Intrastriatal Cografts of Autologous Adrenal Medulla and Sural Nerve in MPTP-Induced Parkinsonian Macaques: Behavioral and Anatomical Assessment

Immunological Responses to Injury and Grafting in the Central Nervous System of Nonhuman Primates

Allogeneic transplantation for the therapy of human Parkinson's disease is being considered as a viable approach at several clinical centers worldwide. As an attempt to understand the basic biology of central nervous system (CNS) transplantation, our laboratory has developed an experimental nonhuman primate model for human Parkinson's disease and carried out preliminary studies directed at evaluating the potential pathology at the graft site. In addition, studies have been conducted to examine whether such transplantation procedures lead to specific and/or nonspecific immunologic sensitization of the host or results in generalized immunosuppression. Groups of rhesus macaques (Macaca mulatta) were either controls operated (n = 6), autografted with adrenal medullary and peripheral nerve tissue (n = 3), or allografted with fetal mesencephalic tissue (n = 6). Immunohistological studies demonstrated the presence of mononuclear cell infiltrates as early as 1 wk and up to 1 yr postoperatively, although the frequency of the infiltrating cells declined with time. The infiltrates consisted of variable numbers of cells which express CD2+, CD3+, CD4+, CD8+, CD19+, CD22+, CD25+, and CD68+. There appeared to be no difference in the frequency, kinetics, or phenotype of the infiltrating cells in operative controls compared with recipients of auto- or allografts. Tissue sections obtained postoperatively showed low levels of major histocompatibility complex (MHC) Class I antigens and no detectable level of MHC-Class II antigens in neural tissue. A small aliquot of tissue from the operative site was placed in vitro with media containing interleukin-2 (IL-2), which led to the exudation and growth of mononuclear cells that were predominantly CD4+ cells. Phenotypic studies of peripheral blood mononuclear cells (PBMC) from operative controls, auto- and allograft recipient monkeys performed at varying time periods postoperatively failed to show differences in the frequencies of subsets of T-cells, B-cells, NK-cells, or monocytes. Studies on aliquots of the same PBMC failed to show major functional differences in NK-cells, LAK cells, or response to polyclonal mitogens. Finally, recipients of allogeneic mesencephalic grafts failed to show evidence of donor-specific humoral or cellular sensitization. These data indicate that transplantation of autograft adrenal or allograft fetal mesencephalic tissues in the CNS of nonhuman primate did not induce detectable donor-specific sensitization nor nonspecific immunosuppression.

Implantation of autologous peripheral nerve grafts into the substantia nigra of subjects with idiopathic Parkinson's disease treated with bilateral STN DBS: a report of safety and feasibility

OBJECTIVE One avenue of intense efforts to treat Parkinson's disease (PD) involves the delivery of neurotrophic factors to restore dopaminergic cell function. A source of neurotrophic factors that could be used is the Schwann cell from the peripheral nervous system. The authors have begun an open-label safety study to examine the safety and feasibility of implanting an autologous peripheral nerve graft into the substantia nigra of PD patients undergoing deep brain stimulation (DBS) surgery. METHODS Multistage DBS surgery targeting the subthalamic nucleus was performed using standard procedures in 8 study participants. After the DBS leads were implanted, a section of sural nerve containing Schwann cells was excised and unilaterally delivered into the area of the substantia nigra. Adverse events were continuously monitored. RESULTS Eight of 8 participants were implanted with DBS systems and grafts. Adverse event profiles were comparable to those of standard DBS surgery. Postoperative MR images did not reveal edema, hemorrhage, or significant signal changes in the graft target region. Three participants reported a patch of numbness on the outside of the foot below the sural nerve harvest site. CONCLUSIONS Based on the safety outcome of the procedure, targeted peripheral nerve graft delivery to the substantia nigra at the time of DBS surgery is feasible and may provide a means to deliver neurorestorative therapy. Clinical trial registration no.: NCT01833364 ( clinicaltrials.gov ).

A patient with Huntington's disease and long-surviving fetal neural transplants that developed mass lesions

Transplantation of human fetal neural tissue into adult neostriatum is an experimental therapy for Huntington's disease (HD). Here we describe a patient with HD who received ten intrastriatal human fetal neural transplants and, at one site, an autologous sural nerve co-graft. Although initially clinically stable, she developed worsening asymmetric upper motor neuron symptoms in addition to progression of HD, and ultimately died 121 months post transplantation. Eight neural transplants, up to 2.9 cm, and three ependymal cysts, up to 2.0 cm, were identified. The autologous sural nerve co-graft was found adjacent to the largest mass lesion, which, along with the ependymal cyst, exhibited pronounced mass effect on the internal capsules bilaterally. Grafts were composed of neurons and glia embedded in disorganized neuropil; robust Y chromosome labeling was present in a subset of grafts and cysts. The graft-host border was discrete, and there was no evidence of graft rejection or HD pathologic changes within donor neurons. This report, for the first time, highlights the potential for graft overgrowth in a patient receiving fetal neural transplantation.

Two-year follow-up study of a patient with Parkinson's disease and severe motor fluctuations treated by co-grafts of adrenal medulla and peripheral nerve into bilateral caudate nuclei: case report

We performed co-grafts of adrenal medulla and peripheral nerve into the bilateral caudate nuclei of a 43-year-old patient with advanced Parkinson's disease who showed severe daily motor fluctuations before surgery. There were no postoperative complications, and a 2-year follow-up result is presented. The patient showed a gradual and significant amelioration of the parkinsonian symptoms starting 2 weeks after transplantation. The alleviation of akinesia during "off" periods was the most apparent clinical improvement and continued for 2 years after surgery. The dosage of L-dopa/benserazide was significantly reduced after surgery compared with that before surgery. The results indicate that co-grafts of adrenal medulla with peripheral nerve may be useful for the treatment of Parkinson's disease in the long term.