Early-onset inflammatory bowel disease and common variable immunodeficiency–like disease caused by IL-21 deficiency

Extending the clinical and immunological phenotype of human interleukin-21 receptor deficiency

“…Interestingly, all 4 previously reported IL-21R-deficient patients, 1 and to a lower extent the IL-21-deficient patient, 3 had increased levels of IgE, while serum IgE levels were within the normal range in our patient (Table 1). Thus elevated IgE serum levels are common in IL-21R/IL-21 deficiency but are possibly enhanced by cryptosporidial infection.…”

“…As outlined in the described alterations of the B-cell homeostasis in IL-21 deficiency, 3 the expansion of transitional B cells ( Figure 1D) might indicate a previously unknown role of IL-21/IL-21R signaling in early peripheral B-cell maturation, while the B-cell development in the bone marrow was unaffected except for a relative increase in immature B cells (Table 1).…”

Advances of the interleukin-21 signaling pathway in immunity and angiogenesis

“…Numerous studies have shown that IL-21 has therapeutic effects in animal models of a wide range of diseases [including cancer (12), immunity-deficient disease (39), type 1 diabetes (40) and inflammatory bowel disease (41)] and various clinical trials are underway (42).…”

Identification of ITK deficiency as a novel genetic cause of idiopathic CD4+ T-cell lymphopenia

“…5 Unexpectedly, we identified a homozygous nonsense mutation located within the first exon of the Interleukin-2-inducible T-cell kinase (ITK) gene (c.C49T:p.Q17X) likely leading to nonsense-mediated decay of the corresponding gene product. The mutation was validated using capillary sequencing and showed perfect segregation under the assumption of autosomalrecessive inheritance ( Figure 1C).…”