Serositis tied to autoimmune thyroid disease in SLE patients
Serositis appears to be an important risk factor for autoimmune thyroid disease (AITD) in people with systemic lupus erythematosus (SLE), reports a new study.
Thirty-eight patients with SLE and AITD (SLE-AITD; mean age 35.36±11.65; 89.5 percent female) were included in the study along with 190 age- and gender-matched SLE-only controls (mean age 35.36±11.54 years; 89.5 percent female). Multivariate logistic regression models were constructed to determine important factors associated with the prevalence of AITD among SLE patients.
Hyperthyroidism was reported in nine of the SLE-AITD participants, all of whom had signs of Graves’ disease. The remaining 29 SLE-AITD patients had hypothyroidism, most of whom (93.10 percent) received thyroxin replacement therapy. All the SLE-AITD participants tested positive for antithyroid antibodies.
Serositis (odds ratio [OR], 3.27; 95 percent CI, 1.59–6.75; p=0.00), the presence of anti-dsDNA antibodies (OR, 0.28; 0.13–0.64; p=0.01), and reduced levels of the complement 3 (OR, 0.30; 0.12–0.74; p=0.01) and 4 (OR, 0.44; 0.20–0.97; p=0.04) proteins were all significantly associated with AITD in SLE.
Upon adjustments for potential confounders, only serositis remained a significant risk factor for AITD in SLE (adjusted OR, 3.64; 1.65–8.04; p=0.00). On the other hand, the presence of anti-dsDNA antibodies seemed to have a significant protective effect (adjusted OR, 0.12–0.72; p=0.01).
The present study had important limitations, such as its retrospective design and the failure to screen all SLE patients for thyroiditis antibodies. In contrast, key strengths of the present study included the large study sample and the low interference from drugs, as participants were recruited before medication had been administered.