Thyroid-stimulating hormone (TSH) is associated with recurrent Guillain-Barre syndrome (RGBS), according to study findings published in Muscle & Nerve.
GBS, an immune-mediated peripheral neuropathy, is typically considered a monophasic disease but roughly 4% of patients experience recurrences after remission, termed RGBS. Miller Fisher syndrome (MFS) recurrence rate can be up to 12%. Patients who experience more GBS recurrences tend to have increased disease severity and disability, and early prediction of recurrence would help doctors improve treatment outcomes, the researchers said.
A systematic study indicated thyroid autoantibodies may be biomarkers that can distinguish GBS from chronic inflammatory demyelinating polyneuropathy (CIDP). The objective of the current study was to identify any association of thyroid parameters and RGBS in China.
Researchers analyzed medical history; serum levels of THS, free thyroxoine, and free triiodothyronine; cerebrospinal fluid (CSF) data of 320 adult patients who had monophasic GBS (n=302) or RGBS (n=18) who were admitted to a university hospital and did not have history of thyroid disease.
TSH serum levels were lower and FT3 levels were higher in patients with monophasic GBS compared with patients with RGBS. The 2 groups had statistically significant differences in age at onset, incidence of antecedent illness, time from onset to nadir, proportion with acute inflammatory demyelinating polyradiculoneuropathy, and Hughes Functional Grading Scale score at nadir.
Multivariate regression analysis indicated that antecedent illness, acute inflammatory demyelinating polyneuropathy (AIDP), and high TSH were independently associated with RGBS. Risk of recurrence in patients with GBS increased when TSH concentration exceeded 3.87 μIU/mL. Sensitivity was 88.9%, and specificity was 90.4%.
Study limitations included the possibility that monophasic recurrent GBS in some patients occurred after the end of the study period, small sample of patients with RGBS, and the need to confirm the mechanism of how the biomarkers affect RGBS.
“Excess ROS, as a product of oxidative stress, has been widely considered to be a mediator of demyelination and axonal injury,” the researchers said.
TSH may cause oxidative damage via oxidative stress, the researchers explained. However, they emphasized that while studies have shown patients with both GBS and hyperthyroidism or hypothyroidism, the relationship between TSH and RGBS is unknown. “Our results demonstrate an association between TSH and RGBS, but it is unknown whether TSH can indirectly cause repeated myelin and axonal damage in RGBS patients through oxidative stress,” they said.
Wang S, Luo Z, Peng T. Serum thyroid-stimulating hormone is an independent risk factor of recurrent Guillain-Barré syndrome. Muscle & Nerve. 2022;65:688-692. doi: 10.1002/mus.27539