Abstract / Summary
Guillain-Barré syndrome (GBS) is an immune-mediated peripheral neuropathy encompassing demyelinating and axonal subtypes such as acute inflammatory demyelinating polyradiculoneuropathy (AIDP), Acute Motor Axonal Neuropathy (AMAN) and Acute Motor Sensory Axonal Neuropathy (AMSAN). Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is another immune-mediated peripheral neuropathy with overlapping clinical and electrophysiological features with GBS. Recent evidence suggests a potential link between thyroid dysfunction and these conditions, though the clinical significance remains unclear. This systematic review examines the possible role of thyroid hormone and thyroid autoantibodies in GBS and CIDP. A comprehensive search was conducted across PubMed, Embase, Scopus, and Web of Science, identifying studies assessing thyroid function or autoantibodies in patients with GBS, CIDP, and their subtypes. The review included studies focusing on thyroid function tests (Thyroid-stimulating hormone; TSH, free Triiodothyronine; FT3, and free Thyroxine; FT4) or thyroid autoantibodies (Thyroid Peroxidase Antibodies; TPOAb and Thyroglobulin; TgAb). Seven studies, covering 1,302 participants, were included. Unfortunately, due to scarcity and heterogeneity of data, meta-analysis could not be done and only qualitative systematic review was performed. In this review abnormal levels of TSH, FT3, FT4, and T4 were found in GBS patients. Moreover, these abnormalities were associated with increased disease severity, respiratory failure, and higher recurrence risk. In contrast, only a few studies highlighted the thyroid abnormalities in CIDP patients. However, due to the retrospective nature of the studies, determining the prognostic role of thyroid function was not possible. Further studies with meta-analysis synthesis are needed to clarify the exact role of these laboratory markers and their clinical value.