Efficacy of preoperative therapeutic plasma exchange in patients with hyperthyroidism and factors affecting the number of sessions

Purpose: Achieving preoperative euthyroidism in patients with hyperthyroidism for whom antithyroid drugs (ATDs) cannot be used for treatment is a serious clinical problem. We aimed to evaluate the effectiveness of therapeutic plasma exchange (TPE) in hyperthyroid patients scheduled for surgery and predictive factors for a high number of TPE sessions.

Methods: We retrospectively analyzed the data of 21 patients with hyperthyroidism who were treated with TPE for preoperative euthyroidism in our institution. Pre- and post-TPE thyroid function tests were compared to assess efficacy. Binary logistic regression analysis was applied to determine predictors of patients requiring a high number of TPE sessions.

Results: All patients (20 patients with Graves' disease and 1 patient with toxic multinodular goiter; 12 women and 9 men; mean age 35.71 ± 12.38 years) had severe hyperthyroidism before TPE. The changes before and after TPE in fT3, fT4, and TSH levels were statistically significant (p < 0.001, p < 0.001, p = 0.002, respectively). The median number of TPE sessions was 8 (range: 1-24). Levels of fT3 before TPE were significantly higher in patients for whom higher numbers of TPE sessions were required (≥8) (OR: 1.427, 95% CI: 1.038-1.961, p = 0.028). Receiver operating characteristic curve analysis revealed an optimum cut-off value of 12.8 pg/ml for fT3 before TPE (91% sensitivity, 80% specificity, area under the curve: 0.927).

Conclusion: TPE should be considered as an effective alternative treatment option that can be used to rapidly achieve euthyroidism before surgery when ATDs cannot be used. Pre-TPE fT3 levels of >12.8 pg/ml may be an independent factor predicting the need for higher numbers of TPE sessions (≥8).