Clinical spectrum of glutamic acid decarboxylase antibodies in a Taiwanese population

다국어 초록 (Multilingual Abstract)

High levels of autoantibodies against glutamic acid decarboxylase (GAD‐abs) are associated with stiff‐person syndrome (SPS). However, the full clinical spectrum associated with GAD‐abs in Asians is unclear. The clinical and immunological features of patients positive for GAD‐abs were reviewed in a large Taiwanese series.
Retrospective case series and immunological investigations were conducted between July 2007 and July 2017 at a tertiary referral centre in Taiwan. Amongst 361 patients with GAD‐ab reactivity, 185 with detailed clinical records were included.
Twenty‐seven patients (14.59%), with a mean age at assessment of 54.8 ± 13.9 years, presented with neurological symptoms. The major neurological presentations (mean GAD‐ab concentrations) were SPS (n = 9, 33.3%; 135.45 ± 27.84 U/ml), cerebellar ataxia (n = 3, 11.1%; 95.61 ± 49.63 U/ml), encephalopathy (n = 2, 7.4%; 51.8 ± 49.64 U/ml) and epilepsy (n = 1, 3.7%; 83.3 U/ml). Notably, eight patients fulfilling the clinical diagnosis of multiple system atrophy had relatively lower GAD‐ab concentrations (2.57 ± 0.82 U/ml), which has not been reported previously. There was no correlation between disease severity and GAD‐ab concentration. Patients presenting with comorbid endocrinopathies (n = 15, 55.5%) had higher GAD‐ab concentrations than those without endocrinopathies (n = 12, 44.4%; 104.45 ± 22.51 U/ml vs. 34.08 ± 21.83 U/ml, P = 0.04). Of 158 patients (85.4%) without a neurological presentation, 133 had type 1 diabetes mellitus and 20 had diabetes of other aetiologies (type 2 or gestational diabetes mellitus, or diabetes secondary to pancreatitis); the remaining four patients had pure thyroid disorders.
A clinical and immunological evaluation of East Asian patients positive for GAD‐abs is presented and a different clinical spectrum of anti‐GAD syndrome is identified compared to Caucasians.