Success Rates of Stem Cell Therapy: Children vs. Adults

If I boil the data down to one point, it’s this: children often have better stem cell transplant outcomes than adults, but the evidence in kids is much smaller.

If you’re comparing the two groups, here’s what stands out right away:

• Children in small pediatric studies had higher survival, lower relapse, and lower treatment-related mortality
• Adults have a much larger data set, but results vary more by disease type, organ damage, and when transplant happens
• Autologous HSCT is the main treatment used for this comparison because it has the clearest results in autoimmune disease
• The main outcome measures are overall survival (OS), progression-free survival (PFS), relapse, drug-free remission, and treatment-related mortality (TRM)
• In one long-term pediatric cohort, 7 out of 7 children survived and all reached remission
• In adult autoimmune HSCT studies, 5-year overall survival was about 85% and 5-year PFS was about 43%
• Risks in both groups include infection, viral reactivation, sepsis, infertility risk from cyclophosphamide, and later autoimmune problems

This also helps explain why age matters so much in treatment planning. Younger patients often start with fewer health problems and less lasting organ injury, which can improve long-term disease control after transplant.

Quick Comparison

Measure	Children	Adults
Main evidence base	Small single-center and cohort studies	Large registry and trial data
Overall survival	As high as 100% in one small long-term cohort	About 85% at 5 years across autoimmune diseases
Progression-free survival	Around 69.8% in pooled comparison data	About 43%–46.8%
Relapse	10.3%	31.2%
TRM in newer reports	0% in some pediatric series	About 5% in newer large studies
Main driver of results	Careful patient selection and center experience	Disease type, timing, organ damage, and center experience

So if I had to sum up the full article in plain English: kids often do better, adults have more mixed results, and transplant center experience matters for both.

Stem cell therapy success rates in children with autoimmune diseases

Data on pediatric AHSCT are still limited. Most of what we have comes from small, single-center studies. Even so, the studies available point to durable remission in carefully selected children.

Remission, survival, and response rates in pediatric studies

A 2024 RMD Open study followed seven children for a median of 17 years. All seven survived and reached clinical remission. Three reached drug-free remission, while the other four stayed in remission with medication.

Pediatric PFS has been reported at 100% at 1 year and 77% at 2 years. For children with refractory juvenile-onset systemic sclerosis, a November 2022 report from UPMC Children's Hospital of Pittsburgh described four adolescents. All four engrafted, were discharged after a median of 19 days, stopped immunomodulatory drugs, and showed gains in skin thickness and lung function.

There is one important exception: severe sJIA-related lung disease. Here, the evidence comes from allogeneic transplant rather than autologous transplant, so the survival numbers are not directly comparable with the autologous studies above.

A 2025 Lancet Rheumatology cohort followed 13 children treated across nine hospitals in the U.S. and Europe. Overall survival was 69% (9 out of 13). All nine survivors reached a complete response with no active disease, no supplemental oxygen, and no corticosteroids at a median follow-up of 16 months.

Safety and long-term follow-up in children

Modern pediatric series from experienced centers have reported 0% treatment-related mortality (TRM). That marks a major shift from older registry data, which showed TRM as high as 11% for JIA and SLE. Put simply, where a child is treated - and how carefully they are selected - can make a huge difference.

Short-term risk is driven mostly by infection, including:

• Viral reactivation
• HHV-6 and CMV
• Sepsis
• Fungal disease

The RMD Open cohort also recorded one case of secondary Graves' disease four years after transplant and one case of permanent infertility from ovarian failure after cyclophosphamide conditioning. That matters because late effects can appear years later, especially secondary autoimmunity and infertility.

These pediatric findings provide a starting point for the more varied adult evidence that comes next.

Stem cell therapy success rates in adults with autoimmune diseases

Adults have a much larger AHSCT evidence base than children, but the results are less even. The EBMT registry has recorded more than 3,300 autoimmune transplants in adults. That gives us a bigger pool of data to work with. It also makes one thing clear: outcomes can swing a lot based on the disease, how early treatment starts, and whether there’s already organ damage that can’t be reversed.

Adult remission and progression-free survival data

The treatment goal in adults is the same as in children: stop disease activity and keep it under control for as long as possible. But adult data shows more variation from one condition to another.

Across all autoimmune diseases, adult AHSCT studies report a 5-year overall survival of 85% and a 5-year progression-free survival (PFS) of 43%. Those headline numbers are useful, but they don’t tell the whole story. The diagnosis matters a lot.

Autoimmune Disease	5-Year Overall Survival	5-Year PFS
Rheumatoid Arthritis (RA)	94%	18%
Multiple Sclerosis (MS)	92%	45%
Systemic Sclerosis (SSc)	76%	55%
Systemic Lupus (SLE)	76%	44%

MS stands out for a safer profile. Recent transplant-related mortality (TRM) is just 0.2%, and no disease activity rates range from 66% to 93%.

Systemic sclerosis tells a different story. Its PFS numbers are stronger, reaching 74% in the ASTIS trial, but the mortality risk is higher. Even so, newer trial data shows how much results can improve when centers gain more experience and choose patients more carefully. The North American SCOT trial brought TRM down to 3%, and the later CAST study lowered it again to 2.4%.

Timing also plays a big part. Earlier treatment tends to lead to better outcomes. RA is now rarely treated with HSCT because biologics changed standard care.

Adult risks, treatment-related mortality, and late effects

Any discussion of success in adults has to sit next to the risk profile. Adult risk is still higher than in pediatric cohorts.

Early adult AHSCT reports showed TRM as high as 12%. In newer large-scale studies, that figure has dropped to about 5%. That’s a major shift, but it doesn’t erase the early dangers. The main short-term risks include infection, especially viral reactivation, sepsis, fungal disease, and cardiac toxicity, which is reported at 8.4%.

Late effects also matter. Infertility from ovarian failure remains a shared concern across age groups, and it is driven largely by cyclophosphamide conditioning.

There’s also a clear center effect here. Higher-volume centers report lower 100-day TRM. Put simply, experience matters.

Children vs. adults: where outcomes differ most

Children and adults don't respond to stem cell therapy in the same way. The biggest differences show up in survival, relapse, and toxicity. That makes age one of the clearest ways to compare long-term disease control and safety.

Measure	Children (<18 years)	Adults (>18 years)
5-Year Overall Survival	100% in a 7-patient long-term pediatric cohort	70.2% in a large EBMT survey
5-Year Progression-Free Survival	69.8%	~43%–46.8%
Relapse Incidence	10.3%	31.2%
1-Year Complete Response (selected cohorts)	67%	~30% across subgroups

The relapse gap stands out right away. Adults relapse at a rate of 31.2%, compared with 10.3% in children. That's a statistically significant difference, and it helps explain why long-term results split so sharply by age.

Why younger age can improve outcomes

Children often reach transplant with fewer comorbidities and a shorter disease history. In plain English, they usually have less wear and tear on the body before treatment even starts.

That matters. Many children can tolerate intensive conditioning without the added strain that cardiovascular disease, diabetes, or renal disease can bring. Their thymus is also still highly active, which helps the immune system rebuild more effectively after transplant. That may lower infection-related mortality during recovery and directly support better relapse rates, PFS, and survival.

Why adult evidence is broader but more complex

The adult evidence base is larger, but it's also less uniform. Adults often begin treatment with accumulated organ damage and other comorbidities, which can push complication risk higher.

Reduced-intensity conditioning can help limit early toxicity. But there's a tradeoff: it may also leave more room for relapse over time. So the adult picture gets messier, with outcomes tied closely to disease type, treatment timing, and the transplant center's experience.

These age-based differences also shape access, timing, and fertility planning. For families considering future options, cord blood banking provides a source of young, potent stem cells that may bypass some of the complications seen in adult-derived transplants.

What these differences mean for family planning and stem cell access

These differences matter when families plan for the long term. Children usually have more years ahead to benefit from treatment. And across the data, earlier intervention keeps lining up with better results. So timing isn't just a medical detail. It's part of how many families think about future access.

How newborn stem cell banking connects to autoimmune research

That age-related edge helps explain why early cell preservation gets attention from families thinking ahead about treatment access.

Cord blood is a direct source of hematopoietic stem cells (HSCs). That's the same cell type used in HSCT to reset the immune system in autoimmune diseases such as MS, SLE, and systemic sclerosis. Cord blood is already used in established stem cell treatments.

Cord tissue and placental tissue contain mesenchymal stem cells (MSCs), which researchers are studying for their immune-modulating and anti-inflammatory effects. Exosomes, small signaling carriers released by MSCs, are another growing area of regenerative medicine research. Banking at birth preserves these cells before age-related decline sets in.

Newborn banking preserves cord blood, cord tissue, and placental tissue for future stem cell research and possible therapy use.

Conclusion: the main child-versus-adult takeaway

Put together, the data point in the same direction: younger patients tend to do better, while adult outcomes depend more on disease burden and timing.

Pediatric patients with severe, treatment-refractory autoimmune diseases can reach long-term remission with minimal morbidity and high survival rates, including 100% survival in one cohort with a median follow-up of 17 years. Adult evidence is broader and more established, but the outcomes are more complex because of comorbidities, disease duration, and treatment timing.

Both age groups can benefit from stem cell therapy, but the results are not the same. The core takeaway is straightforward: earlier access to younger cells may keep more future treatment paths open. For families, newborn banking preserves those options at the point when cell quality is highest.

FAQs

Why do children often have better outcomes than adults?

Children often do better with stem cell therapy because their thymus glands are usually more active, which helps the body make healthy T cells. They also tend to be treated earlier in the course of a disease.

That timing matters. It can make treatment possible before major or permanent organ damage sets in. Americord Registry supports this work by banking newborn stem cells, including cord blood and cord tissue, for possible future therapeutic use.

Which autoimmune diseases respond best to HSCT?

HSCT is used mostly for severe autoimmune diseases that haven't responded to treatment after standard options have failed.

The conditions studied most often are multiple sclerosis, systemic sclerosis, and Crohn’s disease. Together, they account for about 80% of HSCT procedures done for autoimmune disorders.

Doctors have also seen good responses in other diseases, including systemic lupus erythematosus, juvenile idiopathic arthritis, juvenile dermatomyositis, and some forms of scleroderma and fasciitis.

How do doctors decide who is a good transplant candidate?

Doctors take a careful, multidisciplinary approach when they weigh the possible upside of a transplant against its serious risks.

For refractory autoimmune diseases, candidates are usually people who haven't responded to standard treatments, such as corticosteroids or other immunosuppressive drugs. The care team also looks at disease severity, overall health, quality of life, and whether any other workable options remain.