The Application of Two Different Blood Cell Separators to Harvest CD34+ Cells in Patients Suffering from Non Hodgkin's Lymphoma

From January 1996 until now, thirty-eight PBSC procedures were carried out on 20 patients suffering from NHL, mobilized by polichemotherapy regimens plus recombinant human Granulocyte-Growth Factor (rhG-CSF). Patients were enrolled in PBSC procedures using Dideco Excel (group A) and Cobe Spectra v.4.7 (group B) blood cell separators. Twelve patients were enrolled in group A (6 males and 6 females, median age 33) and 9 patients in group B (5 males and 4 females, median age 55). The mean White Blood Cell (WBC) and Mononuclear Cells Fraction (MNC) peripheral blood counts were not statistically different in either group and neither were blood CD34+ cell peripheral counts. CD34+ cell peripheral value was predictive of the CD34+ yield while mean values of harvested CD34+ cells were not significantly different. CD34+ cell efficiences were statistically the same. The CD34+ cell purity of the apheresis harvest was statistically different between the two groups (group A = 3.0 ± 2.2%; group B = 1 ± 0.9%) p = 0.001. High CD34+ cell yields were observed in both groups which confirms that both blood cell separators are able to harvest hematopoietic progenitor cells from peripheral blood.

Long-term immune recovery after CD34+ immunoselected and unselected peripheral blood progenitor cell transplantation: a case-control study

BACKGROUND AND OBJECTIVE

CD34+ stem cell selection induces extensive T-cell depletion as a consequence of ex vivo manipulation. The impact of T-cell depletion on long-term immunologic recovery after autologous CD34+ peripheral blood progenitor cell transplantation (CD34+ PBPCT) is not well characterized. We compared the long term immunologic recovery in two groups of patients submitted to CD34+ PBPCT or unselected autologous peripheral blood progenitor cell transplantation (uPBPCT).

DESIGN AND METHODS

Eight patients in both groups were closely matched for diagnosis, age, disease status at transplantation and conditioning regimen and lymphocyte phenotype was prospectively evaluated during long-term post-transplantation follow-up.

RESULTS

At a median of 18 months after transplantation, CD3+ lymphocyte subset remained below the normal range in both groups. CD19+ B lymphocytes subset after CD34+ PBPCT was within the normal range in both groups. CD4+ lymphocytes were depressed while the CD8+ lymphocyte subset was increased in group A and in the normal range in group B. As a result, inversion of CD4/CD8 ratio was documented in both groups. T-activated lymphocytes (CD3DR+) and natural killer (CD16/56+) cells were increased in both groups.

INTERPRETATION AND CONCLUSIONS

Long-term immune recovery appears to be unaffected by extensive ex vivo manipulation in this adult population when compared to recovery after unmanipulated PBPCT. CD34+ selection, although causes an extensive depletion of T lymphocytes in the graft does not represent a risk factor for delayed CD4+ recovery late after transplantation. Elevated numbers of NK cells and activated T-cells, which have antineoplastic activity, are maintained late after autologous CD34+ transplantation.

The application of two different blood cell separators to harvest CD34+ cells in patients suffering from non Hodgkin's lymphoma

From January 1996 until now, thirty-eight PBSC procedures were carried out on 20 patients suffering from NHL, mobilized by polichemotherapy regimens plus recombinant human Granulocyte-Growth Factor (rhG-CSF). Patients were enrolled in PBSC procedures using Dideco Excel (group A) and Cobe Spectra v.4.7 (group B) blood cell separators. Twelve patients were enrolled in group A (6 males and 6 females, median age 33) and 9 patients in group B (5 males and 4 females, median age 55). The mean White Blood Cell (WBC) and Mononuclear Cells Fraction (MNC) peripheral blood counts were not statistically different in either group and neither were blood CD34+ cell peripheral counts. CD34+ cell peripheral value was predictive of the CD34+ yield while mean values of harvested CD34+ cells were not significantly different. CD34+ cell efficiencies were statistically the same. The CD34+ cell purity of the apheresis harvest was statistically different between the two groups (group A = 3.0+/-2.2%; group B = 1+/-0.9%) p = 0.001. High CD34+ cell yields were observed in both groups which confirms that both blood cell separators are able to harvest hematopoietic progenitor cells from peripheral blood.

Long-lasting complete remission in plasma cell leukemia after aggressive chemotherapy and CD34-selected autologous peripheral blood progenitor cell transplant: molecular follow-up of minimal residual disease

Plasma cell leukemia is a rare disease associated with very poor survival with standard treatment. We report a patient affected by plasma cell leukemia treated with aggressive chemotherapy and autologous CD34-selected PBPC who achieved a complete remission now lasting more than 2 years. Molecular studies confirmed the presence of minimal residual disease (MRD) despite the absence of disease activity. High-dose chemotherapy with stem cell rescue may be applied to selected patients considering the impact of the treatment on survival. The meaning of molecular MRD in this setting is unclear.

Highly fluorescent reticulocytes after CD34+ peripheral blood progenitor cell transplantation

Highly fluorescent reticulocyte (HFR) counts were evaluated in 13 consecutive patients affected by hematological malignancies and submitted to autologous selected CD34+ peripheral blood progenitor cell (PBPC) transplantation. Results were compared with a historical group of patients comparable for age, disease and conditioning regimen submitted to unfractionated PBPC transplantation. HFR counts of the CD34+ group declined to an undetectable level from day +4 to day +10 when they became detectable and reached 5% of total reticulocyte count by day +12. In the historical group, the nadir was identical but the recovery was faster (day +9). Total reticulocyte count > 1% was achieved at days +17 and +11, respectively. The absolute neutrophil count (ANC) recovery was identical in both groups, achieving a value > 0.5 x 10(9)/l at day +13 after reinfusion. Hence, in the historical group, HFR count gave advance notice of complete and stable hemopoietic engraftment while in the CD34+ group HFR and ANC count showed almost simultaneous recovery.

Granulocyte colony-stimulating factor-primed leukocyte transfusions in candida tropicalis fungemia in neutropenic patients

Optimal management of fungemia in neutropenic patients is still controversial. Several reports have already stressed the poor prognosis in invasive candidiasis (80% mortality in several reports). Therefore granulocyte transfusions would appear to be useful in the management of these infections. We report the use of rhG-CSF-primed granulocyte transfusions plus amphotericin B in two neutropenic patients who developed life-threatening systemic fungal infections. This approach was successful and both patients fully recovered from the infection.

RhG-CSF-mobilized CD34+ peripheral blood progenitors are myeloperoxidase-negative and noncycling irrespective of CD33 or CD13 coexpression

Cycling status, myeloperoxidase expression, informative surface markers, and proliferative potential of peripheral blood hemopoietic progenitors (PBHP) were evaluated by flow cytometry in 10 patients affected by resistant lymphoma, and submitted to stem cell mobilization with combination chemotherapy (MiCMA) followed by recombinant human granulocyte colony-stimulating factor (rhG-CSF, 5 micrograms/kg/day). CD34+ PBHP coexpressed myeloid-associated and activation antigens, i.e., CD33 (96%, range 85-99), CD13 (99.5%, range 99.4-99.8), HLA-DR (99%, range 96.5-99.8), and CD38 (98%, range 90-100), lacked intracytoplasmic myeloperoxidase (MPO, < 3%), and resided in the Gzero/G1 phase of the cell cycle (96.5%, range 81-99.5, compared with 70%, range 49-78 bone marrow HP; p = 0.0007), independently of surface membrane phenotype; S-phase percentages of sorted CD34+ CD33(+)/-, CD34+CD38(+)/-, CD34+HLA-DR(+)/-, CD34+CD45RA(+)/-, CD34+CD45RO(+)/-, and CD34+CD41a(+)/- subpopulations were always negligible. In colony assays, 5-week-old long-term cultures seeded with CD34+CD33- cells yielded as many colonies as did CD34+CD33+ cells. In conclusion, rhG-CSF-mobilized CD34+ PBHPs contain noncycling, highly immature progenitors in which the expression of myeloid-associated antigens, i.e., CD33 or CD13, might not be indicative of myeloid commitment.

In vitro expansion of CD34+ cells mobilized with chemotherapy and G-CSF

Hemopoietic CD34+ progenitors were isolated by immunomagnetic method from normal bone marrow (BM) or from peripheral blood (PB) of patients with non-Hodgkin's lymphoma treated with chemotherapy and granulocyte colony-stimulating factor (GCSF). Aliquots were seeded in long-term cultures (LTC) on bone marrow-derived stromal layers; non-adherent and adherent clonogenic content of the cultures was assayed weekly. The final recovery and the clonogenic efficiency of the CD34+ cells were slightly higher in PB samples than in BM controls. In long term cultures PB cells sustained hemopoiesis as much as BM cells; at week 3 and 4 PB total mononuclear cells and CD34+ cells showed a non-adherent cell recovery higher than the respective BM controls. Furthermore, PB CD34+ cells were expanded in liquid culture in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF alone or combined with interleukin 3 (IL3), stem cell factor (SCF), interleukin 1 (IL1), interleukin 6 (IL6). The combination of GM-CSF, IL3, SCF, IL1 and IL6 produced the maximum increase of both mononuclear cells (30-fold) and granulocyte-macrophage colony forming units (CFU-GM) (4.6-fold) after 7 days of cultures; yet after 14 days a strong decrease of the CFU-GM occurred. These data suggest that G-CSF following chemotherapy mobilizes both early and committed hemopoietic progenitors.

In Vitro Expansion of CD34+ Cells Mobilized with Chemotherapy and G-CSF

Hemopoietic CD34+ progenitors were isolated by immunomagnetic method from normal bone marrow (BM) or from peripheral blood (PB) of patients with non-Hodgkin's lymphoma treated with chemotherapy and granulocyte colony-stimulating factor (GCSF). Aliquots were seeded in longterm cultures (LTC) on bone marrow-derived stromal layers; non-adherent and adherent clonogenic content of the cultures was assayed weekly. The final recovery and the clonogenic efficiency of the CD34+ cells were sligthly higher in PB samples than in BM controls. In long term cultures PB cells sustained hemopoiesis as much as BM cells; at week 3 and 4 PB total mononuclear cells and CD34+ cells showed a non-adherent cell recovery higher than the respective BM controls. Furthermore, PB CD34+ cells were expanded in liquid culture in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF alone or combined with interleukin 3 (IL3), stem cell factor (SCF), interleukin 1 (IL 1), interleukin 6 (IL6). The combination of GM-CSF, IL3, SCF, IL 1 and IL6 produced the maximum increase of both mononuclear cells (30-fold) and granulocyte-macrophage colony forming units (CFU-GM) (4.6-fold) after 7 days of cultures; yet after 14 days a strong decrease of the CFU-GM occurred. These data suggest that G-CSF following chemotherapy mobilizes both early and committed hemopoietic progenitors.