Kinetics of the use of cryopreserved autologous stem cell grafts: a GITMO-SIDEM survey

Storage, Utilization, and Disposal of Hematopoietic Stem Cell Products in Patients with Multiple Myeloma

High-dose chemotherapy (HD-CHT) and autologous blood stem cell transplantation (ABSCT) represent the standard of care in multiple myeloma (MM) for transplantation-eligible patients. Up to 3 HD-CHT/ABSCT treatments may be administered during the course of disease, including during late-onset relapse. Transplantation centers routinely collect more than 1 peripheral blood stem cell (PBSC) graft; however, subsequent HD-CHT/ABSCT treatments are often not performed, for various reasons. Currently, little is known about the actual utilization rate of stored PBSCs. The collection, storage, and disposal of PBSC products was analyzed in a large cohort of patients with MM (n = 1114) over a 12-year period with a minimum follow-up of 6 years. The final dataset analysis was performed in March 2019, which was set as the reference date. Based on institution-specific charges, the costs for PBSC collection, processing, and storage were estimated. The median number of sufficient PBSC transplantations per patient was 3 (range, 0 to 6), which were stored in a median of 3 (range, 1 to 11) cryopreserved bags (overall, n = 3644). A total of 95% of all patients (n = 1059) underwent at least 1 HD-CHT/ABSCT treatment. However, multiple ABSCTs were performed in 51% of the patients (n_{2/3 ABSCTs} = 538), and only 14% of the patients underwent ABSCT 3 times (n_{3 ABSCTs} = 149). Only a small proportion of collected PBSC bags (5%; n = 109) were used after being stored for longer than 5 years. Overall, 23% of the products (n = 830) were discarded, and 16% (n = 566) were kept in storage until the reference date. From a retrospective standpoint, the collected and discarded (definitively not used) or stored (potentially not used) cryostored PBSCs were associated with considerable costs for long-term cryostorage of approximately €1,600,000. We identified considerable discrepancies between the collection/storage and utilization of PBSCs. This is associated with significant efforts and costs on the one hand; on the other hand, disposal may raise legal and ethical questions. Therefore, we implemented comprehensive guidelines for the systematic reevaluation of stored PBSC grafts at our institution.

Is long term storage of cryopreserved stem cells for hematopoietic stem cell transplantation a worthwhile exercise in developing countries?

Background

Stem cell units (SCUs) that are cryopreserved prior to both autologous and allogeneic hematopoietic stem cell transplants (for donor lymphocyte infusion) remain unused or partially used several times, and become an increased burden to blood banks/SCU repositories. Because of the scarcity of data regarding the duration for which the storage is useful, there is no general consensus regarding disposal of SCUs.

Methods

We conducted a retrospective audit of SCU utilization in 435 patients who planned to undergo either autologous stem cell transplantation (auto-SCT) (N=239) or allogeneic stem cell transplantation (allo-SCT) (N=196) at a tertiary cancer care center between November 2007 to January 2015.

Results

Our cohort consisted of 1,728 SCUs stored for conducting auto-SCT and 729 SCUs stored for conducting donor lymphocyte infusions (DLIs) after allo-SCT. Stem cells were not infused in 12.5% of patients who had planned to undergo auto-SCT, and 80% of patients who underwent allo-SCT never received DLI. Forty-one percent of SCUs intended for use in auto-SCT remained unutilized, with a second auto-SCT being performed only in 4 patients. Ninety-four percent of SCUs intended for carrying out DLIs remained unused, with only minimal usage observed one year after undergoing allo-SCT.

Conclusion

The duration of storage of unused SCUs needs to be debated upon, so that a consensus can be reached regarding the ethical disposal of SCU.

A policy for the disposal of autologous hematopoietic progenitor cells: report from an Italian consensus panel

BACKGROUND

Autologous stem cell transplantation (ASCT) requires collection and cryopreservation of hematopoietic progenitor cells (HPCs), which in turn may be partially or never reinfused. Thus, HPC storage has become a logistic, ethical, and economic issue. SIDEM, GITMO, and CNT/ISS endorsed a project aimed to define national criteria for HPC disposal aimed to guarantee appropriateness and equity.

STUDY DESIGN AND METHODS

A multidisciplinary panel was convened including HPC harvest and manipulation experts from apheresis units, hematologists with clinical expertise in ASCT, a representative of the national health authority, and a bioethicist. An analytic hierarchy process (AHP) was carried out to select disposal criteria.

RESULTS

The AHP selected two criteria for prompt disposal of freshly collected HPCs: an abnormal freezing procedure causing highly reduced viability or major microbiology contamination. Moreover, AHP selected six major criteria, each one of them allowing for the disposal of stored HPC units: patient death, withdrawal of consent to ASCT, contraindications or loss of indications to ASCT, a damaged label that prevents correct identification of the unit, and time elapsed since harvest longer than 10 years. Three minor criteria were additionally identified that allowed to anticipate disposal only provided that viability levels are below the limit of acceptance: a documented cold chain interruption, loss of bag integrity, and total amount of stored CD34+ cells lower than 1 × 10(6) /kg or lower than 2 × 10(6)/kg in patients with a successfully completed stem cell transplantation program.

CONCLUSIONS

A formal consensus process allowed SIDEM and GITMO to propose a policy for autologous HPC disposal that fulfills clinical, ethical, and economic criteria.