[Primary humoral immunodeficiencies associated with enteropathies: An update]

Inflammatory enteropathies are frequent in primary immune deficiencies (PID) (up to 21%). Their pathophysiology is complex and combines immune abnormalities (loss of tolerance, deficit in mucosal IgA secretion and altered infectious response) with an abnormal environment (dysbiosis, production of pro-inflammatory endotoxins, epigenetic and epitranscriptomic alterations). This leads to a deregulated inflammatory state of the gastrointestinal tract and thus to enteropathy. These conditions are heterogeneous and manifest not only as an inflammatory bowel disease but also as in lymphocytic, autoimmune, or eosinophilic colitis. Most of the time PID associated enteropathies remain unspecified. Their clinical, biological, and scannographic features are difficult to distinguish from enteropathies in immunocompetent patients. However, some histological specificities are described including graft-versus-host disease phenotype, with apoptotic bodies, and absence of mucosal plasma cells. There is no standardized treatment for this specific condition. Treatments of inflammatory bowel disease in immunocompetent patients are usually used, although refractory cases are more frequent. This entity is associated with an increased risk of autoimmune manifestations notably including autoimmune cytopenia. Finally, IBD in PID are associated with an increased risk of death related to the enteropathy and its treatments.