Peripheral endothelial progenitor cells (CD133 +) for therapeutic vasculogenesis in a patient with critical limb ischemia. One year follow-up

We present a patient with critical limb ischemia who was successfully treated with the injection of autologous peripheral blood (PB) CD133+ purified stem cells (SC) into the gastrocnemius muscle. No serious adverse events related to G-CSF administration, mononuclear cells harvest or CD133+ SC administration was observed. After 17 months of follow-up, our patient has experienced limb salvage, symptomatic relief and functional improvement. Moreover, we have observed the appearance of flow in the right posterior tibial artery that was absent before the procedure. To our knowledge, this is the first case of critical limb ischemia treated with PB CD133+ SC.

Short-term endothelial progenitor cell colonies are composed of monocytes and do not acquire endothelial markers

BACKGROUND

The aim of this study was to identify circulating endothelial progenitor cells (EPC) with colony-forming capacity and compare them with the monocytic-macrophage lineage.

METHODS

Forty-two healthy donors were analyzed. EPC were cultured with VEGF and b-FGF. Sequential studies were performed on days +7 (colonies) +21 and +35. Monocytic cells were cultured using the same conditions as EPC until day +21 or alternatively by adding IGF.

RESULTS

The number of EPC colonies was higher in BM than in mobilized or steady-state PB. Using EPC medium, monocytic cells formed cord-like structures but no colonies. However, colonies grew when IGF was added to the medium. By immunocytochemistry, colonies showed CD45, CD31 and lysozyme but no vWF. Colonies were CD4+, CD13+dim, CD14+, CD15++, CD16-/+dim, CD31+dim, CD33+dim, CD45+, CD105-/+dim, lysozyme+ and VE-cadherin+, and constantly negative for CD34, CD133 and KDR, when flow cytometry was used. The immunophenotype of pre-cultured and cultured monocytes was similar to that described for EPC.

DISCUSSION

Our results suggest that the so-called 'EPC' obtained at 7 days of culture belong to the monocyte-macrophage lineage, as they share immunophenotypic and molecular features.

Bortezomib induces selective depletion of alloreactive T lymphocytes and decreases the production of Th1 cytokines

We explored the ability of the proteasome inhibitor bortezomib, which prevents nuclear factor kappaB (NF-kappaB) activation, to block T-cell activation, proliferation, and survival within alloreactive compared with resting T cells. For this purpose, T cells were stimulated with PHA, alphaCD3/alphaCD28, or allogeneic dendritic cells or through mixed lymphocyte cultures. NF-kappaB expression increased in activated T lymphocytes compared with resting T cells. Of interest, the higher the NF-kappaB expression, the more intense the proliferative blockade induced by bortezomib. Moreover, after mixed lymphocyte reaction (MLR) cultures, alloreactive T cells were 2 logs more sensitive to bortezomib-induced apoptosis than the resting T-cell counterpart. This effect was due to a selective induction of apoptosis among activated T cells that was related to caspase activation and cleavage of the antiapoptotic bcl-2 protein and was partially abolished by the addition of the pancaspase inhibitor Z-VAD-FMK. In addition, after secondary MLR, the number of activated T cells was significantly reduced among T lymphocytes previously cultured with bortezomib when cells from the same donor were used as stimulating cells. By contrast, when third-party donor cells were used as stimulating cells, no significant differences were observed between T lymphocytes previously exposed or not to the drug, indicating a highly specific depletion of T lymphocytes alloreactive against primary donor antigens. The addition of bortezomib decreased not only the proliferation and viability of activated T lymphocytes but also the levels of IFNgamma and IL-2, which were significantly decreased among activated T cells cultured with bortezomib at doses ranging from 10 to 100 nM. In conclusion, at concentrations reached in the clinical setting, bortezomib induces selective apoptosis and decreases Th1 response among alloreactive T lymphocytes while it barely affects unstimulated T cells. These results establish the basis for the clinical use of bortezomib in the management of graft-versus-host disease (GVHD).

Autologous skeletal myoblast transplantation in patients with nonacute myocardial infarction: 1-year follow-up

OBJECTIVE

To determine the feasibility and safety of skeletal myoblast transplantation in patients with chronic myocardial infarction undergoing coronary artery bypass grafting.

METHODS

Twelve patients with a previous myocardial infarction and ischemic coronary artery disease underwent treatment with coronary artery bypass grafting surgery and intramyocardial injection of autologous skeletal myoblasts cultured with autologous serum. Global and regional cardiac function was assessed by echocardiogram. Fluorine 18 fluorodeoxyglucose and nitrogen 13-ammonia positron emission tomography studies were used to determine cardiac viability and perfusion. A group of historical control patients (n = 14) treated with coronary artery bypass grafting surgery without myoblast transplantation was analyzed.

RESULTS

The left ventricular ejection fraction improved from 35.5% +/- 2.3% (mean +/- SEM) before surgery to 55.1% +/- 8.2% at 12 months (P < .01) in the myoblast group and from 33.6% +/- 9.3% to 38.6% +/- 11% in the control group. Regional contractility also improved in the myoblast group, particularly in cardiac segments treated with skeletal myoblasts (wall motion score index: 3.02 +/- 0.17 at baseline vs 1.36 +/- 0.14 at 12 months; P < .0001). Quantitative fluorine 18-fluorodeoxyglucose and nitrogen 13-ammonia positron emission tomography showed an increase in viability and perfusion 12 months after surgery both globally and in segments treated with myoblasts (P = .012 and P = .004). Skeletal myoblast implantation was not associated with adverse events or an increased incidence of cardiac arrhythmias.

CONCLUSIONS

In patients with previous myocardial infarction, treatment with skeletal myoblasts in conjunction with coronary artery bypass is safe and feasible and is associated with an increased global and regional left ventricular function, improvement in viability, and perfusion of cardiac tissue and no significant incidence of arrhythmias.

Long-term bone marrow culture data are the most powerful predictor of peripheral blood progenitor cell mobilization in healthy donors

BACKGROUND AND OBJECTIVES

There is wide interindividual variation in progenitor cell mobilization. The present study was aimed to analyze steady state hematopoiesis in healthy donors and its influence on hematopoietic progenitor cell (HPC) mobilization.

DESIGN AND METHODS

Bone marrow (BM) was aspirated from 72 healthy donors prior to administration of recombinant human granulocyte colony-stimulating factor (G-CSF). Analyses of CD34+ cells and semisolid cultures as well as long-term cultures were performed from BM or leukapheresis products.

RESULTS

Male donors showed a higher number of BFU-E (p=0.007) and committed progenitors (p=0.05), a better stromal layer (p=0.02), and higher long-term bone marrow culture (LT-BMC) counts (p<0.05) when compared to those in female donors. When correlating the culture pattern of the BM with the data from the leukapheresis products, we observed that the number of the immature progenitors in BM correlated significantly with both the number of CD34 + cells and CFU-GM in the first leukapheresis. Univariate analysis revealed that the following variables had a beneficial impact on the number of CD34+ cells: male sex, body weight >73 Kg, G-CSF schedule and results of LT-BMC, although in the multivariate analysis only the number of CFU-GM obtained after LT-BMC showed a significant influence (p<0.001).

INTERPRETATION AND CONCLUSIONS

These results confirm the interindividual variation in HPC mobilization among healthy subjects, with LT-BMC counts being the most reliable predictor, expressing the behavior of the immature progenitors and their relationship with the microenvironment.

Effect of pre-transplant cumulative doses of chemotherapeutic drugs on early and long-term hematological recovery after autologous bone-marrow transplantation for lymphoma

BACKGROUND AND OBJECTIVES

It has recently been demonstrated that autologous bone-marrow transplantation (ABMT) is feasible in heavily pretreated patients who do not mobilize peripheral blood progenitor cells (PBPC), suggesting that bone marrow (BM) progenitor-cells are not as sensitive to chemotherapy as are PBPC. However, information regarding the impact of previous chemotherapy on the performance of BM grafts is scanty.

DESIGN AND METHODS

We have retrospectively analyzed 40 consecutive lymphoma patients treated with the BEAM regimen and ABMT at our institution. The impact of the chemotherapeutic drugs (individual cumulative doses) received before transplant on stem-cell yield and hematologic recovery was investigated. Univariate analysis failed to identify any variable that significantly affected progenitor-cell content.

RESULTS

Regarding the impact of pre-transplant chemotherapy on early engraftment, only cumulative doses of cytarabine (r=0.28, p=0.04) and cisplatin (r=0.32,p=0.02) had a negative influence on neutrophil recovery (to >0.5x10(9)/L), but the significance of this was not maintained in multivariate analysis. We did not find any chemotherapeutic drug that negatively affected platelet recovery (to >20x10(9)/L). By contrast, administration of several drugs, including doxorubicin, procarbazine, nitrogen mustard, cytarabine and cisplatin, significantly delayed complete trilineage reconstitution. In multivariate analysis, only previous doxorubicin retained statistical significance (p=0.014).

INTERPRETATION AND CONCLUSIONS

Our results show that pre-transplant chemotherapy has little or no influence on progenitor-cell yield and short-term engraftment after ABMT. In contrast, we found that cumulative doxorubicin doses have an independent influence on long-term engraftment. In heavily pretreated lymphoma patients in whom poor PBPC mobilization is expected, BMT may represent an attractive option.

Mesenchymal stem cells are present in peripheral blood and can engraft after allogeneic hematopoietic stem cell transplantation

BACKGROUND AND OBJECTIVES

Whether human mesenchymal stem cells (MSC) can be transplanted is controversial and their presence in peripheral blood is not fully accepted. In the present study we have analyzed whether, within the allogeneic transplantation setting, MSC are of host or donor origin.

DESIGN AND METHODS

Bone marrow MSC from 19 patients who had undergone allogeneic transplantation were expanded and identified using immunophenotypic markers. After that, chimerism studies were performed using reverse transcription polymerase chain reaction of short tandem repeat (STR) loci. Analyses were carried out at different time-points after transplantation, with a total of 44 samples studied. Bone marrow was used as the source of stem cells for transplantation in 4 cases and peripheral blood in 15 cases. The conditioning regimen was standard in 9 patients and non-myeloablative in 10 patients.

RESULTS

Our results show that in the great majority of cases analyzed (17 out 19), MSC were of host origin. However, in 2 patients with multiple myeloma who had received a reduced intensity transplantation using peripheral blood stem cells, MSC were partially of donor origin (60.17% and 26.13% of total MSC).

INTERPRETATION AND CONCLUSIONS

These findings indicate that after allogeneic transplantation MSC from the donor can engraft in bone marrow. Moreover, since the stem cells were obtained from peripheral blood, it can be concluded that MSC circulate among mobilized peripheral blood stem cells and can engraft in bone marrow after allogeneic transplantation.

Analysis of hematopoietic progenitor cells in patients with myelodysplastic syndromes according to their cytogenetic abnormalities

The present work analyzes the hematopoietic progenitor cells (HPC) in myelodysplastic syndrome (MDS) patients using both an immunophenotypical and a functional approaches in order to know whether they are similar in patients with or without cytogenetic abnormalities. Among CD34+ HPC, the proportion of myeloid committed progenitors was higher in patients with an abnormal karyotype. Ninety MDS patients were studied. Patients with abnormal karyotype showed a similar platting efficiency than patients with normal cytogenetics. Trisomy 8 and 5q- showed a significant higher P.E. than patients with normal karyotype or monosomy 7. We observed that when the most immature HPC were studied, the total number of granulo-monocytic colonies produced by LTBMC was higher in the normal karyotype group. In summary, the present study shows that in MDS the HPC are impaired; this impairment is deeper in patients with abnormal karyotype.

Results of autologous transplantation in lymphoma are not improved by increasing the dose of etoposide in the BEAM regimen: a single-centre sequential-cohort study

We have undertaken a retrospective sequential-cohort analysis of 131 lymphoma patients treated with the BEAM regimen and autologous stem cell transplantation, to compare BEAM at standard doses (sBEAM; n = 67 from May 1990 to April 1995) and BEAM with escalated etoposide dose from 800 to 1600 mg/m(2) (eBEAM; n = 64 from May 1995 to June 1999). Transplant-related mortality and incidence of secondary malignancies were similar in both groups. Disease progression was significantly lower in indolent lymphoma (IL) patients receiving eBEAM (7 vs 43%), although survival was comparable due to a higher toxic mortality in the eBEAM group. The 5-year event-free survival and overall survival were better in Hodgkin's disease (HD) patients treated with eBEAM (70 and 77%, respectively) compared to sBEAM (58 and 69%, respectively), but the difference was not statistically significant. In aggressive lymphomas, no difference was detected between groups. Our results indicate that while escalation of the etoposide doses in the BEAM conditioning regimen does not appear to improve outcome, encouraging results in IL and HD may warrant further studies.

Autologous intramyocardial injection of cultured skeletal muscle-derived stem cells in patients with non-acute myocardial infarction

AIM

Experimental animal studies suggest that the use of skeletal myoblast in patients with myocardial infarction may result in improved cardiac function. The aim of the study was to assess the feasibility and safety of this therapy in patients with myocardial infarction.

METHODS AND RESULTS

Twelve patients with old myocardial infarction and ischaemic coronary artery disease underwent treatment with coronary artery bypass surgery and intramyocardial injection of autologous skeletal myoblasts obtained from a muscle biopsy of vastus lateralis and cultured with autologous serum for 3 weeks. Global and regional cardiac function was assessed by 2D and ABD echocardiogram. 18F-FDG and 13N-ammonia PET studies were used to determine perfusion and viability. Left ventricular ejection fraction (LVEF) improved from 35.5+/-2.3% before surgery to 53.5+/-4.98% at 3 months (P=0.002). Echocardiography revealed a marked improvement in regional contractility in those cardiac segments treated with skeletal myoblast (wall motion score index 2.64+/-0.13 at baseline vs 1.64+/-0.16 at 3 months P=0.0001). Quantitative 18F-FDG PET studies showed a significant (P=0.012) increased in cardiac viability in the infarct zone 3 months after surgery. No statistically significant differences were found in 13N-ammonia PET studies. Skeletal myoblast implant was not associated with an increase in adverse events. No cardiac arrhythmias were detected during early follow-up.

CONCLUSIONS

In patients with old myocardial infarction, treatment with skeletal myoblast in conjunction with coronary artery bypass is safe and feasible and is associated with an increased global and regional left ventricular function,improvement in the viability of cardiac tissue in the infarct area and no induction of arrhythmias.