The Severe Combined Immunodeficiency is a rare condition often afflicting children, causing their immunity systems to fail. There are two types, the X-linked SCID and the Enzyme SCID. Stem cells are often the cure for the poor children whose lives were greatly altered by this devastating malady. In this picture a child with SCID, David Vetter is in his 24-hour bubble protector against outside infections.
The Severe Combined Immunodeficiency is a rare condition often afflicting children, causing their immunity systems to fail. There are two types, the X-linked SCID and the Enzyme SCID. Stem cells are often the cure for the poor children whose lives were greatly altered by this devastating malady. In this picture a child with SCID, David Vetter is in his 24-hour bubble protector against outside infections.
SEVERE COMBINED IMMUNODEFICIENCY (SCID)
Children, who were lucky enough to acquire a fully matched donor, have shown a higher chance of survival. The less fortunate, however, experienced a lower percentile of endurance rate, often passing away after months of rigorous treatments. The Duke University Medical Center performed SCID transplants, and the data is presented in the following graphs.
(CITATION 97, 98, 99)
WHAT IS SCID?
THE TWO TYPES
SCID is an inherited genetic mutation that causes a fail in the immune system of the patient. Often resulting in death, this illness most frequently occurs in children. Babies are not able to fight of infection, resulting in a premature death. This life-threatening condition results in numerous toddlers perishing at an early age.
Shown in the image to the right, David Vetter died after ONLY 12 YEARS, living his short life in a plastic, germ-free bubble, locked out from the outside world.
One of the types of SCID is the Classical X-linked SCID, affecting only males and young boys. Due to a mutation occurring in a vital protein, responsible for the development and differentiation of white blood cells into B cells and T cells, the immunity system of the patient is unable to produce the cells necessary for defense against foreign intruders. The T cells are often damaged or are missing altogether. B cells, in turn, if present, are not able to generate antibodies due to the absence or defectiveness of the T cells. The entire immunity system, therefore, is not capable of successfully reacting to the introduced source of infection, eliminating it.
The other type of SCID may affect any newborn child, modifying the generation of enzymes. An abnormal Adenosine Deaminase enzyme leads to decimation in immune cell production, causing a lower count of B cells and T cells in the body. Also known as ADA Deficiency SCID, it is less common than the Classical X-linked SCID, but is nevertheless capable of appearing in both girls and boys.
(CITATION 97, 98, 99)
THE CURE
Although the practice of preventing infections beforehand is quite common, a bone marrow transplant provides a real cure. Transplant hematopoietic stem cells, acquired from a donor, are resettled into the damaged organism. Hematopoietic stem cells are undifferentiated blood cells, which are later able to develop into B cells and T cells of the immune system,
allowing the patient’s immunity system to function normally.
The difficulty of locating a “fully-matched” donor reduces the long term survival rate of the patients. According to Marrow.org, the lifespan of the child afflicted with SCID is additionally determined by the following factors, with the child having a higher chance of survival if:
• “A transplant is done early, within the first few months of life, if possible.
• The child has not had severe infections or shown a failure to thrive.
• The child has a type of SCID with normal B cell function.
• The donor is a close match. A matched sibling offers the highest likelihood of success, but a partly matched (haploidentical) family member or an unrelated donor or cord blood unit can also provide a good outcome.”
(CITATION 97, 98, 99)
THE TRANSPLANT OUTCOMES