ABSTRACT
Los síndromes poliendocrinos autoinmunes (APS) asocian enfermedades endocrinas autoinmunes con otros desórdenes autoinmunes no endocrinos. El APS tipo II se caracteriza por compromiso primario suprarrenal, tiroideo y/o DM tipo I. Presentamos un paciente masculino de 46 años que fue internado por astenia, adinamia, hiporexia, severa disminución de peso, mareos y vómitos. Antecedente de obesidad y diabetes diagnosticada 3 años antes. Presentaba hipotensión arterial, hiperpigmentación de mucosas y pliegues, anemia, hiponatremia e hipoglucemias frecuentes a pesar de la disminución de la dosis de insulina. Se diagnosticó insuficiencia suprarrenal, concomitantemente con hipotiroidismo y diabetes tipo 1, todas de origen autoinmune, iniciándose reemplazo hormonal. Se encontró una posible asociación del HLA DRB1*-DQB1* en los estudios genéticos. Conclusiones: Nuestro paciente presenta el HLA DQB1*0302 descripto en el APSII, pero el HLA DRB1 *08 encontrado no está descripto en este síndrome ni en ningún otro desorden autoinmune. En pacientes con Diabetes tipo 1 que disminuyan el requerimiento insulínico, habría que descartar insuficiencia suprarrenal, un componente del APS II, como factor etiológico, a pesar de su baja prevalencia.
Autoimmune polyendocrine syndromes (APS) are the association of autoimmune endocrine diseases with other non-endocrine autoimmune disorders. Type II APS is defined by occurrence of Addison´s disease with thyroid autoimmune disease and/or type 1 diabetes mellitus. We present a 46-year-old male patient who was hospitalized because of asthenia, adynamia, hyporexia, severe loss of weight, dizziness and vomiting. Diabetes mellitus had been diagnosed 3 years earlier when he was obese. He presented arterial hypotension, anemia, darkening of the skin and oral mucosa, hyponatremia and frequent hypoglycemia although his insulin dose was decreased. Adrenal insufficiency was diagnosed together with hypothyroidism and type 1 diabetes, all of them of autoimmune origin. Hormonal replacement treatment was initiated. Genetic studies were performed and a new polymorphism was found. Conclusions: HLA DRB1 *08 found in our patient has not been described in APS II or in any other autoimmune disorders. He also has HLA DQB1*0302 described in previous reports related to APS II. In type 1 diabetic patients whose insulin requirement decreases, it would be advisable to rule out adrenal insufficiency, a component of APS II, as an etiologic factor in spite of its low prevalence. In diabetic obese patients (mainly young) who lose weight without a defined cause, type 1 diabetes mellitus should be excluded.
Subject(s)
Humans , Male , Middle Aged , Polyendocrinopathies, Autoimmune/complications , Polyendocrinopathies, Autoimmune/diagnosis , Polyendocrinopathies, Autoimmune/immunology , Genetic Association StudiesABSTRACT
La enfermedad tiroidea autoinmune es la patología autoinmune más prevalente y afecta hasta el 5% de la población general. Su desarrollo está dado por la interacción entre susceptibilidad genética y otros factores. Una característica es la temprana producción de anticuerpos antiperoxidasa tiroidea (aTPO) que a menudo predicen el desarrollo clínico de la enfermedad. La susceptibilidad genética para AIT es generada por genes del HLA y por otros candidatos del cromosoma 2q33. Esta región contiene los genes CTLA-4 y CD 28, y sus polimorfismos estarían asociados. Objetivo: Analizar y comparar la distribución de los polimorfismos de simple nucleótido (SNP) de CD28 (IVS3+17 T/C) y CTLA-4 (+49 A/G) en pacientes con aTPO >10 IU/ml (AIT) comparados con un grupo control aTPO ≤ 10 IU/ml sin AIT. Sujetos y métodos: Estudiamos 69 pacientes y 36 sujetos considerados controles. Para determinar aTPO se utilizó IMMULITE 1000 y muestra sérica. Para el estudio de los SNP se extrajo ADN de sangre periférica. La amplificación de los genes se realizó por PCR. Las diferencias entre grupos fueron comparadas usando el test de Chi Cuadrado. Resultados: Observamos diferencia significativa en el genotipo CD28 C/T entre AIT y controles (p=0.026). Analizando los genotipos de los polimorfismos CTLA-4 no observamos diferencia significativa entre AIT y controles. Del análisis de asociación de genotipos CD28 C/T y CTLA-4 A/A o A/G, observamos diferencia significativa comparando AIT vs. controles (p=0,013). Conclusión: Encontramos una posible asociación significativa del genotipo CD28 C/T en individuos con AIT, y estos portadores tendrían un riesgo tres veces mayor de adquirir AIT. La combinación de los genotipos CD28 C/T y CTLA-4 A/A o A/G incrementaría cuatro veces el riesgo de adquirir AIT. Estos resultados permitirían llevar a cabo un diagnóstico precoz, con la adecuada caracterización de una posible enfermedad tiroidea autoinmune en pacientes con AIT.
The autoimmune thyroid disease is the most prevalent autoimmune affection and affects until 5% of the general population; its development is given by the interaction between genetic susceptibility and other factors. One particularity is the early production of thyroid autoantibodies against thyroid peroxidase (aTPO) which often predicts the clinical development of the disease. The genetic susceptibility for the thyroid autoimmunity (AIT) is generated by genes of the HLA and by other genes candidates of the chromosome 2q33. This region contains the genes: CTLA-4 and CD 28. Several polymorphisms of both would be associated according to previous studies. Objective: To analyze and to compare the simple nucleotide polymorphism distribution (SNP) of CD28 (IVS3+17 T/C) and CTLA-4 (+ 49 A/G) in patients with aTPO> 10 IU/ml (AIT) compared to a control group aTPO ≤ 10 IU/ml with no AIT. Subjects and Methods: We have studied 69 patients with AIT and 36 control subjects. Serum aTPO were measured by using chemiluminescence immunoassay (IMMULITE1000, Siemens). Genomic DNA was prepared from peripheral white blood cells. The amplification of the genes was carry out by polymerase chain reaction (PCR). Statistical analyses : the differences between groups were made using the chisquare test. P less than 0.05 was considered statistically significant. Results: There was a significant difference of genotype CD 28 C/T in patients with AIT compared with controls (p=0.026). The genotypes of CTLA-4 was analyzed and there was no significant difference between AIT and controls. Analysis of genotypes association CD 28 C/T and CTLA-4 A/A or A/G, revealed significant difference comparing AIT versus controls (p= 0.013). Conclusions: We found a possible association of genotype CD 28 C/T in individuals with AIT, since carriers of genotype C/T would have a risk three times higher to acquire AIT. The combination of genotypes CD 28 C/T and CTLA-4 A/A or A/G would increase the risk of acquiring AIT four times. These results could be useful in order to make a premature diagnosis, with adequate characterization of a possible autoimmune thyroid disease in patients with AIT.
ABSTRACT
El APS es la asociación de enfermedades endocrinas autoinmunes, con otros desórdenes autoinmunes no endocrinos, denominados componentes mayores y menores. Este síndrome se clasificó en 4 tipos. Las alteraciones de la respuesta inmune provocan fallas regulatorias de la misma; y polimorfismos de HLA, entre otros, sumado a factores adquiridos o permanentes, representan gatillos disparadores de la autoinmunidad. Nuestro objetivo fue buscar la asociación de HLA-DRB1*-DQB1* en individuos pertenecientes a dos familias, con diagnóstico en uno o más de ellos de APS, o con enfermedades autoinmunes aisladas. Determinar los anticuerpos séricos: a21-OH, aGAD y aTPO y observar la asociación con el haplotipo HLA. Estudiamos padres e hijos de dos familias, dos integrantes padecían APS tipo 2 y 3; y otros con enfermedades autoinmunes. Buscamos HLA-DRB1*-DQB1* y cuantificamos a21-OH, aTPO y aGAD. Los pacientes con APS 2 y 3 presentaron el HLA-DRB1*0301-DQB1*0201. De los individuos estudiados, 5/9 tenían este haplotipo HLA y al menos un autoanticuerpo positivo. Hallamos el factor genético en 2/3 de los integrantes con enfermedades autoinmunes correspondientes a componentes mayores. La relación observada, entre APS y HLA-DRB1*0301-DQB1*0201, aumenta la posibilidad de identificar personas en riesgo de contraer afecciones autoinmunes en grupos familiares, en los cuales algún integrante padece APS.
The APS is the association of autoimmune endocrine diseases, with other non-endocrine autoimmune disorders, named mayor and minor components. This syndrome was classified in 4 types. The alterations of the immune response cause regulatory faults; and HLA polymorphisms, among others; taken in conjunction with acquired or permanent factors, these represent triggers of autoimmunity. Our objective was to find out the association of HLA-DRB1*-DQB1* in individuals belonging to two families, with diagnosis in at least one of them APS, or with isolated autoimmune diseases. To determine serum antibodies: a21-OH, aGAD and aTPO and to observe the association with HLA haplotype. We have studied parents and offspring of two families, two members who suffered APS type 2 and 3, and others with autoimmune diseases. We have looked for HLA-DRB1*-DQB1* and quantified a21-OH, aTPO and aGAD. Patients with APS 2 and 3 showed HLA-DRB1*0301-DQB1*0201. Among the population we have studied, 5/9 had this HLA haplotype and at least one positive auto antibody. We have found the genetic factor in 2/3 of the members with autoimmune diseases corresponding to greater components. The observed relation between APS and HLA-DRB1*0301-DQB1*0201, increases the possibility of identifying people at risk of catching autoimmune affections in familiar groups in which at least one member suffers APS.