The prediction effects of thyroid function in the severity of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS), an acquired immune-mediated inflammatory disorder affecting the peripheral nervous system (PNS), is usually complicated with autoimmune diseases including thyroid diseases. Herein, we explored roles of thyroid function and thyroid autoantibodies in the disease severity and its short-term prognosis of GBS. In addition, we further investigated the predictive value of thyroid function for GBS respiratory insufficiency.We retrospectively analyzed the clinical data of 219 GBS patients. According to the thyroid function, the enrolled subjects were divided into 2 groups, that is, patients with abnormal thyroid function (case group) and those with normal thyroid function (control group). The clinical characteristics, disease severity, and short-term prognosis of the patients in 2 groups were compared. In addition, we also divided the 219 GBS patients into mechanical ventilation (MV) group and non-MV group according to whether MV was performed within 1 week after admission. The clinical characteristics, disease severity, short-term prognosis, Erasmus GBS respiratory insufficiency score (EGRIS), and the thyroid function were compared in the two groups.We found that GBS patients with abnormal thyroid function had longer duration of hospitalization, higher frequency of cranial nerve damage, and higher incidence of weakened tendon reflexes. Medical Research Council (MRC) scores on admission, at nadir, and at discharge were lower, and Hughes Functional Grading Scale (HFGS) scores on admission and at discharge were higher in GBS patients with abnormal thyroid function group. More patients in the abnormal thyroid function group had myelin, axonal, and myelin-axonal injuries. In the MV group, the time from onset to admission, MRC scores on admission, and the levels of free triiodothyronine (FT3) were lower; the levels of thyroglobulin antibody (TgAb) and EGRIS were significantly higher than those in the non-MV group. The combination of EGRIS and FT3 serum levels to predict GBS patients with MV, the area under the curve (AUC) was 0.905 (95% CI: 0.861 to 0.948, P 0.05), sensitivity was 88.9%, and specificity was 84.7%.Our results suggest that the serum FT3 levels are negatively correlated with disease severity; the serum FT3 might be a biomarker for the incidence and severity of GBS. Both EGRIS and serum FT3 have a predictive value for the occurrence of acute respiratory insufficiency in GBS patients, and the combination of these two indicators can more accurately predict the risk of acute respiratory insufficiency in GBS patients.