Treatment of acute and chronic graft-versus-host disease with extracorporeal photopheresis: Update of best practice recommendations from Italian Society of Hemapheresis and Cell Manipulation (SIdEM) and the Italian Transplant Group for Bone Marrow Transplantation, Hematopoietic Stem Cells and Cell Therapy (GITMO)

These guidelines represent a GRADE-method revision of the recommendations produced by the Italian Society of Hemapheresis and Cell Manipulation (SIDEM) and the Italian Transplant Group for Bone Marrow Transplantation, Hematopoietic Stem Cells and Cell Therapy (GITMO) in 2013. Since 2013 several studies have been published that have strengthened the role of ECP in the management of GVHD. Thus, it was deemed appropriate to proceed with an update, with the aim to define uniform criteria for the application of ECP in adult and pediatric patients affected by GVHD throughout the national territory, in line with international guidelines, in maintaining of high standards of safety for patients and quality of the procedures provide. Post-HSCT GvHD therapies other than ECP and ECP therapy of other diseases, such as CTCL, are not covered by these guidelines.The development panel for this guideline includes professionals from various specialties who routinely interact in the management of the patient with GVHD, namely the transfusionist, the adult and pediatric hematologist, and the hospital pharmacist. A hematologist experienced in systematic reviews and GRADE guideline development ccordinated the development process, and an experienced transfusionist coordinated the assignment of tasks and reporting. External reviewers of the guideline included a patient representative.

Immune Monitoring Assay for Extracorporeal Photopheresis Treatment Optimization After Heart Transplantation

Background

Extracorporeal photopheresis (ECP) induces immunological changes that lead to a reduced risk of transplant rejection. The aim of the present study was to determine optimum conditions for ECP treatment by analyzing a variety of tolerance-inducing immune cells to optimize the treatment.

Methods

Ten ECP treatments were applied to each of 17 heart-transplant patients from month 3 to month 9 post-HTx. Blood samples were taken at baseline, three times during treatment, and four months after the last ECP treatment. The abundance of subsets of tolerance-inducing regulatory T cells (T_regs) and dendritic cells (DCs) in the samples was determined by flow cytometry. A multivariate statistical model describing the immunological status of rejection-free heart transplanted patients was used to visualize the patient-specific immunological improvement induced by ECP.

Results

All BDCA⁺ DC subsets (BDCA1⁺ DCs: p < 0.01, BDCA2⁺ DCs: p < 0.01, BDCA3⁺ DCs: p < 0.01, BDCA4⁺ DCs: p < 0.01) as well as total T_regs (p < 0.01) and CD39⁺ T_regs (p < 0.01) increased during ECP treatment, while CD62L⁺ T_regs decreased (p < 0.01). The cell surface expression level of BDCA1 (p < 0.01) and BDCA4 (p < 0.01) on DCs as well as of CD120b (p < 0.01) on T_regs increased during the study period, while CD62L expression on T_regs decreased significantly (p = 0.04). The cell surface expression level of BDCA2 (p = 0.47) and BDCA3 (p = 0.22) on DCs as well as of CD39 (p = 0.14) and CD147 (p = 0.08) on T_regs remained constant during the study period. A cluster analysis showed that ECP treatment led to a sustained immunological improvement.

Conclusions

We developed an immune monitoring assay for ECP treatment after heart transplantation by analyzing changes in tolerance-inducing immune cells. This assay allowed differentiation of patients who did and did not show immunological improvement. Based on these results, we propose classification criteria that may allow optimization of the duration of ECP treatment.

Inline and offline extracorporeal photopheresis: Device performance, cell yields and clinical response

BACKGROUND

Extracorporeal photopheresis (ECP) is an effective treatment for graft-vs-host-disease (GvHD). Photopheresis can be performed in offline or inline method. The first uses a conventional cell separator for collection of mononuclear-cells that are photoactivated by a separate device and manually reinfused; the second one involves a dedicated device performing the entire procedure (collection, photoactivation and reinfusion).

STUDY DESIGN AND METHODS

The objective was to compare the two methods and cell product features to highlight key process, devices performance, and to evaluate ECP clinical response. Patients developing steroid-resistant GvHD underwent ECP as second-line treatment using either inline (Therakos CellEx) or offline system (Terumo BCT Spectra or Optia and UVA PIT system). Data about patients' features, pre-apheresis blood-count, cell product characteristics and clinical response were collected for analysis.

RESULTS

We evaluated 494 procedures performed on 28 patients from April 2018 to March 2019. The offline procedure allows to achieve greater cell yield, it is characterized by larger processed blood volume, longer runtime, and higher ACD consumption. The inline procedure shows shorter runtime, high mononuclear-cells percentage and low percentage of granulocytes in cell product. We observed a significant difference in cell yields between inline and offline system; furthermore we did not find a significant relationship between cell dose and clinical response.

CONCLUSION

Inline ECP is fast, highly automated and productive, making it particularly suitable for ECP treatments. Offline ECP collects high cell yields implying longer procedure and greater operator intervention. Our study did not find a significant relationship between cell dose and GVHD response.

Collection of hematopoietic stem cells and immune effector cells in small children

Apheresis procedures are standard of care for a wide range of indications in children, collection of hematopoietic stem cells being the most frequent one. With increasing numbers of hematopoietic stem cell transplants, advances in graft manipulation techniques and the development of innovative therapies using immune effector cells and gene therapy, apheresis within the pediatric population is growing in demand. While young children have higher circulating white blood cell counts and robustly mobilize hematopoietic stem cells, apheresis machines were designed for use within the adult population and apheresis procedures in children, particularly small children, can be more challenging as vascular access, collection techniques and impact of extracorporeal volumes increase the rate of adverse events. In this article we review topics of particular relevance to hematopoietic stem cell and immune effector cell collections in small children.

A paired trial comparing mononuclear cell collection in two machines for further inactivation through an inline or offline extracorporeal photopheresis procedure

BACKGROUND

Extracorporeal photopheresis (ECP) is an effective treatment. However, protocols differ widely, and some questions, such as the number of cells to be collected or the number of ECP treatment days per treatment cycle, are still unsolved. The aim of this study was to compare a multistep (offline) (Spectra Optia and Macogenic G2) against an integrated (inline) ECP system (Therakos Cellex system) with respect to mononuclear cell (MNC) collection.

STUDY DESIGN AND METHODS

The number and quality parameters of the MNC products collected were evaluated together with some machine parameters, such as collection time. Comparisons were made through paired sample analysis with the t test.

RESULTS

Fourteen patients underwent 15 double-paired procedures using both ECP protocols. The average MNC collected in the multistep procedure was 77.4 × 10⁸ , four times more than in the integrated procedure (18.5 × 10⁸ ). MNC purity (84.4% vs. 63.8%) and enrichment (27.9 vs. 5.9) in the product collected were also higher in the multistep procedure. The whole ECP time was higher in the multistep than in the integrated procedure (272 vs. 106 min), but the calculated time to collect 25 × 10⁸ MNCs in the multistep was shorter compared with the one-step procedure (77.8 vs. 172 min). All these differences between the two protocols were statistically significant.

CONCLUSIONS

These two ECP protocols are different with respect to MNC collection and length of procedure. Some unresolved questions, such as the better MNC dose to inactivate or the number of consecutive days that ECP should be performed for optimal clinical efficacy, require further review.