Serum from patient CD11 showed a strong basket-like immunoreactivity pattern surrounding the PCs (Figure5h), in contradistinction to the pattern seen in mice (Figure4g). cerebellar and cerebral cortex extracts were analysed by Western blot probed with CD and control sera. Immunofluorescence microscopy was used on mouse and monkey cerebellar sections immunostained with CD and control sera to detect cross-reacting IgG antibodies. Western blot analysis of cerebellar and cerebral cortex extracts probed with CD sera did not demonstrate any specific immunoreactivity unique to the cerebellum. An identical twin pair with CD produced different patterns of reactivity. Immunofluorescence staining of mouse and monkey cerebellar sections showed most control and CD sera reacted non-specifically, with the exception of two CD and one control sera, each having a unique BMS-777607 staining pattern. == Conclusions == CD patient sera with high titre GAb do not detect a common Purkinje cell or cerebellar-specific epitope. The pattern of reactivity is not solely dependent on genetic background. Keywords: Gluten ataxia, Coeliac disease, Ataxia, Purkinje cell, Cerebellum, Anti-gliadin == Background == Classical coeliac disease (CD) is a chronic immune-mediated enteropathy, triggered by the ingestion of gluten proteins from wheat, rye and barley in genetically susceptible individuals positive for HLA DQ2 and/or DQ8, and resulting in malabsorption [1, 2]. Non-classical CD is increasingly recognised, and consists of enteropathy without malabsorption [2]. Gliadin is a moiety of wheat prolamins, and IgA anti-gliadin antibodies have been used to support the diagnosis of CD. They are, however , relatively non-specific, being found in about 1 in 10 individuals in Anglo populations [3], compared with a prevalence of classical plus non-classical CD of about 1 in 100 in the USA [4]. Recent Australian figures are similar, showing GAb IgG in 17% and GAb IgA in 7%, compared with an estimated prevalence of coeliac disease 1 . 6% in a random community sample [5]. Gliadin is deamidated in the gut wall by tissue transglutamidase (transglutamidase-2 TG2) and this deamidated protein stimulates a cellular immune response in HLA DQ2/8 individuals [6]. Antibodies to deamidated gliadin peptide, to TG2, and anti-endomysial antibodies are now used to support the diagnosis of CD, being much more specific than anti-gliadin antibodies [2]. However , diagnosis of CD in adults and most children still requires confirmatory small bowel biopsy [2, 7]. An area of recent interest has been the relationship between gluten sensitivity and (otherwise) idiopathic sporadic cerebellar ataxia. Gluten ataxia (GA) is currently defined as (otherwise) idiopathic sporadic BCL2L8 ataxia with anti-gliadin antibodies [2]. The presentation is usually as a pure ataxia of insidious onset with or without an accompanying sensory-motor, length-dependent neuropathy, although a subacute course, myoclonus, opsoclonus and palatal tremor are all described [1]. Most but not all studies have shown a high prevalence of gluten sensitivity in sporadic ataxia patients BMS-777607 eg. [3, 6]. There is only partial overlap with CD, with only about one third having enteropathy, and less than 40% having anti-TG2 antibodies [1]. Conversely, ataxia and/or neuropathy are found in about 6-10% of CD patients [7, 8]. This incomplete overlap has recently been illuminated by the finding that antibodies to TG-6 (especially IgG) are found in about 75% of patients with GA [9]. TG-6 is a predominantly neural isoform of transglutaminase, and is found extracellularly as well as intracellularly [10]. The extracellular location implies that it might be a pathogenic target of humoral autoimmunity, and indeed an anti-TG2 BMS-777607 antibody cross-reactive with TG-3 and TG-6 induced transient ataxia in mice when injected intraventricularly [11]. Moreover, a mutation in TG-6 has been reported to cause dominantly-inherited SCA 35 in three Chinese families with three different heterozygous mutations [12, 13], emphasising the potential for TG-6 as a pathogenic target in GA. GA does remain somewhat contentious, however. In part, this may arise from the use of the relatively non-specific anti-gliadin antibodies to define the syndrome. Furthermore, some studies.