Síndrome de insensibilidad a andrógenos: revisión bibliográfica a propósito de 5 casos / Androgen insensitivity syndrome: literature review about 5 cases

El síndrome de insensibilidad a andrógenos (AIS en la sigla inglesa) es una entidad muy poco frecuente en endocrinología. Se caracteriza por la mutación del receptor de andrógenos de magnitud variable, por medio del cual individuos 46,XY no se virilizan normalmente, a pesar de conservar sus testículos y tener concentraciones de testosterona en rango masculino. El cuadro clínico es variable y depende la profundidad de la alteración del receptor. En un extremo, hay casos de insensibilidad androgénica completa (CAIS) con fenotipo femenino. En el otro extremo hay insensibilidad parcial (PAIS) que se extiende desde el fenotipo femenino, con o sin ambigüedad genital, hasta los casos de hombres infértiles o con subvirilización, que presentan insensibilidad androgénica más leve. En los fenotipos femeninos, los testículos suelen estar en posición ectópica y aquellos ubicados dentro del abdomen tienen riesgo de malignizarse, por lo que suelen extirparse. Estos son los casos de más difícil manejo, pues aparte de la necesidad de gonadectomía seguida de terapia hormonal femenina, existe una vagina estrecha y en fondo de saco ciego y que suele requerir corrección quirúrgica para permitir la actividad sexual. En este trabajo presentamos 5 casos de AIS vistos recientemente en 2 centros clínicos de Santiago y que ilustran la heterogeneidad de presentación. Además, hacemos una revisión actualizada de los criterios diagnósticos, los tratamientos más adecuados y el manejo global de esta condición.

The Androgen insensitivity syndrome (AIS, in its English acronym) is a very rare entity in endocrinology. It is characterized by a variable magnitude androgen receptor mutation, whereby 46, XY individuals are not normally virilized, despite retaining their testicles and having testosterone concentrations in the male range. The clinical picture is variable and depends on the depth of the receptor alteration. At one extreme, there are cases of complete androgenic insensitivity (CAIS) with a female phenotype. At the other extreme, there is partial insensitivity (PAIS) that extends from the female phenotype, with or without genital ambiguity, to cases of infertile or undervirilized men, who have milder androgenic insensitivity. In female phenotypes, the testes are usually in an ectopic position and those located within the abdomen are at risk of malignancy, and therefore are usually removed. These are the most difficult cases to manage because apart from the need for gonadectomy followed by female hormonal therapy, there is a narrow vagina and a deep blind pouch that usually requires surgical correction to allow sexual activity. In this work, we present 5 cases of AIS recently seen in 2 clinical centers in Santiago and that illustrate the heterogeneity of presentation. In addition, we make an updated review of the diagnostic criteria, the most appropriate treatments, and the overall management of this condition.

Elevada frecuencia de enfermedad tiroidea funcional en embarazadas chilenas sin antecedentes de patología tiroidea utilizando el estándar de TSH internacional / Frequency of subclinical thyroid problems among women during the first trimester of pregnancy

Background: Thyroid hormones play an important role in fetal neural and cognitive development. Therefore thyroid abnormalities should be detected and treated early during pregnancy. Aim: To assess the frequency and risk factors for functional thyroid disorders during the first trimester of pregnancy. Material and Methods: A blood sample was obtained from women during their first trimester of pregnancy, consulting in a prenatal care facility. Women with known thyroid diseases were excluded from the study. Thyroid stimulating hormone (TSH), total thyroxine (T4) and free thyroxine (fT4) were measured by electrochemoluminiscence. Antithyroid peroxidase antibodies (anti TPO) were measured by enzyme immunoassay. Results: Five hundred and ten women aged 25.7 ± 6.6 years were assessed. The frequency of clinical hypothyroidism was 0.6%, subclinical hypothyroidism 35.3% and clinical hyperthyroidism 1%. Five percent of women with hypothyroidism and 3.5% of euthyroid women had positive anti TPO antibodies. There was no association between the frequency of thyroid diseases and risk factors for thyroid diseases. Conclusions: There is a high frequency of subclinical thyroid diseases among women consulting in this prenatal care clinic.

Miopatía grave de curso agudo en un paciente con hipotiroidismo reciente y asintomático / Severe myopathy in a hypothyroid patient: report of one case

Diffuse muscular involvement is common in hypothyroidism and ranges from asymptomatic elevation of creatine kinase levels to severe muscle weakness and rhabdomyolysis. We report a 74 years old male that developed a progressive muscle weakness without muscle pain, during the course of an hypothyroidism secondary to a silent thyroiditis. Laboratory showed a TSH of 149 uUI/ml, a thyroxin of 1.5 ug/dl a free thyroxin of less than 0.15 ng/dl and a creatine kinase of 4345 U/l. Treatment with levothyroxine rapidly reverted the muscular alterations.

Púrpura trombocitopénico inmune asociado a infección por virus hepatitis C en paciente hemofílico: Caso clínico / Immune thrombocytopenic purpura associated to hepatitis C virus infection: Report of one case

Hepatitis C Virus (HCV) is a cause of secondary chronic immune thrombocytopenic purpura (ITP). We report a 43 year old man with mild Hemophilia A, who received blood transfusions during childhood, that consulted for epistaxis and ecchymoses. The laboratory showed a platelet count of 23.000/mm³, positive HCV serology and elevated transaminases. Steroids administered in pulses followed by oral doses resulted in a partial response requiring a second pulse and association of azathioprine. A steroidal diabetes appeared. Given his refractoriness, splenectomy and liver biopsy were performed. He continued on azathioprine maintaining a platelet count near 50.000/mm³ but continued with bleeding episodes. Liver biopsy showed a chronic active hepatitis.