What is Immune Deficiency?

The immune system is composed of multiple types of cells, tissues,  organs and proteins. The primary function of the immune system is to  distinguish between self and non-self (foreign). When something that is  non-self, or foreign, is encountered, (such as bacteria, virus or fungi)  the immune system attacks it to help prevent infection or other injury.  

Immune deficiency conditions (also referred to as immunodeficiency) occur when the immune system is unable to do its job, either partially or entirely. When a baby is born, they are protected from infections  by immune cells transmitted to them by their mothers. Within the first  six months, though, babies’ immune systems develop and begin to assume  responsibility for fighting off infections. But sometimes, babies have  immune deficiencies and they don't have the ability to fight off routine  infections on their own. The symptoms of immune deficiency depend on what part of  the immune system is affected and can range from mild to  life-threatening.

Immune deficiency conditions can be present at birth as a result of  genetic defects in any of the components of the immune system. Such  conditions are called primary immune deficiencies. Immune deficiencies  can also be caused as a result of infections, cancer treatments, or  medications. There are more than 150 types of primary immune deficiencies. Immune deficiency conditions weaken the body’s ability to fight off infection. Symptoms include:  

• Frequent infections
• Severe infections
• Non-respondent infections (don’t respond to treatment)

Recurrent infections Repeated infections in children can interfere with nutrition, leading to failure to gain weight (also known as failure to thrive),  weight loss, slow growth, and slow development. Chronic sinusitis and  bronchitis are also commonly associated with immune deficiency  conditions.  Recurrent infections in infancy and childhood may be the  first indication of a primary immune deficiency.  Although reducing exposure to infectious agents and  treating infections are important in managing immune deficiency  conditions, several primary immune deficiencies can now be treated  through replacement of defective immune system components. As a result  of advances in treatment, children with potentially fatal primary immune  deficiencies are now living into adulthood. 

These disorders lead to severe abnormalities of the immune system  with reduced or malfunctioning T- and B-lymphocytes, the specialized  white blood cells made in the bone marrow to fight infection. When the  immune system doesn't function properly, it can be difficult or  impossible for it to battle viruses, bacteria, and fungi that cause  infections.

One example of a life-threatening immune deficiency is Severe Combined Immune Deficiency (SCID).   SCID and other severe immune deficiencies can be successfully treated  if identified early. Otherwise, they can be fatal within the first year of life. 

Through the addition of Severe Combined Immune  Deficiency (SCID) to the core panel of 29 genetic disorders on the  national Recommended Uniform Screening Panel, the diagnosis process will  initiate before the child has experiences an infection increasing their  ability to survive. Children with severe immune deficiency should not be  immunized with live viruses — like the chickenpox (varicella),  rotavirus, or measles, mumps, and rubella (MMR) vaccines — because they  lack the normal defense of antibodies to the viruses. Introducing a  virus, even a weakened vaccine virus, can be dangerous. Doctors may also  administer an infusion of intravenous immune globulin (IVIG) to help  the body fight infection.  The most effective treatment for immune deficiencies like SCID is Cord Blood or Bone Marrow transplantation.  

These disorders lead to severe abnormalities of the immune system  with reduced or malfunctioning T- and B-lymphocytes, the specialized  white blood cells made in the bone marrow to fight infection. When the immune system doesn't function properly, it can be difficult or  impossible for it to battle viruses, bacteria, and fungi that cause  infections. One example of a life-threatening immune deficiency is Severe Combined Immune Deficiency (SCID). SCID and other severe immune deficiencies can be successfully treated  if identified early. Otherwise, they can be fatal within the first year  of life.   

Through the addition of Severe Combined Immune  Deficiency (SCID) to the core panel of 29 genetic disorders on the  national Recommended Uniform Screening Panel, the diagnosis process will  initiate before the child has experiences an infection increasing their  ability to survive. Children with severe immune deficiency should not be  immunized with live viruses — like the chickenpox (varicella),  rotavirus, or measles, mumps, and rubella (MMR) vaccines — because they  lack the normal defense of antibodies to the viruses. Introducing a  virus, even a weakened vaccine virus, can be dangerous. Doctors may also  administer an infusion of intravenous immune globulin (IVIG) to help  the body fight infection.  The most effective treatment for immune deficiencies like SCID is Cord Blood or Bone Marrow transplantation.  

Cord Blood / Bone Marrow Transplant Cord blood comes from a newborn baby's umbilical cord  and placenta containing lifesaving cells.  Bone marrow is the spongy  material found in the center of large bones. Bone marrow produces  special cells with unique functions:   
Red blood cells carry oxygen through the body
White blood cells fight off infection
Platelets help the blood to clot During a Cord Blood or Bone Marrow Transplant, the  collected cells are introduced into the body in the hopes that the new  cells will rebuild the immune system. To provide the best chances for success, a transplant is usually done using the cord blood or bone  marrow of a sibling. However, a parent's bone marrow might also be  acceptable. Some children do not have family members who are suitable  donors — in such cases, doctors may use cells from an unrelated banked  cord blood or adult donor through the National Marrow Donor Program. The  likelihood of a good outcome also is higher if the transplant is done  early, within the first few months of life, if possible. Key steps in the life saving transplant journey:  

Preparation: Days leading to the  transplant day.  Preparatory medication, usually chemotherapy, is  administered to remove the damaged immune system

• Day 0 / Transplant:   The donor cells are injected via IV into the recipient.
• Day +1 thru +20: Meticulous monitoring of infections while the immune system is rebuilt
• Day +21 thru +28: White blood cells reactivate and the new immune system begins to take hold
• Ongoing: From there forward the  immune system is engaged in protecting the body from potential  infections as it grows.  Follow-up visits to the doctor are critical to  ensure proper care and progress.
  
  To learn more about the topics covered in this section, we encourage you to visit:
  http://primaryimmune.org/
  http://marrow.org/