Children with SCID are born defenceless against infections

The Star

3 days ago

As a parent, you'd probably never guess that if your child repeatedly gets an infection, it could be due to a genetic disorder.
Even medical practitioners may not be aware of this.
Primary immunodeficiencies – now often referred to as inborn errors of immunity (IEI) – are a group of more than 500 rare, inherited conditions where a part of the immune system is missing or severely impaired.
These genetic flaws can affect anyone regardless of age, gender or race, leading to an increased susceptibility to infections, autoimmune diseases or other immune problems.
The infections may show up in the skin, sinuses, throat, ears, lungs, brain, spinal cord, or in the urinary or intestinal tracts.
IEI patients often have repeated infections, infections that won't clear up, or unusually severe infections.
They can also present with tumours, severe allergies, multiple enlarged lymph nodes or an enlarged liver.
Researchers are discovering more and more IEI, with the most common one being antibody deficiency.
Antibodies are proteins that protect you when unwanted substances such as bacteria, viruses and toxins enter your body.
'Some people may have mild IEI, but do not display any symptoms.
'Perhaps those with recurrent episodes of upper respiratory tract infection [URTI] could have it, but they don't know because they have never done a blood test to check if there is a problem with the function of antibodies,' says Hospital Sultan Abdul Aziz Shah (HSAAS) consultant paediatrician and clinical immunologist and allergist Associate Professor Dr Intan Hakimah Ismail.
An emergency situation
Prof Intan says babies with SCID seldom live past a year old without a bone marrow transplant due to the frequent infections they get. — Photos: GLENN GUAN/The Star
Out of all the IEI, severe combined immunodeficiency (SCID) is the most critical one.
This condition impacts the T cells, as well as the B cells and natural killer cells – all immune cells that originate from the bone marrow and are crucial for fighting off infections.
Infants with SCID appear healthy at birth, but are highly vulnerable to severe and potentially fatal infections.
Usually, the prognosis is poor, as babies don't live past a year unless they get a bone marrow transplant.
Says Assoc Prof Intan: 'We consider SCID as a paediatric emergency, so we have to go all out to get them a transplant as quickly as possible.
'With other IEI, there is time to discuss a transplant, but here, there is no time – they will die.
'The majority of SCID babies will have an infection within the first few weeks of life.
'This can include URTI, pneumonia, diarrhoea, gastroenteritis, fungal infection, oral thrush, pus at the BCG vaccination site, etc.'
If the baby has had only one episode of infection, it may be hard for the paediatrician to make the right diagnosis.
Only after repeated infections may the doctor suspect something amiss and order further blood tests to check.
Possible to cure
While breastfeeding is generally beneficial for infants, it can pose risks for babies with SCID due to the potential transmission of cytomegalovirus through breast milk.
Treatment for SCID includes intravenous immunoglobulin (IVIG) replacement therapy, enzyme replacement therapy and gene therapy, but the latter two are not available in Malaysia.
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At HSAAS, once a SCID child is diagnosed or referred from other hospitals, they are started on IVIG immediately, along with antibiotics, antifungals and anti-tuberculosis drugs to prevent infection.
'If they have recurrent viral infections, we also start them on antiviral medications – all these are temporary solutions while waiting for a bone marrow transplant for a cure.
'The ideal donors are usually the siblings [without SCID] as they are likely to have a 100% genetic match.
'If not, the parents come next or someone unrelated with a 100% genetic match.
'Thankfully, we can now get the donor's stem cells from the peripheral blood instead of the bone marrow directly, which is a less invasive procedure.
'The child has to be infection-free as much as possible before the transplant, but in some situations, this is not possible, so if the infection is minimal, the transplant can proceed,' explains Assoc Prof Intan.
In most instances, only one transplant is required for a cure.
Inaccurate numbers
Currently, like most rare diseases, there is no national registry for IEI or SCID. Jaasritha is not out of the woods yet and still needs IVIG treatment monthly, but Manonmani is happy that her baby's smile has returned.
The prevalence of SCID worldwide is estimated to be one in 50,000 to 100,000 live births.
Based on that statistic, Malaysia should have 60-100 cases annually.
However, this number might be an underestimate, as some cases may be missed due to death before diagnosis.
'In UPM [Universiti Putra Malaysia], I have my own data in our centre and we are only picking up three to four cases a year.
'Although we are the leading IEI referral centre in the country, not all cases are referred to us.
'Our data from 2012 shows we have more than 1,000 IEI cases, but for SCID alone, it's 44, so we're definitely missing out on the actual numbers,' says Assoc Prof Intan.
That's why she is fighting hard to get newborns screened for SCID,
She says: 'We had two cases where the first child was born and died within three or four months.
'It was the same story with the second child, and only when the couple had their third child, we diagnosed the infant with SCID.
'The treating doctor didn't think of SCID as a possibility, or maybe he wasn't aware of the disease.
'Sometimes, the child may be too sick to travel to HSAAS, so we ask the hospitals to send us their blood sample first, as we have labs here that can deliver the results within 24 hours.'
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'Blessed child'
When Jaasritha Sai was born in 2023, she weighed 2.1kg – a low birth weight – but she was otherwise healthy.
A beautiful, smiley baby, she gained weight quickly, but at three months old, started developing flu symptoms and skin issues.
'We thought her rashes were due to the diapers and we changed the brand, but it didn't help.
'And despite her phlegm, she could drink the whole bottle of milk at one go.
'But suddenly, at six months, Jaasritha would become breathless after drinking two ounces, vomit and purge.
'She became considerably weak and we took her to the hospital's emergency department where she was warded after being diagnosed with pneumonia,' recalls her mother Manonmani Suparamany, 42.
Upon discharge, the diarrhoea didn't stop and Jaasritha's weight dropped drastically.
Manonmani sensed something was wrong and consulted multiple specialists from various hospitals before she was referred to Assoc Prof Intan, who confirmed a SCID diagnosis.
That was in November 2023 when Jaasritha was nine months old.
The single mother from Klang, Selangor, says: 'I didn't even know there was such a condition where both parents carry the mutated gene – my world came crumbling down.
'She was immediately started on treatment and had to stay in an isolated room for nine months.
'Everyone who came in had to wear PPE [personal protective equipment] and mask up because she caught a major infection three times.'
Manonmani's employer agreed to let her go on unpaid leave to look after her sick child.
It was tough being confined to a room for so long and when there was no one watching, the anxiety-ridden Manonmani would cry buckets.
As Jaasritha has no siblings, her mother was the next best bone marrow donor. (Her father is not involved with the family.)
Alas, Manonmani was only a 50% match – not ideal – and was rejected by Hospital Kuala Lumpur, where Jaasritha was on the wait list for a transplant.
Because time was crucial to save Jaasritha's life, Assoc Prof Intan pooled her resources and found an opportunity at the Apollo Cancer Specialty Hospital in Chennai, India.
They accepted Manonmani as a donor, but the transplant cost was high at RM200,000.
She says: 'Still, it was cheaper than the RM1mil quoted in one local private hospital.
'Since I was utilising my employer's insurance, it did not cover overseas medical expenses, so with the help of the non-profit Malaysian Patients Organisation for Primary Immunodeficiencies (Mypopi), we crowdfunded to raise RM300,000 in a week.
'But the final cost came up to RM415,000 as Jaasritha had to do the transplant thrice due to some complications.
'She didn't do well after the first transplant and lost her smile along the way.
"She refused to say any words – that frightened me as I didn't know how I would handle losing her.'
It was also a painful process for Manonmani, as she had to be in bed for five hours without moving while her stem cells were being extracted.
Finally, Jaasritha was given the green light to fly home after five months.
'In total, we spent 14 months in hospital.
'She's still not out of the woods yet and needs IVIG every month at HSAAS until her antibodies stabilise.
'Since her transplant, she has not caught any infections except Covid-19, but she managed to fight it off, which is a good sign.
'I'm still traumatised and don't like to expose her too much, although I take her to the park when it's not crowded,' says Manonmani.
More importantly, Jaasritha's smile has returned and she can now walk, climb stairs and baby talk again at 28 months.
Assoc Prof Intan concludes: 'Jaasritha is a blessed child and a fighter indeed.'