cd25 deficiency cd25 deficiency 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 or a scid. cd25 deficiencyother namesinterleukin-2 receptor alpha chain deficiencythis condition is inherited in an autosomal recessive manner. 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 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. 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.