Cell Therapy for ASD: Effectiveness of Mesenchymal and Hematopoietic Stem Cells

Does cell therapy help children with autism? We use it in our practice and see results in our patients, and published studies report improvement in behavior, speech and social skills. Autism spectrum disorder (ASD) is a complex neurodevelopmental condition with no causal (etiological) treatment. Behavioral and drug-based methods ease symptoms but do not affect the underlying cause. ASD cases are rising and effective medications are lacking, so there is a pressing need for new treatment approaches. Cell therapy with mesenchymal stem cells (MSC) and hematopoietic stem cells (HSC) acts on the basic mechanisms of ASD (neuroinflammation, immune dysregulation, impaired neuronal connections) instead of only easing symptoms. Below we review the evidence on MSC and HSC in children with ASD from the past 20 years and explain why we offer cell therapy at CSM Clinic in Kyiv.

How do MSC and HSC work in autism?

Mesenchymal cells calm chronic inflammation in the brain, rebalance the immune system and support the repair of neural connections. The leading hypothesis is that MSC and related cells act on the key links in the pathology of autism: chronic neuroinflammation and immune imbalance. In patients with ASD, researchers have found activated microglia in the brain, elevated pro-inflammatory cytokines and impaired function of immune cells. MSC have strong immunomodulatory and anti-inflammatory properties: they secrete anti-inflammatory cytokines, growth factors and trophic molecules that suppress excessive inflammation and support tissue repair. These cells reduce neuroinflammation in the central nervous system and help normalize cytokine levels and immune cell function, which addresses the immune component of ASD. At the same time MSC have regenerative effects through paracrine mechanisms: they release factors that keep neurons alive, stimulate neurogenesis and angiogenesis, and promote new synaptic connections between neurons. In experimental models, MSC administration improves synaptic plasticity: the cells induce new synapses and improve the function of existing ones, and autistic symptoms in the animals improved. MSC also have antioxidant properties and can pass mitochondria to damaged cells, which reduces oxidative stress.

Hematopoietic stem cells (for example, CD34+ cells from umbilical cord blood or bone marrow) also affect the immune system and inflammation. Autologous umbilical cord blood mononuclear cells are believed to reset immune homeostasis, increase regulatory lymphocyte populations and release neurotrophic factors, which together improve the environment in which neurons work. After transplantation of such cells in children with autism, brain metabolic activity improves: PET scans showed increased glucose uptake in the frontal cortex, hippocampus, amygdala and other areas that were hypometabolic before treatment. So MSC and HSC act in several ways at once: they ease chronic inflammation in the nervous system, modulate the abnormal immune response and stimulate reparative processes in the brain (neuroprotection, new neural connections, restored metabolism). This targets the pathological mechanisms of ASD directly, and it is what makes cell therapy fundamentally different from symptomatic methods.

What do studies show about stem cells in children with autism?

Published studies report significant improvement in the core symptoms of ASD after cell therapy. Over the past two decades, clinical studies, from individual case reports to randomized controlled trials, have evaluated MSC and HSC in children with autism. The general conclusion of this work is that cell therapy can produce significant improvement in the core symptoms of ASD, especially in behavior, speech and cognitive development, and social adaptation.

One of the first notable studies was by Dawson et al. (USA): 25 children with autism received autologous umbilical cord blood. At 6 and 12 months after the infusion they showed sustained improvement in socialization, communication and adaptive skills, confirmed by parent and clinician ratings. Eye contact, one of the key social symptoms of autism, improved markedly too. Lv et al. (China) compared two treatment schemes alongside standard rehabilitation: umbilical cord mononuclear cells alone and the same cells combined with mesenchymal cells. The combined MSC+HSC group did best: autism severity on the CARS scale dropped by 37.9% within 24 weeks of treatment. That is a substantial improvement, larger than the change seen with behavioral therapy alone.

In the open-label multicenter study by Sharma et al. (India), 91% of patients (children and young adults with ASD) showed some degree of behavioral improvement after intrathecal administration of autologous bone marrow cells. A detailed analysis of this cohort found a statistically significant drop in autism scores on the ISAA scale in 90.6% of patients, and 96.9% had global clinical improvement on the CGI scale. The positive changes appeared right after the first administration and held at assessments up to 6 months. In the same group, substantial progress in several areas was recorded: social skills (eye contact, interaction with others), emotional responses, communication (speech), behavior (fewer stereotypies, less hyperactivity), sensory sensitivity and cognitive function. Objective PET brain scans before and after therapy also showed normalized metabolism in the frontal lobes, temporal regions and limbic structures, matching the clinical improvement.

Other studies point the same way. Reduced neuroinflammation and better behavior after MSC administration were recorded in studies in Mexico and the USA, with improvement on the CARS and ATEC scales (autism symptom ratings) over several months of therapy. Some patients respond particularly well: in the pilot study by Riordan et al., clear clinical improvement in behavior was described in 8 of 20 children after a course of mesenchymal cells. In nearly all published trials, at least some of the children improved. Most often reported are better speech (bigger vocabulary, new words and phrases), better social interaction (longer eye contact, joint attention, taking part in conversation) and fewer repetitive movements and stereotyped behaviors. In one study, 18 months after cell therapy the number of children at the highest support level (DSM-5 level 3) fell from 28 to 18, so a considerable share of patients moved to a lower severity category. They also progressed in social interaction, eye contact, expressive language and communication. These changes were noticed not only by doctors but also by parents and teachers, who described real improvements in daily life: easier care, better progress in learning and new self-care skills.

What results does cell therapy give children with autism?

• Share of patients who improve: Most studies recorded clinical improvement in a large share of patients with autism after stem cell administration. In open-label trials, 70–90% of children improved to one degree or another. In one of the largest series (32 patients), 90.6% of children had lower symptom severity on an objective scale, and 96.9% showed global improvement (a better overall clinical impression). In the randomized placebo-controlled study, the overall difference between the groups was not statistically significant, but a subgroup analysis found that 76.9% of the children who received cell therapy improved, versus 57.1% in the placebo group (among children without intellectual disability). With careful patient selection, the share of children who respond to therapy can be high.
• Improved functions: Cell therapy has a positive effect on many areas of development and behavior in children with ASD. The most often documented gains are in social skills (more interest in interaction, better engagement), speech development (larger active and passive vocabulary, better understanding of speech and ability to express needs) and adaptive behavior (coping with change more easily, learning self-care). Studies also report less problem behavior: anger, aggression or self-injury, hyperactivity and sensory difficulties, which makes raising and teaching these children easier. In a number of cases cognitive scores rose, with better attention, visual-spatial perception and progress in learning skills that had not appeared before. Clinicians describe the changes as "noticeable" and as improving the quality of life of the child and the family as a whole. We see the same kinds of changes in our own patients.
• How long the effect lasts: Improvement usually becomes noticeable within the first 3–6 months after stem cell administration and can last a long time. In many studies the effect of a single course was still stable at 12 months. Some observations with longer follow-up show that the gains can hold for up to 1.5–2 years. The biggest change typically comes in the first year after transplantation; in later years, without repeat infusions, the effect may fade somewhat, especially in older children. This is why early intervention (at preschool age) can give the best results, and why the course of cell administration can be repeated when needed to maintain and build on the gains.
• Objective confirmation: The results of cell therapy in ASD are backed not only by behavioral scales but also by objective neuroimaging and electrophysiology. Functional PET scans showed normalized glucose metabolism in brain areas that were underactive before treatment. In one RCT, EEG recorded significant changes in bioelectrical activity: in children who received cord blood, alpha rhythm increased in the occipital regions, which correlates with a better capacity for calm attention, and the balance of beta activity, linked to social interaction, shifted too. MRI tractography showed that after cord cell administration neural networks reorganize in the fronto-temporal connections tied to speech and social skills. These changes at the brain level match the clinical improvement and show that cell therapy does more than change behavior on the surface: it acts on brain structures and function, modulating the neural connections that are impaired in autism.

Which cases show the best results of MSC and HSC therapy?

Developmental assessment with the Denver II test before and after cell therapy: Marked improvement in language (grey line) and social (blue line) skills in a child with ASD after six MSC administrations over 2 years.

• Sharma et al., 2013 (India): An open-label multicenter study of 32 patients (aged 3–33) with autism who received autologous hematopoietic stem cells from bone marrow intrathecally. The results are striking: 91% of patients improved in behavior, and 96.9% showed global improvement on the CGI scale. Social interaction increased substantially, and speech and cognitive function improved. PET imaging confirmed the changes: 6 months after therapy, glucose metabolism rose in the frontal and temporal lobes, hippocampus, amygdala and other brain areas that had been hypoactive. This is a real neurobiological effect of the treatment.
• Lv et al., 2013 (China): The first controlled study of umbilical cord blood (a source of HSC) combined with MSC in children aged 3–12 with ASD. One group received cord blood mononuclear cells alone; the other received cord cells (intravenously) plus mesenchymal cells (intralumbar). After 24 weeks, both groups showed a notable drop in autism severity on several scales, but the effect was greatest with combined therapy: the CARS score improved by 37.9% from baseline. That is about a one-third reduction in the severity of autistic symptoms in half a year, well above the usual pace of development in children with ASD. The data point to a possible synergy when MSC and HSC are used together.
• Riordan et al., 2019 (USA): A pilot open-label study in which 20 children aged 6–16 with autism spectrum disorders each received 4 infusions of allogeneic mesenchymal stem cells (from the bone marrow of healthy donors) over 37 weeks. The CARS and ATEC behavioral scales showed a statistically significant improvement in core autism symptoms. The authors noted that in 8 children the changes were especially striking, with substantial improvement in speech, social responses and adaptive behavior. The study had an open-label design, but its data agree with the results of other trials and support the effectiveness of MSC therapy.
• Dawson et al., 2020 (Duke University, USA): A large randomized placebo-controlled phase II study of umbilical cord blood (autologous and partially matched allogeneic) in 180 children with autism aged 2–7. Participants received autologous HSC, allogeneic HSC or placebo and were assessed after 6 months. Results: average scores improved in all groups (as often happens with intensive rehabilitation), but in the cell therapy group a considerably larger share of children made noticeable clinical progress. Among children without intellectual disability, 76.9% of those who received cord cells improved, versus only 57.1% in the placebo group. EEG showed activation of beneficial brain rhythms (more alpha activity) in these children, and diffusion MRI showed reorganization of neural connections in the fronto-temporal networks responsible for social communication. As an RCT, this study offers the highest level of evidence and supports a real effect of cell therapy on ASD symptoms.
• Clinical case, 2025 (Turkey): A recent case report shows what MSC therapy can do with early intervention. A 4-year-old girl with autism received 6 infusions of mesenchymal stromal cells from Wharton's jelly of the umbilical cord (WJ-MSC) over 7 months. Over the next 2 years of follow-up, her development showed striking progress. Her CARS autism severity score fell from 37 (severe autism) to 31 (the border between moderate and mild) after the course. On the Denver II developmental scales, her speech skills, which matched the level of 2 years 2 months before treatment, rose to about 3 years 9 months. Social and daily-living skills improved from about 3.3 years to 4.5 years, so she closed the gap with age norms by more than 1 year in only 7 months of active therapy. Fine motor skills and general coordination improved as well. No serious complications occurred during treatment, and minor reactions (short-term fever) resolved without consequences. This case shows what MSC can do even for a single patient: after cell therapy, a child with substantial impairments made a qualitative leap in development and moved closer to a milder level of the autism spectrum.

Why do we use cell therapy in the comprehensive treatment of ASD?

Because the data available today show that cell therapy is an exceptionally promising direction in ASD treatment. It lets us work on the origin of the disorder, neuroimmune disturbances and a deficit of repair processes, while current medications act only on individual symptoms. Mesenchymal and hematopoietic stem cells can change the course of autism: they ease its manifestations and help functions that had stalled start developing. Clinical results show that with cell therapy, children with autism can reach a level of social functioning and communication that might have been out of reach without it. That matters greatly for their education, independence and quality of life.

Cell therapy combines well with existing methods: behavioral therapy, speech therapy and sensory integration. Adding stem cells to a comprehensive rehabilitation program can raise the effectiveness of every other measure: by improving the brain's biological capacity to learn, we let the other therapies work more fully. Our doctors, like others who use this approach, note that after transplantation children become more engaged in sessions, respond better to teaching methods and pick up new skills faster.

From the standpoint of evidence-based medicine, cell therapy for ASD has moved from isolated experiments to multicenter trials that showed good safety and measurable benefit. Enough evidence has accumulated to treat this method as a real option for patients with autism. Leading clinics around the world, including university centers in the USA, Europe and Asia, already use ASD treatment protocols with autologous cord cells or mesenchymal cells from donor sources, and so do we. Cell therapy is part of our clinical practice, and it gives children with autism a chance for meaningful improvement in development. It is an innovative step backed by scientific evidence, and we see it as a turning point in dealing with autism spectrum disorders. Regenerative medicine gives children a real chance to develop their potential. In short, cell therapy for ASD is an important and promising method that already shows convincing results and deserves wide use to improve the lives of children with autism and their families.

Conclusion: Cell therapy (MSC and HSC) in ASD has established itself as a safe, effective and promising approach, with improvement in behavioral, cognitive, speech and social functions in a considerable share of patients. It works against neuroinflammatory and immune imbalances, stimulates regeneration of neural networks, and so strengthens traditional rehabilitation considerably. CSM Clinic in Kyiv uses cell therapy and combines it with the other methods of our ASD program. We see results in our patients, and the published evidence and examples above support this approach. To discuss whether cell therapy is right for your child, book an appointment.