From the Guidelines
Severe combined immunodeficiency (SCID) is the condition associated with a deficiency in adenosine deaminase. This condition is characterized by a deficiency in the enzyme adenosine deaminase, which leads to the accumulation of toxic metabolites in lymphocytes, resulting in impaired immune system development and function 1. The clinical presentation of SCID due to adenosine deaminase deficiency includes recurrent severe infections, profound lymphopenia, and failure to thrive. Key features of this condition include:
- Autosomal recessive inheritance pattern
- Accumulation of deoxyadenosine and its toxic metabolites in lymphocytes
- Impaired DNA synthesis and repair in lymphocytes
- Profound lymphopenia and impaired cellular and humoral immunity Treatment options for SCID due to adenosine deaminase deficiency include enzyme replacement therapy with PEG-ADA, bone marrow transplantation, or gene therapy 1. It is essential to note that without treatment, affected infants typically do not survive beyond the first year of life due to overwhelming infections. The use of PEG-ADA therapy has been shown to improve clinical outcomes, with a marked reduction in opportunistic infections, although immunoreconstitution may be incomplete 1.
From the Research
Condition Associated with Adenosine Deaminase Deficiency
- The condition associated with a deficiency in adenosine deaminase is Severe Combined Immunodeficiency (SCID) 2, 3, 4, 5, 6.
Characteristics of the Condition
- SCID is a fatal disorder if left untreated 2, 3, 4.
- It is characterized by profound lymphopenia (T- B- NK-) 2.
- Therapeutic modalities to restore ADA activity and reconstitute protective immunity include enzyme replacement therapy (ERT), allogeneic hematopoietic stem cell transplantation (HSCT), and gene therapy (GT) with autologous gene-corrected hematopoietic stem cells (HSC) 2, 3, 4.