The Immune Tolerance Network (ITN) opened up a new observational transplant trial, ALLTOL, with the enrollment of its first two participants at the University of California, San Francisco (UCSF) June 30, 2016. ALLTOL is a prospective cohort study to enroll “operationally tolerant” kidney and liver transplant recipients who have successfully discontinued immunosuppressive medications and continue to have normal function in their transplanted organ. The goal is to collect specimens and follow these individuals to monitor long-term health and understand immune characteristics unique to this rare patient population.
Achieving a state of tolerance to a transplanted organ is rare and the mechanism of tolerance is not well understood. ITN’s transplant trials have employed a variety of novel strategies to create organ tolerance (e.g., mixed chimerism approaches with bone marrow transplantation or unique induction regimens), or have attempted staged immunosuppression withdrawal in selected populations to determine who can achieve operational tolerance (see here and here). These (and other) efforts have produced a cohort of more than 40 organ recipients who have been involved in ITN research trials and are currently off immunosuppression and in a state of operational tolerance. The ALLTOL study provides a mechanism to continue to follow this valuable population.
The ALLTOL study is also open to operationally tolerant individuals outside of ITN trials, and is therefore a catch-all for tolerant organ recipients all over the country. To our knowledge, this is the first US trial of its kind. We look forward to this trial becoming a valuable resource for understanding long-term outcomes in this population and for identifying biomarkers related to transplant tolerance.