Methods: Total 878 CIU patients were performed ASST to identify autoreactivity. Further, serum antibodies to thyroglobulin (ATG) and thyroid peroxidase (ATPO), ANA, and total IgE were measured. Clinical severity of CIU was estimated by urticaria severity score (UAS) and maximum level of medication (1∼4) to abrogate wheal and pruritus. We analyzed association among ASST, laboratory markers and clinical severity in different subgroups based on ASST and laboratory markers.
Results: A total of 255 (29.0%) patients were tested positive in the ASST and 28/192 (14.6%) patients were tested positive for ATPO or ATG. Positive percent of ANA was 18.6% (106/571) with female preponderance. Serum total IgE level was measured in 521 of the 878 patients and was found to be elevated in 258 (49.5%). When ASST was analyzed in relation to laboratory markers, inverse correlation between ASST and serum IgE level was observed but significantly higher percentage of positive ANA was found in patients with positive ASST (31.5%) compared to patients with negative ASST (13.4%). Correlations of ATPO and ATG with ASST had no significant statistical difference. The patients with positive ASST had significantly higher scores of UAS compared with the patients with negative ASST. However, there was no significant statistical difference between maximum level of medication and ASST. Maximum levels of medication in the patients with elevated IgE were significantly higher than those with normal IgE.
Conclusion: Significant association between ASST and thyroid autoimmunity was not identified in this study. Patients with positive ASST had more disease activity but patients with elevated total IgE were found more refractory to lower level of medication like antihistamine.