Pediatric Stem Cell Therapy - A Review

Introduction

A stem cell therapy or transplant is also known as a bone marrow transplant and is a way to insert healthy stem cells into a child's body, creating new bones. The child undergoing this stem cell therapy requires medications in case of cancers, blood disorders, or immune system disorders. The conditions that usually require stem cell therapy include neuroblastoma, brain cancer, lymphoma, and leukemia.

Stem cells have proven to be a revolutionary therapy for many pediatric diseases, but the optimal therapeutics from stem cells are yet to be specified. Many clinical trials have been conducted, and trials for diseases involving pulmonary, endocrine, cardiac, neurological, orthopedic, and hematological systems have proven efficient using stem cells in treating the pathologies related to those.

Many different types of stem cells are used, and each stem cell has unique characteristics that are used to treat disorders. Stem cells can be divided into three groups:

1. Embryonic stem cells.

2. Umbilical cord stem cells.

3. Adult stem cells.

Stem cell transplantation is a life-saving treatment method that can be used to treat various malignant and non-malignant diseases. Approximately more than 40,000 stem cell transplants are being performed worldwide every year. These stem cell therapies in pediatric patients treat several malignant conditions, such as leukemia and specific cancers.

What Are the Sources to Derive Stem Cells?

Various types of stem cells, the method of delivering stem cells, the treatment timing, the growth conditions, and the critical factors related to donor and recipient have been studied. The essential factors that describe stem cells include:

1. They must be plastic adherent when properly maintained in the required culture condition.

2. The stem cells must differentiate into mature cells such as osteoblasts, chondroblasts, and adipocytes in vitro.

Some of the main sources to derive stem cells include:

1. Bone marrow-derived stem cells.

2. Umbilical cord blood-derived stem cells.

3. Umbilical cord tissue-derived stem cells.

4. Placenta-derived stem cells.

5. Adipose tissue-derived stem cells.

6. Amniotic fluid-derived stem cells.

The bone marrow-derived stem cells are prototypical and the most well-studied ones. Pittenger reported some characteristics of bone marrow-derived stem cells, including their osteogenic, chondrogenic, and adipogenic potential. Mostly, they are readily available from the iliac crest of humans, the femur, and the tibia. Vertebrae can also be a source of obtaining bone marrow-derived stem cells. These cells are isolated from adults, and the increased age of the donor is related to a decreased ability to proliferate. This makes using stem cells derived from humans less desirable for pediatric patients.

What Are the Pediatric Diseases Treated With Stem Cells?

Studies and experiments have been conducted to learn more about the success of bone marrow use in pediatric diseases. Specific disorders are discussed below:

Disorders of Bone:

The stem cells in pediatrics have been used to treat osteogenesis imperfecta. This is also referred to as a brittle bone disease. It is an inherited disease affecting collagen and represents skeletal deformity and bones prone to fracture. Significant results are seen in bone grafts obtained from siblings. There was a significant improvement in several fractures and bone growth velocity. Bovine serum was used for culturing of stem cells. The patients who did not respond were those who were affected by toxicity and that was treated with hydrocortisone.

Graft Versus Host Disease:

The bone marrow stem cells have been used successfully in treating graft versus host disease. This disease could complicate hematopoietic stem cell transplants. This affects the skin, liver, GI tract, lungs, and kidneys. Traditional therapy includes immunosuppressants such as steroids and also cyclosporine.

Lysosomal Storage Disease:

Bone marrow stem cells may be helpful for the treatment of pediatric patients suffering from lysosomal storage disorders such as Hurler syndrome, leukodystrophy, and Hunter syndrome. This disease is characterized by bone abnormalities and growth disorder, cognitive and motor skill deterioration, and may also cause death due to cardiorespiratory failure.

Spinal Muscular Atrophy:

This is a progressive neurodegenerative disease that is usually present in the first year of life and, in severe cases, requires ventilatory support. No strengthening of muscles has been seen. Intrathecal and intravenous administration of stem cells showed a significant improvement in muscle strength. In a few cases, the improvements seen with the use of stem cells were lost within 6 to 7 months of discontinuing the therapy. This suggests that it is a maintenance effect in many diseases more than a repair effect.

Bronchopulmonary Dysplasia:

This disease is common in most neonates and is a common long-term pulmonary morbidity, usually in prematurely born infants. This disorder is represented by pulmonary hypertension, neurodevelopmental impairment, and, in severe cases, death. Preterm infants suffering from this disorder require ventilation, and additional stem cells are required.

Cerebral Palsy:

It is a nonprogressive disorder affecting motor movement and tone. This is also seen mostly in premature infants with low birth weight. A combination of intrathecal and intravenous stem cells has proven to be helpful. Some adverse effects were noted for intrathecal infusions, such as fever and vomiting. These adverse effects may also be because of general anesthesia. There were no treatment-related negative effects.

Cardiovascular Diseases:

The stem cell-engineered heart valves could not withstand normal blood pressure to replace the aortic valve. The stem cell-engineered valves were believed to be efficient for pulmonary replacement.

Diabetes Mellitus:

Type I diabetes mellitus is characterized by insulin deficiency, leading to Ketoacidosis crises, poor healing, renal failure, and heart disease. After three days of treatment, basal insulin requirement decreased.

Reconstructive Surgery:

Skull bone reconstruction treats several pathogenic processes, including tumors, resection, and congenital abnormalities. The Iliac crest was ground and placed on a scaffold, and fibrin glue was placed. Three months later, ossification was noted in the size of the defect.

Conclusion

Stem cell transplant has proven efficient in treating many disorders in pediatric patients. Further studies are required to gain more knowledge about the potential of treating diseases using stem cells. To successfully treat disorders with stem cells, there needs to be an efficient investment of time, energy, and attention to all the details in the pediatric population. Developing and optimizing the protocol for efficiency evaluation for better clinical condition results is imperative.