Pediatric Severe Combined Immunodeficiency

What Is Pediatric Severe Combined Immunodeficiency?

Pediatric severe combined immunodeficiency (SCID) is a rare and fatal syndrome that is genetically inherited (the disease is passed down from parent to child) and causes a weak immune system in children due to the absence of T cells and B cells. This is also known as the “living bubble” syndrome because living in a normal environment may be life-threatening to the child, as children with this disorder are more prone to infections like pneumonia, meningitis, or bloodstream infections.

This is the primary immune deficiency in children. Children with severe combined immunodeficiency may lose their life before their first birthday. The most common types of severe combined immunodeficiency are X-LINKED SCID, ADA SCID, and IL7R SCID. Treatments are available that can be successful.

What Are the Causes of Severe Combined Immunodeficiency?

Genetic problems in children usually cause severe combined immunodeficiency. These are generally inherited from parents or grandparents. This severe combined immunodeficiency is due to defects that affect the function of T cells and B cells or the complete absence of T cells and B cells which will affect the fighting capacity of the child against various infections. Children may not develop adequate immunity resulting in a high risk of infections.

What Are the Types of Severe Combined Immunodeficiency?

The most common types of severe combined immunodeficiency are X-LINKED SCID, ADA SCID, and IL7R SCID.

• X-linked SCID: This is caused by mutations on the X- chromosome, and this generally occurs in males. This is the most common cause of severe combined immunodeficiency.

• ADA SCID or Adenosine Deaminase Deficiency SCID: This is the second most common cause of severe combined immunodeficiency. Normally, the ADA enzyme will remove a molecule called deoxyadenosine. ADA converts deoxyadenosine, which is harmful, to a different molecule which is harmless. When there is a lack of ADA enzyme, the harmful deoxyadenosine builds up in the child’s system and destroys the immunity of the child. A lack of ADA enzymes may also lead to neurological problems.

What Are the Signs and Symptoms of Severe Combined Immunodeficiency?

There are many symptoms associated with severe combined immunodeficiency in children. These symptoms start at the very early stages of life, that is, one year after birth, and the child may lose life before his or her first birthday. Medications also will not work in children with severe combined immunodeficiency disorder. Pay attention if the child has recurrent, unusual severe multiple infections.

The most common symptoms are:

• Failure to thrive means that the child will not gain weight or grow as expected.

• Inflammation and infections in internal organs.

• Blood disorders such as low platelet count or anemia.

• Digestive problems such as nausea, chronic diarrhea, loss of appetite, and cramping.

• Recurrent respiratory infections like pneumonia and bronchitis.

• Skin rashes.

• Recurrent ear infections.

• Sinus infections.

• Fungal (candida) infection in mouth and diaper area.

• Liver infections.

How to Detect Severe Combined Immunodeficiency Detection?

Early detection is very important. Screening and treating the disorder in the initial stages will have a higher chance of success. A genetic test called full gene sequencing is done to confirm severe combined immunodeficiency disorder by counting the number of T cells and B cells. This gene sequencing is performed by taking a blood sample from children who are prone to recurrent infections before one year of age.

How to Take Care if a Child Is Detected With Severe Combined Immunodeficiency?

As children with severe combined immunodeficiency are more likely to get infections and various other health issues, it is better to take proper care. The following are the precautions to be taken:

• Treatment should start as early as possible. The earlier the treatment starts, the higher the chances of preventing infections.

• Limit visitors.

• Do not go into public places.

• Maintain proper hygiene to avoid infections.

• Should avoid live vaccinations, which include rotavirus MMR, flu vaccine, and chicken pox (other alternative vaccines can be given instead of these live vaccines.)

• Caregivers should wash their hands before touching the baby.

• Stay away from elderly people.

• Keep following up with the specialist.

Infants with severe combined immunodeficiency rarely survive after their first birthday, but getting treated will help the child live longer.

What Is the Treatment and Management of Pediatric Severe Combined Immunodeficiency?

• Do not delay the treatment once it is detected.

• Immediately find out the specialist who treats immunodeficiency disorders.

• Various kinds of treatment options depending on the severity of the condition of the infant, may be suggested by the doctor.

• The doctor may prescribe a few antibiotics, antifungals, and antiviral medications to treat the existing infections. These may not cure the disease completely, but they will help in the further progression of the disease.

• Enzyme replacement therapy may not be that effective, but this therapy will help the child's immunity work better. In this therapy, the child will be injected with healthy enzymes from cows.

• Stem cell transplantation is the only accurate treatment where there are better results.

• In this procedure, stem cells are taken from a healthy matching donor and are transplanted into a child suffering from severe combined immunodeficiency. Sometimes chemotherapy is also done to destroy already damaged or infected cells before going for stem cell transplantation.

• Still, scientists are looking for different ways to treat severe combined immunodeficiency.

Conclusion:

Pediatric severe combined immunodeficiency is a rare genetic disorder that is caused in children within one year after birth and exhibits multiple recurrent infections, and the children may lose their life before their first birthday. There are a few treatments, but they may not be successful due to very poor immunity in infants. In order to detect or rule out severe combined immunodeficiency, full gene sequencing has to be done in all newborns who have a family history of genetic disorders or the child fails to grow in weight and size. They may not be treated completely but can prevent the child from the progression of infections which affects their health in the long term. Still, various research has been going on to find out the proper treatment where the condition can be cured completely.