Details

Autor(en) / Beteiligte

• Duggleby, Richard Charles
• Tsang, Hoi Pat
• Strange, Kathryn
• McWhinnie, Alasdair
• Lamikanra, Abigai
• Roberts, David
• Hernandez, Diana
• Madrigal, J. Alejandro
• Danby, Robert

Titel

Cellular Enumeration of Tregs and CD3+ Cells in Cryopreserved Umbilical Cord Blood Units

Ist Teil von

• Biology of blood and marrow transplantation, 2020-03, Vol.26 (3), p.S282-S283

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Allogeneic haematopoietic cell transplantation (HCT) is a curative therapy for severe haematological disorders, including acute leukaemia. However, it carries significant morbidity and mortality due to infection, graft-versus-host disease and relapse. The cellular content of HCT grafts, in particular the ratio between regulatory T cells (Treg) and conventional T cells, is an important factor influencing the severity of these complications. Whilst previous studies have been performed in fresh adult peripheral blood mobilised grafts, it has not been applied in umbilical cord blood (CB) HCTs. CB enumerations are more challenging as they must be performed from small cryopreserved segments stored alongside the CB units used for HCT. Fresh CB units and thawed segments were analysed for their Treg and T cell content using both flow cytometry (the benchmark technique) and an epigenetic, DNA-based methodology. The two methods were compared for their agreement, consistency and susceptibility to error when assessing Treg and CD3+ cell numbers in both fresh and cryopreserved samples. Epigenetic enumeration gave consistent results in both fresh and frozen samples, providing Treg/CD3 estimates that were similar. Assessment of Tregs and CD3+ cells by flow cytometry and epigenetic assessments in fresh samples showed that these two methods were correlated. Conversely, significant cell death was observed in the thawed segments which affected Treg and CD3 cell estimates by flow cytometry. Epigenetic assessments offer significant advantages over flow cytometry for analysing cryopreserved CB. Unlike with flow cytometry assessments of thawed segments, similar cell numbers were observed in fresh and frozen samples, with material requirements not being limiting and being unaffected by high cell death. With this method, multiple epigenetic assessments can be performed from extracted DNA, to provide statistical confidence and confirm observed results. Finally, the method raises the possibility of retrospective studies of historical samples where only DNA is available.