Digestive histopathological presentation of IPEX syndrome

Immunodysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (IPEX) syndrome is a well recognized and particularly severe form of autoimmune enteropathy. It has an X-linked recessive transmission, and is caused by mutations in the FOXP3 gene. We studied the intestinal morphological changes characterizing IPEX syndrome in a series of 12 children with a molecularly confirmed diagnosis. Histological examination of duodenal, gastric and colonic biopsies were retrospectively reviewed and compared by two independent experienced pathologists. In parallel, the presence of circulating anti-enterocyte antibodies was analysed using an indirect immunofluorescence technique and a quantitative radioligand assay against the 75-kDa autoantigen. The morphology of the inflammatory gut lesions could be categorized into three different entities, namely graft-vs-host disease-like changes (9/12 patients), a coeliac disease-like pattern (2/12) and an enteropathy with a complete depletion of goblet cells (1/12). Our results do not suggest any phenotype-genotype correlation. Circulating antibodies were detected in all 12 patients, with an anti-brush border pattern (11/12) and anti-goblet cell antibodies (1/12), as well as by a radioligand assay. The histological presentation of autoimmune enteropathy is rather variable. However, a graft-vs-host disease-like pattern associated with positive anti-enterocyte antibodies is the most frequent intestinal presentation of IPEX syndrome, and constitutes a very valuable tool for pathologists to suspect this diagnosis.