Immunology and Immunogenetics Insights

Aim: To assess serum Anti-Neutrophil cytoplasmic Antibody (ANCA—PR3 and MPO) and Anti-Saccharomyces Cerevisiæ Antibody (ASCA) levels in autistic children with severe gastrointestinal (GI) disease and to test the hypothesis that there is generalized autoimmunity in a subpopulation of autistic children with severe GI disease and that this autoimmunity is associated with the severity of GI disease.

Subjects and Methods: Serum from 40 autistic children with chronic digestive disease (most with ileo-colonic lymphoid nodular hyperplasia (LNH) and inflammation of the colorectum, small bowel and/or stomach), and 24 controls (13 age matched autistic children with no GI disease and 11 age matched children without autism or GI disease) were tested using ELISAs designed to quantitate ANCA (PR3 and MPO) and ASCA levels. ANCA and ASCA concentration of autistic children with GI disease were compared to GI disease severity (including LNH and erythema).

Results: We previously reported that 6 of the 40 autistic children with GI disease in this study had anti-PR3 ANCA. All 6 of these also had anti-MPO IgG. In this study, we found that 6 of the 40 autistic children also had ASCA and 4 of these children with ASCA also had both anti-PR3 and anti-MPO ANCA. These 4 with ANCA and ASCA had significantly higher GI disease severity, particularly associated with LNH and erythema.

Discussion: These results suggest a general autoimmune response (ANCA and ASCA) in a sub group (high GI disease severity) of autistic children with GI disease. The presence of these autoantibodies may be a useful biomarker for autistic children with severe GI disease.