CD71 surface analysis of T cells: a simple alternative for extracorporeal photopheresis quality control.

BACKGROUND: Extracorporeal photopheresis (ECP) is a leukapheresis-based cellular therapy that is used with increasing frequency worldwide to treat various T-cell-mediated diseases. Currently, the inhibition of T-cell proliferation after photopheresis is analysed frequently using time-consuming assays including radioactive thymidine assays or carboxyfluorescein succinimidyl ester (CFSE) staining. We investigated whether simple surface T-cell staining using surrogate markers of T-cell proliferation can replace time-consuming measurement of T-cell proliferation in ECP quality control. STUDY DESIGN AND METHODS: T-cell activation markers were investigated by flow cytometry after ECP. Candidates were validated by direct comparison with the classical CFSE T-cell proliferation inhibition test and apoptosis staining. Finally, surface T-cell staining was performed in patient samples in comparison with classical methods. RESULTS: CD71 expression exhibited the fastest and most robust upregulation, which was detectable as early as 6-8 h after T-cell stimulation and almost completely abrogated by ECP. In a direct comparison with the CFSE T-cell proliferation assay, suppression of CD71 expression after ECP was almost identical and detectable as early as 16 h after stimulation in peripheral blood mononuclear cells of healthy donors. Furthermore, in direct comparison with classical apoptosis staining, the inhibition delta of CD71 after ECP was significantly higher. Moreover, in patients under T-cell suppressive therapy, T-cell-dependent CFSE and CD71 assays exhibited decreased sensitivity to detect ECP treatment and were inferior in comparison to apoptosis staining. CONCLUSION: Surface CD71 analysis represents a very simple quality control alternative to detect ECP-mediated T-cell proliferation inhibition in normal PBMC samples devoid of T-cell suppressive drugs.

Comparison of the CELLEX™ and UVAR-XTS™ closed-system extracorporeal photopheresis devices in the treatment of chronic graft-versus-host disease.

Extracorporeal Photopheresis (ECP) is a cellular immunotherapy frequently used for steroid-refractory graft-versus-host disease (GVHD). Chronic GVHD (cGVHD), response to ECP is associated with survival benefit. The UVAR-XTSTM system and the more recently developed CELLEXTM device (both TherakosTM ) are the mainstay for ECP-delivery in the UK and US. No comparison of treatment outcomes has been reported. We retrospectively compared cGVHD response and steroid reduction and withdrawal in patients treated exclusively over 12 months with either the XTS (n = 51) or CELLEX (n = 50). Our hypothesis was that there would be no difference in clinical outcome or steroid changes in the 2 matched cohorts. We also compared infection incidence, infection-related death (IRD), and treatment time. Significant clinical improvement and regular capacity to reduce or cease steroids was encountered in both cohorts; at 6 months of ECP 70% of cutaneous cGvHD patients had partial or complete responses and 85% of patients receiving steroids pre-ECP had reduced dosage. In the XTS group we unexpectedly encountered both superior steroid reduction (86% dose at least halved vs. 61% for CELLEX, P = 0.01) and withdrawal (15 vs. 5 CELLEX, P = 0.01) and a trend for superior skin disease response in the CELLEX-treated cohort at 3 months. No inter-relationship was evident. Halving or greater reduction of steroid dose by 3 or 6 months was associated with reduced risk of IRD in the XTS cohort as was withdrawal at 6 months for the combined cohorts. By 6 months, XTS-treated patients had experienced fewer antibiotic-requiring infections (mean 1.9 vs. 2.8, P = 0.025). Origins for the disparities are unclear and warrant investigation.

Extracorporeal photopheresis in pediatric patients: Practical and technical considerations.

In adults, extracorporeal photopheresis (ECP) is widely utilized for a variety of indications, most commonly cutaneous T-cell lymphoma, acute or chronic graft-versus-host disease (GVHD), solid organ transplant rejection, and other autoimmune and T-cell-mediated disorders. In pediatric patients, the majority of case series and reports have focused on its use in the management of acute and chronic GVHD. Currently utilized ECP technologies were designed for adult patients and there are several challenges in adapting these technologies for use in children. In our review, we focus on practical considerations and procedural modifications for ECP use in pediatric patients, with special attention to patient safety.

An alternative mini buffy coat preparation method for adult patients with extracorporeal photopheresis contraindications.

BACKGROUND: Extracorporeal photopheresis (ECP) is an important cell-based therapy for various diseases but is limited to patients eligible for apheresis. We developed an alternative mini buffy coat (BC) preparation method using the Spectra Optia® apheresis system and compared its efficacy of white blood cell (WBC) recovery with the standard mini BC preparation method already established for pediatric patients. METHODS: Whole blood (450 ± 45 mL) samples were collected from 30 randomly selected healthy volunteer blood donors and divided into two groups. In the first group, WBCs were separated with a fully automated separator device (Compomat G4® ). In the second group, BCs were separated with the bone marrow processing program of the Spectra Optia apheresis system. RESULTS: There were no significant differences in total leukocyte counts per product between the two groups. In contrast, lymphocyte counts per product were significantly higher (P < 0.001) in BCs separated from apheresis. CONCLUSION: Our novel technique resulted in similar WBC yields but higher lymphocyte yields than the standard mini BC preparation method. This method can serve as an alternative to WBC collection in conventional ECP for adult patients with apheresis contraindications. J. Clin. Apheresis 32:12-15, 2017. © 2016 Wiley Periodicals, Inc.

Extracorporeal Photopheresis for Second-Line Treatment of Chronic Graft-versus-Host Diseases: Results from a Health Technology Assessment in Italy.

OBJECTIVES: To develop a comparative, cost-effectiveness, and budget impact analysis of Therakos online extracorporeal photopheresis (ECP) compared with the main alternatives used for the treatment of steroid-refractory/resistant chronic graft-versus-host disease (cGvHD) in Italy. METHODS: The current therapeutic pathway was identified by searching medical databases and from the results of a survey of practice in Italian clinical reference centers. A systematic review was performed to evaluate the efficacy and safety of second-line alternatives. Budget impact and cost-effectiveness analyses were performed from the Italian National Health Service perspective over a 7-year time horizon through the adaption of a Markov model. The following health states were considered: complete and partial response, stable disease, and progression. A discount rate of 3% was applied to costs and outcomes. RESULTS: The most common alternatives used in Italy for the management of steroid-refractory/resistant cGvHD were ECP, mycophenolate, pentostatin, and imatinib. The literature review highlighted that complete and partial responses are higher with ECP than with the alternatives while serious adverse events are less common. The economic analysis showed that Therakos online ECP represents the dominating alternative, in that it delivers greater benefit at a lower cost. In fact, according to the alternatives considered, cost saving ranged from €3237.09 to €19,903.51 per patient with 0.04 to 0.21 quality-adjusted life-year gained. CONCLUSIONS: Therakos online ECP should be considered an effective, safe, and cost-effective alternative in steroid-refractory/resistant cGvHD. There is inequality in access, and a dedicated reimbursement tariff, however, should be introduced to overcome these barriers.

Quality control of extracorporeal photochemotherapy: Proliferation assay using CFSE validated according to ISO 15189:2007 standards.

BACKGROUND: For the last 40 years, the technique of extracorporeal photopheresis (ECP) has constantly developed. Among irradiation systems, those called "off-line" allow the validation of the quality of the cell therapy product. The inhibition of the proliferation of lymphocytes after ultraviolet irradiation (UVA) is usually verified by the tritiated thymidine assay as in vitro proliferation assay. The document presented here describes the results obtained while performing the setting up of an alternative proliferation assay using flow cytometry according to ISO 15189:2007 Standard. METHODS: Cells samples taken before and after UVA irradiation were labeled with CarboxyFluorescein Succinimidyl Ester (CFSE) and then cultured with phytohemagglutinin-A (PHA). After 3 days, an analysis of the CFSE staining was realized by flow cytometry. In order to validate the shift in the method used according to Standard, the following tests were performed: 1) comparison with the reference method, 2) robustness test, 3) reagents stability. RESULTS: Comparison method demonstrated that the sensitivity of the CFSE test is 100%, the specificity is 89%, and the concordance is almost complete. The CFSE test is robust regarding parameters like cell concentration or PHA concentration. PHA and CFSE are stable for 6 months and one year, respectively. CONCLUSION: Validation of this alternative test, according to the ISO 15189:2007 Standard, has demonstrated good concordance with reference method. The results of the robustness and stability of reagents are appropriate for its routine use. Thus, the benefits of alternative technique make it a wise choice for the quality control of ECP in a cell therapy laboratory.

The role of extracorporeal photopheresis in the treatment of cutaneous T-cell lymphomas.

Extracorporeal photochemotherapy (ECP) is an effective treatment modality for patients with erythrodermic myocosis fungoides (MF) and Sezary syndrome (SS). During ECP, a fraction of peripheral blood mononuclear cells is collected, incubated ex-vivo with methoxypsoralen, UVA irradiated, and finally reinfused to the patient. Although the mechanism of action of ECP is not well established, clinical and laboratory observations support the hypothesis of a vaccination-like effect. ECP induces apoptosis of normal and neoplastic lymphocytes, while enhancing differentiation of monocytes towards immature dendritic cells (imDCs), followed by engulfment of apoptotic bodies. After reinfusion, imDCs undergo maturation and antigenic peptides from the neoplastic cells are expressed on the surface of DCs. Mature DCs travel to lymph nodes and activate cytotoxic T-cell clones with specificity against tumor antigens. Disease control is mediated through cytotoxic T-lymphocytes with tumor specificity. The efficacy and excellent safety profile of ECP has been shown in a large number of retrospective trials. Previous studies showed that monotherapy with ECP produces an overall response rate of approximately 60%, while clinical data support that ECP is much more effective when combined with other immune modulating agents such as interferons or retinoids, or when used as consolidation treatment after total skin electron beam irradiation. However, only a proportion of patients actually respond to ECP and parameters predictive of response need to be discovered. A patient with a high probability of response to ECP must fulfill all of the following criteria: (1) SS or erythrodermic MF, (2) presence of neoplastic cells in peripheral blood, and (3) early disease onset. Despite the fact that ECP has been established as a standard treatment modality, no prospective randomized study has been conducted so far, to the authors' knowledge. Considering the high cost of the procedure, the role of ECP in the treatment of SS/MF needs to be clarified via well designed multicenter prospective randomized trials.

Update on the mechanism of action and on clinical efficacy of extracorporeal photopheresis in the treatment of acute and chronic graft versus host disease in children.

Extracorporeal photopheresis (ECP) has been used for treatment of steroid-refractory graft versus host disease (GVHD) with encouraging results. Although its exact mechanism of action is not fully understood, photoapheresed cells seem to induce a selective immune response directed against alloreactive T cell populations without causing generalized immunosuppression. Current pediatric experience with ECP for GVHD is available in the form of a few retrospective small studies concerning children with steroid refractory GVHD. Reviewing these data we conclude that ECP is a safe procedure, well tolerated even in low-weight pediatric patients, which warrants further evaluation in well-designed, prospective, controlled studies.

CFSE flow cytometric quantification of lymphocytic proliferation in extracorporeal photopheresis: use for quality control.

Quality control is essential to validate extracorporeal photopheresis (ECP) processes. There is just one protocol based on PHA-induced proliferation. Since it involves the use of radioactive thymidine, we developed another technique using CFSE labeling. We compared the two tests in a paired series including 18 procedures. The thymidine test was valid. Once proliferation was obtained (10 patients out of 13), the CFSE test was in close agreement with it. In particular, two cases of residual proliferation after ECP were simultaneously detected by both techniques. Only the CFSE test allows targeted analysis of lymphocytes, thus identifying a surviving lymphocytic sub-population.

A survey of blood purification techniques.

Apheresis may be performed with many different techniques. The basis for different therapeutic approaches lies in the pathophysiological processes present in the diseases that have to be treated. Over the years more sophisticated devices have been developed. The most frequent treatment is plasma exchange (plasmapheresis) using centrifugation or single filtration techniques. In addition cascade filtration and subsequent adsorption from plasma is done. Thereby removal is done by adsorption of molecules such as bilirubin, immunoglobulins (immunoadsorption), circulating immune complexes, various antibodies including those against blood types. Such adsorption technologies have also been developed to allow adsorption directly from a column perfused by whole blood (hemoperfusion). By combining various techniques, systems are available that allow bridging of patients with hepatic failure to transplantation (MARS, Prometheus). By adding e.g., hepatic cells to such systems, besides dialysis and adsorption, cells will help to degrade toxic molecules. Such bioreactors are in clinical use. Apheresis includes also the removal or retrieval of cells from blood for e.g., stemcell transplantation, polycythaemia or hemochromatosis. Removal of leukocytes from blood using leukocyte filters is indicated in inflammatory bowel diseases. By specifically irradiating lymphocytes and monocytes with UV light using the technique of extra corporeal photochemotherapy (ECTP) various immunological diseases are treated. On the other hand, various alternative techniques may be used for the same disorder. Thus for patients with high plasma LDL-cholesterol not responding to other lipid lowering strategic treatment, alternative therapy may be done either by cascade filtration, adsorption technology from plasma, heparin precipitation (HELP-system) or hemoperfusion. This article describes various techniques in clinical use.

Extracorporeal photopheresis technical aspects.

Extracorporeal photochemotherapy is a monotherapy first developed by Edelson et al. in 1987. It is a therapy in which 8-methoxypsoralen (8-MOP) containing lymphocytes are exposed to a long wavelength ultraviolet radiation (UVA) in an extracorporeal system. The initial design of the treatment was based on the use of the UVAR system (Therakos) for both the collection and photoirradiation of the mononuclear cells. This machine is replaced now by XTS apparatus, which is fully automatic and has integrated the fluid logic module (the "heart" of the system). Another principle is used: the two independent steps technique. It consists in first collection of mononuclear cells by a continuous blood cell separator and secondly irradiation in an independent machine: UV-MATIC irradiator (VILBER LOURMAT). These three techniques are analyzed through numerous parameters: technical, biological, hematological data. In the future, we consider we need to precise our requirements for adequate UVA energy and 8-MOP concentration. We also have to define therapeutic dose of irradiated cells and so standardize the process.

Quality control for the validation of extracorporeal photopheresis process using the Vilbert-Lourmat UV-A irradiation's system.

In agreement with good practices for therapeutic use of human cells, quality control has to be performed to valid the process of extracorporeal photopheresis (ECP) with the Vilbert-Lourmat system. Since no protocol exists, we evaluated a technique based on the measurement of the inhibition of mitogen (PHA, Con-A, OKT3)-induced proliferation, in 164 procedures from 16 patients. Whatever the pathology, we observed a high proliferation rate in most samples, and we obtained over 90% ECP-induced inhibition in as many as 94% of the cases. Since this approach proved to be relevant regarding our objective, a protocol for the ECP process validation is proposed.

Extracorporeal photochemotherapy for treatment of acute and chronic GVHD in childhood.

BACKGROUND: Extracorporeal photochemotherapy (EPC) has recently been proposed for the treatment of adults with either acute or chronic GVHD. However, data on children given this therapy are scarce. A Phase I-II study was carried out on EPC in children experiencing GVHD after allogeneic transplantation of HPCs. STUDY DESIGN AND METHODS: Nine patients with steroid-resistant, grade II-IV acute GVHD and 14 with chronic GVHD, all of whom had been refractory to at least one line of treatment, were enrolled in this study and analyzed. The median age was 10.3 years (range, 5.4-18.1), and the median body weight was 35 kg (range, 17-89). RESULTS: Seven of the nine patients with acute GVHD showed a response to EPC, whereas the disease progressed in the remaining two children (both with skin, gastrointestinal, and liver GVHD), and they died of grade IV acute GVHD. Among the seven children who responded to EPC, it was possible to completely discontinue immunosuppressive treatment in three. In the 14 children with chronic GVHD, 4 and 5 patients experienced complete and partial response to EPC, respectively, whereas the remaining 5 patients, all with extensive chronic GVHD, had stable disease or disease that progressed during EPC. Among these latter 5 patients, 3 died. In 6 of the 9 patients with chronic GVHD responding to EPC, immunosuppressive therapy was discontinued. CONCLUSION: EPC is safe, feasible, and effective in children with either acute or chronic GVHD occurring after an allograft.

Phototherapy for atopic dermatitis.

The beneficial effects of ultraviolet (UV) radiation on atopic dermatitis has been appreciated for many years. While broadband UVB and psoralen UVA have been the mainstay of phototherapy for some time, the past 5 years have seen the introduction of phototherapeutic modalities, including UVA-1 and 311nm UVB. The best modality and mode of usage is dependent on the type of atopic dermatitis, severity and body site. T lymphocytes play an important role in disease pathogenesis and UV radiation has profound effects on skin and systemic immune responses.