The "Pittsburgh Protocol" involves only one immunosuppressive agent (monotherapy) and an infusion of bone marrow stem cells from the limb donors. Transplant recipients receive maintenance therapy with a drug, tacrolimus, starting the day of the operation. The drug is titrated carefully for the first three months and adjusted at six- and 12-month follow-up periods. "To date, the transplants have been maintained on only one drug. That's all the patients take," Dr. Gorantla said. The patients also have a one-time infusion of bone marrow cells obtained from nine of the donors' vertebral bodies two weeks after the surgical procedure. "By using stem cells, we aim to facilitate an immunomodulatory state, which could help enable minimi-zation of maintenance immunosuppressive therapy from two or more drugs down to one drug," Dr. Gorantla explained.

Surgeons at the University of Pittsburgh are working with the American Society for Reconstructive Transplantation to share their insights and fine-tune transplantation procedures and protocols. The American Society for Reconstructive Transplantation is the only medical society in the world that focuses on composite tissue and reconstructive transplantations. "We want to improve our protocol by sharing our experiences and learning from other centers. We hope to conduct multicenter trials that will compare results from transplant patients who have received triple or double immunosuppressive therapy or who have received low-dose monotherapy with cellular therapy. We want to see which protocol works better and why and achieve consensus at the society level about standardizing protocols that are proven for safety, efficacy, and long term outcomes," Dr. Gorantla said.

"The insights we gain going forward will help us balance treatment in a manner that modulates or suppresses the immune system of the transplant recipient to prevent rejection of the graft but does not expose the patient to the potential toxic effects of high-dose immuno-suppressive drugs. The primary goals of protocols like ours are to reduce the risk and optimize the benefits that can be achieved in upper extremity transplants," he explained.

Source: University of Pittsburgh