A conversation with Dr. Raphael Guzman, Professor of Neurosurgery and Neurosciences at University Hospital Basel; Dr. Miroslaw Janowski, Associate Professor of Radiology at the Johns Hopkins University School of Medicine; and Dr. Piotr Walczak, Associate Professor of Radiology at Johns Hopkins University.
Interviewed by Dr. Kaustubh Limaye (@kaustubhslimaye), Assistant Professor of Neurology in the division of Cerebrovascular Diseases at the University of Iowa.
They will be discussing the paper “Intra-Arterial Delivery of Cell Therapies for Stroke,” published in the May issue of Stroke. The article is part of a Focused Update in Cerebrovascular Disease centered on stem cells and cell-based therapies.
Dr. Limaye: I read your review in Stroke that deals with intra-arterial cell therapy for stroke recovery with great interest and enthusiasm. Can you summarize the important points of your article for our readers?
Authors: The concept of using stem cells as a strategy for treatment of stroke is a few decades old. There were hundreds of animal studies, dozens of clinical trials, and we are still far from effective therapy. Perhaps it is time to take a step back and think whether something has to be changed with the approach to developing cell therapy for stroke. One problem is that we scientists and clinicians have been overly optimistic or even ignorant. The typical approach for research on stem cell-based therapies was: Let’s inject some cells into the brain lesion and hope for the best. The challenge was immense as the stem cells of choice after transplantation are required to find their way migrating to the target, survive, proliferate, appropriately differentiate and exert therapeutic effect. We see first-hand that such a simplistic approach was not constructive. While open label preclinical studies were optimistic, practically all rigorous clinical trials failed to demonstrate satisfactory therapeutic effects. This status quo has hurt the field of stem cell therapy for stroke as scientists, grant reviewers and funding agencies gradually lose enthusiasm and abandon the concept of brain regeneration after stroke with stem cells, stifling any further progress. It is urgent that we work towards reversing that trend, and our strategy is to shift from a “do all” approach to addressing very basic challenges in a systematic manner. After identifying promising and highly potent sources of stem cells, which is now largely accomplished, the next step is to develop methods for effective and safe delivery of stem cells to the site of brain injury.