BackgroundHLA-haploidentical hematopoietic stem cell transplantation (HSCT) is suitable for patients lacking related or unrelated HLA-matched donors. Herein, we investigated whether plerixafor (MZ), as an adjunct to G-CSF, facilitated the collection of mega-doses of hematopoietic stem cells (HSC) for TCR-αβ/CD19-depleted haploidentical HSCT, and how this agent affects the cellular graft composition.MethodsNinety healthy donors were evaluated. Single-dose MZ was given to 30 ‘poor mobilizers’ (PM) failing to attain ≥40 CD34+ HSCs/μL after 4 daily G-CSF doses and/or with predicted apheresis yields ≤12.0x106 CD34+ cells/kg recipient’s body weight.ResultsMZ significantly increased CD34+ counts in PM. Naïve/memory T and B cells, as well as natural killer (NK) cells, myeloid/plasmacytoid dendritic cells (DCs), were unchanged compared with baseline. MZ did not further promote the G-CSF-induced mobilization of CD16+ monocytes and the down-regulation of IFN-γ production by T cells. HSC grafts harvested after G-CSF + MZ were enriched in myeloid and plasmacytoid DCs, but contained low numbers of pro-inflammatory 6-sulfo-LacNAc+ (Slan)-DCs. Finally, children transplanted with G-CSF + MZ-mobilized grafts received greater numbers of monocytes, myeloid and plasmacytoid DCs, but lower numbers of NK cells, NK-like T cells and Slan-DCs.ConclusionsMZ facilitates the collection of mega-doses of CD34+ HSCs for haploidentical HSCT, while affecting graft composition.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-014-0240-z) contains supplementary material, which is available to authorized users.

HLA-haploidentical family donors represent a valuable option for children requiring allogeneic hematopoietic stem cell transplantation (HSCT). Because graft-versus-host diseases (GVHD) is a major complication of HLA-haploidentical HSCT because of alloreactive T cells in the graft, different methods have been used for ex vivo T cell depletion. Removal of donor αβ T cells, the subset responsible for GVHD, and of B cells, responsible for post-transplantation lymphoproliferative disorders, have been recently developed for HLA-haploidentical HSCT. This manipulation preserves, in addition to CD34 progenitors, natural killer, γδ T, and monocytes/dendritic cells, contributing to anti-leukemia activity and protection against infections. We analyzed depletion efficiency and cell yield in 200 procedures performed in the last 3 years at our center. Donors underwent CD34 hematopoietic stem cell (HSC) peripheral blood mobilization with granulocyte colony-stimulating factor (G-CSF). Poor CD34 cell mobilizers (48 of 189, 25%) received plerixafor in addition to G-CSF. Aphereses containing a median of 52.5 × 10 nucleated cells and 494 × 10 CD34 HSC were manipulated using the CliniMACS device. In comparison to the initial product, αβ T cell depletion produced a median 4.1-log reduction (range, 3.1 to 5.5) and B cell depletion led to a median 3.4-log reduction (range, 2.0 to 4.7). Graft products contained a median of 18.5 × 10 CD34 HSC/kg recipient body weight, with median values of residual αβ T cells and B cells of 29 × 10/kg and 33 × 10/kg, respectively. Depletion efficiency monitored at 6-month intervals demonstrated steady performance, while improved recovery of CD34 cells was observed after the first year (P = .0005). These data indicate that αβ T cell and B cell depletion of HSC grafts from HLA-haploidentical donors was efficient and reproducible.

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Carbon tetrachloride (CCl4 )-induced hepatotoxicity is likely the result of a CCl4 -induced free radical production which causes membrane lipid peroxidation and activation of transcription factors regulating both the TNF-alpha gene and the early-immediate genes involved in tissue regeneration. IRFI 042 is a novel vitamin E-like compound having a masked sulphydryl group in the aliphatic side chain. We studied the effect of IRFI 042 on CCl4 -induced liver injury. Liver damage was induced in male rats by an intraperitoneal injection of CCl4 (1 ml/kg in vegetal oil). Serum alanine aminotransferase (ALT) activity, liver malondialdehyde (MAL), hydroxyl radical formation (OH*), calculated indirectly by a trapping agent, hepatic reduced glutathione (GSH) concentration, plasma TNF-alpha, liver histology and hepatic mRNA levels for TNF-alpha were evaluated 48 h after CCl4 administration. Hepatic vitamin E (VE) levels were evaluated, in a separate group of animals, 2 h after CCl4 injection. A control group with vitamin E (100 mg/kg) was also treated in order to evaluate the differences versus the analogue treated groups. Intraperitoneal injection of carbon tetrachloride produced a marked increase in serum ALT activity (CCl4 = 404.61 +/- 10.33 U/L; Controls= 28.54 +/- 4.25 U/L), liver MAL (CCl4 = 0.67 +/- 0.16 nmol/mg protein; Controls= 0.13 +/- 0.06 nmol/mg protein), OH(7) levels assayed as 2,3-DHBA (CCl4 = 8.73 +/- 1.46 microM; Controls= 0.45 +/- 0.15 microM) and 2,5-DHBA (CCl4 = 24.61 +/- 3.32 microM; Controls= 2.75 +/- 0.93 microM), induced a severe depletion of GSH (CCl4 = 3.26 +/- 1.85 micromol/g protein; Controls= 17.82 +/- 3.13 micromol/g protein) and a marked decrease in VE levels (CCl4 = 5.67 +/- 1.22 nmol/g tissue; Controls= 13.47 +/- 3.21 nmol/g tissue), caused liver necrosis, increased plasma TNF-alpha levels (CCl4 = 57.36 +/- 13.24 IU/ml; Controls= 7.26 +/- 2.31 IU/ml) and enhanced hepatic mRNA for TNF-alpha (CCl4 = 19.22 +/- 4.38 a.u.; Controls= 0.76 +/- 0.36 a.u.). IRFI 042 (100 mg/kg, 30 min after CCl4 injection) blunted liver MAL (0.32 +/- 0.17 nmol/mg protein), decreased the serum levels of ALT (128.71 +/- 13.23 U/L), and restored the hepatic concentrations of VE (9.52 +/- 3.21 nmol/g tissue), inhibited OH* production (2,3-DHBA= 3.54 +/- 1.31 microM; 2,5-DHBA= 7.37 +/- 2.46 microM), restored the endogenous antioxidant GSH (12.77 +/- 3.73 mmol/g protein) and improved histology. Furthermore IRFI 042 treatment suppressed plasma TNF-alpha concentrations (31.47 +/- 18.25 IU/ml) and hepatic TNF-alpha mRNA levels (11.65 +/- 3.21 a.u.). The acute treatment with vitamin E failed to exert any protective effect against CCl4 -induced hepatotoxicity. These investigations suggest that IRFI 042 treatment may be of benefit during free radical-mediated liver injury.