What is the influence of rheumatologic conditions on response to medical therapy of Graves disease?
Kavita Gulati1,2, Miriam OSullivan1, Michael Molloy2, Mary Stapleton1, Sinead Harney1, John OHalloran1, John Ryan1 & Antoinette Tuthill1
Anecdotal reports suggest that management of Graves disease (GD) is more challenging in patients with concomitant autoimmune disease, however there are few studies evaluating this premise and thus no satisfactory evidence base to guide clinicians. We aimed to identify the impact of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) on treatment outcomes of GD.
We identified all GD patients (n=265) who attended endocrinology clinics at a large tertiary referral hospital (19942001). Patients with GD and either RA or SLE (n=16) were selected as cases and matched by age and gender to patients with GD alone (n=48) and those with RA or SLE alone (n=48).
Patients were excluded as controls if they had another autoimmune disease or treatment with steroid therapy >3 months. Factors assessed included patient demographics, immunologic markers and treatment outcomes.
Patients with GD were predominantly female (86%) with a mean age of 50 years (range 1696 yrs). 14% of patients with GD had another autoimmune disease, the commonest being RA. 44% of patients suffered from Graves ophthalmopathy with significantly (P=0.04) increased risk of ophthalmopathy in smokers.
We found that there were no differences in response to initial anti-thyroid drug therapy between patients with GD alone and those with GD+RA/SLE (P=0.75).
However, patients with GD+RA/SLE relapsed much more quickly after 1st treatment (mean 6.2±5.8 months) compared to the GD alone group (mean 22.48±37.2 months) (P=0.034).
A greater proportion of patients with GD alone underwent radioactive iodine therapy (45.8%) than in the GD+RA/SLE group (13%) P=0.03. This was partially explained by difference in rates of Graves ophthalmopathy between groups.
We found that concomitant RA or SLE did not alter initial response rates to anti-thyroid medication, although this group had significantly higher relapse rates, suggesting that close monitoring for relapse is required even when the patient has achieved euthyroid state.