Anti-nuclear antibody, anti-DNA, and aCL in Graves' disease patients treated with propyluracil or methimazole

One hundred and forty patients with Graves' disease [32 new patients, 54 treated with propylthiouracil (PTU) for a mean of 27.2 months and 54 treated with methimazole (MMI) for a mean of 48.6 months] were tested for anti-thyroid microsomal antibody (AMA), anti-thyroglobulin antibody (ATA), thyroid binding inhibitory immunoglobulin (TBII), and the non organ specific autoantibodies [i.e., anti-nuclear antibody (ANA), anti-double stranded DNA antibody (anti-dsDNA Ab), anti-cardiolipin antibody (aCL Ab) and anti-β2- glycoprotein I antibody (IgG β2GPI)]. Treatment with MMI or PTU produced a significant difference in IgG aCL Ab production but not in ANA, dsDNA Ab, IgM aCL or IgG β2GPI. For those treated with MMI but not those treated with PTU, ANA and anti-dsDNA Ab were positively correlated. IgG and IgM aCL Ab were positively correlated overall and for those on MMI but not PTU treatment. No significant difference was found for any of the four non organ specific antibodies in AMA positive or negative patients but there was a significant difference in IgG aCL positivity rates for ATA positive and negative patients. On the other hand, ANA negative patients were significantly more likely to have higher TBII values. These results suggest that the appearance of the non organ specific autoantibodies is probably largely a coincidental effect of polyclonal activation - except, perhaps, for IgG aCL, which may be related to treatment.