{{Infobox medical condition (new) | synonyms = Interleukin-2 receptor alpha chain deficiency | name = CD25 deficiency | image = Autosomal recessive - en.svg | caption = This condition is inherited in an autosomal recessive manner. | pronounce = | field = | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = }} '''CD25 deficiency''' or '''interleukin 2 receptor alpha deficiency''' is an immunodeficiency disorder associated with mutations in the interleukin 2 receptor alpha (CD25) (IL2RA) gene. The mutations cause expression of a defective α chain or complete absence thereof, an essential part of high-affinity interleukin-2 (IL-2) receptors. The result is a syndrome described as IPEX-like<ref name="Caudy2007">{{cite journal|title=CD25 deficiency causes an immune dysregulation, polyendocrinopathy, enteropathy, X-linked–like syndrome, and defective IL-10 expression from CD4 lymphocytes|journal=J Allergy Clin Immunol|year=2007|volume=119|issue=2|pages=482–7|doi=10.1016/j.jaci.2006.10.007|pmid=17196245|vauthors=Caudy AA, Reddy ST, Chatila T, Atkinson JP, Verbsky JB|doi-access=free}}</ref> or a SCID.<ref name=Bonilla2003>{{cite journal|title=12. Primary immunodeficiency diseases|journal=J Allergy Clin Immunol|year=2003|volume=111|issue=2 Suppl|pages=S571-81|doi=10.1067/mai.2003.86|pmid=12592303|vauthors=Bonilla FA, Geha RS}}</ref>
In one patient, deficiency of CD25 on CD4+ lymphocytes caused significantly impaired sensitivity to IL-2. This was demonstrated by a lack of measurable response in anti-inflammatory interleukin-10 (IL-10) secretion to low-dose IL-2 incubation. Greatly reduced IL-10 secretion compared to healthy humans results in a syndrome comparable to IPEX syndrome, a type of autoimmunity which is caused by FoxP3 transcription factor dysfunction. In addition to IPEX-like symptoms, CD25 deficiency increases susceptibility to viral infections<ref name=Caudy2007 /> and possibly fungal and bacterial infections.
As IL-2 is an important inducer of lymphocyte proliferation, the absence of highly sensitive IL-2 receptors may also significantly hinder activation and clonal expansion of CD8+ and CD4+ lymphocytes and NK cells.<ref name=Bonilla2003 /> One case also reported the absence of CD1, a MHC-like glycoprotein involved in the presentation of lipid antigens to T cells, in a CD25 deficient patient. Furthermore, chronic upregulation of anti-apoptotic Bcl-2 in thymocytes was also described possibly allowing autoreactive T cells to escape deletion.<ref>{{cite journal|title=Human immune disorder arising from mutation of the alpha chain of the interleukin-2 receptor|journal=Proc Natl Acad Sci U S A|year=1997|volume=94|issue=7|pages=3168��71|pmid=9096364|vauthors=Sharfe N, Dadi HK, Shahar M, Roifman CM|pmc=20340|doi=10.1073/pnas.94.7.3168|bibcode=1997PNAS...94.3168S|doi-access=free}}</ref>
==References== {{reflist}}
== External links == {{Medical resources | DiseasesDB = | ICD10 = D81.2 | ICD9 = | ICDO = | OMIM = 606367 | MedlinePlus = | eMedicineSubj = | eMedicineTopic = | MeshID = | Orphanet = 169100 }} {{Immune disorders}}
Category:Noninfectious immunodeficiency-related cutaneous conditions