One purpose of this study is to determine whether the amount of cultured thymus tissue implanted into DiGeorge anomaly infants has any effect on the immune outcome. Another purpose of this study is to determine whether parental parathyroid transplantation (in addition to cultured thymus tissue implantation (CTTI) can help both the immune and the calcium problems in DiGeorge infants with hypocalcemia. \[Funding Source - FDA Office of Orphan Products Development (OOPD)\]
DiGeorge anomaly is a congenital disorder in which infants are born with defects of the thymus, heart, and parathyroid gland. Complete DiGeorge Anomaly is usually fatal within the first two years of life. This trial evaluates the role of cultured thymus tissue dose in cultured thymus tissue implantation (CTTI) in complete (typical) DiGeorge anomaly infants, and continues safety assessments. DiGeorge infants who have successful CTTIs but remain with hypoparathyroidism must go to the clinic for frequent calcium levels and to the hospital for calcium infusions; these infants are at risk for seizures from low calcium. Approximately ½ of infants with profound hypoparathyroidism will develop nephrocalcinosis. This protocol had a parental parathyroid transplant arm for complete DiGeorge infants with athymia and profound hypoparathyroidism.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
7
Thymus tissue (from unrelated donor), thymus donor, and thymus donor's birth mother screened for safety. CTTI was done under general anesthesia. Cultured thymus tissue was implanted into quadriceps. Thymus dose at least 4grams/m2 body surface area (0.2 grams/kg body weight) and not \>18 grams/m2 body surface area (1.0 grams/kg body weight). At time of CTTI, skin biopsy was obtained to look for preexisting T cells. 2-3 months post-CTTI allograft biopsy was done to evaluate for thymopoiesis \& graft rejection. At time of biopsy, skin biopsy done to look for T cell clonal populations. (Allograft biopsy not done if subject medically unstable.) Post-CTTI, subjects followed by immune evaluations, using blood samples.
Parental parathyroid donors screened for eligibility and safety. If both parents meet eligibility criteria, the parathyroid will be harvested from parent who shares the most Human Leukocyte Antigens (HLA) alleles with thymus donor. Parathyroid harvest \& transplant preferably done at same time as CTTI. (If parathyroid transplant cannot be done at same time, then it is done within 3-8 weeks of CTTI.) Parathyroid harvest done under general anesthesia. One parathyroid gland is minced \& placed in quadriceps muscle; there is no dose in mg. No biopsy done of the parathyroid. Parathyroid donors are monitored as outpatients until recipients' discharge. Recipients' calcium and PTH levels are monitored indefinitely.
Duke University Medical Center
Durham, North Carolina, United States
Survival at 1 Year Post-CTTI
Survival at 1 year post CTTI was assessed using the Kaplan Meier Estimated Survival. This mathematical function estimates the survival for a certain length of time.
Time frame: 1 year post-CTTI
Survival at 2 Years Post-CTTI
Survival at 2 years post CTTI was assessed using the Kaplan Meier Estimated Survival. This mathematical function estimates the survival for a certain length of time.
Time frame: 2 years post-CTTI
Immune Reconstitution Efficacy - CD3 T Cells
The development of total CD3 T cells at one year as measured using flow cytometry
Time frame: 1 year post-CTTI
Immune Reconstitution Efficacy - CD4 T Cells
The development of total CD4 T cells at one year as measured using flow cytometry
Time frame: 1 year post-CTTI
Immune Reconstitution Efficacy - CD8 T Cells
The development of total CD8 T cells at one year as measured using flow cytometry
Time frame: 1 year post-CTTI
Immune Reconstitution Efficacy - Naive CD4 T Cells
The development of naive CD4 T cells at one year as measured using flow cytometry
Time frame: 1 year post-CTTI
Immune Reconstitution Efficacy - Naive CD8 T Cells
The development of naïve CD8 T cells at one year as measured using flow cytometry.
Time frame: 1 year post-CTTI
Immune Reconstitution Efficacy - Response to Mitogens
The development of a T cell proliferative response to the mitogen phytohemagglutinin.
Time frame: 1 year post-CTTI
Thymus Allograft Biopsy
Evidence, on biopsy of the thymus tissue implanted in the recipient muscle, that shows the development of new T cells.
Time frame: 2 to 3 months post-CTTI
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