A recent study suggested that digestion-resistant
peptides derived from wheat
gluten (mainly
gliadin) could induce the secretion of anti-
gliadin IgG antibodies in patients with
schizophrenia. This research was then designed to replicate this initial finding in 134 drug-naïve patients with first-episode
schizophrenia and 160 healthy controls. An
enzyme-linked
immunosorbent assay was developed in-house with 8
gliadin-derived
peptide antigens to test anti-
gliadin IgG antibodies in the circulation. The results showed that
schizophrenia patients had significantly higher levels of plasma anti-AL2G2
IgG and anti-ABO3a
IgG than healthy controls. Based on the specificity of 95%, anti-AL2G2
IgG assay had a sensitivity of 12.7% and anti-ABO3a
IgG assay had a sensitivity of 17.2% for anti-ABO3a
IgG assay. Increased levels of anti-AL2G2 and anti-ABC3a
IgG antibodies were not correlated with total
IgG levels in either the patient group or the control group. In conclusion, circulating
IgG against AL2G2 and ABO3a may be useful
biomarkers for identification of a
gluten-sensitive subgroup of
schizophrenia in the Chinese population although the present results are rather different from the work performed in a British population.