Antineutrophil cytoplasmic antibodies in patients treated with methimazole: a prospective Brazilian study / Anticorpos anticitoplasma de neutrófilos em pacientes tratados com metimazol: um estudo prospectivo brasileiro

Abstract Introduction: The side effects of antithyroid drugs are well known. Antineutrophil cytoplasmic antibody-associated vasculitis is a severe adverse reaction. Most studies evaluating antineutrophil cytoplasmic antibodies related to antithyroid drugs have been carried out with patients treated with propylthiouracil, but less information is available for methimazole. Furthermore, most studies that investigated antineutrophil cytoplasmic antibodies related to antithyroid drugs were conducted on Asian populations. Objective: To evaluate the frequency of antineutrophil cytoplasmic antibodies and antineutrophil cytoplasmic antibodies-positive vasculitis in an adult population of Brazilian patients treated with methimazole. Methods: This was a prospective study. We evaluated patients ≥18 years with Graves' disease who have been using methimazole for at least 6 months (Group A, n = 36); with Grave's disease who had been previously treated with methimazole but no longer used this medication for at least 6 months (Group B, n = 33), and with nodular disease who have been using methimazole for at least 6 months (Group C, n = 13). Results: ANCA were detected in 17 patients (20.7%). Four patients (4.9%) had a strong antineutrophil cytoplasmic antibodies-positive test. The frequency of antineutrophil cytoplasmic antibodies was similar in the groups. When Groups A and B were pooled and compared to Group C to evaluate the influence of Grave's disease, and when Groups A and C were pooled and compared to Group B to evaluate the influence of methimazole discontinuation, no difference was found in the frequency of antineutrophil cytoplasmic antibodies. No difference was observed in sex, age, etiology of hyperthyroidism, anti-TSH receptor antibodies, dose or time of methimazole use between patients with versus without antineutrophil cytoplasmic antibodies. The titers of these antibodies were not correlated with the dose or time of methimazole use. None of the antineutrophil cytoplasmic antibodies-positive patient had clinical event that could potentially result from vasculitis. Conclusion: This clinical study of a Brazilian population shows a considerable frequency of antineutrophil cytoplasmic antibodies in patients treated with methimazole but the clinical repercussion of these findings remains undefined.

Resumo Introdução: Os efeitos adversos de drogas antitireoidianas são conhecidos. Vasculite associada a anticorpos anticitoplasma de neutrófilos é uma reação adversa grave. A maioria dos estudos que avaliam anticorpos anticitoplasma de neutrófilos relacionado a drogas antitireoidianas envolveu pacientes tratados com propiltiouracil, entretanto menos informação se encontra disponível para o metimazol. Além disso, a maioria dos estudos que investigaram anticorpos anticitoplasma de neutrófilos relacionado a drogas antitireoidianas foi conduzida em populações asiáticas. Objetivo: Avaliar a frequência de anticorpos anticitoplasma de neutrófilos e vasculite anticorpos anticitoplasma de neutrófilos-positivo em uma população adulta de pacientes brasileiros tratados com metimazol. Método: Este foi um estudo prospectivo. Avaliamos pacientes ≥ 18 anos com doença de Graves com o uso de metimazol há pelo menos seis meses (Grupo A, n = 36); com doença de Graves previamente tratados com metimazol, mas que não usaram esse medicamento por pelo menos seis meses (Grupo B, n = 33) e com doença nodular em uso de metimazol há pelo menos seis meses (Grupo C, n = 13). Resultado: Anticorpos anticitoplasma de neutrófilos foram detectados em 17 pacientes (20,7%). Quatro pacientes (4,9%) tinham anticorpos anticitoplasma de neutrófilos fortemente positivos. A frequência de anticorpos anticitoplasma de neutrófilos foi semelhante nos grupos. Quando os Grupos A e B foram somados e comparados ao Grupo C para avaliar a influência da doença de Graves, e quando os Grupos A e C foram somados e comparados ao Grupo B para avaliar a influência da interrupção do metimazol, não foi encontrada diferença na frequência de anticorpos anticitoplasma de neutrófilos. Não houve diferença em relação a sexo, idade, etiologia do hipertireoidismo, anticorpos antirreceptor de TSH, dose ou tempo de uso de metimazol entre pacientes com e sem anticorpos anticitoplasma de neutrófilos. Os títulos desses anticorpos não se correlacionaram com dose ou tempo de uso de metimazol. Nenhum paciente anticorpos anticitoplasma de neutrófilos-positivo apresentou evento clínico resultante de vasculite. Conclusão: Este estudo clínico de uma população brasileira apresenta frequência considerável de anticorpos anticitoplasma de neutrófilos em pacientes tratados com metimazol, mas a repercussão clínica desse achado permanece indefinida.

Conversion to Graves disease from Hashimoto thyroiditis: a study of 24 patients

ABSTRACT Objective: The conversion of Hashimoto's thyroiditis (HT) to hyperthyroidism due to thyrotropin receptor antibodies is intriguing and considered rare. The contribution of TSH receptor blocking antibodies (TRAb), which may be stimulators (TSAb) or blockers (TBAb), is suspected. We describe clinical and biological variables in a series of patients switching from Hashimoto's thyroiditis to Grave's disease. Subjects and methods: Retrospective case study of 24 patients with Hashimoto's thyroiditis followed during 48 ± 36 months that developed later Graves' disease (GD). These variables were analysed in the hypo and hyperthyroid phase: age, sex, initial TSH, free triiodothyronine (fT3), free thyroxine (fT4), anti-TPO, TBII antibodies, parietal cell autoantibodies, time between hypo and hyperthyroidism, thyroid volume and levothyroxine doses (LT). Results: In HT, mean TSH was 9.4 ± 26.1 UI/L and levothyroxine treatment was 66.2 ± 30.8 µg/day. The switch to GD was observed 38 ± 45 months after HT diagnosis. As expected, we found significant differences on TSH, FT3, FT4 and TBAb levels. Three out of 14 patients had parietal cell autoantibodies. In two of these three cases there was an Helicobacter pylori infection. There were no significant differences between HT and GD groups with respect to thyroid volume. Conclusions: To our knowledge, large series documenting the conversion of HT to GD are scarce. Although rare, this phenomenon should not be misdiagnosed. Suspicion should be raised whenever thyroxine posology must be tapered down during the follow-up of HT patients. Further immunological and genetic studies are needed to explain this unusual autoimmune change.

Relación entre linfocitos T reguladores (T regs) y anticuerpos anti-receptores de TSH (TRab) y el riesgo de cáncer de tiroides en enfermedad de Graves / Relationship between T regulatory lymphocytes (Tregs) and TSH receptor antibodies (TRab) on risk of thyroid cancer in Graves disease

Durante los últimos años se ha estudiado la relación entre enfermedad de Graves (EG), TSH, TRAb y cáncer de tiroides, existiendo estudios que demuestran mayor prevalencia y agresividad del cáncer de tiroides en pacientes con EG, mientras otros refutan estos hallazgos sugiriendo que serían producto del sesgo de selección. Aquellos estudios que plantean una relación causal entre EG y el desarrollo de cáncer de tiroides, la atribuyen a la presencia de autoanticuerpos TSI, que estimularían el foco de malignidad. Se cree que las citoquinas producidas localmente en pacientes con EG trabajarían en conjunto con los TRAb para determinar la agresividad del cáncer papilar de tiroides en estos pacientes. Dentro de las células reclutadas por el tumor para evadir la respuesta inmune se encuentran los linfocitos Treg, que estarían elevados en paciente con EG, llevando a la disminución de la respuesta inmune y creando un ambiente permisivo para la proliferación celular. Por tratarse de una línea de investigación reciente, no existe consenso sobre el tema y sus implicancias en el tratamiento de los pacientes con EG. La finalidad de este artículo es realizar una revisión de la literatura que exponga y contraste la información disponible a la fecha.

In recent years the relationship between Graves’ disease (GD), TSH, TRAb and thyroid carcinoma has been studied. Research studies show a higher prevalence and aggressiveness of thyroid carcinoma in patients with GD, however other researchers refute these findings suggesting it’s due to selection bias. Increasing evidence suggests a causal relationship between GD and the development of thyroid carcinoma, mainly because of the existence of TSI autoantibodies that could stimulate the focus of malignancy. It is believed that cytokines produced locally in patients with GD work alongside with TRAb regulating the aggressiveness of papillary thyroid carcinoma in these patients. Within the cells recruited by the tumor to elude the immune system we find Treg lymphocytes, which have been found to be increased in patients with GD, leading to a diminished immune response, creating a permissive environment for cell proliferation. Since this is a relatively new line of research, there is no consensus on the subject and its relevance for the treatment of patients with GD. The aim of this article is to show recent literature available on the subject.

The unusual association of Graves' disease, chronic spontaneous urticaria, and premature ovarian failure: report of a case and HLA haplotype characterization / A associação incomum entre doença de Graves, urticária crônica idiopática e insuficiência ovariana prematura: relato de caso clínico e tipagem HLA

Chronic spontaneous urticaria (CSU), defined as the occurrence of spontaneous wheals for more than six weeks, has been associated with autoimmune diseases. Herein, we report the unusual association of CSU, Graves' disease, and premature ovarian failure. Human leukocyte antigen (HLA) studies were performed. A 36-year-old woman presented symptoms and signs of hyperthyroidism for three months. In the same period, the patient complained of widespread urticarial wheals, intensely itchy, and poorly responsive to therapy with antihistaminic agents. Hyperthyroidism was confirmed biochemically, and treatment with methimazole was started. As hyperthyroidism improved, a marked improvement in her urticaria was also observed. However, the patient continued to complain of amenorrhea. Endocrine evaluation, at the age 38, was consistent with premature ovarian failure. This is the first report of coexistence of GD, CSU, and POF. The genetic background of such unusual association is a specific combination of HLA.

A urticária crônica idiopática, caracterizada pelo aparecimento de pápulas espontâneas e persistentes por pelo menos seis semanas, tem sido associada a doenças autoimunes. Apresentamos aqui o caso da associação incomum entre urticária crônica idiopática, doença de Graves e falência ovariana prematura. Foram conduzidos estudos de tipagem HLA. Uma mulher de 36 anos apresentou sinais e sintomas de hipertireoidismo por três meses. No mesmo período, a paciente queixou-se do aparecimento de pápulas urticariformes generalizadas que coçavam intensamente e não eram responsivas ao tratamento com anti-histamínicos. O hipertireoidismo foi confirmado bioquimicamente, e o tratamento com metimazol foi iniciado. Assim que os valores hormonais se normalizaram, observou-se uma melhoria significativa do quadro de urticária. No entanto, a paciente continuou a apresentar amenorreia. A avaliação endocrinológica, com a idade de 38 anos, mostrou falência ovariana prematura. Este é o primeiro caso de associação entre doença de Graves, urticária idiopática crônica e falência ovariana prematura. A base genética dessa associação incomum é representada por combinações específicas de haplótipos HLA.

The increased but non-predominant expression of Th17- and Th1-specific cytokines in Hashimoto’s thyroiditis but not in Graves’ disease

Hashimoto’s thyroiditis (HT) is considered to be mediated mainly by Th1 cells, but it is not known whether Graves’ disease (GD) is associated with Th1 or Th2 predominance. Th17 cells, a novel subset of Th cells, play a crucial role in the pathogenesis of various autoimmune disorders. In the present study, the expression of IL-17A and IFN-γ was investigated in patients with HT or GD. mRNA expression of IL-17A and IFN-γ in peripheral blood mononuclear cells (PBMC) from 43 patients with autoimmune thyroid disease (AITD) and in thyroid tissues from 40 AITD patients were measured by real-time qRT-PCR. The protein expression of IL-17A and IL-23p19 was examined by immunohistochemistry in thyroid tissues from 28 AITD patients. The mRNA levels of IL-17A and IFN-γ were higher in both PBMC and thyroid tissues of HT patients than in controls (mRNA levels are reported as the cytokine/β-actin ratio: IL-17 = 13.58- and 2.88-fold change and IFN-γ = 16.54- and 2.74-fold change, respectively, P < 0.05). Also, the mRNA levels of IL-17A and IFN-γ did not differ significantly in GD patients (P > 0.05). The high protein expression of IL-17A (IOD = 15.17 ± 4.8) and IL-23p19 (IOD = 16.84 ± 7.87) in HT was confirmed by immunohistochemistry (P < 0.05). The similar high levels of IL-17A and IFN-γ suggest a mixed response of Th17 and Th1 in HT, where both cells may play important roles in the destruction procedure by cell-mediated cytotoxicity.

Enfermedad de Basedow Graves en pacientes pediátricos / Graves-Basedow disease in pediatric patients

Objective: Determine differences in the epidemiology, clinical features and diagnosis of Graves-Basedow disease (GBD) in prepubertal and pubertal patients. Method: Retrospective study analyzing medical records of 38 patients with GBD at Pontificia Universidad Católica de Chile between 1992-2007. Statistical analysis was performed with non parametric test of Mann-Whitney U and proportions difference with Fisher Test (SPSS 10.0 for Windows and Graphpad Prism 4). Results: 21 patients were prepubertal and 17 were pubertal, with ages between 3 and 15,9 years. There were more girls than boys in both groups (5:2 and 15:2, respectively; p = 0.2). The most common clinical presentations were diffuse goiter, hyperactivity, frequent bowel movements, insomnia and heat intolerance. The prepubertal group had a taller stature (+2.4 SDS) compared with the pubertal group (+0.2 SDS; p = 0.03) and the most frequent ocular manifestation was exophthalmus in both groups. Conclusions: We did not find any differences in the clinical presentations of Graves-Basedow disease among prepubertal and pubertal patients. Neuropsychiatric symptoms such as hyperactivity and insomnia, together with tall stature are common features in children with GBD.

Objetivo: Determinar si existen diferencias en las características epidemiológicas y clínicas al momento del diagnóstico de hipertiroidismo por Basedow Graves (BG) en sujetos pre-púberes y púberes. Pacientes y Método: Estudio descriptivo y retrospectivo. Universo: Pacientes con diagnóstico de BG en control en endocrinología pediátrica en la Pontificia Universidad Católica de Chile, entre 1991 y abril 2007 (n = 38). Se registraron los hallazgos clínicos y de laboratorio. Se evaluó las diferencias entre los grupos con pruebas no paramétricas (Mann-Whitney U), las diferencias de proporciones con la Prueba de Fisher (SPSS 10.0 para Windows y graphpad Prism 4). Resultados: El rango de edad fue 3 a 15,9 años. Veintiún sujetos eran pre-púberes y 17 eran púberes; hubo más mujeres que hombres (5: 2 y 15: 2, respectivamente; p = 0,2). Los síntomas y signos más frecuentes fueron bocio difuso, hiperactividad, polidefecación, insomnio e irradiación de calor. No hubo diferencias entre los pre-púberes y púberes. El grupo pre-púber tenía talla más alta que su carga genética (+2,4 DS) comparados con los púberes (+0,2 SDS; p = 0,03). El compromiso ocular más frecuente fue el exoftalmo. Conclusión: No encontramos diferencias en la forma de presentación del BG entre los niños pre-púberes y púberes. Los síntomas neuropsiquiátricos tales como hiperactividad e insomnio, y una talla mayor a la esperada para la diana familiar, fueron hallazgos frecuentes en los niños con BG.

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.

autoimmune diseases manifested by production of autoantibodies: the autoantigens identified by random peptide library

Phage-displayed random peptide libraries [RPL] provide a powerful technique for identification, structural and functional analysis of ligands for many different target molecules, including, antibodies, receptors or other proteins. This strategy has been verified to be an effective tool for research in immunology and successfully has been used to determine the target sequence for monoclonal and polyclonal antibodies. The peptide library approach provides great promise for characterization of ligands with no prior information concerning antibody specificity. This would allow the recognition of candidate antigens involved in initiation or perpetuation of autoimmune diseases. This technology also offers the potential for new therapeutic opportunities, production of diagnostic reagents, or even development of effective new vaccines. This review focuses on studies regarding the identification of autoantigens recognized by antibodies in autoimmune diseases using phage-display peptide libraries

Auto-imunidade ANCA (Anticorpo Anti-Citoplasma de Neutrófilos) positiva induzida por propiltiouracil: relato de caso e revisão da literatura / Antineutrophil Cytoplasmic Antibody (Anca)-Associated autoimmune disease induced by propylthiouracil

A terapêutica com drogas antitireoidianas pode ser acompanhada de efeitos colaterais. Propiltiouracil (PTU) pode induzir vasculites anticorpo anti-citoplasma de neutrófilos (ANCA) positivas, na maioria das vezes relacionadas ao subtipo mieloperoxidase (ANCA-MPO). O nosso objetivo é relatar o caso de uma paciente com doença de Graves que desenvolveu auto-imunidade induzida por PTU, com manifestações cutâneas, pulmonares e renais, associadas à positividade do ANCA. O exame anátomo-patológico pulmonar revelou hemorragia difusa e a biópsia renal demonstrou glomeruloesclerose segmentar e focal. Foi tratada com pulsoterapia com corticóides e ciclofosfamida, com boa evolução clínica. Este caso enfatiza a necessidade de detecção e tratamento precoce deste efeito adverso relativamente raro do PTU.

Antithyroid drugs sometimes cause severe complications. Propylthiouracil (PTU) can be associated to ANCA positive vasculitis, most often related to myeloperoxidase subtype (ANCA-MPO). Our objective is to describe a female patient with Graves' disease, who developed PTU induced-autoimmune disease, with cutaneous, pulmonary, and renal lesions, associated with ANCA. Histopathological examination revealed diffuse pulmonary hemorrhage, and focal segmental glomerulosclerosis at the kidney biopsy. She was treated with systemic corticosteroid therapy and cyclophosphamide, with clinical improvement. This case highlights the need for greater awareness of this relatively rare adverse effect of propylthiouracil.

Autoantibodies, human T lymphotropic virus type 1 and type 1 diabetes mellitus in Jamaicans

The clinical characteristics, autoantibody profiles and seroprevalence of human T lymphotropic virus Type 1 (HTLV-1) were assessed in 30 Jamaican patients with Type 1 diabetes mellitus. Two hundred and fifty-two blood donors and 108 patients with Graves' disease were included as controls for the HTLV-1 component of the study. The mean age of onset of diabetes mellitus was 20.5 +/- 9.2 years and the mean duration of diabetes mellitus was 10.5 +/- 6.1 years. The remarkable clinical data included an absence of other associated organ-specific autoimmune diseases, and clinical evidence and history of congenital rubella in one patient. Islet cell cytoplasmic antibodies (ICA) were absent but 17 (5/30) of the diabetic patients tested positive for glutamic acid decarboxylase (GAD) antibodies. No other organ-specific autoantibodies were detected but non-organ-specific autoantibodies were present in 9 (30) of the sera of diabetic patients. The seroprevalence of HTLV-1 in the patients with diabetes mellitus was significantly higher than that in the healthy controls (17 (5/30) versus 4 (11/252), p = 0.05). Autoantibodies were found in the sera of 4/5 (80) of the diabetic patients who were positive for HTLV-1. None of the patients with onset of diabetes mellitus below age 15 years was HTLV-1 positive. The likely polyaetiological nature of Type 1 diabetes mellitus in Jamaicans is being further investigated at the molecular level.

Vitiligo y tiroiditis de Hashimoto: asociación o síndrome autoinmune? / Vitiligo and Hashimoto's thyroiditis: an association or an autoimmune syndrome?

Se sospecha de ciertos virus y otros agentes como causantes de la tiroiditis de Hashimoto, siendo bien conocida la asociación con otras entidades inmunes, entre ellas el vitiligo. Una vez disparados los fenómenos inmunológicos se generan anticuerpos contra los antígenos microbianos (o de otro tipo), pero también Ac. contra antígenos propios como los de la estructura tiroidea y la piel. En el vitiligo hay alta incidencia de anticuerpos organoespecíficos, pero también otros anticuerpos no organoespecíficos, sugiriéndose para los síndromes autoinmunes múltiples y las colagenopatías un fuerte parentesco clínico, laboratorial y quizá etiológico. En este caso clínico en particular la tarea del dermatólogo cobró importancia pues toda la investigación generada se debió a la repentina aparición de vitiligo en un paciente con síntomas vagos

Associaçäo de alelos do complexo principal de histocompatibilidade de classe II com a Doença de Graves, em pacientes brasileiros / Association of major histocompatibility complex class II alleles with Graves' Disease in brazilian patients

A Doença de Graves (DG) é a causa mais freqüente de hipertireoidismo. Sua origem é multifatorial, complexa, na qual a susceptibilidade genética interage com o meio ambiente e fatores endógenos para causar a doença. Os alelos do Complexo Principal de Histocompatibilidade (CPH) de classe II têm sido associados com a DG, em populações de diferentes etnias e muitas evidências apontam para a associaçäo do antígeno HLA-DR3 em caucasianos. O envolvimento dos alelos do CPH na nossa populaçäo, altamente miscigenada, foi estudado em pacientes com a DG e em indivíduos-controle da mesma área geográfica, utilizando-se DNA genômico amplificado e hibridado com iniciadores de sequência específica (SSP). O alelo HLA-DRB1*0301 esteve presente com maior freqüência (44,7 por cento) em pacientes com DG, relativamente à populaçäo-controle (22,3 por cento, pc=0,0068), conferindo Risco Relativo (RR) de 2,8 e uma Fraçäo Etiológica de 28,7, enquanto o alelo HLA-DQB1*0602 esteve, significativamente, diminuído nesses pacientes (8 por cento) em relaçäo aos pacientes-controle (31,9 por cento, pc=0,00062), conferindo RR de 1,8 e uma Fraçäo Preventiva de 26,7. Apesar de a populaçäo brasileira ser altamente miscigenada, a confirmaçäo do alelo HLA-DRB1*0301, conferindo susceptibilidade à doença, aponta esse alelo com um marcador importante na predisposiçäo à doença. Em contraste, a proteçäo conferida pelo alelo HLA-DQB1*0602 parece ser peculiar aos pacientes brasileiros

Positividade dos anticorpos antitiroidianos na doença de Graves / Positivity of antithyroid antiboidies in Graves' disease

Os auto-anticorpos descritos na doença de Graves säo imunoglobulinas pertencentes à classe IgG que dirigem-se especificamente a certos antígenos tiroidianos, destacando-se entre eles: tireoglobulina (antitireoglobulina), peroxidade tiroidiana (antimicrossomia/antiperoxidade) e receptor do hormônio tireotrófico (TRab). Com o objetivo de avaliar a prevalência dos auto-anticorpos na doença de Graves descompensada, estudamos 46 pacientes virgens de tratamento. Concordante com os dados da literatura, o anticorpo anti-receptor de TSH mostrou-se o melhor marcador da doença de Graves, com 92,4 por cento de positividade

Autoimmune and non-autoimmune thyroid diseases have different patterns of cellular HLA class II expression

CONTEXT: Surface HLA-DR antigen is usually only expressed by antigen-presenting cells (APC). In autoimmune thyroid disease, follicle cells function as APC, thus expressing HLA-DR. However, non-autoimmune thyroid diseases may also express surface class II antigens. OBJECTIVE: To evaluate the presence and pattern of HLA class II expression in autoimmune and non-autoimmune thyroid disorders. DESIGN: Retrospective: histopathological and immunohistochemical analysis. LOCATION: Referral center, university hospital. SAMPLE: Ten histologically normal thyroids, 11 GravesÆ disease, 7 HashimotoÆs thyroiditis, 10 atoxic multinodular goiter and 3 toxic adenomas were analyzed by immunohistochemistry, using a monoclonal antibody anti-HLA-DR. MAIN MEASUREMENTS: The presence of these antigens in thyroid follicular cells and their relation to inflammatory infiltrate was evaluated. The pattern of HLA-DR expression in thyroid follicular cells was analyzed: membrane, cytoplasmic or both. RESULTS: Although HLA-DR antigens were sparsely present in one of the 8 normal thyroids, in 6 of the 9 atoxic multinodular goiter and in 2 of the 3 toxic adenomas a net positivity could be seen in large areas. In all 5 HashimotoÆs thyroiditis and in 7 of the 10 GravesÆ disease cases. This expression occurred in follicle cells either in contact with inflammatory cells or not. In non-autoimmune thyroid disease, HLA-DR positivity was essentially cytoplasmic, whereas in GravesÆ disease and Hashimoto thyroiditis it was mainly in cell membranes. CONCLUSIONS: It is suggested that the HLA class II expression on the surface of follicle cells could be related to auto-antigen presentation to the immune system by these cells, leading to inflammation

Reactivity of anti-thyroid antibodies to thyroglobulin tryptic fragments: comparison of autoimmune and non-autoimmune thyroid diseases

Studies concerning the antigenicity of thyroglobulin fragments allow the characterization of the epitopes but do not consider the role of heavier antigenic fragments that could result in vivo from the action of endoproteases. Here we assess the relative importance of the fragments obtained from thyroglobulin by limited proteolysis with trypsin and compare by immunoblotting their reactivity to serum from patients with autoimmune (Graves' disease and Hashimoto's thyroiditis) and non-autoimmune (subacute thyroiditis) disease. The results showed no difference in frequency of recognition of any peptide by sera from patients with autoimmune thyroiditis. In contrast, sera from patients with subacute thyroiditis reacted more frequently with a peptide of 80 kDa. These results suggest the presence of antibody subpopulations directed at fragments produced in vivo by enzymatic cleavage of thyroglobulin. This fragment and antibodies to it may represent markers for subacute thyroiditis.

Thyrotoxic periodic paralysis in mexican mestizo patients: a clinical, biochemical and HLA-Serological study

Background. Thyrotoxic periodic paralysis (TPP) is characterized by episodes of neuromuscular weakness occurring in the context of hypokalemia and hyperthyroidism and has been predominantly described in Oriental populations. Whereas it is uncommon in Caucasians and Blacks, TPP does occur in individuals of Native American descent. The objective was to analyze the clinical, biochemical, and HLA characteristics of group of Mexican mestizo patients with TPP. Methods. The sample was comprised of 14 men with TPP diagnosed since january 1990, based on one or more episodes of flaccid paralysis, accompanied by hypokalemia and occurring in the context of clinical and biochemical hyperthyroidism. Eight were available HLA testing. Results. Hyperthyroidsm was diagnosed before the development of periodic paralysis in five of the patients, whereas in six it occurred afterward. The severity of paralysis did not correlate with the degree of either hypokalemia or hyperthyroidism. An increased frequency of HLA-DR3 was found in Graves' patients without paralysis but not in those with paralysis, as compared to the general population. Conclusions. TPP is more common than previously thoought in Mexicans, in whom it behaves as in other Native American groups. The lack of HLA-DR3 association in Graves' patients with TPP is interesting, but at the moment has no pathophysiological implications

Avaliaçäo fenotípica dos infiltrados celulares e da expressäo de HLA-DR em tireóides de pacientes com doença de Graves tratados com propiltiouracil / Phenotype evaluation of the cell infiltrated and of the HLA-DR expression in the thyroid of patients with Graves' disease treated with propylthiouracil

É sabido que as tireóides de pacientes com doença de Graves apresentam uma infiltraçao por mononucleares, principalmente linfócitos. Com a intençao de se avaliar estes infiltrados linfocitários, células T e a associaçao entre estes e o HLA-DR, caso os tireócitos estejam positivos para este antígeno de classe II, oito amostras de tecido tireoideano, obtidas cirurgicamente de oito pacientes com a doença de Graves e tratados com propiltiouracil (PTU), foram estudadas em secçoes criostáticas utilizando-se anticorpos monoclonais específicos (UCHT1: CD3, 16H5: CD4, OKT8: CD8, OKM1: CD14 e MID3: HLA-DR) através de imuno-histoquímica (APAAP). Em sete dos oito pacientes foi identificada a presença de células T, com predominância de células CD4+ sobre as CD8+ em quase todos. A expressao anormal de HLA-DR nos tireócitos foi observada em todos os tecidos estudados, sendo que aqueles com maior densidade de infiltraçao linfocitária foram os que apresentaram a maior positividade para o HLA-DR. Nao houve significância estatística quando testadas as combinaçoes HLA-DR e a infiltraçao linfocitária total, as subpopulaçoes linfocitárias entre si (CD4+ e CD8+) e cada uma destas isoladamente com as células T total (CD3+). Uma provável influência do PTU nos infiltrados celulares intraglandulares, como na expressao anormal de HLA-DR nos tireócitos, nao foi possível de ser avaliada, pois todos os tecidos estudados foram expostos a esta droga antitireoideana.