Do TNF Inhibitors Increase the Frequency of Thyroid Nodules in Axial-spondyloarthritis Patients? A Case–control Study

Objectives: Tumor necrosis factor (TNF) inhibitors have made great progress in the management of axial spondy-loarthritis (axSpA). An increase in malignancies associated with TNF inhibitors has always raised suspicions but is unproven. The aim of this study is to investigate whether there is an increase in the frequency of thyroid nodules in axSpA patients treated with TNF inhibitors and to determine the predictive factors. Methods: In this retrospective case–control study, axSpA patients who received and did not receive TNF inhibitor treatment were divided into two groups. Patients were enrolled by age, gender, symptom duration, duration of anti-TNF therapy, human leukocyte antigen B27 (HLA-B27) status, smoking history (current smokers), and family history of thyroid malignancy. Thyroid ultrasound was performed in all patients, and thyroid nodule positivity, number, and nodule characteristics were recorded. Results: A total of 75 patients with axSpA (37 patients were in the TNF inhibitor group and 38 patients were in the control group) were included in the study. Nodule positivity was similar in both groups (p=0.571), and no malignancy was detected in patients with thyroid nodules. No difference was found between nodule positivity and gender, HLA B27, smoking, or family history (p=0.10, p=0.10, p=0.726, and p=0.843, respectively). Age was the only predictor for thyroid nodule positivity in all axSpA patients (p:0.009, 95% of CI: 0.004–0.02). Conclusion: TNF inhibitors do not increase thyroid nodules or malignancies in axSpA patients.