Long-term clinical outcome of fetal cell transplantation for Parkinson disease: two case reports

Abstract

Importance: Recent advances in stem cell technologies have rekindled an interest in the use of cell replacement strategies for patients with Parkinson disease. This study reports the very long-term clinical outcomes of fetal cell transplantation in 2 patients with Parkinson disease. Such long-term follow-up data can usefully inform on the potential efficacy of this approach, as well as the design of trials for its further evaluation.

Observations: Two patients received intrastriatal grafts of human fetal ventral mesencephalic tissue, rich in dopaminergic neuroblasts, as restorative treatment for their Parkinson disease. To evaluate the very long-term efficacy of the grafts, clinical assessments were performed 18 and 15 years posttransplantation. Motor improvements gained gradually over the first postoperative years were sustained up to 18 years posttransplantation, while both patients have discontinued, and remained free of any, pharmacological dopaminergic therapy.

Conclusions and relevance: The results from these 2 cases indicate that dopaminergic cell transplantation can offer very long-term symptomatic relief in patients with Parkinson disease and provide proof-of-concept support for future clinical trials using fetal or stem cell therapies.

Figure 1. Motor Scores Before and After Transplantation

Motor scores on the Unified Parkinson’s Disease Rating Scale (UPDRS) during “off” phases for patients 7 (A) and 15 (B) pretransplantation (point 0) and at different follow-up times posttransplantation: “practically defined off”; morning motor evaluations after 12-hour withdrawal of Parkinson disease medication; and worst “off.” Motor evaluations to reflect severity of motor disability documented at other points during an inpatient admission.

Figure 2. 6-L-Fluorodopa F 18 Positron Emission Tomography Images Before and After Transplantation

Fetal mesencephalic grafts restored dopaminergic innervation in the striatum of 2 patients with Parkinson disease. The images portray striatal uptake before (A and C) and after (B and D) transplantation for patients 7 and 15.