Thyroid Autoimmunity in Chronic Urticaria

Abstract

A subset of patients with idiopathic chronic urticaria (CU) has been recently classified as autoimmune on the basis of two main findings: association with thyroid autoimmunity and with anti-IgE and/or anti-IgE receptor antibodies. The association of CU with thyroid autoimmunity has been known since 1983, but its frequency varies in different reports. The objective of the present study was to verify the prevalence of thyroid antibodies (anti-thyroid peroxidase, TPO; thyroglobulin, TG; TSH-receptor, TSH-R) in two distinct series of CU: of known cause (70 cases, group A) and idiopathic (52 cases, group B). Twenty-three patients (M/F:7/16) of group A (33%) and 12 (M/F:4/8) of group B (23%) tested positive for at least one type of thyroid antibody. The difference was not statistically significant. Thyroid disease or altered serum TSH levels (requiring treatment) were present in 39% of group A and 42% of group B seropositive patients. In conclusion, the present study shows that CU, either of known cause or idiopathic, is more common in females than in males and is significantly associated with thyroid autoimmunity. These results were not expected on the assumption that autoimmune phenomena are a specific pattern of idiopathic CU. Thus, screening for thyroid autoimmunity and function is advisable in all patients with CU for the early identification of patients requiring either treatment of underlying thyroid dysfunction or follow-up.

Association between chronic spontaneous urticaria and thyroid autoimmunity: a case control study from a tertiary care centre

“…Female predilection was more prominent in chronic urticaria with high anti TPO antibody which was consistent with previous studies. [2][3][4][5][6][7] Severe urticaria was seen in patients with high anti TPO antibody in our study unlike most of the previous studies. 7,16,17 ASST positive patients also had high urticaria activity in our study, in concordance with other reports but unlike other studies where no correlation was found between the severity of urticaria and ASST positivity.…”

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

“…A associação entre UC e DAT foi descrita por vários autores, sendo considerada bem estabelecida (7)(8)(9)(10)(11)(12)(13)(14)21). Em nosso trabalho, concordando com poucos relatos, esta associação não ocorreu (16,17).…”

“…Assim, considerando que pelo menos uma parcela dos pacientes com UCI tem, na verdade, uma doença autoimune, seria plausível acreditar que uma associação com DAT realmente exista, visto tratar-se de duas doenças com mecanismos patogênicos semelhantes. No entanto, entre os trabalhos que encontraram uma associação entre DAT e UC, a maioria apresentou dificuldades metodológicas (7)(8)(9)(10)(11). A prevalência de anticorpos anti-tireoidianos em pacientes com UC variou de 11,7% a 28,6%.…”

“…Como resultado desses esforços, vários autores encontraram maior prevalência de DAT em pacientes com UCI (7)(8)(9)(10)(11)(12)(13)(14). Esses achados levantam a possibilidade de uma relação entre essas doenças.…”

“…No entanto, a freqüência de DAT em pacientes com UC variou, nos diversos estudos, de 1,14% a 28,6% (7)(8)(9)(10)(11)(12)(13)(14)16,17). Alguns autores, procurando reforçar a associação encontrada em muitos trabalhos, investigaram a freqüência de UCI em pacientes com DAT, obtendo resultados discrepantes (13,18).…”