Avaliação da associação entre doença auto-imune de tireóide e urticária crônica idiopática

Abstract

Vários estudos encontraram maior prevalência de Doença Auto-imune de Tireóide (DAT) em pacientes com Urticária Crônica (UC). Essa relação pode ocorrer devido à possível etiologia auto-imune em até um terço dos casos de Urticária Crônica Idiopática (UCI). No entanto, a freqüência de DAT variou de 1,14% a 28,6%. O princípio deste estudo foi determinar se ocorre associação entre DAT e UCI em uma população atendida em um mesmo centro de saúde. Comparamos a freqüência de anticorpos anti-tireoidianos e disfunção tireoidiana entre 49 pacientes com UCI (grupo 1) e 112 controles (grupo 2). Com a finalidade de fortalecer o resultado encontrado, estudamos a prevalência de UCI em 60 pacientes com DAT (grupo 3) comparados com 29 com doença não auto-imune de tireóide (DNAT) (grupo 4). Não encontramos diferença estatística quanto à presença de anticorpos anti-tireoidianos ou disfunção tireoidiana entre os grupos 1 e 2 (12,24% x 9,82% e 12,24% x 7,14%, respectivamente). O mesmo ocorreu quanto à presença de UCI entre os grupos 3 e 4 (3,33% x 3,44%). Em nosso estudo não foi possível demonstrar uma relação entre DAT e UCI, o que significa que diferentes populações podem apresentar maior ou menor grau de associação entre essas doenças.

Autoimmune thyroid disease as a risk factor for angioedema in patients with chronic idiopathic urticaria: a case-control study

“…1,17 Consistent with these reports, more women than men participated in the present study (3.79 females for each male). The mean age of our patients was 36.5 years, which is similar to what was reported by other authors, 15,17,18 and most patients had white skin. This is in agreement with Silvares et al who, in an assessment on CIU patients from the same area, found that most of them were Caucasian (94%) and female (3:1).…”

“…3 The reason why a higher frequency of angioedema was found in our patients remains unclear, but it may be associated with regional iodine sufficiency, or with the fact that the ATD rate found in this study was higher (19.1%) than what was reported by Feibelmann et al (12.3%), 15 and higher than in American studies on the general population (3-10%). 8,29 The association between angioedema and ATD was evident.…”

“…observed angioedema in 49.97% of their patients with CIU, 15 while others have reported rates of about 40%. 13 Silvares et al…”

“…10,15,18,25 The association between CIU and ATD has long been recognized as significant, [9][10][11]17,25,26 notwithstanding biasing factors such as ATD diagnostic bias, 26 lack of a control group 10 and small sample size. 25 The pathophysiology of the association is not well understood, but it seems that anti-thyroid antibodies are not directly responsible for the lesions seen in patients and only serve as an indicator of autoimmunity.…”

“…At our center, etiological investigation of CIU is conducted rigorously, as recommended in the literature. 15 Patients with other types of urticaria, contact eczema, or systemic autoimmune diseases, such as systemic lupus erythematosus and scleroderma, were excluded. The diagnosis of angioedema was based on compatible history, i.e.…”