Participation in the CRYOSTEM cohort

Patients & Donors

Every year in France, almost 2,000 patients, adults and children of all ages, are treated by Hematopoietic Stem Cell Transplantation (HSCT), more commonly known as bone marrow transplant, the ultimate therapeutic option for treating and curing serious blood diseases, whether malignant or not.

Why taking part in the CRYOSTEM cohort?

While this procedure is saving more and more lives, it can also lead to early or late complications in 50% of patients, such as Graft-versus-Host Disease (GvHD), infectious complications (linked to patient immunosuppression) and toxic complications (linked to the treatments used during conditioning), which are very disabling in everyday life and fatal in 25% of cases. These complications vary greatly from one patient to another, but the reasons for this variability remain largely unknown. Thanks to recently developed analysis technologies (proteomics, metabolomics, etc.), progress has been made in terms of understanding and predicting the occurrence of complications, but the treatment of these complications remains to be improved. Although physicians have treatments to control them, they can significantly alter the patient’s quality of life, both on a daily basis and over the long term.

Moreover, until recently, it was difficult to carry out large-scale studies in the field of HSCT, due to the relatively small number of allogeneic transplant patients per year compared with other healthcare indications, and the sometimes very low numbers of allogeneic transplant patients in individual centers. It was against this backdrop that the CRYOSTEM project was launched, with the aim of mobilizing a national network of clinical services and BRCs to provide a significant and sufficient number of qualified biological samples and associated data, offering an unprecedented level of data collection in this health indication, and enabling large-scale scientific studies.

Participating in the CRYOSTEM cohort means:

  • Agree to be actively followed up for nearly two years after inclusion in the cohort, according to a precise schedule of visits included in the care program (ranging from 4 to 8 visits maximum);
  • Donate some of your blood during these visits to derive biological samples that can be used for scientific research;
  • Contribute to a collective effort mobilizing medical teams (transplant physicians, nurses, clinical research associates, etc.), laboratory staff and researchers to enable scientific research;
  • Participate in improving understanding and prediction of early and late complications of HSC allogeneic transplantation, in order to adapt allogeneic transplant protocols to each patient and match the donor/recipient pair as closely as possible to limit their occurrence.

A priority: patient confidentiality

From the outset, the teams involved in the CRYOSTEM project have made every effort to collect biological samples and associated data while respecting the confidentiality and anonymity of each patient, and thus meeting the prerequisites of the Commission Nationale Informatiques et Libertés (CNIL) and the General Data Protection Regulation ( GDPR).
All the necessary regulatory authorizations were obtained before the project began, and are renewed and updated in line with regulatory developments.

The CRYOSTEM project management team is backed by experts in the field to ensure that your data is protected, from collection through to availability for scientific research projects in France and abroad.

We also remind you that :

  • The transfer of data from patients included in the CRYOSTEM cohort, which is necessary for the realization of a scientific project, is made only after the research team has verified that all mandatory legal and regulatory formalities have been undertaken;
  • Access is governed by the implementation of specific agreements between CRYOSTEM and the researcher’s host structure in compliance with the RGPD, and is done in a secure manner;
  • Data processing is based on confidentiality and pseudonymization, preventing access to your identity.

Regarding the use of your personal data as part of the biological resources collection, you can refer to the informed consent form and information note that have been delivered at the time of your inclusion.

For the use of personal data related to the consultation of our website, you can go to the “Privacy policy” page to read all the provisions.

What progress has the CRYOSTEM cohort made to date?

Between 2012 and 2021, almost 6,000 adult and pediatric patients, as well as around 2,500 donors (both registered volunteers and intrafamiliar donors) have agreed to join the CRYOSTEM cohort.

To date, the CRYOSTEM cohort inclusions and follow-up samples have been completed.

In 2015, the CRYOSTEM collection was opened up to the scientific community by making samples and associated data from patients included in the cohort available to national and international, public and private healthcare research teams working on a variety of topics around the theme of post-allograft complications.

Nearly 9,000 samples have already been made available to 22 research projects, selected according to precise criteria by CRYOSTEM’s Scientific Committee, who scrupulously verify the project’s objectives and ensure compliance with medical research conditions.

The list of supported projects can be consulted in the “Research” tab, with a summary for the general public and a description of each project, including the number of patients involved, samples made available and progress made. It is updated regularly.
The CRYOSTEM project coordinating team is delighted to announce the emergence of 9 scientific publications that will have an impact in the coming years on improving transplant procedures and the management of allograft patients. You can find out more about these publications in the “About us” section.

CRYOSTEM, a cohort in constant search of optimization

For several years now, the CRYOSTEM project coordinating team has been implementing various optimization strategies to optimize the long-term viability of its collection, preserve qualified samples and data with high release potential, and encourage sample releases.

1. Recovering the consent of minors who have reached the age of majority

The first initiative is the recovery of consents from minor patients who have reached the age of majority, to avoid the destruction of pediatric biological resources due to their uniqueness and rarity.

For the inclusion of minors (allograft recipients or donors), consent must be signed by the child’s legal representatives. However, at adulthood, the individual must sign an adult consent that allows him/her to confirm his/her agreement to participate in the CRYOSTEM cohort.

With regard to the GDPR, the non-recovery of consents from individuals who have reached the age of majority leads to the destruction of these biological resources. Indeed, insofar as the consent is no longer valid, the legal basis is no longer respected, and the CRYOSTEM coordination must therefore proceed with the destruction of these resources.

To enable these samples to be kept in the collection, we have been recovering the consents of patients who have reached the age of majority since 2021. If you participated in the CRYOSTEM cohort as a child, it is highly likely that you will be contacted by a member of the medical team (nurse or clinical research associate) at your center to renew your consent and sign the appropriate adult form.

In the event of it being impossible to contact these individuals again (for ethical reasons, or because they have been lost to sight or are deceased), the CRYOSTEM coordinating team plans to submit a request for exemption to the French Comité de Protection des Personnes (CPP) to keep these samples, given their precious nature.

2. Data verification and optimization

The second initiative is the verification and retrieval of clinical and biological data associated with samples. The aim is to guarantee the quality and reliability of the data in order to obtain usable and reproducible results for subsequent research projects.

  • On the one hand, clinical data are optimized in two ways:
    By comparing the data entered in the CRYOSTEM database with that of the European registry of allograft patients. Recovery of these data began during 2018. Almost all files have been verified;
  • By completing missing clinical and/or biological data, retrievable from clinical departments through patients’ medical records. This work, also started in 2018, is currently still in progress.

3. Priority conservation of unique biological samples with high value-added potential

The latest initiative was set up to provide a partial response to the problem of storage saturation at the CRYOSTEM network’s Biological Resource Centers (BRCs), by implementing a policy of prioritizing the most relevant biological samples with high value-added potential, such as those from:

  • Healthy donors: these resources are interesting because they come from individuals who are a priori “naïve” to any pathology;
  • Pediatric patients, due to their under-representation in the transplant population;
  • Patients with complete sampling kinetics, enabling medium-term follow-up of the patient at the onset of GvHD.

Today, nearly 200,000 samples are stored in 28 decentralized CRBs.

The CRYOSTEM coordinating team, aware of this opportunity, and wishing to engage in a Corporate Social Responsibility (CSR) dynamic, has initiated a reflection since 2022 in collaboration with the Strategic Committee on the destruction of unusable samples, defined as having a low probability of being made available.

This dynamic is intended to be of mutual benefit, and to set an example for other promoters of so-called “dormant” cohorts. To date, just over 5,000 samples have been destroyed, with a target of around 14,500 by the end of 2023.

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