Correction of DiGeorge anomaly with EBV-induced lymphoma by transplantation of organ-cultured thymus and Epstein-Barr-specific cytotoxic T lymphocytes.
A young woman with DiGeorge anomaly showed normal immune tests as a child and did not experience the symptoms of profound T cell immunodeficiency. However, she had chronic pulmonary infections which led to bronchiectasis. At age 14, she developed an Epstein-Barr virus-induced lymphoma and her T cell function tests were markedly abnormal. After intensive chemotherapy, she received an organ-cultured thymus transplant but because of an abnormally high EBV DNA titer was also given autologous EBV-specific cytotoxic T cells, prepared prior to transplant. Titers fell from 80,000 genome copies/mg DNA to 2000 within 6 weeks. She was clinically well and her T cell tests improved. Sixteen months after the transplant, however, her tumor returned; EBV DNA levels had risen to 40,000 copies/mg DNA. She again received autologous EBV-specific cytotoxic T lymphocytes and valcyclovir and Cytogam as well. Her tumor resolved on this therapy and she has remained well to this date, 29 months after the recurrence. T cell tests, which had deteriorated with the recurrence of the tumor, now show normal responses. This experience records a number of unique features of thymus transplantation. This is the first recorded successful thymus transplant in a patient with partial T cell immunity and thus expands the potential of this treatment modality to patients other than infants with complete DiGeorge anomaly. The patient demonstrates cytotoxic activity against mouse cells, demonstrating the ability to respond to a new antigen which requires host antigen presenting cells. Measurement of alpha 1 TRECs (T cell receptor excision circles) shows evidence of increasing and sustained thymopoiesis since the transplant at a level consistent with the age of the transplant donor rather than that of the recipient.