Carlos Fardella B

Anticuerpos anti-tiroglobulina en el seguimiento de pacientes con cáncer diferenciado de tiroides: ¿Marcadores de enfermedad residual o recidivante?

Background: Anti thyroglobulin antibodies are present in 25% of patients treated for a differentiated thyroid cancer, invalidating thyroglobulin determination. Those patients subjected to total thyroidectomy and free of disease, should reduce the production of these antibodies, due to the lack of antigenic stimulus. Therefore, anti thyroglobulin antibodies could be useful to detect early relapses. Aim: To assess the relationship between anti thyroglobulin antibodies and the evolution of the disease in patients treated for thyroid cancer. Material and methods: Retrospective analysis of 26 patients treated for thyroid cancer with positive anti thyroglobulin antibodies, followed for three years. These were divided in those with or without lymphocytic thyroiditis (19 and 7 respectively). Results: At the first year of follow up, anti thyroglobulin antibody concentration was 401±94.9 UI/ml (x±sem) in patients with thyroiditis and 38.9±8.9 UI/ml in those without thyroiditis (p < 0.005). During the three years of follow up, no differences in anti thyroglobulin antibodies were observed between patients with or without tumor relapse. Conclusions: Concentration of anti thyroglobulin antibodies was higher in patients with thyroiditis and did not differentiate patients with tumor relapse (Rev Med Chile 2002; 130: 167-72)

Exceso de mineralocorticoides en hipertensos esenciales: enfoque clínico-diagnóstico

Background: Primary hyperaldosteronism is more frequent among subjects with essential hypertension than previously thought. The prevalence, according to local and international evidence could fluctuate between 9 and 10%. Aim: To investigate if subjects with essential hypertension have different aldosterone and renin plasma levels than normotensive subjects. Patients and methods: One hundred twenty five subjects with essential hypertension, not receiving medications for at least two weeks prior to the study and 168 age and sex matched normotensive controls were studied. Blood was drawn between 9 and 10 AM during a sodium free diet to determine plasma aldosterone, plasma renin activity and potassium. Results: Plasma aldosterone was higher in hypertensive subjects than controls (11.6 ± 7.6 and 9.9 ± 5.1 ng/dl respectively; p=0.04). Plasma renin activity was lower in hypertensives than controls (1.42 ± 1.28 and 1.88 ± 1.39 ng/ml/h respectively; p<0.001). Thus, plasma aldosterone/plasma renin activity ratio was higher in hypertensives (13.8 ± 13.5 and 8.3 ± 7.8; p<0.001). A pathological ratio was defined as over 25, corresponding to the mean plus two standard deviations of the control group. Primary hyperaldosteronism was found in 5/125 hypertensives (4%) and 1/168 normotensive subject (0.6%). None had hypokalemia. Conclusions: Subjects with essential hypertension have higher plasma aldosterone and lower plasma renin activity than normal controls. A plasma aldosterone/plasma renin activity over 25 was defined as abnormal. (Rev Med Chile 2000; 128: 955-61)

Trastornos del ánimo, psicofármacos y tiroides

For more than 40 years thyroid hormones and mood disordershave been associated. Some psychiatric symptoms are produced by thyroid illnesses and there isa frequent association of thyroid dysfunction with mood disorders. Therefore, routine thyroidfunction assessment in patients with mood disorders and the treatment of sub-clinical thyroiddysfunctions is recommended. The usefulness of adding thyroid hormones to antidepressivetreatment in euthyroid patients to obtain a potentiation effect has been probed repeatedly. Themost common strategy is potentiation with T3, but high doses of T4 have been also used in pa-tients with resistant depression. Thyroid hormones exert their action in the central nervous sys-tem through a variety of mechanisms: modulation of gene expression of several groups ofproteins, some of them with known physiopathological implications in mood disorders and theinfluence over serotonin and noradrenergic neurotransmission, known to be one of the modesof action of antidepressants. Finally, it is also important to stress the complex relationship be-tween psychiatric drugs, deiodinases and thyroid hormones, that can potentially help to under-stand the mechanisms of action of these drugs (Rev Med Chile 2004; 132: 1413-24).(

Características de presentación del microcarcinoma papilar del tiroides: Experiencia retrospectiva de los últimos 12 años

BACKGROUND Thyroid microcarcinoma is a tumor of 10 mm or less, that should have a low risk of mortality. However, a subgroup of these carcinomas is as aggressive as bigger tumors. AIM To describe the pathological presentation of these tumors, and compare them with larger tumors. MATERIAL AND METHODS All pathological samples of thyroid carcinoma that were obtained between 1992 and 2003, were studied. In all biopsies, the pathological type, tumor size, the focal or multifocal character, the presence of lymph node involvement and the presence of lymphocytic thyroiditis or thyroid hyperplasia, were recorded. RESULTS One hundred eighteen microcarcinomas and 284 larger tumors were studied. The mean age of patients with microcarcinoma and larger tumors was 42.7+/-14 and 49.3+/-16 years respectively (p <0,001) and 83% were female, without gender differences between tumor types. Mean size of microcarcinomas was 8.6 mm and 116 (98%) were papillary carcinomas. Of these, 109 (94%) were well differentiated and seven (6%) were moderately differentiated. Thirty six (31%) were multifocal and in 10 (8,6%), there was lymph node involvement. The mean size of larger tumors was 23.8 mm and 241 (85%) were papillary carcinomas. Of these, 200 (83%) were well differentiated, and 41 (17%) were moderately differentiated. Eighty five (35%) were multifocal and in 44 (18%) there was lymph node involvement. The prevalence of thyroiditis and hyperplasia was significantly higher among microcarcinomas than in larger tumors (15 and 2.5%, respectively, p <0.001, for the former; 32.4 and 1.7%, respectively, p <0.001, for the latter). CONCLUSIONS In this series, one third of microcarcinomas were multifocal and 10% had lymph node involvement. Therefore, the aggressiveness of these tumors is higher than what is reported in the literature and they should be treated with total thyroidectomy.

Alta prevalencia de enfermedad tiroidea subclínica en sujetos que concurren a control de salud

Background: There is no information about the prevalence of thyroidal diseases in the general Chilean population. Aim: To assess the prevalence of thyroidal diseases in individuals attended in occupational health examinations. Subjects and methods: Four hundred seventy two individuals were examined between 1998 and 1999. In all, serum levels of thyroid hormones, TSH and anti thyroidal antibodies (anti microsomal, anti thyroid peroxidase and anti thyroglobulin) were measured. Results: Forty four subjects were excluded from the study due to an incomplete medical record and 18 due to a personal history of thyroidal disease. Abnormal serum levels of thyroid hormones or TSH were detected in 28 subjects (6.8%). Four (1%) had hypothyroidism, 23 a subclinical hypothyroidism (5.6%) and one (0.2%) had hyperthyroidism. In 87 subjects (21.2%) at least one of the antibodies was positive. Positive anti thyroid antibodies were found in 14 of 28 subjects (50%) with abnormal thyroid hormone levels, compared with 73 of 382 subjects (19.1%) with normal thyroid hormone levels. Thyroid dysfunction was twice as frequent in women than in men. Conclusions: In this sample, a 6.8% prevalence of abnormal thyroid function tests was detected. (Rev Med Chile 2001; 129: 155-60).

Trastorno de pánico e hipertiroidismo: curso clínico en dos pacientes

In two females aged 27 and 32 years old, an aggravation of their panic disorder coincided with the appearance of clinical signs of hyperthyroidism. The clinical diagnosis was confirmed with the finding of raised thyroid hormone levels and undetectable TSH levels. These two cases highlight the importance of routine thyroid function assessment in patients with panic disorder, mainly in those with partial response to medications or when symptoms aggravate, despite an adequate treatment (Rev Med Chile 2001; 129: 187-90).

Microcarcinoma tiroideo de evolución agresiva: Report of one case

The treatment of papillary thyroid carcinoma of less than 10 mm diameter is a matter of controversy. The incidental finding of papillary microcarcinomas in autopsies is frequent and some authors postulate that these tumors are biologically inactive and should only be observed. We report a 21 years old woman with a papillary thyroid cancer of 6x5x5 mm and bilateral paratracheal metastases, that was subjected to a total thyroidectomy. She received 200 mCi of radioiodine. Two years after surgery, a new nodule of 9.6 mm diameter was detected by ultrasound, that was treated with a new dose of 200 mCi of radioiodine. One year later a suprasternal mass of 2 cm diameter and 3 enlarged lymph nodes were detected. She was subjected to a surgical lymph node dissection of the neck and the biopsy confirmed the presence of cancer. She received a new dose of 300 mCi of radioiodine. The mother of the patient had a 7 mm thyroid nodule that was also a papillary carcinoma (Rev Med Chile 2005; 133: 323-6)The treatment of papillary thyroid carcinoma of less than 10 mm diameter is a matter of controversy. The incidental finding of papillary microcarcinomas in autopsies is frequent and some authors postulate that these tumors are biologically inactive and should only be observed. We report a 21 years old woman with a papillary thyroid cancer of 6 x 5 x 5 mm and bilateral paratracheal metastases, that was subjected to a total thyroidectomy. She received 200 mCi of radioiodine. Two years after surgery, a new nodule of 9.6 mm diameter was detected by ultrasound, that was treated with a new dose of 200 mCi of radioiodine. One year later a suprasternal mass of 2 cm diameter and 3 enlarged lymph nodes were detected. She was subjected to a surgical lymph node dissection of the neck and the biopsy confirmed the presence of cancer. She received a new dose of 300 mCi of radioiodine. The mother of the patient had a 7 mm thyroid nodule that was also a papillary carcinoma.

Análisis de un Programa Universitario de Formación de Postgrado en Endocrinología, luego de 24 años de su inicio

The Pontificia Universidad Catolica de Chile has a two decades experience in training endocrinology specialists. This communication explains the operation of the training program and the results of a survey, answered by 90% of Endocrinologists that were trained at the center. This survey covers different aspects of the program such as the strengths and weaknesses of the academic teaching and the present position of the trainees. Questions about the working environment and the relationship with their teachers during the application of the program are also included. These results can be useful for other University centers that are planning a training program in endocrinology and for those physicians that are planning to become endocrinologists

Actividad de 11 beta hidroxiesteroide dehidrogenasa tipo 2 en hipertensos chilenos

Background: Half of hypertensive patients with low plasma renin activity have a primary hyperaldosteronism. Among the remaining half, 11s-hydroxysteroid dehydrogenase type 2 (11sHSD2) deficiency plays an important role. This enzyme catalyzes the conversion of cortisol to cortisone, avoiding the interaction of cortisol with the mineralocorticoid receptor. If the enzyme fails, cortisol will stimulate sodium and water reabsorption and increase blood pressure. Aim: To determine biochemical alterations, suggestive of 11sHSD2 deficiency, in low-renin hypertensive patients. Patients and Methods: Twenty eight hypertensive patients with a plasma renin activity of less than 0.5 ng/ml/h and with a plasma aldosterone of less than 5 ng/dl were studied. Twenty eight normotensive patients were studied as controls. Serum cortisol (RIA), cortisone (ELISA) and the serum cortisol/cortisone ratio were determined in all of them, between 9 and 10 AM. Measurements were confirmed by high pressure liquid chromatography. The serum cortisol/cortisone ratio was considered abnormal when its Ln (cortisol/cortisone) value was over 2 standard deviations of the mean. Results: Serum cortisol was higher in hypertensive subjects than in controls (11.1±3.3 and 9.2±2.8 µg/dl, respectively; p <0.05). No differences were observed in serum cortisone (3.4±1.3 and 3.7±1.2 µg/dl, respectively). Four hypertensive subjects had an abnormally high Ln (cortisol/cortisone) value (1.86; 1.73; 2.07 and 2.01, considering a normal value of less than 1.61). Conclusions: Four of 28 hypertensive subjects with low plasma renin activity and aldosterone had biochemical alterations suggestive of 11sHSD2 deficiency (Rev Med Chile 2002; 130: 1201-8).