Prevalencia de hipotiroidismo y relación con niveles elevados de anticuerpos antiperoxidasa y yoduria en población de 35 y más años en Armenia. 2009-2010 / Hypothyroidism prevalence and its relationship to high levels of thyroid peroxidase antibodies and urinary iodine in a population aged 35 and over from Armenia, 2009-2010

Objetivos Determinar la frecuencia de hipotiroidismo y su relación con anticuerpos antiperoxidasa y yoduria elevada, con la finalidad de realizar recomendaciones a las autoridades sanitarias sobre el consumo de sal yodada y detección temprana de enfermedad tiroidea. Métodos Participaron 437 personas de la población general de Armenia (Quindío). Se realizaron pruebas ELISA para Tiroxina-L, hormona estimulante de la tiroides, anticuerpos antiperoxidasa y análisis fotocolorimétrico para yoduria. Resultados La prevalencia de hipotiroidismo fue de 18,5 %. Los anticuerpos antiperoxidasa fueron positivos en el 28,9 %, con prevalencia significativamente más alta entre aquellos con hormona estimulante de la tiroides mayor a 10 uUI/ml comparados con valores de 5,1 a 10 uUI/ml (O.R 3,2) y en fumadores (O.R 3,4). La Tiroxina-L fue normal en el 98,2 % de participantes con hormona estimulante de la tiroides mayor a 5 uUI/ml y en el 92 % de aquellos con valores mayores a 10 uUI/ml. El promedio de yoduria fue de 565,1; niveles por encima de 300 µg/l se obtuvieron en un 81,8 % de los participantes. Conclusiones El aumento en la prevalencia de anticuerpos antiperoxidasa positivo a medida que aumentan los valores de hormona estimulante de la tiroides podría evidenciar una elevado riesgo en Armenia de desarrollo de hipotiroidismo de origen autoinmune; a pesar de los elevados niveles de yoduria, no se logró establecer relación con los niveles de anticuerpos antiperoxidasa ni de hormona estimulante de la tiroides.

Objectives Determining the prevalence of hypothyroidism and its interrelationship with peroxidase antibodies and high urinary iodine levels as a means for devising a set of recommendations for health authorities regarding the consumption of iodised salt and the early detection of thyroid disease. Methods 437 people in the municipality of Armenia (Quindío) participated in the study. ELISA tests were performed for free thyroxine, thyroid-stimulating hormone and thyroid peroxidase antibodies; a photocolorimetric analysis was carried out to determine urinary iodine levels. Results Hypothyroidism prevalence was 18.5%. Thyroid peroxidase antibodies were positive in 28.9% of the study population, with significantly higher prevalence amongst those with levels > 10 mIU/mL thyroid-stimulating hormone compared to 5.1 to 10 mIU/mL in those without it (OR 3.2) and smokers (O.R 3,4). Free thyroxine was normal in 98.2% of participants (> 5 mIU/mL thyroid-stimulating hormone levels) and 92% in those in whom > 10 mIU/mL thyroid-stimulating hormone levels were found. The average iodine level was 565.1; levels above 300µg/L were obtained in 81.8% of the participants. Conclusions Increased positive thyroid peroxidase antibody prevalence with increasing thyroid-stimulating hormone values could demonstrate a high risk of developing autoimmune hypothyroidism in Armenia; despite high iodine levels, a relationship with thyroid peroxidase antibodies or thyroid-stimulating hormone levels could not be established.

Thyroid hormonal disturbances related to treatment of hepatitis C with interferon-alpha and ribavirin

OBJECTIVE: To characterize thyroid disturbances induced by interferon-alpha and ribavirin therapy in patients with chronic hepatitis C. INTRODUCTION: Interferon-alpha is used to treat chronic hepatitis C infections. This compound commonly induces both autoimmune and non-autoimmune thyroiditis. METHODS: We prospectively selected 26 patients with chronic hepatitis C infections. Clinical examinations, hormonal evaluations, and color-flow Doppler ultrasonography of the thyroid were performed before and during antiviral therapy. RESULTS: Of the patients in our study, 54 percent had no thyroid disorders associated with the interferon-alpha therapy but showed reduced levels of total T3 along with a decrease in serum alanine aminotransferase. Total T4 levels were also reduced at 3 and 12 months, but free T4 and thyroid stimulating hormone (TSH) levels remained stable. A total of 19 percent of the subjects had autoimmune interferon-induced thyroiditis, which is characterized by an emerge of antithyroid antibodies or overt hypothyroidism. Additionally, 16 percent had non-autoimmune thyroiditis, which presents as destructive thyroiditis or subclinical hypothyroidism, and 11 percent remained in a state of euthyroidism despite the prior existence of antithyroidal antibodies. Thyrotoxicosis with destructive thyroiditis was diagnosed within three months of therapy, and ultrasonography of these patients revealed thyroid shrinkage and discordant change in the vascular patterns. DISCUSSION: Decreases in the total T3 and total T4 levels may be related to improvements in the hepatocellular lesions or inflammatory changes similar to those associated with nonthyroidal illnesses. The immune mechanisms and direct effects of interferon-alpha can be associated with thyroiditis. CONCLUSION: Interferon-alpha and ribavirin induce autoimmune and non-autoimmune thyroiditis and hormonal changes (such as decreased total T3 and total T4 levels), which occur despite stable free T4 and TSH levels. A thyroid hormonal evaluation, including the analysis of the free T4, TSH, and antithyroid antibody levels, should be mandatory before therapy, and an early re-evaluation within three months of treatment is necessary as an appropriate follow-up.

Frequency Of Pancreatic Beta-Cell Autoimmunity Markers In Patients With Autoimmune Thyroid Disease / Frecuencia de marcadores de autoinmunidad beta pancreática en pacientes con enfermedad tiroidea autoinmune

A total of 305 ambulatory patients recruited at the Division of Endocrinology, Hospital de Clínicas, University of Buenos Aires, with autoimmune thyroid disease (AITD) were studied to search for associations between autoimmune thyroid disease and presence of serum markers of autoimmune diabetes mellitus. Screening for markers of pancreatic beta-cell autoimmunity was performed by radioligand binding assays (RBA) as follows: autoantibodies to glutamic acid decarboxylase (GADA) and proinsulin (PAA) were determined in all sera, whereas autoantibodies to protein tyrosine phosphatase (IA-2A) and insulin (IAA) were additionally measured in 200 sera randomly selected from the total collection. In addition, every GADA positive serum among the remaining 105 sera was systematically tested for the presence of IA-2A and IAA. In the cohort of 305 AITD patients 22 (7.2%) were previously diagnosed as type 1, type 2 or insulin-requiring type 2 diabetics. Ten of these patients presented serum marker positivity specific for β-cell autoantigens and 12 were marker negative. On the other hand, considering the majority of non-diabetic AITD patients (n=283), β-cell marker positivity was detected in 17 individuals (6.0%). The prevalence of autoimmune diabetes markers was much higher in the studied population than in the general population utilized as a control group, and GADA was the most frequent marker.

Se investigó la asociación entre enfermedad tiroidea autoinmune y la presencia de marcadores séricos de diabetes mellitus en 305 pacientes ambulatorios con enfermedad tiroidea autoinmune reclutados en la División Endocrinología. La búsqueda de marcadores de autoinmunidad contra las células beta pancreáticas se realizó por la técnica de unión de radioligandos (RBA) como se detalla a continuación: se determinaron autoanticuerpos contra la decarboxilasa del ácido glutámico (GADA) y proinsulina (PAA) en todos los sueros, mientras que los anticuerpos contra la proteína tirosina fosfatasa (IA-2A) e insulina (IAA) fueron medidos en 200 de estos sueros tomados al azar de la colección total. Además, en los restantes 105 pacientes, la presencia de IA-2A y IAA fue evaluada en todos los sueros positivos para GADA. Del grupo de 305 pacientes con enfermedad tiroidea autoinmune 22 (7.2%) fueron diagnosticados previamente como diabéticos tipo 1, tipo 2 o tipo 2 insulino-requirientes. Diez de ellos presentaron positividad para marcadores específicos de autoantígenos de célula β, en tanto 12 fueron negativos. Por otra parte, en 17 de los 283 pacientes (6.0%) con enfermedad tiroidea autoimmune y sin diagnóstico previo de diabetes, se detectó positividad para marcadores de célula β. La prevalencia de marcadores de autoinmunidad asociados a diabetes fue mayor en la población estudiada que en la población general usada como grupo control, siendo GADA el marcador más frecuente.

Serum cytokines in autoimmune and toxic multinodular thyroid diseases

Measuring serum cytokine levels in patients with Grave's disease, Hashimoto's thyroiditis, toxic multinodular goiter and compared them to a normal control group, to see if there is any correlation between the level of the serum cytokines and the pathophysiology of autoimmune and toxic multinodular thyroid diseases. Serum INF gamma [Th1], IL-10 and IL-4 [Th2] and IL-6 cytokine levels were studied in 26 patients with Graves thyrotoxicosis, 27 patients with goitrous Hashimoto's thyroiditis, 18 patients with toxic multinodular goiter and 40 normal controls. INF-GAMMA was detected in all Graves' and Hashimoto's patients with mean values of 142.11 +/- 29.53 unit/ml and 85.70 +/- 25.86 unit/ml. The mean levels of INF-gamma in Graves was significantly higher compared to Hashimoto's [P<0.001]. IL-10 was detected in all Graves' patients with a mean value of 583.85 +/- 253.35 pg/ml and 19 out of 27 Hashimoto's patients with a mean value of 332.63 +/- 213.20 pg/ml. The level of IL-10 was significantly higher in Graves' than in Hashimoto's [P<0.001]. Both INF gamma and IL-10 were not detected in toxic multinodular goiter or normal individual. IL-4 was significantly elevated in Graves' with a mean value of 132.4 +/- 44.52 but not in any of the other study groups. IL- 6 was detected in the serum of 25 Graves' with a mean value of 496.80 +/- 180.43 pg/ml, 10 Hashimoto's with a mean value of 293.50 +/- 196.61 pg/ml and 10 toxic multinodular goiter patients with a mean value of 228.75 +/- 73.96 pg/ml but not in the serum of normal individuals. The levels of IL-6 was significantly elevated in autoimmune thyroid disease [Graves and Hashimoto's] compared to toxic multinodular goiter [P<0.001]; also IL-6 level was significantly higher in Graves' than Hashimoto's [P <0.001]. The immunopathology seen in both the Grave's disease and goitrous Hashimoto's thyroiditis groups that we studied are related in part to the presence and interplay of mixed Th1 and Th2 cytokines in which there is a down regulation of cytotoxic effect and production of high levels of autoantibodies. The raised level of IL-6 that we observed in autoimmune [Grave's disease and Hashimoto's thyroiditis] and toxic multinodular goiter could be an indication of a long standing inflammatory and destructive process of the diseases