Neurol India. 2013 May-Jun;61(3):226-30.
Gluten ataxia of sporadic and hereditary cerebellar ataxia in patients from mainland China.
Guan WJ, Liu XJ, Tang BS, Liu YT, Zhou Y, Jiang H, Shen L, Xia K, Wang JL.

Department of Neurology, Xiangya Hospital; State Key Laboratory of Medical Genetics of China; Neurodegenerative Disorders Research Center, Central South University, Changsha, Hunan, China.

Background: Gluten sensitivity (GS) is a spectrum of disorders with diverse manifestations. Recent evidence suggests that ataxia may be the only manifestation of GS and that it may be one of the causes of sporadic ataxia. Aim: To investigate the prevalence of gluten ataxia among patients with ataxia in China. Materials and Methods: Serum levels of anti-gliadin, anti-transglutaminase 2 (TG2), and anti-transglutaminase 6 (TG6) antibodies measured in 125 patients with ataxia (100 patients with sporadic ataxia and 25 patients with hereditary ataxia) and 51 healthy controls by enzyme-linked immunosorbent assay (ELISA). Results: The serum concentrations of anti-gliadin, anti-TG2 IgG, IgA, and TG6-IgG antibodies were elevated in ataxia patients, but the increase was not statistically significant. However, TG6-IgA serum levels were significantly higher in sporadic ataxia as compared to those in healthy controls (P < 0.05). Conclusions: These results provide evidence that sporadic ataxia in a subgroup of patients may be due to gluten ataxia in mainland China. Measurement of serum anti-TG6 antibodies along with anti-TG2 and anti-gliadin antibodies may be useful for diagnosing gluten ataxia.

[PubMed - in process]

I don't know if TG-6 is available through mainstream labs but Cyrex offers it for both IgA and IgG.