Encefalitis autoinmune mediada por anticuerpos contra el receptor N-Metil-N-Aspartato: reporte de cuatro casos en Perú / Autoimmune encephalitis mediated by antibodies against the N-Nethyl-N-Aspartate receptor: report of four cases in Peru

RESUMEN La encefalitis autoinmune por anticuerpos contra el receptor N-metil-D-aspartato (anti-NMDAR) es un desorden mediado por anticuerpos contra antígenos de superficie neuronal, cuyo diagnóstico temprano y tratamiento oportuno mejoran el pronóstico de la enfermedad. Se presentan cuatro casos con el diagnóstico definitivo de encefalitis autoinmune por anti-NMDAR, tratados en el Instituto Nacional de Ciencias Neurológicas en Lima-Perú. Todos los pacientes presentaron crisis epilépticas y tres casos desarrollaron un estado epiléptico refractario. Asimismo, tres pacientes presentaron alteraciones neuropsiquiátricas, discinesias y disautonomías. Dos casos requirieron soporte ventilatorio. Todos presentaron un electroencefalograma anormal, dos casos tuvieron pleocitosis en líquido cefalorraquídeo, y sólo uno mostró anormalidades cerebrales en la resonancia magnética. Respecto al tratamiento, todos los pacientes recibieron inmunoterapia con metilprednisolona y sólo dos de ellos requirieron plasmaféresis por respuesta ineficaz al tratamiento con corticoides. A los 12 meses del alta hospitalaria, tres pacientes quedaron libre de crisis epilépticas y sólo un caso no logró la independencia funcional. Estos casos muestran que la encefalitis anti-NMDAR es una condición tratable y su reconocimiento temprano junto con un tratamiento adecuado (inmunoterapia/plasmaféresis) son esenciales para una evolución favorable.

ABSTRACT Autoimmune encephalitis with antibodies against the N-methyl-D-aspartate receptor (anti-NMDAR) is a disorder mediated by antibodies against neural surface antigens, whose early diagnosis and timely treatment improve the prognosis of the disease. Four cases with the definitive diagnosis of autoimmune encephalitis by anti-NMDAR are presented, treated at the National Institute of Neurological Sciences in Lima-Peru. All patients had epileptic seizures and three cases developed a refractory epileptic state. In addition, three patients presented neuropsychiatric alterations, dyskinesias, and dysautonomia. Two cases required ventilatory support. All presented an abnormal electroencephalogram; two cases had pleocytosis in cerebrospinal fluid, and only one showed brain abnormalities on MRI. Regarding treatment, all patients received methylprednisolone immunotherapy and only two of them required plasma exchange for an ineffective response to corticosteroid treatment. After 12 months of hospital discharge, three patients were free of epileptic seizures and only one case did not achieve functional independence. These cases show that anti-NMDAR encephalitis is a treatable condition and its early recognition together with appropriate treatment (immunotherapy/plasmapheresis) are essential for a favorable evolution.

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.

Encefalitis autoinmune por anticuerpos contra el receptor GABA-A: caso clínico / Autoimmune encephalitis induced by antibodies against GABA-A receptor

Among autoimmune encephalitides, a prevalent group are those associated with antibodies against the N-Methyl-D-aspartate receptor, which present with behavior abnormalities, psychosis, seizures and abnormal movements. A new variant, mediated by antibodies against the GABA-A receptor, was recen­tly described. We report a 66-years-old female with this form of encephalitis whose main manifestation was the presence of severe seizures leading to status epilepticus. The patient had a good response to immunomodulatory therapy with intravenous methylprednisolone, azathioprine and anticonvulsants. The laboratory tests initially detected anti-thyroid peroxidase antibodies which lead to the misdiagnosis of Hashimoto Encephalitis, which was ruled out after the detection of antibodies against GABA-A receptor. No malignancy was detected.

IgG4-related Hashimoto’s thyroiditis – A new variant of a well known disease / Tireoidite de Hashimoto associada a IgG4 – Uma nova variante de uma doença bem conhecida

Hashimoto’s thyroiditis (HT) has been characterized for many years as a well-defined clinicopathologic entity, but is now considered a heterogeneous disease. IgG4-related HT is a new subtype characterized by thyroid inflammation rich in IgG4-positive plasma cells and marked fibrosis. It may be part of the systemic IgG4-related disease. We report a case of a 56-year-old Portuguese man who presented with a one-month history of progressive neck swelling and dysphagia. Laboratory testing revealed increased inflammatory parameters, subclinical hypothyroidism and very high levels of thyroid autoantibodies. Cervical ultrasound (US) demonstrated an enlarged and heterogeneous thyroid gland and two hypoechoic nodules. US-guided fine needle aspiration cytology was consistent with lymphocytic thyroiditis. The patient was submitted to total thyroidectomy and microscopic examination identified typical findings of HT, marked fibrosis limited within the thyroid capsule and lymphoplasmacytic infiltration, with >50 IgG4-positive plasma cells per high-power field and an IgG4/IgG ratio of >40%. After surgery, serum IgG4 concentration was high-normal. Symptoms relief and reduction in laboratory inflammatory parameters were noticed. Thyroid function is controlled with levothyroxine. To our knowledge we report the first case of IgG4-related HT in a non-Asian patient. We also perform a review of the literature regarding IgG4-related disease and IgG4-related HT. Our case highlights this new variant of the well known HT, and helps physicians in recognizing its main clinical features, allowing for proper diagnosis and treatment.

A tireoidite de Hashimoto (TH) foi caracterizada durante muitos anos como uma entidade clinicopatológica bem definida, mas é atualmente considerada uma patologia heterogênea. A TH associada a IgG4 apresenta-se como um novo subtipo, sendo caracterizada por inflamação da tireoide com numerosos plasmócitos IgG4-positivos e fibrose extensa. É possível que pertença ao espectro da doença sistêmica associada a IgG4. Relatamos o caso de um homem português de 56 anos que se apresentou com aumento progressivo do volume cervical e disfagia, com um mês de evolução. A avaliação laboratorial revelou elevação dos parâmetros inflamatórios, hipotireoidismo subclínico e níveis muito elevados de autoanticorpos tireoidianos. Por ultrassonografia cervical demonstrou-se tireoide aumentada, heterogênea, com dois nódulos hipoecoicos. Foi realizada citologia aspirativa com agulha fina guiada por ultrassom, compatível com tireoidite linfocítica. O doente foi submetido à tireoidectomia total e o exame histológico revelou achados típicos de TH, extensa fibrose localizada dentro da cápsula tireoidiana e infiltrado linfoplasmocitário, com >50 plasmócitos IgG4-positivos por campo de grande ampliação e uma relação IgG4/IgG >40%. Após cirurgia, a concentração sérica de IgG4 encontrava-se no limite superior do normal. Ocorreu melhoria sintomática e redução dos parâmetros inflamatórios. A função tireoidiana foi controlada com levotiroxina. Relatamos o primeiro caso de TH associada a IgG4 num indivíduo não asiático. Além disso, realizamos uma revisão da literatura sobre doença associada a IgG4 e TH associada a IgG4. Este caso destaca uma nova variante da TH e permite aos médicos reconhecerem suas principais características clínicas, proporcionando diagnóstico e tratamento adequados.

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.

Interleukin-10 but not interleukin-18 may be associated with the immune response against well-differentiated thyroid cancer

OBJECTIVES: The aim of this study was to investigate the role of the interleukin-18 +105A/C and interleukin-10 -1082A/G germline polymorphisms in the development and outcome of differentiated thyroid carcinoma associated or not with concurrent thyroiditis. METHODS: We studied 346 patients with differentiated thyroid carcinomas, comprising 292 papillary carcinomas and 54 follicular carcinomas, who were followed up for 12-298 months (mean 76.10 ± 68.23 months) according to a standard protocol. We genotyped 200 patients and 144 control individuals for the interleukin-18 +105A/C polymorphism, and we genotyped 183 patients and 137 controls for the interleukin-10 -1082A/G polymorphism. RESULTS: Interleukin-18 polymorphisms were not associated with chronic lymphocytic thyroiditis or any clinical or pathological feature of tumor aggressiveness. However, there was an association between the presence of interleukin-10 variants and chronic lymphocytic thyroiditis. Chronic lymphocytic thyroiditis was present in 21.74 percent of differentiated thyroid carcinoma patients, most frequently affecting women previously diagnosed with Hashimoto's thyroiditis who had received a lower 131I cumulative dose and did not present lymph node metastases. CONCLUSIONS: We conclude that the inheritance of a G allele at the interleukin-10 -1082A/G polymorphism may favor a concurrent thyroid autoimmunity in differentiated thyroid carcinoma patients, and this autoimmunity may favor a better prognosis for these patients.

Association between helicobacter pylori infection and autoimmune hypothyroidism in Egyptian population

Autoimmune hypothyroidism commonly affecting females is one of the commonest causes of thyroid disease in adults. Among the various autoantibody tests applied in research and clinical practice, the determination of thyroid microsomal antibodies [TPO] and thyroglobulin antibodies [TG Ab] still retains its strong value in the screening for thyroid autoimmunity. Helicobacter pylori [H. pylori] infection plays an important role in the pathogenesis of chronic gastritis, peptic ulcer disease, MALT [Mucosa Associated lymphocyte T] Lymphoma and gastric cancer. The aim of this work was to study the relationship between H.pylori infection and autoimmune hypothyroidism in Egyptian population. This study was carried out on 147 Egyptian persons divided into 3 groups: Hypothyroid Group: Included 49 patients with autoimmune hypothyroidsm and positive antithyroid antibodies with no history of dyspeptic symptoms or peptic ulcer. H.pylori positive Group: Included 50 patients with dyspeptic symptoms or peptic ulcer with H.pylori positive antibodies with no history of any thyroid disease. Control Group: Included 48 apparently healthy persons serving as control. Serum Free T3, Free T4 and TSH were done for all subjects together with Antimicrosomal antibodies [TPO-Ab], Antithyroglobulin antibodies [TG-Ab] and Helicobacter Pylori antibodies [H. pylori Ab]. There was no significant difference between all groups as regards age. Also there was significant difference between Hypothyroid and H.pylori positive groups as regarding TSH and Free T3, TG-Ab, TPO-Ab and H. pylori Ab. There is also significant difference between Hypothyroid and control groups regarding TSH, free T3, TG-Ab, TPO-Ab, and H. pylori Ab. There is significant difference between H.pylori positive and control groups regarding FT3 and H. pylori AB. Hypothyroid Group was divided according to the presence of H. pylori Ab into ve and +ve H. pylori Ab subgroups. There was significant difference between the ve and +ve subgroups as regard TSH, free T4 and TG-Ab. H.pylori positive Group was divided according to the presence of TG Ab and TPO Ab into-ve and +ve subgroups. There was significant difference between the -ve and +ve cases in TSH, free T45 Free T3, and H.Pylori Antibody. Positive correlation was found between H pylori Ab titer and age, TSH, TG-Ab and TPO-Ab titers. There was also negative correlation between H. pylori Ab titer and free T4. There is no correlation between H. pylori Ab titer and free T3. [Correlation is referred to all subjects of the study = 147]. This study revealed that patients with positive TG and TPO antibodies, showed [+ve] H. pylori Ab, with significant high titer in their sera, The patients with positive H. Pylori Ab showed high serum titer of TG-Ab. In our study H. pylori-Ab correlates to thyroid function tests and thyroid antibodies

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.