INTERLEUKIN-6 LEVELS ARE NOT INCREASED IN WOMEN WITH POSTPARTUM THYROID-DYSFUNCTION

Postpartum thyroid dysfunction (PPTD) is an autoimmune-mediated thyroi d destructive process. Human interleukin-6 (IL-6) is a cytokine found to be increased in subacute thyroiditis, amiodarone-induced thyrotoxic osis, Graves' disease, and other thyroid destructive processes. We rep ort serum IL-6 levels in PPTD in two independent studies. New York Stu dy: In a previous prospective study we demonstrated that PPTD occurred in 25% (7/28) of women with type 1 diabetes mellitus. IL-6 determinat ions were made on the frozen serum samples of these 28 women during ea ch trimester of their pregnancy and at 1.5, 3, 6, 9, and 12 months pos tpartum. IL-6 levels were found to be similar in women with PPTD compa red with women without PPTD (mean 3.06 +/- 2.25 vs. 2.51 +/- 2.21 pg/m L; P = 0.15). No difference in IL-6 levels was found between the pre-a nd the postpartum periods (mean 2.67 +/- 1.82 vs. 3.04 +/- 2.44 pg/mL; p = 0.30) in all 28 women. Cardiff Study: Serum IL-6 levels were meas ured on frozen serum samples of 30 women with PPTD. IL-6 levels were b elow the detection limit (25 fmol/L or 0.65 pg/mL) in 94 (67%) of thes e samples. No significant difference in the mean serum IL-6 levels wer e found between any time points in the study. There was no correlation between serum IL-6 levels, thyroid peroxidase (TPO)-antibodies and se rum thyrotropin (TSH) levels at any time point. IL-6 levels during pre gnancy or postpartum were not found to be significantly different in w omen with PPTD compared with women without PPTD.