Administration of Antithymocyte Globulin (Rabbit) to Treat a Severe, Mixed Rejection Episode in a Pregnant Renal Transplant Recipient

Pregnancy in solid organ transplant recipients carries numerous risks to the mother such as increased risk of rejection, gestational diabetes mellitus, and preeclampsia. The developing fetus is subjected to risks such as birth defects, preterm delivery, and low birth weight. Typically, these risks can be managed through intensive, multidisciplinary prenatal care and a proper immunosuppressive regimen. In the setting of rejection, however, little data are available to suggest safe and effective treatment of acute cellular rejection, antibody-mediated rejection, or mixed rejection episodes in the pregnant solid organ transplant recipient. We describe the first case, to our knowledge, in which antithymocyte globulin (rabbit) was used to successfully treat a pregnant renal transplant recipient who experienced a mixed rejection episode. A 22-year-old, African American woman with stage 6 chronic kidney disease received a deceased donor renal transplant after undergoing hemodialysis for 3 years. Her maintenance immunosuppressive regimen at the time of transplantation consisted of tacrolimus, prednisone, and mycophenolate mofetil. Despite counseling efforts on the importance of having a planned pregnancy after kidney transplantation so that her immunosuppressive medications could be optimized, the patient became pregnant 12 months later; her mycophenolate mofetil was changed to azathioprine to reduce the risk of fetal deformities or death. Three months later, the patient was admitted for biopsy of her transplanted kidney and was evaluated for possible kidney rejection. After confirmation of a mixed 1B acute cellular rejection and antibody-mediated rejection episode, the patient decided to pursue resolution of her rejection episode and continue the pregnancy despite the potential risks to the fetus. She was treated with high-dose corticosteroids, intravenous immunoglobulin, plasmapheresis, and antithymocyte globulin (rabbit). Twenty-nine months after transplantation, the patient was induced and gave birth to a healthy baby boy. Our patient's case offers unique insight into the potential management of a rejection episode requiring aggressive immunosuppressive therapy. Although potent immunosuppressive therapies were successfully used in our patient, further studies are needed to make definitive recommendations regarding the use of such therapies for treatment of rejection episodes in pregnant solid organ transplant recipients. The risks and uncertainties of treating rejection episodes should always be discussed with and understood by the patient before an informed decision is made.