Diagnoses & Conditions

Severe Combined Immune Deficiency (SCID) and Combined Immune Deficiency (CID)

Understanding SCID and CID

Severe combined immune deficiency (SCID) is characterized by an absence of T-cells and little or no B-cell function. Combined immune deficiency (CID) is characterized by impaired T-cell and B-cell function, although T-cells and B-cells are not absent. SCID and CID are inherited disorders - children inherit the gene from their parents. CID is similar to SCID but is a less serious and aggressive form of primary immune deficiency.

Symptoms of SCID and CID

Symptoms of both severe combined immune deficiency (SCID) and combined immune deficiency (CID) include frequent and severe respiratory infections. Other symptoms, which occur in infants, include poor growth, rashes similar to eczema, recurrent thrush in the mouth, chronic diarrhea, though all these symptoms may not occur.

Diagnosing SCID and CID

Since 2018 all states in the U.S and Washington, DC and Puerto Rico screen newborns for SCID as a part of routine newborn screening. Screening for SCID measures a component of DNA, the T-cell receptor excision circle (TREC). Screening at birth affords the opportunity to identify and treat SCID before the onset of symptoms. Most states also screen for CID at birth with a blood test that measures lymphocytes (a type of white blood cell) in the blood.

Treating SCID and CID

Immune globulin therapy administered into the blood stream intravenously (IVIG) is given to infants with SCID and CID along with prophylactic antibiotics, antivirals, and antifungals. Some patients may receive immune globulin therapy administered under the skin subcutaneously (SCIG). Immune globulin therapy will not restore the function of the deficient T-cells; however, it restores antibodies that are missing, resulting from the B-cell defect, which is beneficial to the patient. The most accepted treatment for both SCID and CID is bone marrow or stem cell transplant which is curative.


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