Exosome-Rich Mesenchymal Stem Cell Secretome Improves Symptoms From Parkinson's Disease: A Case Series

Parkinson's disease (PD) is a progressive neurological condition that primarily affects the central nervous system. It causes neurons to eventually degrade, leading to muscle tremors, rigidity, bradykinesia, impaired balance, and mask-like facies, among other symptoms. A combination of levodopa and carbidopa is the most common treatment for PD, though they are also given separately. These treatments have significant side effects, including headache, dizziness, nausea, somnolence, loss of appetite, diarrhea, constipation, and dyskinesia, which further exacerbate the already present PD symptoms. No disease-modifying treatment exists.

Mesenchymal stem cell (MSC) secretome refers to the molecules secreted by stem cells during expansion in culture, which can include growth factors, cytokines, and exosomes. They have shown efficacy in models of PD in numerous preclinical studies and could provide an alternative, minimally invasive, and potentially disease-modifying treatment for PD. We hypothesized that secretome treatment via intranasal instillation would decrease PD symptoms and possibly be disease modifying.

Patients diagnosed with PD were enrolled in the trial and received umbilical cord-derived MSC secretome (AlloEx Exosomes®) intranasal installations over a 2-day period.

All patients were treated in our treatment facility located in Antigua.

Treatment was repeated if desired by the patients at a minimum of 2-month intervals. Efficacy was measured using the Parkinson's Disease Questionnaire (PDQ-39) rating, electroencephalogram (EEG) tests, and patient reports.

Nineteen patients were enrolled in the trial and received a total of 40 doses throughout the treatment. There were no adverse events from treatment. Two patients reported no improvement, 2 patients had transient improvement, while the remaining patients saw a significantly maintained decrease in symptoms with follow-up of up to one year. Average combined PDQ-39 scores decreased with each treatment, indicating an increase in the patient cohort's quality of life. Improvements were seen in the patient's EEG results, tremors, sensory impairments, bladder/bowel dysfunction, and sleep quality.

Limitations of the study included a short follow-up length that limited the ability to determine if the treatment was disease modifying.

Intranasal MSC secretome installation is a safe method that is consistently effective in reducing Parkinson's symptoms and may represent the first-identified PD disease-modifying treatment.