Extracorporeal photopheresis: Is one ounce of blood enough? Case reports.

Extracorporeal photopheresis (ECP) has proven effective in the treatment of several diseases, including acute and chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation. In its standard version, ECP requires leukapheresis to obtain a fraction of mononuclear cells. The possibility of using leukapheresis is limited by the requirements for vascular access and the somatic status of the patient. We have developed a new ECP method that does not require leukapheresis. This paper presents a description of two clinical cases of severe refractory GVHD treated by micro-ECP.

Efficacy and safety of a reduced dose of plerixafor in combination with granulocyte colony-stimulating factor in healthy haploidentical stem cell donors.

BACKGROUND AND OBJECTIVES: Implementation of the technique of immunomagnetic selection requires the procurement of a large number of CD34+ cells from haploidentical donors within a single apheresis procedure. The release of stem cells with granulocyte colony-stimulating factor (G-CSF) alone is unsatisfactory in a number of donors, and plerixafor, a CXCR4 chemokine receptor antagonist, could be used as an additional mobilization agent. The aim of our study was to examine whether a lower dose of plerixafor (0.12 mg/kg) can provide sufficient increase in CD34+ cells in the peripheral blood of allogeneic healthy donors in comparison with a historical control group. In addition, we assessed the risk of inability to provide the recipient with a transplant containing the optimal dose of 8-10 × 106 CD34+ cells/kg body weight of the recipient. MATERIALS AND METHODS: In a prospective, single-arm study, we examined the results of 105 mobilizations in healthy adult haploidentical donors with G-CSF and plerixafor at a dose of 0.12 mg/kg. The historical control group consisted of 106 mobilizations with G-CSF and plerixafor at 0.24 mg/kg. RESULTS: The median increase in the number of CD34+ cells from day 4 to day 5 of mobilization was 69 cells/µl (range, 28-240) versus 77 cells/µl (24-217) in the groups of 0.12 and 0.24 mg/kg of plerixafor, respectively (p-value 0.255). The apheresis products contained a median of 14.4 × 106 /kg recipient body weight CD34+ cells versus 12.9 × 106 /kg in the groups that received 0.12 and 0.24 mg/kg of plerixafor, respectively (p-value 0.118). The obtained differences were not significant, which means the application of a decreased dose of plerixafor did not affect the results of mobilization. CONCLUSION: The obtained differences in collection were not significant, and thus the application of a decreased dose of plerixafor did not affect the results of mobilization.

Quality assessment of red blood cell suspensions derived from pathogen-reduced whole blood.

BACKGROUND: We used laboratory indicators to evaluate the quality of pathogen-reduced red blood cell suspension (RBCS) compared with gamma-irradiated RBCS. MATERIALS AND METHODS: To determine biochemical and metabolic parameters of RBCS, we obtained 50 whole blood units from healthy volunteers and randomized them into 2 groups: 25 were pathogen-reduced, and then, RBCS prepared from them. RBCS from the other 25 was gamma-irradiated. Sampling was carried out on day zero before and after treatment and at 7, 14, 21 and 28 days. To determine lymphocyte inactivation, we collected another 35 whole blood units. Each was sampled to form 3 study groups: untreated, gamma-irradiated and pathogen-reduced. Daily sampling was carried out during 3 days of storage. RESULTS: The quality of RBCS from both groups was largely the same, except for haemolysis and red blood cell fragility, which were more pronounced in the pathogen-reduced group. This finding limited the shelf life of pathogen-reduced RBCS to 14 days. Lymphocyte viability was significantly reduced after both treatments. Proliferation of lymphocytes after pathogen reduction was reduced to the detection limit, while low-level proliferation was observed in gamma-irradiated samples. CONCLUSION: Pathogen-reduced red blood cells have acceptable quality and can be used for transfusion within 14 days. Results of inactivation of lymphocytes demonstrate that pathogen reduction technology, applied on WB, can serve as an alternative to irradiation.

The pathogen-reduced red blood cell suspension: single centre study of clinical safety and efficacy in children with oncological and haematological diseases.

BACKGROUND: Transmission of pathogens through blood transfusion is still of great concern to clinicians, patients and blood providers. Pathogen reduction technologies (PRT) have been successfully applied for the treatment of labile blood components, such as plasma, platelets and whole blood (WB), which are now used in routine in many countries. We report the clinical evaluation of suspension of red blood cells (RBC-S) derived from the WB treated with riboflavin and UV light (RF+UV). STUDY DESIGN AND METHODS: Seventy paediatric patients (0·3-17·1 years old) suffering from different malignant disorders were recruited and assigned to two groups: the control group (C) received transfusions of γ-irradiated RBC-S. The experimental group (T) received RBC-S derived from WB, treated with RF+UV. Clinical efficacy was evaluated during follow-up periods by Hb and Ht increments, and needs for transfusion support. Safety was assessed through active surveillance, recording post-transfusion reactions, anti-erythrocyte's antibody formation, haptoglobin and serum potassium levels. RESULTS: The clinical efficacy of RBC-S in both groups was similar: mean post-transfusion Hb concentration (101·6 ± 7·57 g/l vs. 100 ± 8·3 g/l; P = 0·43), and Ht level (28·5 ± 2·42% vs. 28·2 ± 2·7%; P = 0·66). Transfusion of pathogen-reduced RBC-S did not increase the frequency of transfusion reactions and did not induce an excessive immune response in the follow-up period. CONCLUSION: Transfusion of RBC-S, obtained from pathogen-reduced WB, is a promising method to increase the safety of blood component therapy for paediatric patients with malignant disorders without affecting clinical efficacy. A randomized clinical trial including more patients should follow this pilot study to confirm its results.