Anti-PR3 and Anti-MPO IgG ANCA in Autistic Children with Chronic GI Disease

Aim: To assess both ant-PR3 and anti-MPO IgG anti-neutrophil cytoplasmic antibodies (ANCA), in autistic children with gastrointestinal symptoms and controls, and to test the hypothesis that there is an association between the presence of these antibodies and inflammatory GI disease seen in many autistic children. Subjects and Methods: ELISA’s were used to measure anti-PR3 and anti-MPO IgG in 40 autistic children with chronic digestive disease (many with ileo-colonic lymphoid nodular hyperplasia (LNH) and inflammation of the colorectum, small bowel and/or stomach), and 41 controls (21 age matched autistic children with no GI disease and 20 age matched children without autism or GI disease). Results: Six of 40 autistic children with chronic digestive disease had anti-PR3 antibodies compared to none of the 41 controls (p 0.01). Thirteen of the 40 autistic children with chronic digestive disease had anti-MPO IgG compared to only 3 (1 autistic control with no GI disease and 2 non-autistic controls without GI disease) of 41 controls (p 0.001). All six of those with anti-PR3 IgG also had anti-MPO antibodies. These results suggest a relationship between individuals with ANCA and severity of intestinal disease in a subset. Discussion: These results suggest an association between anti-PR3 and anti-MPO antibodies and a subset of ASD children with GI inflammation.