Endotelina-1, proteína C reactiva ultrasensible y actividad antioxidante en pacientes con hipotiroidismo subclínico y en eutiroideos con autoinmunidad tiroidea. Efectos del tratamiento con levotiroxina / Endothelin-1, high sensitivity C reactive protein and antioxidant activity in subclinical hypothyroid patients. Effects of levothyroxine treatment

RESUMEN La Endotelina-1 (ET1) y Proteína C Reactiva ultrasensible (PCRus) como marcadores de disfunción endotelial (DE) e inflamación vascular en hipotiroidismo subclínico (HS) han mostrado resultados controvertidos. El rol del estrés oxidativo y defensa antioxidante (TRAP) es motivo de discusión. Objetivos Establecer si el HS y la autoinmunidad tiroidea (AIT), excluyendo otros factores de riesgo cardiovascular, pueden causar DE e inflamación vascular, evaluadas a través de ET1 y PCRus, respectivamente. Establecer si TRAP juega algún rol. Evaluar cambios en ET1 y PCRus luego del tratamiento con levotiroxina (LT4). Material y métodos Se evaluaron prospectivamente 70 pacientes divididos en 3 grupos: HS: 41 pacientes (T4 normal,TSH >4,2 y <10 mUI/L), AIT: 10 pacientes eutiroideos (TSH <4,2 mUI/L) con aTPO y/o aTg (+) y Control: 19 pacientes eutiroideos sin AIT. Se excluyeron otros factores de riesgo cardiovascular. Se midió basalmente ET1, PCRus y TRAP plasmáticos, y en HS bajo LT4 (n = 24): ET1 y PCRus. Resultados No hubo diferencias significativas en edad, IMC, perfil lipídico y TRAP. ET1 y PCRus fueron significativamente mayores en pacientes con HS (media ± DS 1,77 ± 0,85 pg/ml y 1,5 ± 0,6 mg/l vs. controles (0,8 ± 0,3 pg/ml y 0,5 ± 0,2 mg/l) p <0,0001 y <0,008 respectivamente. Del mismo modo en AIT (1,4 ± 0.4 pg/ml y 2,3 ± 1,3 mg/l) vs controles p <0,0001 y <0,034, respectivamente. La TSH fue mayor en el grupo AIT vs. Control 2,57 ± 0,88 vs. 1,64 ± 0,5 mUI/L; p = 0,002. En HS bajo LT4 (8,7 ± 3,8 meses) se observó descenso de ET1 (p <0,001). ET1 correlacionó con TSH (r = 0,5 p <0,0001). El punto de corte de ET1 mediante curva ROC fue 1,32 pg/ml (Sensibilidad 81,6%-Especificidad 75%). Conclusiones ET1 y PCRus resultaron marcadores útiles para evaluar DE e inflamación vascular asociadas a HS. La defensa antioxidante no ejercería un rol en estos mecanismos. El tratamiento con LT4 produjo una significativa caída de ET1, pudiendo necesitarse un período más largo de eutiroidismo para normalizarla. En AIT, niveles de TSH >2,5 mUI/L podrían sugerir un mínimo grado de hipotiroidismo justificando la elevación en ET1 y PCR, sin descartar el rol de la AIT "per se".

ABSTRACT The measurement of endothelin-1 (ET1) and high sensitivity C-reactive protein (hsCRP) as markers of endothelial dysfunction (ED) and vascular inflammation in subclinical hypothyroidism (SH) has shown controversial results. The role of oxidative stress and antioxidant defense (TRAP) is a matter of discussion. Objectives To establish if SH and thyroid autoimmunity (TAI), excluding other cardiovascular risk factors, may cause ED and vascular inflammation, evaluated through the measurement of ET1 and hsCRP respectively. To determine if TRAP could have some role. Additionally, changes in these parameters after treatment with levothyroxine (LT4) will be evaluated. Material and methods: 70 patients were prospectively evaluated. They were classified into: SH Group: 41 patients (normal T4, TSH> 4.2 and <10 mIU/L), TAI Group: 10 euthyroid patients (TSH <4.2 mUI/L) with positive aTPO and/or aTg and Control Group: 19 euthyroid patients without TAI. Other cardiovascular risk factors were excluded in patients and controls. Plasma ET1, hsCRP and TRAP were measured basally, and ET1 and hsCRP under LT4 therapy in the HS Group. Results There were no significant differences between the 3 groups in age, BMI, lipids and TRAP. ET1 and hsCRP were significantly higher in patients with SH (mean ± SD 1.77 ± 0.85 pg/ml and 1.5 ± 0.6 mg/l) vs. controls (0.8 ± 0.3 pg/ml y 0.5 ± 0.2 mg/l) p <0.0001 y <0.008 respectively. Similarly, in TAI patients (1.4 ± 0.4 pg/ml y 2.3 ± 1.3 mg/l) vs controls, p <0.0001 and <0.034, respectively. TSH was higher in the TAI patients versus control group (2.5 ± 0.88 versus 1.64 ± 0.5 mIU/L, p = 0.002). Twenty-four patients with SH showed a significant decrease in ET1 (p <0.001) under treatment with LT4 (8.7 ± 3.8 months). ET1 had a highly significant correlation (p <0.0001) with TSH (r = 0.5). The cut-off level of ET1 established by ROC curve was 1.32 pg/ml (Sensitivity 81.6%-Specificity 75%). Conclusions ET1 and hsCRP were useful markers to evaluate ED and vascular inflammation associated with SH. There were no differences in TRAP levels between patients and controls, so it does not appear that oxidative stress would have played any role. Treatment with LT4 produced a significant drop in ET1. Probably, a longer period of euthyroidism might be necessary to normalize ET1 levels. In TAI Group, TSH levels >2.5 mUI/L could suggest a "minimal degree" of hypothyroidism justifying the elevation in ET1 and hs CRP. The role of the TAI "per se" couldn't be completely ruled out.

Evaluation of effect of isoflavone on thyroid economy & autoimmunity in oophorectomised women: A randomised, double-blind, placebo-controlled trial.

Background and objectives: The potential of soy isoflavones to interfere with thyroid function has been reported. However, there are limited data regarding their effect on thyroid function and autoimmunity in surgical menopausal women. The present study aimed to evaluate the effect of isoflavones on thyroid function and autoimmunity, menopausal symptoms, serum follicle stimulating hormone (FSH) and estradiol levels in oophorectomised women. Methods: A randomized, double blind, placebo-controlled trial was conducted in 43 oophorectomised women to evaluate the effect of soy isoflavones (75 mg/day for 12 wk) on serum thyroid profile (free T3 , free T4 , TSH, TBG and anti-TPO antibody titres) assessed at baseline, 6 and 12 wk after randomization. Assessment was also done for menopause symptom score (MSS) three weekly, and FSH and estradiol levels at baseline and at study completion. Results: There was a significant alteration in free T 3 levels in the group receiving isoflavones (4.05 ± 0.36, 4.12 ± 0.69 and 3.76 ± 0.55 pmol/l at baseline, 6 and 12 wk, respectively; P=0.02). However, the mean change in various thyroid parameters at 12 wk from baseline was not significantly different between the two groups. MSS was also significantly decreased at 9 and 12 wk from baseline with isoflavones (12.47 ± 8.15, 9.35 ± 5.23 and 9 ± 5.14 at baseline, 9 and 12 wk respectively; P=0.004) with significant improvement in urogenital symptoms compared to placebo. Isoflavones did not significantly affect other parameters during study period. There were no serious adverse events reported and the proportion of patients experiencing adverse events was similar between the two groups. Interpretation and conclusions: Modest reduction in serum free T3 levels in the isoflavone group in the absence of any effect on other thyroid parameters might be considered clinically unimportant.

Conceptos emergentes de tolerancia y autoinmunidad: Nuevos enfoques terapéuticos / Tolerance and autoimmunity: Novel therapeutic approaches

La función primaria del sistema inmune es resguardar al individuo de los patógenos potencialmente dañinos que invaden el medio ambiente en el cual nos desarrollamos. Este cuenta con dos grandes ramas, la inmunidad innata y la adaptativa, ambas con la propiedad de diferenciar lo peligroso de aquello inofensivo. Estos procesos se hallan regulados por mecanismos homeostáticos que constituyen la tolerancia inmunológica, a los fines de limitar aquellos procesos prolongados y silenciar los potencialmente autoagresivos. Ante la falla de estos mecanismos de control, surgen las enfermedades autoinmunes. Avances en el conocimiento de la fisiopatología de estas entidades, han abierto un nuevo capítulo en el terreno de la inmunofarmacología. Su prometedor potencial actualmente nos ofrece novedosas herramientas terapéuticas para controlar y atenuar el daño causado por este tipo de respuestas. No obstante, debe continuarse la investigación en el campo de los agentes biológicos, ya que ninguno de ellos se encuentra libre de inconvenientes. Seguramente, futuros hallazgos se concretarán en futuros aciertos. Y los aciertos, en Medicina, equivalen a esperanza.

The main function of the immune system is to protect the individual against potentially dangerous pathogens. It comprises innate and adaptive cellular and soluble components, both with the capacity to discriminate between harmful and harmless. These processes are regulated by homeostatic mechanisms that constitute the so-called immunological tolerance, which aims to limit the prolonged action of immune mediators and to silence the generation of potentially autoaggressive components. Failure to silence self-reactive T and B cells results in the generation of autoimmune disease. Recent advances in our knowledge of these pathological entities have opened a new chapter in the pharmacology of the immune system. Its promising potential currently offers new therapeutic agents to control and attenuate pathological tissue damage. Nevertheless, further research regarding these biologic agents is required, since they are not free from inconveniences. It is without question that upcoming findings in this field will instill hope into the quest for the "magic bullet".

Tratamiento del factor autoinmune en el aborto recurrente y en el retardo de crecimiento intrauterino con anti-agregantes plaquetarios / Treatment of autoimmunity factor in recurrent abortion and in intrauterine growth retardation with platelets anti-aggregation

Objetivo: Describir los resultados del tratamiento anti-agregante plaquetario en un grupo de pacientes con auto-anticuerpos y antecedentes de aborto recurrente (AR) y/o retardo de crecimiento intrauterino (RCIU). Material y Métodos: Diecisiete pacientes que consultaron por AR y/o RCIU, mala historia obstétrica o antecedentes de VDRL falso positivo, en cuyo estudio inmunológico se detectaron autoanticuerpos, constituyen el material del presente trabajo. A las pacientes que tenían como antecedente un RCIU, una vez descartados todos los cuadros clínicos que pudieran ocasionarlo, se les efectuó determinación de anticuerpos. Las parejas que consultaban por AR eran sometidas a estudio para descartar un factor uterino, infeccioso, endocrinológico, metabólico, genético, innmunológico y espermático. En algunas pacientes se realizó una laparoscopia para descartar endometriosis. Todas las pacientes fueron tratadas con Acido Acetilsalicílico (AAS) 80 mg diarios, a partir del momento de la detección de autoanticuerpos. A una sola paciente se le administró además heparina subcutánea durante dos embarazos. Resultados: De las diecisiete pacientes en las que se detectaron autoanticuerpos, catorce embarazaron, algunas de ellas en más de una oportunidad, sumando un total de 24 embarazos. De ellos, 5 concluyeron en aborto espontáneo y dieciocho concluyeron en el tercer trimestre con recién nacido vivo. De éstos, siete presentaron un crecimiento fetal normal, mientras que los once restantes desarrollaron RCIU. La vía de terminación fue vaginal en seis casos y abdominal en los doce restantes. Un embarazo se encuentra en evolución al momento de la presente comunicación

Insulin autoantibodies in first degree relatives of type I diabetic patients

Insulin autoantibodies (IAA) of first-degree relatives of type diabetic patient and recent-onset type I diabetics were measured by radioimmunoassay. A cut-off of 60 nU/ml was established on the basis of the values of normal control individuals. The intra-assay coefficient of variation was 9.2% for a moderately positive serum (1908 ñ 176 nU/ml (mean ñ SD), N=7; range, 1708 to 2158 nU/ml). The interassay coefficient of variation was 23.8% for a negative (normal control) serum (28.1 ñ 6.7 nU/ml, N=6; range, 22 to 39 nU/ml) and 14.5% in a highly positive serum (6185 ñ 899 nU/ml, N=7; range, 5053 to 7009 nU/ml). Insulin autoantibody levels (mean ñ SEM) were 19.3 ñ 2.8 nU/ml (range, =-19 to 40 nU/ml) in 25 controls, 24.8 ñ 3.4 nU/ml (range, -17 to 59 nU/ml) in 41 type II diabetic patients, 18.5 ñ 2.4 nU/ml (range, -58 to 268 nU/ml) in 171 first-degree relatives of type I diabetic patients and 208.9 ñ 87.0 nU/ml (range, 10 to 1101 nU/ml) in 16 recent-onset type I diabetic patients. IAA levels were significantly higher in the last group compared with the other groups (P<0.01). None of the controls or type II diabetics exceeded the upper limit of normalyity. In contrast, 9 of 171 (5.3%) first-degree relatives and 9 of 16 (56.0%) recent-onset type I diabetic patients had IAA levels above the 60 nU/ml cut-off point. These data indicate that this method is effective for the detection of individuals who are at high risk to develop type I diabetes

Análise do comportamento de LTa e LTt em pacientes diabéticos quando submetidos in vitro à açäo de corticosteróides / Analysis of the behaviour of active T lymphocyte and total T lymphocyte in diabetic patients when submitted in vitro to the corticosteroid action

Com base nas hipóteses que consideram a Diabete Mellitus como uma doença de caráter näo puramente familiar e sim uma síndrome, e considerando o seu envolvimento com várias doenças autoimunes, pretendeu-se observar o comportamento in vitro dos linfócitos T de pacientes diabéticos, em estágio compensado, frente ao uso de corticosteróide, partindo do princípio de que esta droga inibe a funçäo linfocitária em indivíduos normais. Usando-se três diluiçöes do corticosteróide, observou-se que os linfócitos T de todos os pacientes estudados, através da formaçäo de rosáceas com hemácias de carneiro, eram mais resistentes à imunosupressäo que os controles. Com estes resultados chegou-se à conclusäo de que os linfócitos T de pacientes diabéticos comportam-se de maneira adversa aos de indivíduos normais, frente a diferentes diluiçöes de corticosteróide. Este fato sugere que o estudo da funçäo linfocitária, ao lado de fator genético e outros, poderia vir a ser mais um dos marcadores utilizados no diagnóstico precoce da doença.