Angiogenesis Facilitated by Autologous Whole Bone Marrow Stem Cell Transplantation for Buerger's Disease

Application of nanofat grafting to rescue a severe ischaemic hand with thromboangiitis obliterans: A case report about promising salvage procedure

RATIONALE

Currently, there is no consensus regarding the best treatment for patients with thromboangiitis obliterans (TAO). Regenerative medicine, such as bone marrow stem cells or adipose-derived stem cell (ASC) transplantation, have proven efficacy in improving tissue perfusion and wound healing in clinical trials. In this case, we used nanofat grafting to treat severe conditions in a patient with TAO, with promising outcomes.

PATIENT CONCERNS

This is a case of a 48-year-old smoker who presented with cyanosis in both hands and the right foot, with gangrenous changes. Investigative angiography showed severe vasospasm in the radial and ulnar arteries of the patient's left hand. Progressive cyanosis of the patient's left hand was noted which may eventually require amputation if left untreated.

DIAGNOSES

He was diagnosed with TAO under the Shionoya diagnostic criteria.

INTERVENTIONS

Fasciotomy and necrotic tissue debridement were performed, followed by centrifuged nanofat grafting. The nanofat graft was prepared using Pallua method and deployed with a MAFT-GUN (Dermato Plastica Beauty Co., Ltd., Kaohsiung, Taiwan).

OUTCOMES

Three months later, computed tomography angiography revealed a radial artery patency. The patient's wrist function was preserved with uneventful wound healing.

LESSONS

The regenerative ability of centrifuged nanofat grafts not only helps wound healing but also helps reverse vasospasm and preserve remnant tissue perfusion.

Combination of intramuscular transplantation of autologous mononuclear bone marrow cells with sympathectomy (L2, 3) in patients with peripheral arterial disease(PAD)

BACKGROUND

In most patients with severe, chronic extremity ischemic diseases, intervention or surgical treatment is often not suitable. Combination of intramuscular transplantation of autologous monocular bone marrow cells (AMBMCs) and sympathectomy (L2, 3) has been proved therapeutically beneficial.

METHODS

We studied 170 patients (combined group 80, control group 90) with extremity ischemia (TAO, ASO FontaineⅡ,Ⅲ, Ⅳ) between January 2013 and September 2019.

RESULTS

In contrast to pre-operation, the walking distance of patients increased significantly (from 61.34 ± 52.23 m to 156.0 ± 32.4 m, p < 0.01), and the ankle-brachial index (ABI) remarkably improved (from 0.28 ± 0.13 to 0.59 ± 0.23, p < 0.05).

CONCLUSION

Combined therapy is feasible and effective for patients with peripheral arterial disease (PAD).

Stem Cell Therapy for Thromboangiitis Obliterans (Buerger’s Disease)

Buerger’s disease or Thromboangiitis Obliterans (TAO) is a nonatherosclerotic segmental vascular disease which affects small and medium arteries and veins in the upper and lower extremities. Based on pathological findings, TAO can be considered as a distinct form of vasculitis that is most prevalent in young male smokers. There is no definitive cure for this disease as therapeutic modalities are limited in number and efficacy. Surgical bypass has limited utility and 24% of patients will ultimately require amputation. Recently, studies have shown that therapeutic angiogenesis and immunomodulatory approaches through the delivery of stem cells to target tissues are potential options for ischemic lesion treatment. In this review, we summarize the current knowledge of TAO treatment and provide an overview of stem cell-based treatment modalities.

[Biotherapies for erectile dysfunction and Peyronie's disease: Where are we now?]

INTRODUCTION

Clinical trials of cell therapy for erectile dysfunction (ED) and Peyronie's disease (PD) were recently conducted after preclinical studies.

AIMS

The aims of this study are to give an update on biotherapy for ED and PD and to describe the regulatory framework for these therapies.

MATERIALS AND METHODS

A literature review was performed through PubMed and Clinical.trials.gov addressing cell therapy for ED and PD and using following keywords "erectile dysfunction", "Peyronie's disease", "stem cell", and "platelet-rich plasma".

RESULTS

Preclinical studies in rodent models have shown the potential benefit of cell therapy for ED after radical prostatectomy or caused by metabolic diseases, and PD. The tissues used to obtain the therapeutic product were bone marrow, adipose tissue and blood (PRP, platelet-rich plasma). Mechanism of action was shown to be temporary and mainly paracrine. Four clinical trials were published concerning ED after radical prostatectomy and in diabetic patients and one for PD. Eleven clinical trials including three randomized trials are currently going on. Preclinical and preliminary clinical results suggested the possibility to improve spontaneous erectile function and response to pharmaceutical treatment in initially non-responder patients. This effect is mediated by an improvement of penile vascularization. A reduction of penile curvature without side effect was noted after injections into the plaque of PD patients. Most of these therapeutic strategies using autologous cells were considered as "Advanced Therapy Medicinal Products" with strict regulatory frameworks imposing heavy constraints, in particular in case of "substantial" modification of the cells. The regulatory framework remains unclear and more permissive for PRP and cell therapy processes with extemporaneous preparation/injection and no "substantial" modifications.

CONCLUSIONS

First results on cell therapy for ED and PD are promising. The regulatory framework can significantly change according to cell preparations and origins leading to various constraints. This regulatory framework is crucial to consider for the choice of the procedure.

Thromboangiitis obliterans: Aggressive angioplasty provides a potential solution (randomized pilot study)

Background

Thromboangiitis obliterans is an inflammatory disease affecting both medium- and small-sized vessels. Vasodilators, antiplatelets were proposed for treatment but the effect was minimal.

Objective

This study was conducted to investigate the effect of balloon angioplasty on patients with Buerger's disease compared to medical treatment.

Methods

Between January 2006 and December 2016, 82 patients with Buerger's disease were enrolled in the study, of whom 52 were randomized to the aggressive endovascular intervention and 30 were randomized medically by cilostazol and aspirin as a control group. In all, 23% of the patients presented with severe claudication, 50% with ischemic rest pain and 27% with ischemic ulcers. Randomization was done using the opaque envelope method. Allocation concealment was maintained to ensure no selection bias. Patient groups were compared for the duration of ulcer healing, ankle-brachial index, peak systolic velocity changes and transcutaneous oximetry (TcPO2) level for 30 months.

Results

No major procedural complications occurred in the endovascular group. Angiographic success was achieved in 100% of supragenicular lesions but in 90% of infrapopliteal lesions. The endovascular group showed a statistically significant improvement in the ulcer healing size and duration at 6 months after the procedure with a mean time of 3 ± 0.9 months compared to 5.8 ± 1.69 months for the medical treatment group (p < 0.001), the mean TcPO2 from 27.23 ± 16.75 mm Hg (range: 0-56 mm Hg) before the procedure to 71.32 ± 12.94 mm Hg (range: 52-92 mm Hg) following revascularization (p < 0.01). The mean ankle-brachial index significantly improved from 0.54 ± 0.14 preoperatively to 0.82 ± 0.08 at final follow-up (p < 0.01).

Conclusion

The endovascular therapy should be considered as an effective, safe, minimally invasive method in the light of the promising results after a modification of the standard technique.

Long-term follow-up of patients with Buerger's disease after autologous stem cell therapy

Objective:

We investigated the long-term results of autologous bone marrow mononuclear cells (ABMMNCs) implantation in patients with Buerger’s disease (BD).

Methods:

Twenty-eight patients (25 males and 3 females) who had BD and critical unilateral limb ischemia were investigated between April 2003 and August 2005. The patients were administered multiple injections of CD34+ and CD45+ positive ABMMNCs into the gastrocnemius muscle, the intermetatarsal region, and the dorsum of the foot (n=26) or forearm (n=2) and saline injection into the contralateral limb.

Results:

The mean follow-up time was 139.6±10.5 months. No complication related to stem cell therapy was observed during the follow-up. The ankle–brachial pressure index evaluated at 6 months and 120 months was compared to the baseline scores (p<0.001 and p=0.021, respectively). Digital subtraction angiography (DSA) was performed for all patients at baseline, 6 months, and 120 months. The angiographic improvement was 78.5% and 57.1% at 6 and 120 months, respectively. Patients demonstrated a significant improvement in the quality of life parameters at 6 months compared to baseline (p=0.008) and 120 months compared to the baseline (p=0.009). The 10-year amputation-free rate was 96% (95% CI=0.71-1) in ABMMNC-implanted limbs and 93% (95% CI=0.33–0.94) in saline-injected limbs (p=1).

Conclusion:

Autologous stem cell therapy could be an alternative therapeutic method for BD at long-term follow-up.

Stem Cell Therapies in Peripheral Vascular Diseases — Current Status

Peripheral artery diseases include all arterial diseases with the exception of coronary and aortic involvement, more specifically diseases of the extracranial carotids, upper limb arteries, mesenteric and renal vessels, and last but not least, lower limb arteries. Mononuclear stem cells, harvested from various sites (bone marrow, peripheral blood, mesenchymal cells, adipose-derived stem cells) have been studied as a treatment option for alleviating symptoms in peripheral artery disease, as potential stimulators for therapeutic angiogenesis, thus improving vascularization of the ischemic tissue. The aim of this manuscript was to review current medical literature on a novel treatment method — cell therapy, in patients with various peripheral vascular diseases, including carotid, renal, mesenteric artery disease, thromboangiitis obliterans, as well as upper and lower limb artery disease.

Protein profiling and angiogenic effect of hypoxia-cultured human umbilical cord blood-derived mesenchymal stem cells in hindlimb ischemia

The aim of the present study was to investigate protein profiles of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) cultured in normoxic (21% O₂) and hypoxic (1% O₂) conditions, and evaluate oxygenation effects on angiogenesis in an ischemic hindlimb mouse model using a modified ischemic scoring system. Hypoxic conditions did not change the expression of phenotypic markers and increased adipogenesis and chondrogenesis. Epidermal growth factor (EGF), transforming growth factor alpha (TGF-α), TGF-β RII, and vascular endothelial growth factor (VEGF) were upregulated in the conditioned medium of hypoxic hUCB-MSCs, which are commonly related to angiogenesis and proliferation of biological processes by Gene Ontology. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, significant enrichment of the phosphorylation of abelson murine leukemia viral oncogene homolog 1 (ABL1) (Phospho-Tyr204) and B-cell lymphoma-extra large (BCL-XL) (Phospho-Thr47) as anti-apoptotic pathways was observed in hypoxic hUCB-MSCs. Furthermore, hypoxic conditions induced proliferation and migration, and reduced apoptosis of hUCB-MSCs in vitro. Based on the results of protein antibody array, we evaluated the angiogenic effects of injecting normoxic or hypoxic hUCB-MSCs (1×10⁶) into the ischemic hindlimb muscles of mice. Ischemic scores and capillary generation were significantly greater in the hypoxic hUCB-MSC injection group than in the normoxic hUCB-MSC group. Our findings demonstrate that culturing hUCB-MSCs in hypoxic conditions not only significantly enriches phosphorylation in the anti-apoptosis pathway and enhances the secretion of several angiogenic proteins from cells, but also alleviates ischemic injury of hindlimb of mice.

The Use of Endothelial Progenitor Cells for the Regeneration of Musculoskeletal and Neural Tissues

Endothelial progenitor cells (EPCs) derived from bone marrow and blood can differentiate into endothelial cells and promote neovascularization. In addition, EPCs are a promising cell source for the repair of various types of vascularized tissues and have been used in animal experiments and clinical trials for tissue repair. In this review, we focused on the kinetics of endogenous EPCs during tissue repair and the application of EPCs or stem cell populations containing EPCs for tissue regeneration in musculoskeletal and neural tissues including the bone, skeletal muscle, ligaments, spinal cord, and peripheral nerves. EPCs can be mobilized from bone marrow and recruited to injured tissue to contribute to neovascularization and tissue repair. In addition, EPCs or stem cell populations containing EPCs promote neovascularization and tissue repair through their differentiation to endothelial cells or tissue-specific cells, the upregulation of growth factors, and the induction and activation of endogenous stem cells. Human peripheral blood CD34(+) cells containing EPCs have been used in clinical trials of bone repair. Thus, EPCs are a promising cell source for the treatment of musculoskeletal and neural tissue injury.

Buerger's disease: providing integrated care

Buerger’s disease, also known as thromboangiitis obliterans (TAO), is a segmental inflammatory disease affecting small- and medium-sized vessels, which is strongly associated with tobacco use. Although the etiology is still unknown, recent studies suggest an immunopathogenesis. Diagnosis is based on clinical and angiomorphologic criteria, including age, history of smoking, clinical presentation with distal extremity ischemia, and the absence of other risk factors for atherosclerosis, autoimmune disease, hypercoagulable states, or embolic disease. Until now, no causative therapy exists for TAO. The most important therapeutic intervention is smoking cessations and intravenous prostanoid infusions (iloprost). Furthermore, effective analgesia is crucial for the treatment of ischemic and neuropathic pain and might be expanded by spinal cord stimulation. Revascularization procedures do not play a major role in the treatment of TAO due to the distal localization of arterial occlusion. More recently, immunoadsorption has been introduced eliminating vasoconstrictive G-protein-coupled receptor and other autoantibodies. Cell-based therapies and treatment with bosentan were also advocated. Finally, a consequent prevention and treatment of wounds and infections are essential for the prevention of amputations. To achieve better clinical results, integrated care in multidisciplinary and trans-sectoral teams with emphasis on smoking cessation, pain control, wound management, and social care by professionals, social workers, and family members is necessary.

Early Results of Clinical Application of Autologous Whole Bone Marrow Stem Cell Transplantation for Critical Limb Ischemia with Buerger's Disease

Our goal was to evaluate early results of the clinical application of autologous whole bone marrow stem cell transplantation (AWBMSCT) for critical limb ischemia (CLI) in patients with Buerger's disease. We retrospectively analyzed the data of 58 limbs of 37 patients (mean age, 43.0 years; range, 28-63 years; male, 91.9%) with Buerger's disease with CLI who were treated with AWBMSCT from March 2013 to December 2014. We analyzed Rutherford category, pain score, pain-free walking time (PFWT), total walking time (TWT), ankle brachial pressure index (ABPI), and toe brachial pressure index (TBPI), and investigated wound healing and occurrence of unplanned amputations. The mean follow-up duration was 11.9 ± 7.2 months (range, 0.9-23.9 months) and 100%, 72.4%, and 74.1% of patients were available to follow-up 1, 3 and 6 months after AWBMST, respectively. At 6 months, patients demonstrated significant improvements in Rutherford category (P < 0.0001), pain score (P < 0.0001), PFWT (P < 0.0001) and TBPI (P < 0.0001). ABPI was increased compared to baseline, but the difference was not significant. A total of 76.5% ischemic wounds achieved complete or improved healing. AWBMSCT is a safe and effective alternative or adjunctive treatment modality to achieve clinical improvement in patients with CLI.

Role of a Burr Hole and Calvarial Bone Marrow-Derived Stem Cells in the Ischemic Rat Brain: A Possible Mechanism for the Efficacy of Multiple Burr Hole Surgery in Moyamoya Disease

Objective

This study investigates the role of a burr hole and calvarial bone marrow-derived stem cells (BMSCs) in a transient ischemic brain injury model in the rat and postulates a possible mechanism for the efficacy of multiple cranial burr hole (MCBH) surgery in moyamoya disease (MMD).

Methods

Twenty Sprague-Dawley rats (250 g, male) were divided into four groups : normal control group (n=5), burr hole group (n=5), ischemia group (n=5), and ischemia+burr hole group (n=5). Focal ischemia was induced by the transient middle cerebral artery occlusion (MCAO). At one week after the ischemic injury, a 2 mm-sized cranial burr hole with small cortical incision was made on the ipsilateral (left) parietal area. Bromodeoxyuridine (BrdU, 50 mg/kg) was injected intraperitoneally, 2 times a day for 6 days after the burr hole trephination. At one week after the burr hole trephination, brains were harvested. Immunohistochemical stainings for BrdU, CD34, VEGF, and Doublecortin and Nestin were done.

Results

In the ischemia+burr hole group, BrdU (+), CD34 (+), and Doublecortin (+) cells were found in the cortical incision site below the burr hole. A number of cells with Nestin (+) or VEGF (+) were found in the cerebral parenchyma around the cortical incision site. In the other groups, BrdU (+), CD34 (+), Doublecortin (+), and Nestin (+) cells were not detected in the corresponding area. These findings suggest that BrdU (+) and CD34 (+) cells are bone marrow-derived stem cells, which may be derived from the calvarial bone marrow through the burr hole. The existence of CD34 (+) and VEGF (+) cells indicates increased angiogenesis, while the existence of Doublecortin (+), Nestin (+) cells indicates increased neurogenesis.

Conclusion

Based on these findings, the BMSCs through burr holes seem to play an important role for the therapeutic effect of the MCBH surgery in MMD.

Comparisons between prosthetic vascular graft and saphenous vein graft in femoro-popliteal bypass

PURPOSE

Infrainguinalfemoropopliteal bypass (IFPB) is recommended to peripheral arterial disease (PAD) with a long occlusion of the superficial femoral artery (SFA). The aims of our study were to determine the patency of graft materials, and identify the risk factors of graft failure.

METHODS

From January 1995 to April 2011, we had performed 380 IFPBs in 351 patients, including 302 femoro-above the knee (AK) bypasses and 78 femoro-below the knee (BK) bypasses. We compare age, sex, severity of ischemia between polytetra-uoroethylene (PTFE) graft and saphenous vein (SV) graft, and evaluate patency rate rates of the two groups.

RESULTS

The primary patency rates at 5 years for SV (n = 76 limbs) and PTFE grafts (n = 226 limbs) in AK were 85.2% and 64.5% (log rank = 0.03), and the secondary patency rates at 5 years for SV and PTFE grafts in AK were 88.2% and 79.0% (log rank = 0.13). The primary patency rates at 5 years for SV (n = 50 limbs) and PTFE grafts (n = 28 limbs) in BK were 63.2% and 40.0% (log rank = 0.08), and the secondary patency rates at 5 years for SV and PTFE grafts in BK were 71.6% and 55.5% (log rank = 0.18).

CONCLUSION

There was no statistical significant difference in secondary patency rates between SV and PTFE in IFPB. PTFE grafts as SV grafts can be a good alternative bypass material in IFPB instead of SV grafts.

Clinical application of stem cells for therapeutic angiogenesis in patients with peripheral arterial disease

Peripheral arterial disease (PAD) may ultimately cause to the loss of the affected limb due to gangrene or infection. Some patients with PAD may have severe coexisting diseases and diffuse involvement of their distal arteries, and so they are poor candidates for revascularization procedures. Angiogenesis has recently been suggested to be a new emerging treatment strategy for patients with PAD. Angiogenesis is defined as the sprouting of new capillaries from pre-existing vascular structures; this process plays a major role in the development of collateral vessels in an ischemic limb. Yet, the exact mechanism of angiogenesis is currently poorly understood. It has been established that angiogenesis is initiated by hypoxia and it requires various pro-angiogenic factors such as vascular endothelial growth factor. Therapeutic angiogenesis is aimed at enhancing natural angiogenesis by the administration of the cells or genes that can trigger angiogenesis and this can lead to pain relief and wound healing by the development of collateral vessels. Most of the recent clinical trials have reported that stem cell therapy for promoting angiogenesis in patients with PAD improves the ischemic symptoms and enhances wound healing. However, there are several limitations to approve a standard treatment for PAD such as small sample size in several prevous studies, their diverse inclusion criteria and the lack of standard assessment methods for the safety and outcome. Therefore, multicenter, large-scale and randomized controlled studies are needed to prove the safety and efficacy of the clinically applying stem cells for therapeutic angiogenesis in patients with PAD.

Angiogenesis induced by autologous whole bone marrow stem cells transplantation

BACKGROUND AND OBJECTIVES

It has been presumed that unknown cells and growth factors in bone marrow might promote angiogenesis, so angiogenesis effect could be enhanced by autologous whole bone marrow (WBM) stem cell transplantation. We compared capillary ratio induced by autologous WBM and bone marrow-mononuclear cells (BM-MNCs) to evaluate the anigiogenic effect of auotologous WBM. In addition, the combined effect of WBM transplantation and granulocyte colony-stimulating factor (G-CSF) injection was examined in an ischemic canine model.

METHODS AND RESULTS

After creating ischemic limb model, autologous WBM and isolated BM-MNCs were transplanted into the ischemic muscle. In other experiments, autologous WBM with recombinant human G-CSF (rhG-CSF) and autologous WBM without rhG-CSF were transplanted into the ischemic muscle. In this study, normal saline was injected into the contralateral sites in each ischemic model as a control group. After 8 weeks of transplantation, angiography and muscle harvest were performed, and then the anigiographic findings and capillary density, as assessed by immunohistochemical staining, were investigated and analyzed. In comparison with the control group, BM-MNCs and WBM transplantation groups showed higher ratios of the capillary density (1.5±0.01 times, p<0.001 and 1.6±0.15 times, p=0.005, respectively). Between the BM-MNCs and WBM transplantation groups, the capillary ratio was 1.2 folds higher in the WBM group than that in the BM-MNCs group, but there was no significantly different (p=0.116). The angiogensis ratios of both the WBM without G-CSF group and the WBM with G-CSF groups were higher (1.6±0.15 times, p=0.004 and 1.8 ±0.01 times, p=0.005, respectively) than that of the control groups. In comparison with the WBM without G-CSF group, the WBM with G-CSF transplantation group revealed a 1.1 folds higher angiogenesis ratio, but there was no statistically significant difference (p=0.095).

CONCLUSIONS

Autologous WBM transplantation is a simpler method and it is not inferior for inducing therapeutic angiogenesis as compared with isolated BM-MNCs transplantation. In addition to autologous WBM transplantation, intravenous G-CSF injection enhances the angiogenic effect of autologous WBM in an ischemic limb.

Thromoboagiitis Obliterans (TAO)

Thromboangiitis obliterans (TAO) is nonatherosclerotic inflammatory disease of the peripheral blood vessels, and TAO affects the small and medium sized vessels of the extremities. TAO is mainly seen in young males who smoke, and smoking is strongly associated with the disease course and progression. The diagnosis is made on the basis of the history, the physical examination and the clinical diagnostic criteria. As the bedrock for treating patients with TAO, absolute abstinence from tobacco is most important factor, and patients with TAO are usually managed conservatively. Surgical bypass or endovascular therapy is usually not possible for patients with TAO because of the diffuse segmental involvement and the distal nature of the disease. Therefore, stem cell therapy is considered to be a novel therapeutic modality for treating patients with TAO and who are not eligible for conventional revascularization therapies. In this paper, I have summarized the recent knowledge about TAO and I have reviewed the recent studies that have focused on the treatment of TAO.

Long-term Angiogenesis Efficacy Using a Heparin-Conjugated Fibrin (HCF) Delivery System with HBM-MSCs

BACKGROUND AND OBJECTIVES

Heparin-conjugated fibrin (HCF) is suitable for the release and localization of bFGF. We analyzed the effects of a bFGF delivery system using HCF with human bone marrow-derived mesenchymal stem cells (HBM- MSCs) in a dog ischemic limb model.

METHODS AND RESULTS

Animals were divided into HBM-MSCs, HBM-MSCs＋HCF, bFGF-HCF, and HBM-MSCs＋ bFGF-HCF groups. A total of 1×10(7) HBM-MSCs were injected per animal, and the amount of bFGF was 1 mg per dog. Ischemic muscles were harvested at eight weeks and six months after injection of cells. The HBM-MSCs＋ bFGF-HCF group exhibited decreased proportions of capillaries and arterioles six months after transplantation. However, there were more cells positive for the angiogenic factors, VEGF and PDGF, in the eight-week specimens compared with those harvested six months after transplantation.

CONCLUSIONS

Our results demonstrated that a single injection of HBM-MSCs did not have significant long-term angiogenic effects; however, a bFGF delivery system using HCF exerted prolonged angiogenic effects when combined with HBM-MSCs.

Stem cell therapy in patients with thromboangiitis obliterans: assessment of the long-term clinical outcome and analysis of the prognostic factors

BACKGROUND AND OBJECTIVES

The clinical benefits of stem cell therapy have been reported in patients with peripheral arterial occlusive disease. However, those studies had no standard reporting system to assess the outcomes, so we made a scoring system and assessed the outcomes of the limbs that underwent whole bone marrow stem cell (WBMSC) therapy.

METHODS AND RESULTS

Between July 4 and June 2009, 90 limbs of 67 patients with symptomatic thromboangiitis obliterans (TAO) were enrolled. Autologous whole bone marrow was implanted into the limb by intramuscular injections. The primary outcomes were defined by the clinical and angiographic improvement in all the limbs and the secondary outcomes were the clinical improvement and the amputation-free rates in the critical ischemic limbs (CILs). Clinical improvement and angiographic improvement was observed in 55.6% and 43.2% of all the limbs and in 50% and 50%of the CILs, respectively. The 1, 3 and 5-year amputation-free rates were 91.9%, 88.5% and 84.6% for all the limbs, respectively, and 83.9%, 77.5% and 70.4% for the CILs, respectively. A history of sympathectomy/sympathetic block was shown to be a negative prognostic factor for clinical improvement in all the limbs and in the CILs. In addition, a history of sympathetic block/sympathectomy and the smoking state were the major predictors of amputation for the CILs.

CONCLUSIONS

This study indicated that autologous WMBSC therapy improves the clinical status and reduces amputation factors in the limbs with symptomatic TAO and a history of sympathetic block/sympathectomy and the smoking state are useful prognostic factors.

A phase I study of human cord blood-derived mesenchymal stem cell therapy in patients with peripheral arterial occlusive disease

BACKGROUND AND OBJECTIVES

Half of patients with critical limb ischemia (CLI) are ineligible for revascularization at diagnosis. The aim of this study was to assess the safety and feasibility of intramuscular human umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) therapy in patients with CLI due to atherosclerosis obliterans (ASO) or thromboangiitis obliterans (TAO).

METHODS AND RESULTS

A total of eight patients (all male, median age 52 years, range 31∼77) with CLI were enrolled in this phase I trial. All patients were considered ineligible for further revascularization to improve CLI. We injected 1×10(7) hUCB-MSCs per single dose intramuscularly into the affected limb. The primary end points of safety were occurrence of adverse events (procedure-related complication, allergic reaction to hUCB-MSCs, graft-versus-host disease, cardiovascular and cerebrovascular events) and improvement of symptoms/clinical parameters (healing of foot ulcer, ankle-brachial index, and pain-free walking distance). Angiogenesis was measured with conventional angiography and scored by an independent reviewer. There were four adverse events in three patients. One patient, developed whole body urticaria after injection on treatment day, which disappeared after one day of antihistamine treatment. The other adverse events included diarrhea, oral ulceration, and elevation of serum creatinine level; all conditions improved without treatment. Abnormal results of laboratory parameters were not detected in any patients. Three of four ulcerations (75%) healed completely. Angiographic scores increased in three of eight patients.

CONCLUSIONS

This phase I study demonstrates that intramuscular hUCB-MSC injection is a safe and well tolerated treatment for patients with end-stage CLI due to ASO and TAO.

Reduced circulating endothelial progenitor cells in thromboangiitis obliterans (Buerger’s disease)

To determine the role of endothelial progenitor cells (EPCs) in the pathogenesis of thromboangiitis obliterans (TAO), EPC numbers and colony-forming units, migratory function and tubular structure formation in vitro were compared between 13 young male TAO patients and two age-matched healthy control groups: 11 smokers and 12 non-smokers. TAO patients had significantly lower numbers of EPCs and EPC colonies compared to both non-smokers [190 (97.0–229) vs 528 (380–556), p < 0.001 for EPCs and 0.80 (0.53–1.00) vs 2.80 (2.08–4.00) per mm2, p = 0.001 for EPC colonies] and smokers [190 (97.0–229) vs 272 (229–326), p = 0.012 for EPCs and 0.80 (0.53–1.00) vs 2.80 (1.80–3.93) per mm2, p = 0.001 for EPC colonies]. However, there were no significant differences in migratory function or tube formation between the three groups. These results suggest that TAO patients have an intrinsic decrease in EPCs not entirely associated with smoking, which may be the cause of endothelial dysfunction seen in TAO patients leading to the development of this disease at early ages.

Intracavernous administration of bone marrow mononuclear cells: a new method of treating erectile dysfunction?

While PDE5 inhibitors have revolutionized treatment of ED, approximately 30% of patients are non-responsive. A significant cause of this is vascular and smooth muscle dysfunction, as well as nerve atrophy. Autologous administration of bone marrow mononuclear cells (BMMC) has been performed in over 2000 cardiac patients without adverse effects, for stimulation of angiogenesis/regeneration. Despite its ease of access, and dependence on effective vasculature for function, comparatively little has been perform in terms of BMMC therapy for ED. Here we outline the rationale for use of autologous BMMC in patients with ED, as well as provide early safety data on the first use of this procedure clinically.

Cell therapy of peripheral arterial disease: from experimental findings to clinical trials

The age-adjusted prevalence of peripheral arterial disease in the US population was estimated to approach 12% in 1985, and as the population ages, the overall population having peripheral arterial disease is predicted to rise. The clinical consequences of occlusive peripheral arterial disease include intermittent claudication, that is, pain with walking, and critical limb ischemia (CLI), which includes pain at rest and loss of tissue integrity in the distal limbs, which may ultimately lead to amputation of a portion of the lower extremity. The risk factors for CLI are similar to those linked to coronary artery disease and include advanced age, smoking, diabetes mellitus, hyperlipidemia, and hypertension. The worldwide incidence of CLI was estimated to be 500 to 1000 cases per million people per year in 1991. The prognosis is poor for CLI subjects with advanced limb disease. One study of >400 such subjects in the United Kingdom found that 25% required amputation and 20% (including some subjects who had required amputation) died within 1 year. In the United States, ≈280 lower-limb amputations for ischemic disease are performed per million people each year. The first objective in treating CLI is to increase blood circulation to the affected limb. Theoretically, increased blood flow could be achieved by increasing the number of vessels that supply the ischemic tissue with blood. The use of pharmacological agents to induce new blood vessel growth for the treatment or prevention of pathological clinical conditions has been called therapeutic angiogenesis. Since the identification of the endothelial progenitor cell in 1997 by Asahara and Isner, the field of cell-based therapies for peripheral arterial disease has been in a state of continuous evolution. Here, we review the current state of that field.

Circulating angiogenic factors in patients with thromboangiitis obliterans

Background

Thromboangiitis obliterans (TAO, also known as Buerger's disease) is a non-atherosclerotic inflammatory vascular disease that primarily affects arteries in the extremities of young adult smokers. Since the etiology of TAO is still unknown, therapeutic options are limited. Recent attempts in therapeutic angiogenesis have been promising. Therefore, the aim of our study was to evaluate angiogenic processes and factors including circulating progenitor cells in TAO.

Methodology/Principal Findings

TAO patients with critical limb ischemia and age- and gender-matched nonsmokers and smokers without cardiovascular disease (n = 12 in each group) were enrolled in the study. Flow cytometric analysis of peripheral blood showed significantly decreased levels of circulating CD45^dimCD34⁺ progenitor cells in TAO patients and in smokers compared to nonsmokers. In contrast to both control groups, the proportion of CD45^dimCD34⁺ progenitor cells co-expressing VEGF receptor-2 (VEGFR2) was significantly elevated in TAO patients. Enzyme-linked immunosorbent assay (ELISA) of common angiogenic factors (such as VEGF) did not clearly point to pro- or antiangiogenic conditions in serum or plasma of TAO patients. Serum of TAO patients and controls was evaluated in proliferation, migration (scratch assay) and spheroid sprouting assays using human umbilical vein endothelial cells (HUVECs). Serum of TAO patients exhibited a diminished sprouting capacity of HUVECs compared to both control groups. Proliferation and migration of endothelial cells were impaired after treatment with serum of TAO patients.

Conclusion

Levels of circulating progenitor cells were altered in TAO patients compared to healthy nonsmokers and smokers. Furthermore, serum of TAO patients exhibited an antiangiogenic activity (impaired endothelial cell sprouting, migration and proliferation) on endothelial cells, which may contribute to vascular pathology in this patient population.

Autologous stem cell therapy in the treatment of limb ischaemia induced chronic tissue ulcers of diabetic foot patients

BACKGROUND AND AIM

Despite improvements in surgical revascularisation, limitations like anatomical factors or atherosclerosis limit the success of revascularisation in diabetic patients with critical limb ischaemia. Stem cells were shown to improve microcirculation in published studies. The aim of this study was to evaluate safety, feasibility and efficacy of transplantation of bone marrow derived cellular products regarding improvement in microcirculation and lowering of amputation rate.

METHODS

Bone marrow mononuclear cells (BMCs) in comparison with expanded bone marrow cells enriched in CD90+ cells ('tissue repair cells', TRCs) were used in the treatment of diabetic ulcers to induce revascularisation. Diabetic foot patients with critical limb ischaemia without option for surgical or interventional revascularisation were eligible. Parameters examined were ABI, TcPO(2) , reactive hyperaemia and angiographic imaging before and after therapy.

RESULTS

Of 30 patients included in this trial, 24 were randomised to receive either BMCs or TRCs. The high number of drop-outs in the control group (4 of 6) led to exclusion from evaluation. A total of 22 patients entered treatment; one patient in the TRC group and two in the BMC group did not show wound healing during follow up, one patient in each treatment group died before reaching the end of the study; one after having achieved wound healing (BMC group), the other one without having achieved wound healing (TRC group). Thus, 18 patients showed wound healing after 45 weeks. The total number of applicated cells was 3.8 times lower in the TRC group, but TRC patients received significantly higher amounts of CD90+ cells. Improvement in microvascularisation was detected in some, but not all patients by angiography, TcPO(2) improved significantly compared with baseline in both therapy groups.

CONCLUSION

The transplantation of BMCs as well as TRCs proved to be safe and feasible. Improvements of microcirculation and complete wound healing were observed in the transplant groups.

Autologous stromal vascular fraction therapy for rheumatoid arthritis: rationale and clinical safety

Advancements in rheumatoid arthritis (RA) treatment protocols and introduction of targeted biological therapies have markedly improved patient outcomes, despite this, up to 50% of patients still fail to achieve a significant clinical response. In veterinary medicine, stem cell therapy in the form of autologous stromal vascular fraction (SVF) is an accepted therapeutic modality for degenerative conditions with 80% improvement and no serious treatment associated adverse events reported. Clinical translation of SVF therapy relies on confirmation of veterinary findings in targeted patient populations. Here we describe the rationale and preclinical data supporting the use of autologous SVF in treatment of RA, as well as provide 1, 3, 6, and 13 month safety outcomes in 13 RA patients treated with this approach.

Buerger's disease (Thromboangiitis obliterans): a diagnostic challenge

Buerger's disease or Thromboangiitis obliterans is a segmental inflammatory disease that affects the vessels and nerves of the extremities. It usually affects men below 45 years old and correlates with tobacco, as a predisposing factor. The authors present the case of a 34-year-old male, with ulcers in the fingertips with progressive worsening: acrocyanosis, slow healing, necrosis and finally loss of substance. Dorsalis pedis and posterior tibial pulses were not palpable. Personal history of heavy smoking was (20 pack-years). The angiography revealed proximal occlusion of the left posterior tibial and interosseal arteries, with distal circulation by the anterior tibial artery. He was submitted to disarticulation of the second left toe and therapy with pentoxifyline and iloprost infusion, calcium antagonist, antiplatelet drugs, statin and low molecular weight heparin (later replaced by oral anticoagulation). Improvement was seen of active vascular lesions and pain symptoms.

Regenerative therapy in peripheral artery disease

Patients with peripheral artery disease (PAD) and critical limb ischemia are the main candidates for limb amputations and have a poor life expectancy. Frequently, these patients are not eligible for either surgical or percutaneous interventions aimed at mechanical revascularization. Therefore, new strategies need to be identified to offer these patients a viable therapeutic option. Gene and cell therapy hold great promise for the treatment of peripheral vascular diseases because, in animal models, local delivery of growth factors and endothelial progenitor cells result in new blood vessel formation and regeneration of ischemic tissues. In this article, are reviewed phase I and phase II gene, and cell therapy clinical trials in patients with PAD.

Stem cell-related therapies for vascular diseases

The therapeutic potential of 'adult' or at least non-embryonic stem cells and their progeny has developed gradually over the past half century as a consequence of the wealth of knowledge derived from stem cell research. Translational research coupled with clinical trials and derived from basic research has led the way to the clinic. This commenced with the use of haematopoietic stem cell transplantation (HSCT), to treat haematological malignancies, to be followed by the most recent clinical trials to treat a variety of coronary and peripheral artery diseases. Stem cells and their progeny isolated from bone marrow or blood appear to exert an ameliorating effect in certain vascular disorders. Although promising, some of these treatments remain controversial and further research and, where indicated, appropriately powered trials are required to confirm the safety and determine the efficacy of these novel therapies.

Stem cell therapy for critical limb ischaemia - a review

Critical limb ischaemia is an intractable condition associated with high levels of amputation, leading to a low quality of life and increased morbidity and mortality. It is often not treatable by standard therapeutic modalities. Neoangiogenesis has been proposed as a novel method of treatment of such patients. Vascular endothelial growth factor (VEGF) and cytokine fibroblast growth factor (FGF-1) have been shown to elicit neoangiogenesis. Stem cells are progenitor cells which can differentiate in vivo into different types of cells. Mesenchymal stem cells (MSCs) are a type of adult stem cells which have an immunomodulatory effect. Stem cell therapy has been used in animal studies to improve limb vascularity in rat and rabbit models. Several clinical studies have also validated their use for critical limb ischaemia. However many issues are still unresolved. These include the dosage, delivery and safety issues in relation to stem cell therapy. However stem cells are likely to be an important therapeutic modality to treat critical limb ischaemia in the near future.

Autologous stem cell therapy for peripheral arterial disease meta-analysis and systematic review of the literature

BACKGROUND

Peripheral arterial disease (PAD) is a common cause of disability and mortality. Up to one third of patients are not susceptible to traditional revascularization and may benefit from stem cell therapies.

OBJECTIVE

In this meta-analysis, we sought to determine whether autologous cell therapy is effective in the treatment of PAD.

METHODS

We searched the English literature in Medline, Excerpta Medica and the Cochrane database for trials of autologous cell therapy in patients with PAD published before 31 January 2009. We included controlled and non-controlled, randomized and non-randomized trials using autologous bone marrow or granulocyte colony stimulating factor (G-CSF) mobilized peripheral blood cells to treat PAD. We also collected data from trials of G-CSF monotherapy, as a control treatment.

RESULTS

In a meta-analysis of 37 trials, autologous cell therapy was effective in improving surrogate indexes of ischemia, subjective symptoms and hard endpoints (ulcer healing and amputation). On the contrary, G-CSF monotherapy was not associated with significant improvement in the same endpoints. Patients with thromboangiitis obliterans showed some larger benefits than patients with atherosclerotic PAD. The intramuscular route of administration and the use of bone marrow cells seemed somehow more effective than intrarterial administration and the use of mobilized peripheral blood cells. The procedures were well tolerated and generally safe.

CONCLUSION

This meta-analysis indicates that intramuscular autologous bone marrow cell therapy is a feasible, relatively safe and potentially effective therapeutic strategy for PAD patients, who are not candidate for traditional revascularization. Larger, placebo-controlled, randomized multicenter trials need to be planned and conducted to confirm these findings.

Autologous peripheral blood CD133+ cell implantation for limb salvage in patients with critical limb ischemia

We report the safety and feasibility of autologous CD133+ cell implantation into the lower extremity muscles of patients with critical limb ischemia, whose only other option was limb amputation. Nine patients participated in the study: seven patients suffering from arteriosclerosis obliterans, one with thromboangiitis obliterans (Buerger's disease) and one with thromboembolic disorder. Autologous PBSC were collected after the administration of G-CSF (10 mcg/kg/day). CD133+ cells were selected using the CLINIMACS cell separation device and were injected i.m. without earlier cryopreservation using a 22-gauge needle into multiple sites 3 cm apart in the gastrocnemius/soleus muscle, or depending on clinical circumstances, in the foot or quadriceps muscle, or both, of the involved leg. There were no complications from either leukapheresis or injection. Stem cell injection prevented leg amputation in seven of the nine patients. In this small cohort of patients with end-stage critical limb ischemia, quality of life (Short Form-36) physical component score improved significantly at 3 (P=0.02) and 6 (P=0.01) months, but not at 1 year (P=0.08). There was a trend towards the improvement in pain-free treadmill walking time (P=0.13) and exercise capacity (P=0.16) at 1 year. Lower extremity limb salvage was achieved for seven of the nine treated patients.

Long-term clinical outcome after intramuscular implantation of bone marrow mononuclear cells (Therapeutic Angiogenesis by Cell Transplantation [TACT] trial) in patients with chronic limb ischemia

BACKGROUND

Angiogenic cell therapy by intramuscular injection of autologous bone marrow mononuclear cells was first attempted in patients with peripheral artery disease (PAD) with critical limb ischemia, and the feasibility was shown by a randomized controlled Therapeutic Angiogenesis by Cell Transplantation (TACT) study.

METHODS AND RESULTS

The present study was designed to assess the 3-year safety and clinical outcomes of this angiogenic cell therapy by investigating the mortality and leg amputation-free interval as primary end points. The median follow-up time for surviving patients was 25.3 months (range, 0.8-69.0 months), and 3-year overall survival rates were 80% (95% CI 68-91) in patients with atherosclerotic peripheral arterial disease (11 died in 74 patients) and 100% (no death) in 41 patients with thromboangiitis obliterans (TAO; Buerger's disease). Three-year amputation-free rate was 60% (95% CI 46-74) in PAD and 91% (95% CI 82-100) in patients with TAO. The multivariate analysis revealed that the severity of rest pain and repeated experience of bypass surgery were the prognostic factors negatively affecting amputation-free interval. The significant improvement in the leg pain scale, ulcer size, and pain-free walking distance was maintained during at least 2 years after the therapy, although the ankle brachial index and transcutaneous oxygen pressure value did not significantly change.

CONCLUSIONS

The angiogenic cell therapy using bone marrow mononuclear cells can induce a long-term improvement in limb ischemia, leading to extension of amputation-free interval. The safety and efficacy are not inferior to the conventional revascularization therapies.

Cell therapy in peripheral arterial disease

Management of advanced obstructive vascular disease affecting the extremities poses tremendous challenges for physicians and patients. Peripheral arterial disease is often a consequence of obstructive atherosclerosis affecting the ileofemoral circulation but is also rarely a result of nonatherosclerotic conditions such as thromboangiitis obliterans (Buerger's disease). Consequences range from the presence of asymptomatic obstruction to intermittent claudication, development of rest pain, ulceration, gangrene, and amputation. A relatively new and promising approach using cell therapy has recently been developed to treat intractable symptoms related to ischemia in subjects with peripheral arterial disease in whom conventional medical therapy and revascularization modalities have been exhausted.

Therapeutic pathways of adult stem cell repair

The use of adult stem cells as therapeutic agents to treat disease has become increasingly prevalent. During the last decade, isolated and expanded stem and progenitor cells have demonstrated the capacity to differentiate into multiple cell types. Early optimism that in vitro differentiation capacity would translate into in vivo tissue regeneration has lessened and identifying the mechanisms that underlie the benefit of stem cell repair is an emerging area of investigation. This review considers several of the pathways and mechanisms required for adult stem cell repair. These mechanisms include the mobilization and the homing of stem cells to sites of injury, immunomodulatory effect of stem cells, and the association of stem cells with increased vascularization of injured tissue. These data suggest that the unique properties of adult stem cells can be utilized to treat a wide variety of diseases that cannot be treated with existing pharmacological agents, and prompt new paradigms for the bio-pharmacokinetics of biological expressed by efficacious stem cells.

Simultaneous isolation of human BM hematopoietic, endothelial and mesenchymal progenitor cells by flow sorting based on aldehyde dehydrogenase activity: implications for cell therapy

BACKGROUND

ALDH(br) cells express high aldehyde dehydrogenase (ALDH) activity and have progenitor cell activity in several contexts. We characterized human BM ALDH(br) cells to determine whether cell sorting based on ALDH activity isolates potentially useful populations for cell therapy.

METHOD

We measured the expression of ALDH and cell-surface Ag by flow cytometry and compared the ability of sorted ALDH(br), and BM populations remaining after ALDH(br) cells were removed (ALDH(dim) populations), to develop into several cell lineages in culture.

RESULTS

The ALDH(br) population comprised 1.2+/-0.8% (mean+/-SD, n=30) nucleated cells and was enriched in cells expressing CD34, CD117, CD105, CD127, CD133 and CD166, and in primitive CD34(+) CD38(-) and CD34(+) CD133(+) progenitors. Most of the CD34(+) and CD133(+) cells were ALDH(dim). ALDH(br) populations had 144-fold more hematopoietic colony-forming activity than ALDH(dim) cells and included all megakaryocyte progenitors. ALDH(br) populations readily established endothelial cell monolayers in cultures. Cells generating endothelial colonies in 7 days were 435-fold more frequent in ALDH(br) than ALDH(dim) populations. CFU-F were 9.5-fold more frequent in ALDH(br) than ALDH(dim) cells, and ALDH(br) cells gave rise to multipotential mesenchymal cell cultures that could be driven to develop into adipocytes, osteoblasts and chondrocytes.

DISCUSSION

Hematopoietic, endothelial and mesenchymal progenitor cells can be isolated simultaneously from human BM by cell sorting based on ALDH activity. BM ALDH(br) populations may be useful in several cell therapy applications.