile before ICU admission. During the follow-up performed in 1109 patients, we observed a decrease in T-c, HDL-c, and LDL-c in 28.6%, 42.9%, and 30.4% of patients, respectively, and an increase in TG in 76.8%. The decrease of both T-c and HDL- c was correlated with a decrease in albumin levels (r = 0.39 and r = 0.37, respectively). Kaplan-Meier survival curves found an increased ICU admission in patients with lower T-c (HR 0.55, CI 0.36-0.86), HDL-c (HR 0.61, CI 0.45-0.84), and LDL-c (HR 0.85, CI 0.74-0.97). Higher values of T-c (HR 0.45, CI 0.36-0.57), HDL-c (HR 0.66, CI 0.54-0.81), and LDL-c (HR 0.86, CI 0.78-0.94) showed a protective effect on mortality.

CONCLUSIONS

Abnormalities in lipid profile are a frequent complication of SARS-CoV-2 infection and might be related to morbidity and mortality.

FUNDING

Proyectos de Investigación en Salud (FIS) and cofinanced by FEDER.

Maximum adenoma diameter, regardless of uni- or bilaterality, is a risk factor for autonomous cortisol secretion in adrenal incidentalomas

PURPOSE

To evaluate differences between patients with unilateral and bilateral adrenal incidentalomas (AIs) in the prevalence of autonomous cortisol secretion (ACS) and related comorbidities.

METHODS

In this multicentre retrospective study, AIs ≥ 1 cm without overt hormonal excess were included in the study. ACS was defined by a post-dexamethasone suppression test (DST) serum cortisol ≥ 5.0 µg/dl, in the absence of signs of hypercortisolism. For the association of ACS with the prevalence of comorbidities, post-DST serum cortisol was also analysed as a continuous variable.

RESULTS

Inclusion criteria were met by 823 patients, 66.3% had unilateral and 33.7% bilateral AIs. ACS was demonstrated in 5.7% of patients. No differences in the prevalence of ACS and related comorbidities were found between bilateral and unilateral AIs (P > 0.05). However, we found that tumour size was a good predictor of ACS (OR = 1.1 for each mm, P < 0.001), and the cut-off of 25 mm presented a good diagnostic accuracy to predict ACS (sensitivity of 69.4%, specificity of 74.1%). During a median follow-up time of 31.2 (IQR = 14.4-56.5) months, the risk of developing dyslipidaemia was increased in bilateral compared with unilateral AIs (HR = 1.8, 95% CI = 1.1-3.0 but, this association depended on the tumour size observed at the end of follow-up (HR adjusted by last visit-tumour size = 0.9, 95% CI = 0.1-16.2).

CONCLUSIONS

Tumour size, not bilaterality, is associated with a higher prevalence of ACS. During follow-up, neither tumour size nor bilaterality were associated with the development of new comorbidities, yet a larger tumour size after follow-up explained the association of bilateral AIs with the risk of dyslipidaemia.

One year of the pandemic - how European endocrinologists responded to the crisis: a statement from the European Society of Endocrinology

Changes that COVID-19 induced in endocrine daily practice as well as the role of endocrine and metabolic comorbidities in COVID-19 outcomes were among the striking features of this last year. The aim of this statement is to illustrate the major characteristics of the response of European endocrinologists to the pandemic including the disclosure of the endocrine phenotype of COVID-19 with diabetes, obesity and hypovitaminosis D playing a key role in this clinical setting with its huge implication for the prevention and management of the disease. The role of the European Society of Endocrinology (ESE) as a reference point of the endocrine community during the pandemic will also be highlighted, including the refocusing of its educational and advocacy activities.

COVID-19 and endocrine and metabolic diseases. An updated statement from the European Society of Endocrinology

BACKGROUND

COVID-19 has completely changed our daily clinical practice as well as our social relations. Many organs and biological systems are involved in SARS-Cov-2 infection, either due to direct virus-induced damage or to indirect effects that can have systemic consequences. Endocrine system is not only an exception but its involvement in COVID-19 is so relevant that an "endocrine phenotype" of COVID-19 has progressively acquired clinical relevance.

AIM

We have been appointed by the European Society of Endocrinology (ESE) to update with the current statement ESE members and the whole endocrine community on the emerging endocrine phenotype of COVID-19 and its implication for the prevention and management of the disease.

CONCLUSIONS

Diabetes has a major role in this phenotype since it is one of the most frequent comorbidities associated with severity and mortality of COVID-19. Careful management including treatment modifications may be required for protecting our patients rather with known diabetes from the most dangerous consequences of COVID-19 or hospitalized with COVID-19, but also in patients with SARS-CoV-2 induced newly onset diabetes. Obesity increases susceptibility to SARS-CoV-2 and the risk for COVID-19 adverse outcome. Adequate nutritional management needs to be granted to patients with obesity or undernourishment in order to limit their increased susceptibility and severity of COVID-19 infection. Lack of vitamin D, hypocalcemia and vertebral fractures have also emerged as frequent findings in the hospitalized COVID-19 population and may negatively impact on the outcome of such patients. Also, in patients with adrenal insufficiency prompt adaptation of glucocorticoid doses may be needed. Moreover, in this updated statement role of sex hormones as well as peculiar pituitary and thyroid aspects of COVID-19 have been included. Finally, in view of the mass vaccination, potential implications for endocrine patients should be considered.

Diagnostic approach to subcutaneous nodules in patients with neuroendocrine tumours treated with depot somatostatin analogs: a cross-sectional study

BACKGROUND

The presence of cutaneous nodules in patients with gastroenteropancreatic neuroendocrine tumours (GEP-NETs) receiving depot somatostatin analogs (SSAs) is a diagnostic challenge as differential diagnosis between injection site reactions and metastases is essential.

OBJECTIVE

To characterize the clinical, radiological, cytological and histopathological features of subcutaneous nodules in patients with GEP-NETs treated with SSAs.

MATERIALS AND METHODS

Retrospective, cross-sectional study of patients with GEP-NETs treated with SSAs in whom subcutaneous nodules were detected on routine abdominal computed tomography (CT) scans. High resolution and colour Doppler ultrasonography was performed. Those patients with inconclusive radiological studies went through fine-needle aspiration cytology (FNAC) and/or biopsy.

RESULTS

Twelve patients (five males, seven females) were included (six midgut carcinoid NETs, six pancreatic NETs). Three patients received intramuscular depot octreotide, seven subcutaneous lanreotide, and two both treatments. CT scan findings were nonspecific. Sonography revealed a hyperechoic pattern in recent injections, and a hypoechoic pattern with a characteristic hyperechoic peripheral rim in long-term injections (more than 3 months after injection). On colour Doppler sonography, nodules showed no signs of intralesional vascularity. Fine-needle aspiration cytology (FNAC) was performed in five patients, revealing a characteristic acellular proteinaceous material. Biopsy in four patients showed different reactional infiltrates around the acellular material.

CONCLUSIONS

High resolution and colour Doppler ultrasonography may be very useful for the differential diagnosis of subcutaneous nodules in patients with GEP-NETs treated with SSAs. FNAC and a biopsy are useful tests for confirmation of the diagnosis in patients with inconclusive findings. We propose a management algorithm.

Safety of long-term treatment with Pegvisomant: analysis of Spanish patients included in global ACROSTUDY

PURPOSE

To evaluate the long-term safety of Pegvisomant (PEG) in the Spanish cohort of ACROSTUDY.

METHODS

As of July 2013, 199 Spanish patients were included in ACROSTUDY, a global non interventional safety PEG surveillance study. Patients were observed for safety, biochemical outcome and magnetic resonance imaging evaluations.

RESULTS

PEG was administered during an average period of 6.7 ± 2.1 years and a mean daily dose of 15.5 ± 7.5 mg. 48.2% of patients received PEG monotherapy. 90.9% of patients had received other medical treatment before PEG start. 195 adverse events (AEs) were reported in 88 patients (44.2%), and serious AEs were described in 31 patients (15.6%). There were no cases of liver tests >10 ULN, or permanent liver damage. Tumor size changes were locally reported in 61 cases (33.5%), with increases observed in 11 patients (6%). In acromegalic patients with diabetes mellitus a decrease in fasting serum glucose value was reported, reaching statistical significance after 1 and 4 years of treatment (-24.6 and -25.9 mg/dl, p = 0.04). After 60 months, normal or lower limit of normal (LLN) IGF-I levels were found in 67.9% of patients. 85.5% of patients showed an IGF-I normal or <LLN at any time after PEG start. Most patients with uncontrolled IGF-I levels were on submaximal PEG doses.

CONCLUSIONS

ACROSTUDY carried out with the Spanish cohort confirmed that PEG has a favorable safety and efficacy profile. The percentage of patients considered under control was similar to data reported globally and in other local ACROSTUDY results.

Validation of PHPQoL, a Disease-Specific Quality-of-Life Questionnaire for Patients With Primary Hyperparathyroidism

CONTEXT

Health-related quality of life (HRQoL) is impaired in primary hyperparathyroidism (PHPT) but instruments to specifically assess this are scarce.

OBJECTIVE

Validate the new disease-specific Primary Hyperparathyroidism Quality of Life (PHPQoL) questionnaire in usual clinical practice.

DESIGN

Observational, prospective, and multicenter.

SETTING

Public hospital ambulatory care.

PATIENTS

Patients with PHPT of both sexes, aged more than or equal to 18 years either initiated treatment for PHPT (group A) or had stable PHPT, not requiring therapy (group B). Patients in group A had at least one surgical criterion according to the 2009 Third International Workshop on Management of Asymptomatic PHPT.

INTERVENTION

Sociodemographic, clinical, and HRQoL data (PHPQol, Short Form-36, Psychological Well-Being Index, and patients' self-perceived health status) were collected. Group A underwent 4 evaluations (baseline, 3 ± 1, 6 ± 1, and 12 ± 2 months after a therapeutic intervention) and group B 2, at baseline and 1 month later to assess test-retest reliability.

RESULTS

A total of 182 patients were included (104 group A, 78 group B) with a mean age (SD) of 61.4 (12.1) years; 79.7% were women. Group A increased PHPQoL score (SD) (better HRQoL) (52 ± 23 at baseline; 62 ± 24 at 12 months; P < .001). At baseline, symptomatic patients had a lower PHPQoL score (worse) than asymptomatic ones (51 ± 21 vs 68 ± 21; P < .001). Correlations were seen between PHPQoL and Short Form-36, Psychological Well-Being Index, and self-perceived health status (P < .001). PHPQoL had good internal consistency (Cronbach's α = 0.80), test-retest reliability (group B, intraclass correlation coefficient > 0.80), and sensitivity to detect HQRoL changes over time.

CONCLUSIONS

PHPQoL is a valid HRQoL measure to assess the impact of PHPT on health perception in clinical practice.

Pegvisomant and cabergoline combination therapy in acromegaly

Combination with cabergoline may offer additional benefits to acromegalic patients on pegvisomant monotherapy. We evaluated the safety and efficacy profile of this combination and investigated the determinants of response. An observational, retrospective, cross-sectional study. Fourteen acromegalic patients (9 females), who were partially resistant to somatostatin analogs and on pegvisomant monotherapy. Cabergoline was added because of the presence of persistent mildly increased IGF-I. The mean follow-up time was 18.3 ± 10.4 months. The efficacy and safety profile was assessed. The influence of clinical and biochemical characteristics on treatment efficacy was studied. IGF-I levels returned to normal in 4 patients (28%) at the end of the study. In addition, some decline in IGF-I levels was observed in a further 5 patients. The % IGF-I decreased from 158 ± 64% to 124 ± 44% (p = 0.001). The average change in IGF-I was -18 ± 27% (range -67 to +24%). Lower baseline IGF-I (p = 0.007), female gender (p = 0.013), lower body weight (p = 0.031), and higher prolactin (PRL) levels (p = 0.007) were associated with a better response to combination therapy. There were no significant severe adverse events. Significant tumour shrinkage was observed in 1 patient. Combination therapy with pegvisomant and cabergoline could provide better control of IGF-I in some patients with acromegaly. Baseline IGF-I levels, female gender, body weight, and PRL levels affect the response to this combination therapy.

Somatotroph tumor progression during pegvisomant therapy: a clinical and molecular study

CONTEXT

There is concern that pegvisomant could be associated with a higher risk of tumor growth. The rate and possible determinants of this tumor growth are unknown.

OBJECTIVE

The objective of the study was to investigate the clinical, immunohistological, and molecular factors conditioning tumor growth in patients taking pegvisomant.

DESIGN AND SETTING

This was a cross-sectional study performed from 2004 to 2010 in four university hospitals in Spain.

PATIENTS

Seventy-five acromegalic patients with active disease resistant to somatostatin analogs treated with pegvisomant were followed up for a mean of 29 ± 20 months.

MAIN OUTCOME MEASURES

Magnetic resonance images before initiation of pegvisomant, at 6 months, and then yearly were examined in all patients. Immunohistological and molecular studies were performed in tumors that grew.

RESULTS

A significant increase in tumor size was observed in five patients (6.7%). Absence of previous irradiation (P = 0.014) and shorter duration of prepegvisomant somatostatin analog therapy (P < 0.001) were associated with an increased risk of tumor growth. A stepwise multivariate linear regression analysis (R(2) = 0.334, P < 0.001) identified the duration of somatostatin analog therapy prior to pegvisomant (beta = -4.509, P = 0.014) as the only significant predictor of tumor growth. In those tumors that grew, GH expression and insulin receptor expression were higher (P = 0.033 in both cases) than in the control group.

CONCLUSIONS

No previous radiotherapy, shorter duration of prepegvisomant somatostatin analog therapy, and higher tumor expression of GH and insulin receptor could be risk factors for tumor growth during pegvisomant therapy.

Effectiveness of retinoic acid treatment for redifferentiation of thyroid cancer in relation to recovery of radioiodine uptake

BACKGROUND

Retinoic acid (RA) treatment has been used for redifferentiation of metastatic thyroid neoplasia that have lost radioiodine (131I) uptake with heterogeneous results.

AIM

Retrospective analysis of the recovery rate of 131I uptake after RA treatment in patients from 11 Spanish hospitals.

METHODS

Twenty-seven patients (14 men, 13 women) with papillary [21], follicular [4], and oncocytic [2] thyroid cancer initially treated with total thyroidectomy plus 131I, and with 131I negative metastatic disease, were given 13-cis RA (0.66-1.5 mg/kg for 5-12 weeks) followed by a therapeutic 131I dose (3700-7400 MBq); 3 months later thyroglobulin levels and computed tomography imaging were performed.

RESULTS

In 9 out 27 cases (33%) (8 papillary, 1 follicular) optimal positive 131I scan was observed after RA treatment; in the remaining 18, 10 had a suboptimal uptake (7 papillary, 2 follicular, 1 oncocytic) and in the rest there was no 131I uptake recovery (6 papillary, 1 follicular, 1 oncocytic). In 17 positive responses to RA (either optimal or suboptimal) in which image follow-up was available, decrease or stabilization of metastatic growth was observed in 7, while tumor mass increased at short term in the remaining 10. No major side effects were detected.

CONCLUSION

Quite a high rate of 131I uptake recovery after RA treatment may be obtained in advanced differentiated thyroid cancer, but the potential modification of the natural course of the disease is uncertain. A better biological characterization of these tumors allowing the identification of potential responders to RA may improve the outcome of RA coadjuvant therapy.

Influence of first line treatment in the 5 (5yS) and 10-year (10yS) survival outcomes of patients with gastroenteropancreatic neuroendocrine tumors (GNETs): 2001–2005 Spanish task force GNET group

14058

Background: Data on incidence, morbidity and mortality of GNETs is limited due to the low frequency of these tumors. However this survival data is critical to design studies with new agents. Methods: Data was obtained from medical records of 262 patients with GNETs and centralized in an online registry at www.retegep.net . Among the study parameters were histology, localization, stage, diagnostic workup, 1st line and subsequent treatments, 5yS and 10yS for the whole dataset and for different stages, tumor types and 1st line systemic treatment. Results: Mean age 58, 58% male. Primary tumors: 49% Carcinoids (C), 19% non-functioning pancreatic tumors (PT), 9% insulinomas, 6% gastrinomas and 8% unknown primary. Localizations: midgut (36%), head (17%) and body of pancreas (10%). Functioning symptoms led to diagnosis in 38% of cases. 4% were associated to MEN1. Stage at diagnosis was advanced (Adv) in 46%, localised (L) in 30% and locorregional (LR) in 13% (unknown in 11%). Diagnostic workup were CT Scan (84%), Octreoscan (52%) and US (52%) and serum hormone tests (65%). Treatments for Adv disease included somatostatin analogues (SA) (47%), surgery (S) (43%), chemotherapy (CT) (35%) and interferon (IFN) (34%), embolization (7%) and radiofrequency ablation (3%). 5yS and 10yS for the whole group was 61.6% (SD: 5.2%) and 49.8% (SD: 7.7%) respectively. 5yS and 10yS for the L/LR and Adv stages were 78.1% (SD: 7.3%) and 71% (SD: 10%), and 48.9% (SD: 7.7%) and 29% (SD: 12.4%), respectively. LR PT and C had similar 5 and 10yS but Adv PT did worse than Adv C (5yS of 36.2% and 61.1%, respectively). 1st line systemic treatment for LR and Adv disease (n=90) included SA (39%), CT (34.4%), IFN (5.6%), combinations of SA+IFN (13.3%), A+CT (4.4%) and other combinations (3.3%), with a 10yS rate of 69%, 79%, 50%, 89%, 66% and 50%, respectively. Adv PT perform worse than C regardless of treatment choice. As second line systemic treatment (n=43) 30% received SA, 30% CT, 26% inmunotherapy and 14% combinations. Conclusions: An extensive use of systemic therapy and a scarce use of non-surgical LR treatments is observed in the Adv stages. Choice of 1st line systemic treatment does not seem to influence survival outcomes.

No significant financial relationships to disclose.

[The use of suprarenal scintigraphy in the differential diagnosis of suprarenal incidentaloma]

OBJECTIVES

To assess the usefulness of adrenal scintigraphy for clinical evaluation of adrenal incidentalomas, and its relation with pathological diagnosis and follow-up.

PATIENTS AND METHODS

We have studied 46 patients with unilateral adrenal incidentaloma of size between 10 and 100 mm (average 30.5 +/- 19 mm). The lesions were discovered with abdominal computerized tomography in the study of a primary tumor (22%) or in the evaluation of benign pathology (78%). Adrenal scintigraphy assessed uptake in adrenal incidentaloma. Hormonal study included urinary catecholamines, plasma cortisol after dexamethasone, adrenal androgens, and renin and aldosterone in hypertensive patients. Five patients were operated, FNAB was carried out in three patients, and in the rest average follow-up was 29 +/- 21 months. Adrenal incidentaloma was considered nonfunctional if the lesion did not modified its size nor showed analytical alterations along a follow-up higher than 8 months.

RESULTS

Of 46 adrenal lesions, seven didn't show uptake (three metastases, one cyst, one adrenal carcinoma, one pheochromocytoma, and one angiomyolipoma), 34 showed excessive uptake (29 nonfunctional adrenal nodules and 5 hyperfunctional adrenal nodules), and five had normal uptake (nonfunctional adrenal nodules). Adrenal scintigraphy was compatible in all cases with cytological study or the response to chemotherapy. Along the follow-up, growth of the lesion was demonstrated in 23%, and reduction or disappearance of the lesion in 11%, with no hormonal significant changes.

CONCLUSIONS

Detection of a lesion with no uptake in adrenal scintigraphy forces to carry out complementary explorations in order to rule out malignant pathology. A lesion with excessive uptake is indicative of a benign process and should be assessed with hormonal determinations.

Expression of MAL and MAL2, two elements of the protein machinery for raft-mediated transport, in normal and neoplastic human tissue

Polarized transport of lipids and proteins to the apical and basolateral membrane subdomains is essential for the functioning of epithelial cells. Apical transport is mediated by a direct route from the Golgi and an indirect route, referred to as transcytosis, involving the transport of the protein to the basolateral membrane followed by its internalization and subsequent transcellular transport to the apical subdomain. MAL and MAL2 have been demonstrated to be essential components of the machinery for the direct and indirect routes, respectively. Herein, we review the range of expression of MAL and MAL2 in normal human tissue and compare it with that of neoplastic tissue. Our analysis provides insight into the potential use of MAL- and MAL2-mediated pathways in many types of epithelial cells as well as in nonepithelial cells. In addition, the specific alterations in MAL and/or MAL2 expression observed in specific types of carcinoma provides a basis to understand the loss of the polarized phenotype that frequently accompanies the neoplastic transformation process. This points out potential applications of MAL and MAL2 as markers for tumor characterization.

Thyrocytes from autoimmune thyroid disorders produce the chemokines IP-10 and Mig and attract CXCR3+ lymphocytes

To better understand the selective migration of lymphocytes in autoimmune thyroid disorders (AITDs), we analyzed thyroid samples and demonstrated an enhanced expression of the chemokines interferon (IFN)-inducible protein (Ip)-10 and regulated on activation normal T lymphocyte expressed and secreted (RANTES) in thyroids from AITD patients. Ip-10 and monokine induced by IFN-gamma (Mig) were expressed in vivo in thyroid follicular cells (TFCs) from AITD thyroids. Interestingly, Ip-10 mRNA, although not basally detected in cultured TFCs, was strongly induced by IFN-gamma and synergistically increased by TNF-alpha addition. Furthermore, high levels of Ip-10 protein were detected in the supernatants of IFN-gamma-stimulated TFCs. Likewise, Mig protein was strongly induced in TFCs by the same stimuli as Ip-10. Unlike Ip-10 and Mig, the expression of RANTES was induced mainly by TNF-alpha. In addition, intrathyroidal lymphocytes from AITD patients showed higher expression of CXCR3, CCR2, and CCR5 chemokine receptors than autologous peripheral blood lymphocytes. T lymphoblasts expressing CXCR3 showed an increased migration to supernatants from stimulated TFCs, which was abolished by specific antibodies to the chemokines Ip-10 and Mig, as well as to their receptor CXCR3. Taken together, these data suggest a potential role of TFCs, through the production of the chemokines Ip-10, Mig and RANTES, in regulating the recruitment of specific subsets of activated lymphocytes in AITDs.

Severe respiratory failure secondary to Cushing's myopathy

We report a 55-year-old woman with typical clinical, biochemical and radiological features of Cushing's disease, who developed a severe respiratory insufficiency as the main symptom. She also complained of proximal muscle weakness over the last year and progressive dyspnea over the last four months. Bronchospasm, respiratory infection or cardiologic dysfunction were excluded. Arterial blood gas analysis showed severe respiratory insufficiency with hypoxemia and hypercapnia, respiratory acidosis and a normal alveolar-arterial oxygen gradient. Spirometry and plethysmography showed a restrictive ventilatory failure and maximum inspiratory and expiratory pressures were reduced. These findings were strongly suggestive of neuromuscular disease. Serum creatine kinase, aldolase, sodium, potassium and thyroid function tests were normal. An electromyogram and a muscle biopsy confirmed myopathic disease. Ketoconazole therapy improved her symptoms and respiratory function tests. In conclusion although proximal myopathy is a frequent presenting symptom of Cushing's syndrome, involvement of respiratory muscles with severe restrictive ventilatory dysfunction has not been previously reported as the main initial feature of Cushing's disease. Medical treatment of hypercortisolism improves muscle strength and resolves the respiratory insufficiency.

BENE, a novel raft-associated protein of the MAL proteolipid family, interacts with caveolin-1 in human endothelial-like ECV304 cells

The MAL proteolipid, an integral protein present in glycolipid- and cholesterol-enriched membrane (GEM) rafts, is an element of the machinery necessary for apical sorting in polarized epithelial Madin-Darby canine kidney cells. MAL was the first member identified of an extended family of proteins that have significant overall sequence identity. In this study we have used a newly generated monoclonal antibody to investigate an unedited member of this family, named BENE, which was found to be expressed in endothelial-like ECV304 cells and normal human endothelium. Human BENE was characterized as a proteolipid protein predominantly present in GEM rafts in ECV304 cells. Coimmunoprecipitation experiments revealed that BENE interacted with caveolin-1. Confocal immunofluorescence and electron microscopic analyses indicated that BENE mainly accumulated into intracellular vesicular/tubular structures that partially colocalize with internal caveolin-1. In response to cell surface cholesterol oxidation, BENE redistributed to the dilated vesicular structures that concentrate most of the caveolin-1 originally on the cell surface. After cessation of cholesterol oxidation, a detectable fraction of the BENE molecules migrated to the plasmalemma accompanying caveolin-1 and then returned progressively to its steady state distribution. Together, these features highlight the BENE proteolipid as being an element of the machinery for raft-mediated trafficking in endothelial cells.

CXCR3 chemokine receptor distribution in normal and inflamed tissues: expression on activated lymphocytes, endothelial cells, and dendritic cells

Using new human CXCR3 chemokine receptor-specific monoclonal antibodies, we studied human CXCR3 tissue distribution in lymphoid and nonlymphoid organs, as well as in inflammatory conditions, including rheumatoid arthritis, Hashimoto's thyroiditis, and dermal vasculitis. CXCR3 was expressed by certain dendritic cell subsets, specifically myeloid-derived CD11c positive cells, not only in those present in normal lymphoid organs, but also in germinal centers generated in inflammatory conditions. CXCR3 expression was also detected in some lymphocyte subsets such as intraepithelial lymphocytes of secondary lymphoid organs and infiltrating lymphocytes in inflammatory conditions. In addition, CXCR3 was constitutively expressed by endothelial cells (EC) of vessels of medium and large caliber but not in small vessels from different organs. Finally, enhanced CXCR3 expression was found in EC and in infiltrating lymphocytes with an activated phenotype in inflammatory diseases. The CXCR3 chemokine receptor may play a role in the regulation of leukocyte migration to inflammatory sites.

Transfer of autoimmune hypothyroidism following bone marrow transplantation from a donor with Graves' disease

We describe the transfer of a different autoimmune thyroid disorder by bone marrow transplantation. The donor had euthyroid Graves' disease after treatment with antithyroid drugs and stable oxopthalmos, with persistent thyroid autoantibodies. One year after bone marrow transplant, the recipient developed atrophic autoimmune hypothyroidism. Six months later the donor developed transient subclinical hypothyroidism followed by clinical hyperthyroidism. In both recipient and donor the presence of thyrotropin (TSH)-binding inhibitory immunoglobulins was documented. Although TSH receptor antibodies usually act as a TSH agonist causing thyrotoxicosis, they can also can act as a TSH antagonist causing primary hypothyroidism. This case may be an example of how the same antibody can act as an agonist in the donor and an antagonist in the bone marrow recipient, causing two different autoimmune disorders: primary hypothyroidism in the recipient and Graves' disease in the donor.

Phenotypic and functional characteristics of hematopoietic cell lineages in CD69-deficient mice

AIM/CD69 is the earliest leukocyte activation antigen and is expressed mainly by activated T, B, and natural killer (NK) cells. It is also constitutively expressed by platelets, by bone marrow myeloid precursors, and by small subsets of resident lymphocytes in the secondary lymphoid tissues. The engagement of CD69 by specific antibodies induces intracellular signals, including Ca(++) flux, cytokine synthesis, and cell proliferation. To investigate the physiological relevance of CD69, we generated mice deficient in CD69 (CD69-/-) by gene targeting in embryonic stem cells. CD69 (-/-) mice showed largely normal hematopoietic cell development and normal T-cell subpopulations in thymus and periphery. Furthermore, studies of negative- and positive-thymocyte selection using a T-cell receptor transgenic model demonstrated that these processes were not altered in CD69 (-/-) mice. In addition, natural killer and cytotoxic T lymphocyte cells from CD69-deficient mice displayed cytotoxic activity similar to that of wild-type mice. Interestingly, B-cell development was affected in the absence of CD69. The B220(hi)IgM(neg) bone marrow pre-B cell compartment was augmented in CD69 (-/-) mice. In addition, the absence of CD69 led to a slight increase in immunoglobulin (Ig) G2a and IgM responses to immunization with T-dependent and T-independent antigens. Nevertheless, CD69-deficient lymphocytes had a normal proliferative response to different T-cell and B-cell stimuli. Together, these observations indicate that CD69 plays a role in B-cell development and suggest that the putative stimulatory activity of this molecule on bone marrow-derived cells may be replaced in vivo by other signal transducing receptors.

Pyrrolidine dithiocarbamate protects mice from lethal shock induced by LPS or TNF-alpha

Although important advances have been made in the development of antibiotics and medical intensive care technology in recent years, systemic response to infection remains a major health problem, with growing incidence and high mortality rates. Here we demonstrate the ability of the antioxidant agent pyrrolidine dithiocarbamate (PDTC) to inhibit the in vivo activation of NF-kappaB in lung and liver tissues, as well as the systemic release of TNF-alpha in lipopolysaccharide (LPS)-treated mice. The in vivo effect of PDTC on NF-kappaB activation in liver tissues involved the inhibition of both LPS-induced I kappaB-alpha degradation and the translocation of the p50 and p65 NF-kappaB subunits to the nucleus. In addition to protecting mice against lethal LPS doses, PDTC curtailed TNF-alpha-induced lethal shock. This effect was observed even after LPS injection, and when PDTC was administered at a time when TNF-alpha was already at maximum levels in serum. PDTC-treated mice survived despite high IL-1beta and IL-6 levels, induction of VCAM-1 and ICAM-1 expression or leukocyte infiltration in tissues known to be associated with LPS-induced shock, indicating that PDTC does not act by modifying these responses. Taken together, these results indicate that PDTC interferes with the production as well as the action of TNF-alpha, and points to a possible approach toward the treatment of septic shock.

Pyrrolidine dithiocarbamate protects mice from lethal shock induced by LPS or TNF-alpha

Although important advances have been made in the development of antibiotics and medical intensive care technology in recent years, systemic response to infection remains a major health problem, with growing incidence and high mortality rates. Here we demonstrate the ability of the antioxidant agent pyrrolidine dithiocarbamate (PDTC) to inhibit the in vivo activation of NF-kappaB in lung and liver tissues, as well as the systemic release of TNF-alpha in lipopolysaccharide (LPS)-treated mice. The in vivo effect of PDTC on NF-kappaB activation in liver tissues involved the inhibition of both LPS-induced I kappaB-alpha degradation and the translocation of the p50 and p65 NF-kappaB subunits to the nucleus. In addition to protecting mice against lethal LPS doses, PDTC curtailed TNF-alpha-induced lethal shock. This effect was observed even after LPS injection, and when PDTC was administered at a time when TNF-alpha was already at maximum levels in serum. PDTC-treated mice survived despite high IL-1beta and IL-6 levels, induction of VCAM-1 and ICAM-1 expression or leukocyte infiltration in tissues known to be associated with LPS-induced shock, indicating that PDTC does not act by modifying these responses. Taken together, these results indicate that PDTC interferes with the production as well as the action of TNF-alpha, and points to a possible approach toward the treatment of septic shock.

Regulation of endothelial cell motility by complexes of tetraspan molecules CD81/TAPA-1 and CD151/PETA-3 with alpha3 beta1 integrin localized at endothelial lateral junctions

Cell-to-cell junction structures play a key role in cell growth rate control and cell polarization. In endothelial cells (EC), these structures are also involved in regulation of vascular permeability and leukocyte extravasation. To identify novel components in EC intercellular junctions, mAbs against these cells were produced and selected using a morphological screening by immunofluorescence microscopy. Two novel mAbs, LIA1/1 and VJ1/16, specifically recognized a 25-kD protein that was selectively localized at cell-cell junctions of EC, both in the primary formation of cell monolayers and when EC reorganized in the process of wound healing. This antigen corresponded to the recently cloned platelet-endothelial tetraspan antigen CD151/PETA-3 (platelet-endothelial tetraspan antigen-3), and was consistently detected at EC cell-cell contact sites. In addition to CD151/PETA-3, two other members of the tetraspan superfamily, CD9 and CD81/ TAPA-1 (target of antiproliferative antibody-1), localized at endothelial cell-to-cell junctions. Biochemical analysis demonstrated molecular associations among tetraspan molecules themselves and those of CD151/ PETA-3 and CD9 with alpha3 beta1 integrin. Interestingly, mAbs directed to both CD151/PETA-3 and CD81/ TAPA-1 as well as mAb specific for alpha3 integrin, were able to inhibit the migration of ECs in the process of wound healing. The engagement of CD151/PETA-3 and CD81/TAPA-1 inhibited the movement of individual ECs, as determined by quantitative time-lapse video microscopy studies. Furthermore, mAbs against the CD151/PETA-3 molecule diminished the rate of EC invasion into collagen gels. In addition, these mAbs were able to increase the adhesion of EC to extracellular matrix proteins. Together these results indicate that CD81/TAPA-1 and CD151/PETA-3 tetraspan molecules are components of the endothelial lateral junctions implicated in the regulation of cell motility, either directly or by modulation of the function of the associated integrin heterodimers.

Expression of the MAL gene in the thyroid: the MAL proteolipid, a component of glycolipid-enriched membranes, is apically distributed in thyroid follicles

The MAL proteolipid, an integral membrane protein expressed in T lymphocytes, polarized epithelial MDCK cells, and myelin-forming cells, has been identified as a component of internal glycolipid-enriched membrane (GEM) microdomains. On the basis of its ability to induce vesicle formation by ectopic expression, MAL has been recently proposed as a component of the machinery for GEM vesiculation. Taking into account the proposed role of GEMs in polarized transport, we have investigated the expression of the MAL gene in thyroid cells. Interestingly, MAL messenger RNA species were detected in the human thyroid, whereas they were undetectable in other endocrine glands tested. Moreover, epithelial FRT cells, a polarized rat cell line of thyroid origin, also expressed MAL transcripts. Immunohistochemical analysis of thyroid follicles, with a newly developed anti-MAL monoclonal antibody, indicates that MAL distribution is restricted to the apical zone of thyroid epithelial cells. Biochemical analyses, using FRT cells, indicate exclusive residence of MAL in GEM microdomains, and these analyses allowed the identification of MAL as a major protein component of the GEM fraction in this cell line. Our results are consistent with a role for MAL as a component of GEM microdomains in thyroid epithelial cells.

Up-regulated beta1-integrin expression in autoimmune thyroid disorders

Lymphocytic infiltration of the thyroid gland in autoimmune thyroid disorders requires, as a first step, their attachment to endothelial cells (EC) and, subsequently, interaction with thyrocytes and extracellular matrix proteins. Recent studies have focused on the pathophysiologic role of beta1-integrins as adhesion receptors for extracellular matrix proteins and as cell-to-cell adhesion receptors. In this study, we examine by flow cytometry and immunohistochemical techniques the differences in expression of beta1-integrins in thyrocytes and EC between normal thyroids and thyroid glands from patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT). Remarkably, we found an up-regulated de novo expression of very late antigen (VLA)-alpha6 subunit in thyrocytes in close proximity to lymphocyte infiltrates in GD and HT thyroid glands, with no reactivity in control thyroids. Moreover, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and IL-1beta produced a significant enhancement of VLA-alpha6 expression in vitro in thyrocytes in culture. In addition, an up-regulated expression of VLA-alpha5 and beta1 subunits was found in thyrocytes from GD and HT glands, specifically in those areas more severely inflamed. VLA-alpha2 was basally expressed in middle size and large vessels in control glands, with an increased expression in vessels of all sizes in HT and GD glands. Dendritic cells in thyroid lymphoid follicles were also positive for VLA-beta1, alpha2 and alpha6 subunits. These results indicate the existence of an up-regulatory process in the expression of beta1-integrins, particularly the alpha6 subunit, in several cell types from inflamed GD and HT thyroid glands, suggesting that these integrins could play a relevant role in localizing and perpetuating the autoimmune response in the thyroid gland in autoimmune thyroid disorders.

Expression of functionally active alpha 4 beta 1 integrin by thymic epithelial cells

We have investigated the expression and function of the VLA-4 heterodimer alpha 4 beta 1, a member of the beta 1 integrin subfamily, on human thymic epithelial cells (TEC) derived from cortical epithelium. The expression of the alpha 4 integrin chain was studied in four different cloned TEC lines derived from either fetal or post-natal human thymus by both flow cytometry and immunoprecipitation techniques with anti-alpha 4 MoAbs. All different cell lines assayed expressed significant levels of alpha 4, as revealed by their reactivity with MoAbs specific for distinct alpha 4 epitopes. The alpha 4 subunit expressed by TEC was associated to beta 1 but not to beta 1 chain, and displayed the characteristic 80/ 70 kD pattern of proteolytic cleavage. The VLA-4 integrin in these cells was constitutively active in terms of adhesiveness to both fibronectin and vascular cell adhesion molecule-1 (VCAM-1). In addition, this heterodimer localized to punctate regions of the cell in the area of contact with the substratum, named point contacts assessed by staining with the anti-beta 1 activation epitope 15/7 MoAb. According to the cortical origin of the TEC lines expressing VLA-4, human thymus sections stained with different anti-alpha 4 antibodies revealed the presence of cortical, and in smaller numbers medullary epithelial cells bearing alpha 4 integrin. The expression of alpha 4 in the thymus was also found in both adult and fetal rats, in which epithelial cells were also specifically stained. Altogether, our data show that VLA-4 is an additional component of the integrin repertoire of TEC, and suggest that it could have an important role in thymus epithelial cell-thymocyte interactions.

Thyroid autoimmune disorders in patients with chronic hepatitis C before and during interferon-alpha therapy

BACKGROUND AND AIMS

Hepatitis C virus is involved in the induction of autoimmunity and interferon can also induce hepatic and non-hepatic autoimmune reactions. This study assessed the prevalence of thyroid autoantibodies and autoimmune thyroid disorders in patients with chronic hepatitis C before and during interferon therapy.

PATIENTS AND METHODS

We studied prospectively 207 patients positive for anti-HCV and viral RNA. One hundred and forty-four of them received a therapeutic trial of one year with interferon-alpha. Free thyroxine, TSH and autoantibodies to thyroglobulin and thyroid microsomes were systematically tested at entry and at weeks 12 and 24 in both untreated and treated patients.

RESULTS

Sixteen of the 207 patients (7.7%) had thyroid dysfunction, including positive antithyroid antibodies in 14 (6.7%) and hypothyroidism in 10 (4.8%) prior to interferon therapy. In addition, during pretreatment evaluation one patient developed clinical hyperthyroidism after transient subclinical hypothyroidism and another had subclinical hyperthyroidism. Prevalences of positive antithyroid antibodies and hypothyroidism were significantly higher in women (14.7 and 10.5%, respectively, vs 0% in men, P < 0.01) and were directly associated with increasing age (P < 0.01). The incidence of thyroid dysfunction was also significantly higher in patients with other autoantibodies such as anti-nuclear (ANA) (P < 0.01). A trial with interferon was initiated in 144 patients and 8 of 142 (5.6%) without previous thyroid abnormalities developed thyroid dysfunction, including positive antithyroid antibodies in 7 (4.9%) and hypothyroidism in 4 (2.8%) with a prevalence again significantly higher in women (12.7 and 8.3%, respectively, vs 1% in men, P < 0.01) and also directly related to increasing age (P < 0.01). An association was found between the development of thyroid dysfunction during interferon therapy and the presence of other autoantibodies, including ANA, anti-DNA and anti-Sjögren's antibodies (P < 0.01), as well as with the induction of autoimmune hepatitis and Sjögren's syndrome (P < 0.01 and < 0.05 respectively). Thyroid abnormalities were reversed in all patients when interferon therapy was discontinued.

CONCLUSIONS

No significant association was found between chronic hepatitis C and the presence of thyroid autoimmunity in female patients. On the contrary, interferon therapy induced antithyroid autoantibodies and thyroid dysfunction de novo in patients with chronic hepatitis C without pre-existing thyroid abnormalities. Thyroid dysfunction secondary to interferon was reversible after discontinuation of therapy.

Expression of vascular adhesion molecules on human endothelia in autoimmune thyroid disorders

Cellular activation and expression of certain adhesion molecules within vascular endothelium is a critical event in leucocyte recruitment and emigration. A wide array of different adhesion receptors has been identified to mediate the interaction between endothelial cells (EC) and leucocyte subpopulations. In this study, the tissue expression of E-selectin, P-selectin, CD31, and endoglin endothelial cell adhesion molecules was studied on thyroid tissue from patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT). We found an up-regulated expression of E-selectin in EC in GD and HT thyroids, specifically in those areas more severely inflamed, with no reactivity in control thyroids. P-selectin was basally expressed in postcapillary venules in control glands, with an increased expression in HT and GD glands. On the other hand, increased CD31 expression was found on perifollicular, small and large venule EC from GD and HT glands, that correlated with the severity of mononuclear infiltration. In addition, CD31 expression was observed in some intrathyroidal macrophages and T cells in close proximity to CD31+ EC. Furthermore, a markedly enhanced expression of endoglin, a transforming growth factor-beta binding protein, was mainly located on perifollicular EC and EC from small venules as well as in adjacent macrophages from GD and HT thyroid glands. This enhanced expression of E- and P-selectins, CD31 and endoglin by thyroid EC in GD and HT may reflect their ability to regulate leucocyte trafficking and activation.

B-cell homotypic adhesion through exon-A restricted epitopes of CD45 involves LFA-1/ICAM-1, ICAM-3 interactions, and induces coclustering of CD45 and LFA-1

Lymphocyte interactions with other leukocytes and other cell types, as well as with components of the extracellular matrix, are one of the key steps in the immune response. Three novel monoclonal antibodies (MoAbs) have been produced and selected for their ability to induce intercellular adhesion in B cells. These three MoAbs immunoprecipitated a polypeptide of 220 kD, displaying specific phosphotyrosine phosphatase activity that has been identified as CD45. These MoAbs recognize epitopes located on the alternative spliced exon-A-encoded region of CD45. These epitopes are of polypeptidic nature, but they can be masked by addition of carbohydrate during CD45 biosynthesis. Interestingly enough, CD45 epitopes recognized by these MoAbs appeared to be selectively expressed on both peripheral blood and tonsillar B lymphocytes as well as on peripheral blood natural killer (NK) cells. CD45-mediated intercellular adhesion was abrogated upon incubation with anti-leukocyte function-associated antigen 1 (anti-LFA-1), intercellular cell adhesion molecule 1 (ICAM-1), and ICAM-3 MoAbs, thus indicating that this phenomenon involved both LFA-1/ICAM-1 and LFA-1/ICAM-3 cell adhesion pathways. Moreover, CD45-mediated cell aggregation was also inhibited by preincubation with some conventional anti-CD45 MoAbs. Interestingly, the triggering of cell aggregation through CD45 induced membrane surface relocation of CD45 and LFA-1 molecules, with both of them colocalizing at cell-cell contact areas of B-cell aggregates. Studies with inhibitors of both phosphotyrosine phosphatase and tyrosine kinase activities suggest that CD45 phosphotyrosine phosphatase activity could be involved in CD45-mediated cell aggregation. Taken together, these results support the notion that CD45 is a key molecule in the regulation of LFA-1-mediated cell-cell interactions.

Expression and functional significance of an activation-dependent epitope of the beta 1 integrins in chronic inflammatory diseases

The avidity of VLA integrins for their ligands can be increased by their transition to an active conformational state. This conformational change can be detected with a novel monoclonal antibody (mAb), termed 15/7, that recognizes an activation-dependent conformational epitope on the common beta 1 polypeptide of different VLA alpha beta 1 integrins. In an attempt to understand the possible role of the active conformational state of beta 1 integrins in vivo, we first investigated the expression of 15/7 epitope on T lymphocytes from patients with chronic inflammatory joint diseases. An enhanced expression of the 15/7 epitope was found in the synovial fluid (SF) T lymphocytes from these patients as compared to their peripheral blood (PB) T cells. The effect of different cytokines on the appearance of the 15/7 activation epitope in PB T lymphocytes was subsequently analyzed; interferon-gamma, interleukin-2 and, to a lower extent, tumor necrosis factor-alpha were able to induce an increased expression of the 15/7 epitope. This enhanced 15/7 expression correlated with a higher binding ability to fibronectin of cytokine-activated T cells. The presence of this activation epitope was detected in a small proportion of T lymphocytes scattered within inflammatory foci of synovial membrane from rheumatoid arthritis and thyroid glands from Hashimoto's chronic thyroiditis. We then analyzed the possible role of 15/7 epitope expression on cell adhesion in vitro. Immunofluorescence studies showed that the 15/7 epitope displayed a spot-like distribution, selectively decorating adhesive contacts of U-937 myelomonocytic cells attached to the 80 kDa proteolytic fragment of fibronectin (FN80). Furthermore, the anti-beta 1 15/7 mAb was able to induce both T lymphocyte, Jurkat and U-937 cellular binding and spreading on FN80. Altogether these results indicate that an activated conformation of beta 1 integrins is detected in vivo in lymphocyte infiltrates from chronic inflammatory conditions. The active conformations of beta 1 integrins are regulated by physiologic mediators such as cytokines, play an important role in cellular attachment and spreading, and appear to be involved in the development of inflammatory processes.

Impaired natural killer cytotoxicity in peripheral blood mononuclear cells in Graves' disease

We studied the natural killer (NK) activity of peripheral blood mononuclear cells (PBMC) in patients with Graves' disease (GD). Peripheral blood mononuclear cells from 20 untreated hyperthyroid patients with GD showed a significantly reduced NK activity against 51 Cr-labeled K562 cells (33.9 +/- 15.9%), while in 32 euthyroid patients under antithyroid drug therapy. NK activity was similar to that of controls (46.9 +/- 17.3 and 49.9 +/- 20.2%, respectively). Furthermore, normalization of thyroid function with antithyroid drugs was associated with a significant increase and normalization of NK activity during the follow-up of nine GD patients (from 29.2 +/- 17.9 to 48.1 +/- 16.5%). This phenomenon could not be ascribed to a defective number of NK cells because the amounts of CD56+ and CD16+ cells in PBMC from both hyperthyroid and euthyroid GD patients were within normal ranges. Natural killer activity of PBMC from patients with toxic multinodular goiter was similar to that of normal controls (45 +/- 12.8 to 49.9 +/- 20%). No correlation was found between natural killer activity and serum levels of free thyroxine, TSH-inhibitory immunoglobulins, thyroidal antibodies to thryoglobulin and thyroidal microsomal antigen, dose or duration of antithyroid drug therapy. Natural killer activity from both controls and GD patients was enhanced in vitro by addition of recombinant interleukin 2 (IL-2), reaching control levels in hyperthyroid patients. These abnormalities were not associated with a defective IL-2 production by T cells, nor with a decreased IL-2R expression. We conclude that in untreated Graves' disease there is a decrease in NK cell activity in PBMC, probably dependent on the autoimmune process.(ABSTRACT TRUNCATED AT 250 WORDS)

Adhesion molecules from the LFA-1/ICAM-1,3 and VLA-4/VCAM-1 pathways on T lymphocytes and vascular endothelium in Graves' and Hashimoto's thyroid glands

Lymphocytic infiltration of the thyroid gland in autoimmune thyroid disorders requires, as a first step, their attachment to endothelial cells (EC) and subsequently, their interaction with thyrocytes and extracellular matrix proteins. A number of different ligand molecules have been identified to mediate the interaction between EC and leukocyte subpopulations. In this study, we examined by flow cytometry and immunohistochemical techniques, the expression of integrin receptors and their counter-receptors by infiltrating lymphocytes and vascular endothelium in thyroid glands from patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT). A high proportion of GD intrathyroidal T lymphocytes expressed the CD69 and gp95/85 (Ea2) activation antigens as well as an increased number of LFA-alpha L, VLA-alpha 1, -alpha 4, -alpha 5, and beta 1 integrin receptors, as compared with peripheral blood T lymphocytes from the same patients. The expression of intercellular adhesion molecule (ICAM)-1 was increased in EC from GD and HT thyroids. In addition, an up-regulated de novo expression of vascular cell adhesion molecule (VCAM)-1 was found in EC in GD and HT thyroids, with no reactivity in control thyroids. Dendritic cells in thyroid lymphoid follicles were also positive for ICAM-1 and VCAM-1. In addition, most of intrathyroidal mononuclear cells expressed the ICAM-3 adhesion molecule. This enhanced expression of ICAM-1 and VCAM-1 by thyroid EC in GD and HT may reflect their ability to regulate leukocyte trafficking and activation by means of the expression of specific ligand molecules. Our data suggest that both the LFA-1/ICAM-1, ICAM-3 and VLA-4/VCAM-1 pathways could play a relevant role in localizing and perpetuating the autoimmune response in the thyroid gland in autoimmune thyroid disorders.

B lymphocyte binding to E- and P-selectins is mediated through the de novo expression of carbohydrates on in vitro and in vivo activated human B cells

Cell adhesion to endothelium regulates the trafficking and recruitment of leukocytes towards lymphoid organs and sites of inflammation. This phenomenon is mediated by the expression of a number of adhesion molecules on both the endothelium and circulating cells. Activation of endothelial cells (EC) with different stimuli induces the expression of several adhesion molecules (E- and P-selectins, ICAM-1, VCAM-1), involved in their interaction with circulating cells. In this report, we have studied the binding of nonactivated and activated B cells to purified E- and P-selectins. Activated but not resting B cells were able to interact with both selectins. This binding capacity of activated B cells paralleled the induction of different carbohydrate epitopes (Lewisx, sialyl-Lewisx, CD57 and CDw65) as well as other molecules bearing these or related epitopes in myeloid cells (L-selectin, alpha L beta 2 and alpha X beta 2 integrins, and CD35) involved in the interaction of different cell types with selectins. B cells infiltrating inflamed tissues like in Hashimoto's thyroiditis, also expressed these selectin-binding carbohydrates in parallel with the expression of E-selectin by surrounding follicular dendritic cells. Moreover, the crosslinking of these selectin-binding epitopes resulted in an increased binding of B cells to different integrin ligands. Thus, in addition to the involvement of integrins, E- and P-selectins could play an important role in the interaction of B lymphocytes with the endothelium during B cell extravasation into lymphoid tissues and inflammatory foci as well as in their organization into lymphoid organs.

Recovery of visual and endocrine function following transsphenoidal surgery of large nonfunctioning pituitary adenomas

A series of 35 patients with non-functioning pituitary adenomas undergoing transsphenoidal surgery is presented. In most cases, the presenting symptoms were related to the mass effect of the tumor. There was no operative mortality. Before surgery, visual field defects were documented in 21 patients (60%). After surgery, excluding 3 patients with preoperative blindness, 28% regained normal vision and 67% showed variable improvement. Preoperatively, 24 patients (69%) had abnormal pituitary function, 24 (69%) had hypogonadism, 7 (20%) adrenal insufficiency, 8 (23%) hypothyroidism and 2 (6%) panhypopituitarism. After pituitary surgery, all but one patient with normal preoperative function retained it. Of the patients with hypopituitarism, 11 (46%) had variable improvement and 13 (54%) had persistent deficits. After surgery, 4 patients (57%) with adrenal insufficiency recovered normal adrenal function, 7 patients (29%) with hypogonadism recovered gonadal function and 1 patient (13%) with hypothyroidism recovered thyroid function. Prior to surgery, the presence of a normal or slightly elevated PRL and a rise in TSH after TRH and in LH after GnRH stimulation were of value in predicting possible recovery of pituitary function after surgery. These observations suggest the presence of viable pituitary tissue in these cases and point out that, in some instances, the mechanism of hypopituitarism may be compression of the portal circulation, rather than destruction of the normal pituitary gland.

T lymphocyte activation in Graves' disease

We examined the proliferative response of T lymphocytes from thirty-eight patients with Graves' disease (17 untreated thyrotoxic and 30 euthyroid on antithyroid medication) to phytohemagglutinin, anti-CD3 MoAb and phorbol esters, as well as the capacities of these lymphocytes to produce interleukin 2 and the density of interleukin 2 receptors and major histocompatibility class II antigens. We found that the response of T lymphocytes to phytohemagglutinin, anti-CD3 monoclonal antibody and phorbol esters from untreated thyrotoxic Graves' disease was significantly enhanced as compared to treated patients and normal controls. Interleukin 2 production by mitogen-triggered T lymphocytes in both treated and untreated patients with Graves' disease was comparable to that of the control population. Interleukin 2 receptor density was found to be normal, whereas that of human leukocyte antigen-DR was increased in both untreated and treated patients. Following lymphocyte stimulation, there was an increase in human leukocyte antigen-DR and interleukin 2 receptor expression in patients with untreated Graves' disease. Significant correlations were found between thyroid hormone concentration and the proliferative responses to the polyclonal mitogen phytohemagglutinin, anti-CD3 monoclonal antibody and phorbol esters in untreated Graves' patients. Furthermore, during the follow-up of 9 patients, attainment of normal thyroid function after antithyroid treatment was associated with a decrease in and normalization of T-proliferative responses. Our data reveal that active Graves' disease is associated with T cell activation and this is probably related to immunological dysregulation as well as to hyperthyroxinemia.

Anterior pituitary function after adrenalectomy in patients with Cushing's syndrome

We assessed anterior pituitary function in five patients with Cushing's syndrome before and after the removal of cortisol-secreting adrenal adenomas. Before surgery, all patients lacked response of growth hormone to hypoglycaemia, four had low responses of thyrotrophin to thyrotrophin releasing hormone, three had hypogonadism and two had low prolactin reserve. After successful removal of the adrenal adenoma, all patients developed postoperative hypoadrenocorticism and recovered all impaired anterior pituitary hormones within a period of 3 months. Our results point to a direct inhibiting action of glucocorticoids at the pituitary level as the explanation for the impaired anterior pituitary function. Moreover, direct gonadal suppression by glucocorticoids may be an additional mechanism of hypogonadism in some patients.

Serum bone Gla protein as a marker of bone turnover in acromegaly

Serum bone Gla protein, a sensitive and specific marker of bone turnover, was measured in 35 acromegalic patients (14 untreated, 8 clinically active, and 13 cured) and 21 controls. We also examined 10 acromegalic patients before and after transsphenoidal surgery. Untreated and clinically active acromegalic patients had significantly higher serum bone Gla protein concentrations than the control subjects. Other nonspecific biochemical markers of bone metabolism, such as urinary hydroxyproline and urinary calcium, were also present in significantly greater amounts in active acromegalic patients. After treatment, a significant decrease in levels was observed, with return to control levels. In acromegalic patients, positive correlations were found among serum bone Gla protein and serum growth hormone and serum insulin-like growth factor I levels, as well as among levels of insulin-like growth factor I and serum phosphorus, serum alkaline phosphatase, and urinary hydroxyproline. These results suggest that serum bone Gla protein is a sensitive marker of the action of growth hormone in bone metabolism in acromegaly, a role that is probably mediated by insulin-like growth factor I.

Results of external pituitary irradiation after unsuccessful transsphenoidal surgery in Cushing's disease

Fourteen adult patients (10 females and 4 males; age range 20-60 years) with persistent Cushing's disease after transsphenoidal microsurgery were treated with pituitary irradiation. Supervoltage multiportal administration was employed at a total dose of 50 Gy (+/- 0.65 SD). The interval between microsurgery and pituitary irradiation was less than 6 months in 6 patients and more than 6 months in 8. The pituitary-adrenal axis was evaluated postsurgically, before irradiation and every 6 months thereafter. The remaining anterior pituitary function was simultaneously tested. Remission rates at 12 months and 24 months after radiotherapy were 61 and 70%, respectively. Two patients developed TSH deficiency and another gonadotropin deficiency during the follow-up after radiation. We conclude that pituitary irradiation is the treatment of choice for persistent Cushing's disease after unsuccessful surgery because of its high efficiency and low incidence of adverse reactions when compared with other forms of treatment.

Anterior pituitary function in Cushing's syndrome: study of 36 patients

We studied the anterior pituitary function in 36 patients (25 females and 11 males, mean age: 35 years) with untreated Cushing's syndrome by simultaneous triple stimulus with insulin, TRH and LHRH. Thirty-one patients (86%) had Cushing's disease and five (14%) had an adrenal adenoma. We observed a lack of response of GH to hypoglycemia in 88%, TSH to TRH in 91%, LH to LHRH in 30%, FSH to LHRH in 12% and PRL to TRH in 6% of the patients. Low-to-normal total thyroxine (T4) values were obtained in 37%, with low triiodothyronine levels in 87%. The free-T4 index was normal in all patients. Total testosterone was low in only one adult man, while estradiol and progesterone were low in 45% and 15% of premenopausal women, respectively. We observed no differences in either axis among patients with Cushing's syndrome of different etiologies. Nor was there any statistical difference between the frequency of alteration of each axis and the levels of urinary free cortisol or the duration of the disease. We conclude that hypercortisolism is responsible for the abnormalities in anterior pituitary function in Cushing's syndrome.

Hepatic fibrin-ring granulomas: a clinicopathologic study of 23 patients

Twenty-three patients with characteristic hepatic fibrin-ring granulomas were studied. Q fever accounted for 10 cases (43%), visceral leishmaniasis for five cases (22%), boutonneuse fever for two cases (9%), and toxoplasmosis, Hodgkin's disease, and allopurinol hypersensitivity for one case each (4%). The etiology remained undetermined in three cases (13%). This report broadens the range of etiologies of hepatic fibrin-ring granulomas to include boutonneuse fever and toxoplasmosis in the differential diagnosis of ring granulomas, and it could serve as a guideline to the clinician and pathologist for the most frequent categories of disease associated with this morphologic pattern.