The neurologic significance of celiac disease biomarkers

Abstract

Objective: To report neurologic phenotypes and their etiologies determined among 68 patients with either (1) celiac disease (CD) or (2) no CD, but gliadin antibody positivity (2002-2012). Methods: Neurologic patients included both those with the CD-prerequisite major histocompatibility complex class II human leukocyte antigen (HLA)-DQ2/DQ8 haplotype, and those without. The 3 groups were as follows: group 1 (n544), CD or transglutaminase (Tg)-2/deamidated gliadin immunoglobulin (Ig)A/IgG detected; group 2 (n 5 15), HLA-DQ2/DQ8 noncarriers, and gliadin IgA/ IgG detected; and group 3 (n 5 9), HLA-DQ2/DQ8 carriers, and gliadin IgA/IgG detected. Neurologic patients and 21 nonneurologic CD patients were evaluated for neural and Tg6 antibodies. Results: In group 1, 42 of 44 patients had CD. Neurologic phenotypes (cerebellar ataxia, 13; neuropathy, 11; dementia, 8; myeloneuropathy, 5; other, 7) and causes (autoimmune, 9; deficiencies of vitamin E, folate, or copper, 6; genetic, 6; toxic ormetabolic, 4; unknown, 19) were diverse. In groups 2 and 3, 21 of 24 patients had cerebellar ataxia; none had CD. Causes of neurologic disorders in groups 2 and 3 were diverse (autoimmune, 4; degenerative, 4; toxic, 3; nutritional deficiency, 1; other, 2; unknown, 10). One or more neural-reactive autoantibodies were detected in 10 of 68 patients, all with autoimmune neurologic diagnoses (glutamic acid decarboxylase 65 IgG, 4; voltage-gated potassium channel complex IgG, 3; others, 5). Tg6-IgA/IgG was detected in 7 of 68 patients (cerebellar ataxia, 3; myelopathy, 2; ataxia and parkinsonism, 1; neuropathy, 1); the 2 patients with myelopathy had neurologic disorders explained by malabsorption of copper, vitamin E, and folate rather than by neurologic autoimmunity. Conclusions: Our data support causes alternative to gluten exposure for neurologic dysfunction among most gliadin antibody-positive patients without CD. Nutritional deficiency and coexisting autoimmunity may cause neurologic dysfunction in CD.