Conditions T-cell Related Lymphocyte Deficiencies

T-cell related lymphocyte deficiencies are conditions in which the body’s immune system is not working properly. A person’s immune system is made up of different parts that work together to protect the body from infection. Babies with T-cell deficiencies are born without enough working T-cells. T-cells are a specific type of white blood cell of the immune system that helps to protect the body from certain kinds of illnesses. Individuals with these T-cell related lymphocyte deficiencies may get repeated infections. Early detection through newborn screening and immediate treatment can help prevent these infections.

Condition Type

Other Disorders

Frequency

How common are T-cell related lymphocyte deficiencies?

T-cell related lymphocyte deficiencies are rare. The exact number of babies affected by T-cell related lymphocyte deficiencies is currently unknown. One study in Wisconsin found evidence to suggest that T-cell related lymphocyte deficiencies affects about 5 in 100,000 babies.

Also known as

  • T-cell lymphopenia

Follow-Up Testing

Your baby’s doctor will ask you if your baby is showing any of the signs of a T-cell related lymphocyte deficiency (see Early Signs, below).If your baby has certain signs, your baby’s doctor may refer your child to a pediatric hospital for immediate treatment.

If your baby’s newborn screening result for T-cell related lymphocyte deficiencies was out of the normal range, your baby’s doctor or the state screening program will contact you to arrange for your baby to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. An out-of-range result may occur because the initial blood sample was too small or the test was performed too early. However, a few babies do have the condition so it is very important that you go to your follow-up appointment for a confirmatory test. Because babies with T-cell deficiencies are more likely to get life-threatening infections, follow-up testing must be completed as soon as possible to determine whether or not your baby has the condition.

Follow-up testing will involve checking a sample of your baby’s blood to see if his or her immune system is working correctly. Lymphocytes, a type of white blood cell, are a main part of the immune system. Individuals with T-cell deficiencies have fewer or no function of a specific type of lymphocyte: the T-cell lymphocyte.

About T-cell Related Lymphocyte Deficiencies

Early Signs

From birth, babies with T-cell related lymphocyte deficiencies may not be protected from life-threatening infections. This is why early screening and identification is so important.

Signs of T-cell related lymphocyte deficiencies include:

  • Infections that do not get better with antibiotic treatment for two or more months
  • Diarrhea
  • Poor weight gain or growth (failure to thrive)
  • Thrush (a fungal infection) in the mouth or throat that does not go away

If your baby shows any of these signs, be sure to contact your doctor immediately.

Treatment
Isolation

Your baby may need to be kept away from people other than family members, especially from young children. Isolation reduces the risk of exposure to life-threatening illness.

Immunoglobulin Replacement Therapy

Babies with more severe T-cell related lymphocyte deficiencies may need immunoglobulin replacement therapy. This therapy can replace the missing antibodies that help your baby fight illnesses and infections.

Transplant Surgeries

For severe, life-threatening T-cell related lymphocyte deficiencies, your child may need a bone marrow or thymus transplant. These are parts of the body that help make illness-fighting cells for the immune system, but they may not be working correctly in children with T-cell related lymphocyte deficiencies. In these transplant surgeries, bone marrow cells or a thymus from a person with a working immune system are given to a person with a T-cell related lymphocyte deficiency.  These transplants can strengthen the immune system of the person with the T-cell related lymphocyte deficiency.

Expected Outcomes

Each person with T-cell related lymphocyte deficiency has a different experience. Some people may have mild cases, while others experience very severe T-cell related lymphocyte deficiencies. Some cases can be life threatening.

With early identification and proper treatment, children with T-cell related lymphocyte deficiencies can avoid many life threatening illnesses and infections. These children can lead healthy lives.

Babies who do not receive treatment for T-cell related lymphocyte deficiency are at risk of catching a life-threatening illness.

Causes

Our immune system is made up of special cells and proteins that protect us from illnesses and infections.  Specifically, T-cell lymphocytes are one type of white blood cell that plays a key role in the functioning and strength of our immune system.

If your baby has a T-cell related lymphocyte deficiency, then his or her body either does not make enough or makes non-working T-cell lymphocytes. Without these working cells, the immune system cannot function correctly. This leaves the body unprotected from serious infections and illnesses.

T-cell related lymphocyte deficiencies usually have a genetic cause.  They may be inherited from parents or can be the result of a new genetic change in the child.  Most of the T-cell related lymphocyte deficiencies follow either an autosomal recessive or X-linked recessive pattern of inheritance.

When T-cell related lymphocyte deficiencies are autosomal recessive genetic conditions, a child must inherit two copies of the non-working gene for the deficiency, one from each parent, in order to have the condition. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition. While having a child with a T-cell related lymphocyte deficiency is rare, when both parents are carriers, they can have more than one child with the condition. Learn more about autosomal recessive inheritance.

When T-cell related lymphocyte deficiencies are X-linked recessive genetic conditions, a male must inherit one copy of the non-working gene from his mother to have the condition. A female must inherit two copies of the non-working gene, one from each parent, in order to have the condition. In X-linked conditions, the gene is carried on the X sex chromosome, and the condition affects males more than females. While having a child with a T-cell related lymphocyte deficiency is rare, when one or both parents carry the non-working gene for the deficiency, they can have more than one child with the condition. Learn more about X-linked recessive inheritance.

Support for T-cell Related Lymphocyte Deficiencies

Support Services

Support groups can help connect families who have a child or other family member affected with T-cell related lymphocyte deficiencies with a supportive community of people who have experience and expertise in living with the condition. These organizations offer resources for families, affected individuals, health care providers, and advocates.  

Accessing Care

Work with your baby’s doctor to determine the next steps for your baby’s care.  Your baby’s doctor may help you coordinate care with a physician who specializes in immunology or other medical resources in your community.

Because T-cell related lymphocyte deficiencies are usually genetic conditions, you may want to talk with a genetics specialist. A genetic counselor or geneticist can help you understand the causes of the condition, discuss genetic testing, and understand what this diagnosis means for other family members and future pregnancies. Speak with your baby’s doctor about getting a referral. The Clinic Services Search Engine offered by the National Coordinating Center for the Regional Genetic and Newborn Screening Service Collaboratives and the Find a Genetic Counselor tool on the National Society of Genetic Counselors (NSGC) website are two good resources for you or your baby's health care provider to use to identify local specialists.

Families' Experiences

At this time we have not located a family story for these particular conditions. If your family is affected by T-cell related lymphocyte deficiencies and you would like to share your story, please contact us so other families may learn from your experience.

References & Sources

Visit the Immune Deficiency Foundation for more condition information

Visit the American Academy of Family Physicians to learn more about primary immunodeficiencies

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