CD25 deficiency

Overview

CD25 deficiency is a rare autosomal recessive immunodeficiency disorder characterized by the absence or dysfunction of the interleukin-2 receptor alpha chain (IL-2R_), also known as CD25. This condition leads to impaired immune system function, resulting in increased susceptibility to infections and autoimmune disorders.

Diagram of autosomal recessive inheritance pattern.

Pathophysiology

CD25 is a component of the high-affinity interleukin-2 receptor complex, which is crucial for the proliferation and survival of T cells. In CD25 deficiency, the lack of functional IL-2R_ impairs the signaling pathways necessary for T cell activation and regulatory T cell (Treg) development. This results in a compromised immune response and a failure to maintain immune tolerance, leading to autoimmunity.

Clinical Presentation

Patients with CD25 deficiency typically present in early childhood with recurrent infections, lymphadenopathy, and failure to thrive. Autoimmune manifestations may include autoimmune hemolytic anemia, immune thrombocytopenic purpura, and type 1 diabetes mellitus.

Diagnosis

The diagnosis of CD25 deficiency is based on clinical evaluation, laboratory findings, and genetic testing. Laboratory tests often reveal low or absent CD25 expression on T cells, reduced Treg numbers, and impaired T cell proliferation in response to IL-2. Genetic testing can confirm mutations in the IL2RA gene, which encodes the IL-2R_ chain.

Treatment

Management of CD25 deficiency involves supportive care, including prophylactic antibiotics to prevent infections and immunosuppressive therapy to control autoimmune symptoms. Hematopoietic stem cell transplantation (HSCT) may be considered in severe cases to restore immune function.

Prognosis

The prognosis for individuals with CD25 deficiency varies depending on the severity of the condition and the success of treatment interventions. Early diagnosis and appropriate management can improve outcomes and quality of life.

Related Pages

• Immunodeficiency
• Autoimmune disease
• Interleukin-2 receptor
• Regulatory T cell