Early-onset Crohn's disease, IgA nephropathy, and hemophagocytic lymphohistiocytosis in a patient with IL-10 receptor deficiency

IL-10 receptor (IL-10R) deficiency is a rare immune dysregulation disorder that is characterized by early-onset and life-threatening inflammatory bowel disease (IBD). Activation of the IL-10R inhibits the release of pro-inflammatory cytokines resulting in decreased inflammation. Herein, we present a case of novel homozygous IL-10RA mutation (c.243T>A; p.Y81*) resulting in early-onset Crohn's disease and failure to thrive who was treated with anakinra (IL-1 blocker). His disease course was complicated with IgA nephropathy while anakinra was held for the treatment of osteomyelitis and improved when anakinra was restarted. A year later, he developed inflammatory brain disease and Hemophagocytic Lymphohistiocytosis (HLH), which was treated with high dose steroid and hematopoietic stem cell transplant (HSCT). This case highlights IgA nephropathy, CNS autoinflammation, and HLH as possible extraintestinal manifestations of IL-10 receptor deficiency, especially in the setting of delayed stem cell transplantation.