Is your little one always sick? It could be SCID (Severe Combined Immunodeficiency)! Let's talk about this!

Is your little one always sick? Does one illness get better before another? Sometimes this is normal, but it can also be caused by a very rare but very serious condition. That's what SCID (Severe Combined Immunodeficiency) is. Let's talk about this in a little more detail today, shall we? Don't worry, it's very important to be aware of this.

What is SCID (Severe Combined Immunodeficiency)? Let's understand it simply.

Simply put, SCID is a very rare, rare genetic disorder that affects very few people. It causes our body's immune system , which fights disease, to malfunction. It can be a very serious condition.

We call this a 'primary immune deficiency'. Some books also call it an 'inborn error of immunity'. That is, it is something that is present from the day of birth and can be passed down through generations. Various genetic changes can cause this SCID condition.

Just imagine, even in a country like America, if about 58,000 children are born each year, only about one of them will develop this condition called SCID (Severe Combined Immunodeficiency). You can imagine how rare that is.

What happens inside a baby with SCID?

To understand this, we first need to take a look at how our body's immune system, the army that fights disease, works.

Imagine, when a baby is in its mother's womb, an army of disease-fighting cells begins to form in its body. The headquarters of this army is the bone marrow . There are special cells there, which we call ' stem cells ' . These stem cells can make all three main types of blood cells:

• Red blood cells: These are the ones that carry oxygen throughout the body.
• White blood cells : These are the soldiers in our body that protect us from disease.
• Platelets : These help blood clot.

Now, among these white blood cells, there is a special group called 'lymphocytes' . These are the ones that fight disease directly. There are two main types of these lymphocytes: T-cells and B-cells. Both of these cells are very important in fighting disease.

• T-cells recognize disease-causing 'invaders' – things like bacteria and viruses – that enter the body, attack them, and destroy them.
• B-cells make 'antibodies' . These antibodies are like memories. Once you get sick, you remember it and are ready to fight it off if it comes back.

The word 'Combined' in the name SCID (Severe Combined Immunodeficiency) means that this disease affects both T-cells and B-cells. That is why it is called a 'combined' deficiency.

A child with SCID has very few of these lymphocytes, or the cells they have don't work properly. So, because this immune system doesn't work properly, it's very difficult, sometimes impossible, to fight off germs—viruses, bacteria, and fungi.

What causes SCID?

There are also different types of SCID (Severe Combined Immunodeficiency).

The most common type is caused by a problem with a gene on the X chromosome . This usually only affects boys. Because girls have two X chromosomes, even if one has a problem, their immune system can still function because of the other healthy X chromosome. But boys have only one X chromosome. So if that gene is weak, the disease will develop. Girls can only be 'carriers' of the disease. This means that even if they don't have the disease, their children can pass on the gene.

There is another type of SCID, which is caused by a deficiency of an enzyme that is needed for the development of lymphocytes. Apart from this, SCID can also be caused by various other genetic causes.

What are the symptoms of SCID? How is it diagnosed?

Although babies with SCID may appear healthy at birth , problems may begin to develop over time. Here are some signs to watch out for:

• Failure to thrive, not gaining weight regularly .
• Chronic diarrhea .
• Frequent, sometimes severe, respiratory infections . This means persistent chest congestion and coughing.
• A fungal infection that causes white patches in the mouth and throat (oral thrush)Coming. We also call this 'Ullogam'.
• In addition, other bacterial, viral, or fungal infections that are difficult to treat and can be severe can often occur. For example:
• Ear infections (acute otitis media)
• Sinus infection (sinusitis)
• Skin rashes
• Brain fever, meningitis
• Pneumonia

Imagine how difficult it must be for parents if a small baby keeps getting sick like this, and if one illness gets better before another one comes along. Therefore, if one or more of these symptoms persist, you should definitely see a doctor as soon as possible.

How is SCID (Severe Combined Immunodeficiency) diagnosed?

Fortunately, a simple blood test, called 'newborn screening' , is now done to check for certain diseases in babies as soon as they are born . For example, 'sickle cell disease' and 'cystic fibrosis' can be detected through this. Similar tests are also being done in Sri Lanka. The good news is that SCID (Severe Combined Immunodeficiency) can now also be detected through this newborn screening in some countries.

This way , when the disease is detected early, treatment can begin quickly. Then the results are much better.

If newborn screening suggests SCID, the baby is usually referred to a specialist in immune deficiencies. That doctor will order further blood tests, and possibly genetic testing .

If someone in the family has SCID, or if there is a family history of immunodeficiency, parents can get genetic counseling . They can also get blood tests done as soon as the baby is born . The sooner the diagnosis is made, the sooner treatment can begin and the better the outcome.

Sometimes, if the gene mutation that causes SCID in a family is known, it is possible to test the baby for the disease at birth . However, for babies with no family history or who are not screened through newborn screening, it may be as late as 6 months before the disease is detected. By then, it is too late.

What are the treatments for SCID?

SCID is a pediatric medical emergency. This means that if not treated quickly, these babies are more likely to die before they even reach their first birthday. Therefore, prompt treatment is very important.

The most common treatment is a 'stem cell transplant'. ThisAlso called a 'bone marrow transplant', this involves giving stem cells from a healthy person to a sick baby. The hope is that these new cells will rebuild the baby's immune system.

• The most successful stem cell transplant can be performed if the cells are taken from a genetically matched sibling.
• Sometimes, the parents' cells can also be compatible.
• If no one in the family is a match, doctors can also use stem cells from an unrelated donor.

Some babies with SCID may also need chemotherapy before the transplant.

The most important thing is that this stem cell transplant is done within the first few months of the baby's life, before he or she develops any infections. That's when the results are most successful.

Gene therapy has also shown promising results in clinical trials for several types of SCID. However, it is not yet widely used in many countries around the world. Research into gene therapy for SCID is still ongoing.

When treating a child with SCID, there is usually a medical team made up of several specialists. For example:

• Pediatric immunologist
• Bone marrow transplant physician
• Pediatric infectious disease expert

Babies with SCID are at increased risk of developing life-threatening infections. Therefore, doctors start medications to help prevent infections. For example, antibiotics, antivirals, antifungals , and antibody/immunoglobulin injections . Some babies, depending on their genetic variation, may even need enzyme infusions .

More things to know about SCID

In addition to medication and treatment, there are other precautions you should take to prevent infection. Keep these things in mind when caring for a child with SCID:

• To prevent the spread of infection, he needs to be isolated from others. This means giving him a separate room and making sure that the things he touches are clean.
• It is not advisable to give any 'live vaccine'. This is because it can be dangerous to give a baby with SCID, even a weakened virus, as a vaccine. Examples of this are:Rotavirus vaccine, chickenpox/varicella vaccine, measles-mumps-rubella (MMR) vaccine, oral polio vaccine, BCG vaccine, and live flu vaccines.
• The most important thing is that no one living in the same household as the baby should receive these live vaccines, as they can transmit the disease to the baby.
• If a blood transfusion is needed, it should be specially treated blood. This is done to prevent complications that can occur from blood transfusions.
• You may need to stop breastfeeding for a while until your breast milk is tested for viruses that can cause infections. Follow your doctor's instructions carefully.

How can you as parents help?

While your baby is being tested for SCID, and during treatment, there are many things you as a parent can do to reduce the risk of infection. Here are some of them:

• Limit the number of visitors to the home. It is best to have as few people as possible come to see the baby.
• Avoid taking your baby to crowded public places , such as shopping malls and festivals.
• Do not bring your baby near anyone who has a cold , fever, or cough. If there is someone like that at home, keep them away from your baby.
• Before touching the baby, make sure everyone who will be caring for the baby washes their hands thoroughly. Wash your hands with soap and running water for at least 20 seconds.

Let's think about the future.

A baby with SCID may have to undergo many medical procedures and frequent hospital stays. This can be a very stressful experience for any family. But remember that you are not alone.

The medical team is there to help you and your baby before, during, and after treatment. You can also get help and encouragement from support groups, social workers, family, and friends. There may be organizations in Sri Lanka that help children with this condition, so check them out.

To find more information and support online, you can visit international websites like these (these are in English):

• Immune Deficiency Foundation
• SCID, Angels for Life

The most important things you can take home from this article

Okay, so, from what we've talked about, these are the most important things you need to remember:

• SCID (Severe Combined Immunodeficiency) is a very rare but serious genetic disease that causes a baby's immune system to not function properly.
• If you have symptoms such as frequent serious infections, failure to gain weight, or persistent diarrhea , seek medical advice immediately.
• Newborn screening can sometimes detect SCID early.
• Early diagnosis and treatment are very important. The main treatment is stem cell transplant / bone marrow transplant.
• It is extremely important to protect a baby with SCID from infections, and special precautions must be taken.
• You are not alone. Get help from doctors, family, and support groups.

I hope this information is helpful to you. Wishing your baby a speedy recovery!

` SCID, Severe Combined Immunodeficiency, Immunodeficiency, Pediatrics, Genetic Diseases, Bone Marrow Transplant, Newborn Screening