Abstract
The occurrence of antinuclear antibody (ANA), rheumatoid factor (RF), antibodies to
double-stranded DNA (anti-dsDNA) and to single-stranded DNA (anti-ssDNA) was investigated
in 51 patients with autoimmune thyroid diseases (AITD), and in 25 matched control
subjects. In comparison with controls, the prevalence of anti-dsDNA was 74.5 % in
AITD patients (p = 0.0001), 82.0 % in 39 hyperthyroid Graves' disease (GD) (p = 0.0001),
and 50.0 % in 12 euthyroid Hashimoto's thyroiditis (HT) patients (p = 0.0001). The
prevalence of anti-ssDNA was 90.1 % in AITD (94.8 % in GD and 75 % in HT; p = 0.001).
The concentration of both anti-dsDNA and anti-ssDNA were higher (p = 0.002) in AITD,
in GD (p = 0.001), and in HT (p = 0.01) patients than in controls. Two patients with
AITD were identified as positive for ANA. RF was detected in 4 AITD patients. Positive
correlation was noted between anti-dsDNA with T4 (p = 0.001), T3 (p = 0.002), thyroid
peroxidase antibody (anti-TPO) (p = 0.0001), and TSH (p = 0.001) values but not with
thyroglobulin antibody (anti-Tg). Serum anti-ssDNA values were also correlated with
T3 (p = 0.0001), TSH (p = 0.003), and anti-TPO (p = 0.0001). However, by using a multiple
regression analysis only anti-TPO remained associated with anti-dsDNA and both anti-Tg
and anti-TPO with anti-ssDNA values. The predisposition to develop systemic autoimmune
disorders is not influenced by thyroid hormones. The elevated prevalence of serum
anti-dsDNA and anti-ssDNA in AITD patients points out that we must be aware of the
risk for predisposition for the development of other systemic autoimmune diseases.
Key words
Antinuclear antibodies - Graves' disease - Hashimoto's thyroiditis - thyroid autoantibodies
References
1 Presented in part at the 74th Annual Meeting of the American Thyroid Association,
Los Angeles, CA, USA, October 10 - 13, 2002
jhroma@netpoint.com.br
