Published online Oct 6, 2019. doi: 10.12998/wjcc.v7.i19.2942
Peer-review started: June 29, 2019
First decision: July 31, 2019
Revised: August 14, 2019
Accepted: August 27, 2019
Article in press: August 27, 2019
Published online: October 6, 2019
Processing time: 95 Days and 8.9 Hours
Glutamic acid decarboxylase (GAD) is known to synthesize the inhibitory neurotransmitter of γ-aminobutyric acid, and it is also found in the β-cells in the pancreas. Clinically, anti-GAD Ab is associated with stiff-person syndrome (SPS), type 1 diabetes mellitus (T1DM), and other autoimmune diseases.
There is still a plausible and unclear mechanism in SPS with autoantibodies and related other autoimmune diseases.
To investigate the link of autoimmune endocrine disorders with anti-GAD Ab in SPS subjects.
Patients with SPS collected from January 2001 to June 2018 were retrospectively analyzed. Anti-GAD antibodies were measured using radioimmunoassay and enzyme-linked immunosorbent assay to determine the diagnosis of and association with other autoimmune diseases.
Of the 14 patients, 12 (85.7%) were diagnosed with classic SPS and 2 (14.3%) with stiff limb syndrome (SLS). Among nine classic SPS patients who underwent the anti-GAD Ab test, three were anti-GAD Ab seropositive and each of these three patients also had T1DM, latent autoimmune diabetes in adults, and autoimmune thyroid disease. In contrast, other rare autoimmune diseases co-existed in six anti-GAD Ab seronegative SPS patients. None of the SLS patients had additional autoimmune disease.
The presence of typical clinical symptoms and anti-GAD autoantibody are not only important clues for diagnosis of SPS but also for early detection of this disease and prediction of the association with other autoimmune diseases.
This article reflects that anti-GAD autoantibody may demonstrate the diagnostic accuracy of SPS, although there is a lack of large sample size and unclear mechanism due to rarity. SPS is associated with other autoimmune diseases like T1DM and malignancy, which can cause morbidity and mortality. Further investigation of the link between SPS and T1DM could predict DM and prevent significant disabilities.