Johns Hopkins Transplant Immunology Research

The mission of the Vascularized Composite Allotransplantation (VCA) Research Laboratory is to bring together microvascular surgery, basic science research, and cutting-edge bioengineering to advance our understanding of reconstructive transplantation and promote the development of innovative clinical solutions for transplant recipients.

Our research focuses on multiple areas:

• Transplant Immunology
• Neuroregeneration
• Tissue Cryopreservation and Immunogenicity
• Regenerative Medicine and Material Science
• Microsurgery and Microsurgical Education

What is VCA?

Vascularized Composite Allotransplantation (VCA), a branch of reconstructive transplantation, involves the transfer of a limb or body feature from one person to another. These procedures, such as hand or face transplantation, have become a clinical reality and valid treatment options for patients suffering from complex tissue injuries or defects. The functional outcomes of such treatment options are far superior to the gains afforded by any currently available prosthesis.

However, there are two primary challenges facing widespread implementation of this therapy: immunological rejection and the natural pace of nerve regeneration. To ward against the body’s rejection of the transplanted limb or tissue, patients are required to take a regimen of multiple immunosuppressive drugs over the course of their lifetime. As we learn from the field of solid organ transplantation, chronic use of these drugs predisposes the patient to higher rates of infections and cancer while it also does not fully protect the transplanted tissues in the long term.

Meanwhile, as the transplanted limb or tissue is healing, the nerves grow back at an average pace of one inch per month. Depending on the limb or tissue size, it can take months for patients to regain a sense of feeling. Consequently, the current implementation of VCA must address a delicate balance of risks and benefits.

Getting to the Basics

With a focus on the disciplines of transplant immunology and immunoregulation, regenerative medicine, nerve research, and microsurgical education, we work to overcome the barriers to successful reconstructive transplantation. Starting with obtaining a better understanding of the basic mechanisms of transplant rejection, our research also focuses on unraveling the unique immunological features of VCA. We believe that focusing on these areas of investigation will give us a unique perspective on novel strategies of immunoregulation that could either significantly reduce the side effects of maintenance therapies or completely remove the lifelong need for these drugs.

One of our major strengths is the profound expertise in microsurgery, which allows us to easily implement a vast array of animal models ranging from mouse and rat surgeries to complex interventions in large animals (e.g. miniature swine). An advantage that is not commonly available in most research laboratories. With this capability, we can promptly implement and complete projects in both the area of immunoregulation as well as nerve regeneration for improved functional outcome in VCA.