Autologous peripheral blood-derived stem cells transplantation for treatment of no-option angiitis-induced critical limb ischemia: 10-year management experience

Treatment Options for Buerger Disease: A Systematic Review and Meta-Analysis of Outcomes

INTRODUCTION

Uncertainties exist regarding the optimal management strategy for patients with thromboangiitis obliterans (TAOs). The aim of this study was to investigate the safety and effectiveness of common interventions used for treating patients with TAO.

METHODS

Endovascular treatment, revascularization, sympathectomy, stem cell therapy (SCT), and nonsurgical interventions were selected for inclusion in the study. Changes in mean visual analogue scale score and ankle brachial index (ABI) values were evaluated. In addition, the rate of ulcer healing, postintervention amputation, and overall complication rates were compared across interventions.

RESULTS

A total of 1262 TAO patients (1159 males, 84 females), with a mean age of 38.4 ± 7.8 ys, were included in this systematic review. With an amputation rate of 16.6%, the endovascular treatment group showed statistically significant improvements in mean ABI and visual analogue scale scores (P < 0.05). There was a greater increase in ABI postoperatively with endovascular treatment compared to SCT (P < 0.05), and also a greater increase in ABI postoperatively with revascularization compared to SCT (P < 0.05). Meta-regression showed that both endovascular treatment and open surgical revascularization were superior to stem cell treatment for postoperative mean ABI improvement (P < 0.05). Interestingly, the rate of postoperative amputation was lower in the SCT group compared with the other two interventions.

CONCLUSIONS

Our results indicated that all three interventions may be a reasonable therapeutic option for TAO. Endovascular intervention and open revascularization demonstrated superior outcomes.

Purified CD34+ Cells Transplantation in Patients with Angiitis-Induced Chronic Limb-Threatening Ischemia: A Single-Center Retrospective Study over a 10-Year Period

BACKGROUND

Angiitis-induced chronic limb-threatening ischemia (AICLTI) is defined as chronic limb-threatening ischemia caused by thromboangiitis obliterans or other arteritis-related autoimmunological diseases. In the current study, we aimed to report the 10-year outcomes of AICLTI patients who underwent purified cluster of differentiation 34 positive (CD34+) cells (PCCs) transplantation.

METHODS

AICLTI patients who underwent PCCs transplantation at our center from May 2009 to September 2011 were retrospectively enrolled. The main outcome was major amputation-free survival (MAFS); other outcomes included Rutherford classification, intolerable pain-free walking time, Wong-Baker Faces Pain Rating Scale, recurrence, new lesions, quality of life and patients' posttransplantation work conditions.

RESULTS

Twenty-four patients were enrolled with a mean age of 41.5 ± 7.8 years. Three underwent major amputation during the follow-up, and the 10-year MAFS was 87.5%. Eight were observed to have recurrence, and 2 had new lesions; the 10-year recurrence-free rate was 66.1%. All patients were unable to work at admission, 17 (70.8%) patients were reemployed after transplantation.

CONCLUSIONS

The current study further demonstrated satisfactory long-term efficacy of PCCs transplantation, with a 10-year MAFS of 87.5%. However, the 10-year recurrence-free rate of 66.1% suggested that strict and regular long-term follow-up is necessary.

The Immune-Centric Revolution Translated into Clinical Application: Peripheral Blood Mononuclear Cell (PBMNC) Therapy in Diabetic Patients with No-Option Critical Limb-Threatening Ischemia (NO-CLTI)-Rationale and Meta-Analysis of Observational Studies

Chronic limb-threatening ischemia (CLTI), the most advanced form of peripheral arterial disease (PAD), is the comorbidity primarily responsible for major lower-limb amputations, particularly for diabetic patients. Autologous cell therapy has been the focus of efforts over the past 20 years to create non-interventional therapeutic options for no-option CLTI to improve limb perfusion and wound healing. Among the different available techniques, peripheral blood mononuclear cells (PBMNC) appear to be the most promising autologous cell therapy due to physio-pathological considerations and clinical evidence, which will be discussed in this review. A meta-analysis of six clinical studies, including 256 diabetic patients treated with naive, fresh PBMNC produced via a selective filtration point-of-care device, was conducted. PBMNC was associated with a mean yearly amputation rate of 15.7%, a mean healing rate of 62%, and a time to healing of 208.6 ± 136.5 days. Moreover, an increase in TcPO2 and a reduction in pain were observed. All-cause mortality, with a mean rate of 22.2% and a yearly mortality rate of 18.8%, was reported. No serious adverse events were reported. Finally, some practical and financial considerations are provided, which point to the therapy's recommendation as the first line of treatment for this particular and crucial patient group.

[The application of cell products for the treatment of critical limb ischemia in patients with diabetes mellitus: a review of the literature]

The number of patients with diabetes mellitus (DM) has been progressively increasing worldwide over the past decades, and many international organizations consider DM as a public health emergency of the 21st century.Critical limb ischemia (CLI) is the most severe stage of peripheral arterial disease (PAD) in DM and is characterized by a high risk of limb loss without revascularization. Traditional treatment tactics include open and endovascular revascularization surgical techniques. However, in patients not eligible for revascularization and in cases where performed surgical treatment performed has been ineffective, there are almost no therapeutic alternatives, often leading to amputations and death. As of today, one of the newest non-surgical treatment options is cell therapy. Among different cells, mesenchymal stromal cells (MSCs) are potentially one of the most prospective for use in this patient population.This article provides an overview of clinical trials using cell therapy in patients with CLI.To analyze publications, electronic databases PubMed, SCOPUS, ClinicalTrials, and ScienceDirect were searched to identify published data from clinical trials, research studies, and review articles on cell therapy for critical lower extremity ischemia. After the search, 489 results were received.As a result of systematic selection, 22 clinical trials were analyzed.According to the analyzed literature data, the use of cell products in this category of patients is effective and safe. Cell therapy can stimulate the formation of new vessels and enhances collateral circulation; it is also reported improved distal perfusion, increased pain-free walking distance, decreased amputation rates, and increased survival rates.Nevertheless, further study of the potential use of this category of drugs is needed.

Atorvastatin Treatment Significantly Increased the Concentration of Bone Marrow-Derived Mononuclear Cells and Transcutaneous Oxygen Pressure and Lowered the Pain Scale after Bone Marrow Cells Treatment in Patients with "No-Option" Critical Limb Ischaemia

BACKGROUND

The present study investigated the outcomes and possible predictive factors of autologous bone marrow cells (BMCs) therapy in patients with "no-option" critical limb ischaemia (CLI). It was focused on exploring the clinical background and prior statin and renin-angiotensin system (RAS)-acting agents pharmacotherapy related to the therapeutic efficacy of BMCs treatment.

METHODS

In the present study, we reviewed thirty-three patients (mean age 64.9 ± 10 years; 31 males) with advanced CLI after failed or impossible revascularisation, who were treated with 40 mL of autologous BMCs by local intramuscular application. Patients with limb salvage and wound healing (N = 22) were considered as responders to BMCs therapy, and patients with limb salvage and complete ischemic wound healing (N = 13) were defined as super-responders. Logistic regression models were used to screen and identify the prognostic factors, and a receiver operating characteristics (ROC) curve, a linear regression, and a survival curve were drawn to determine the predictive accuracy, the correlation between the candidate predictors, and the risk of major amputation.

RESULTS

Based on the univariate regression analysis, baseline C-reactive protein (CRP) and transcutaneous oxygen pressure (TcPO2) values were identified as prognostic factors of the responders, while CRP value, ankle-brachial index (ABI), and bone marrow-derived mononuclear cells (BM-MNCs) concentration were identified as prognostic factors of the super-responders. An area under the ROC curve of 0.768 indicated good discrimination for CRP > 8.1 mg/L before transplantation as a predictive factor for negative clinical response. Linear regression analysis revealed a significant dependence between the levels of baseline CRP and the concentration of BM-MNCs in transplanted bone marrow. Patients taking atorvastatin before BMCs treatment (N = 22) had significantly improved TcPO2 and reduced pain scale after BMCs transplant, compared to the non-atorvastatin group. Statin treatment was associated with reduced risk for major amputation. However, the difference was not statistically significant. Statin use was also associated with a significantly higher concentration of BM-MNCs in the transplanted bone marrow compared to patients without statin treatment. Patients treated with RAS-acting agents (N = 20) had significantly reduced pain scale after BMCs transplant, compared to the non-RAS-acting agents group. Similar results, reduced pain scale and improved TcPO2, were achieved in patients treated with atorvastatin and RAS-acting agents (N = 17) before BMCs treatment. Results of the Spearman correlation showed a significant positive correlation between CLI regression, responders, and previous therapy before BMCs transplant with RAS-acting agents alone or with atorvastatin.

CONCLUSIONS

CRP and TcPO2 were prognostic factors of the responders, while CRP value, ABI, and BM-MNCs concentration were identified as predictive factors of the super-responders. Atorvastatin treatment was associated with a significantly increased concentration of BM-MNCs in bone marrow concentrate and higher TcPO2 and lower pain scale after BMCs treatment in CLI patients. Similarly, reduced pain scales and improved TcPO2 were achieved in patients treated with atorvastatin and RAS-acting agents before BMCs treatment. Positive correlations between responders and previous treatment before BMCs transplant with RAS-acting agents alone or with atorvastatin were significant.

Wharton's jelly mesenchymal stem cells transplantation for critical limb ischemia in patients with type 2 diabetes mellitus: a preliminary report of phase I clinical trial

Peripheral artery disease (PAD) affects more than 230 million people worldwide, with approximately 11% of patients presenting with advanced-stage PAD or critical limb ischemia (CLI). To avoid or delay amputation, particularly in no-option CLI patients with infeasible or ineffective revascularization, new treatment strategies such as regenerative therapies should be developed. Mesenchymal stem cells (MSCs) are the most popular cell source in regenerative therapies. They possess significant characteristics such as angiogenic, anti-inflammatory, and immunomodulatory activities, which encourage their application in different diseases. This phase I clinical trial reports the safety, feasibility, and probable efficacy of the intramuscular administration of allogeneic Wharton's jelly-derived MSCs (WJ-MSCs) in type 2 diabetes patients with CLI. Out of six screened patients with CLI, five patients were administered WJ-MSCs into the gastrocnemius, soleus, and the proximal part of the tibialis anterior muscles of the ischemic lower limb. The safety of WJ-MSCs injection was considered a primary outcome. Secondary endpoints included wound healing, the presence of pulse at the disease site, the absence of amputation, and improvement in visual analogue scale (VAS), pain-free walking time, and foot and ankle disability index (FADI). No patient experienced adverse events and foot or even toe amputation during the 6-month follow-up. Six months after the intervention, there were a significantly lower VAS score and significantly higher pain-free walking time and FADI score than the baseline, but no statistically significant difference was seen between other time points. In conclusion, allogeneic WJ-MSC transplantation in patients with CLI seems to be safe and effective.

Autologous Stem Cells Transplantation for No-Option Angiitis-Induced Critical Limb Ischemia: Recurrence and New Lesion

Although satisfying outcomes have been demonstrated in terms of autologous stem cell transplantation in the treatment of angiitis-induced critical limb ischemia (AICLI), few studies have systematically reported the recurrence conditions. In the current study, we aimed to investigate recurrence conditions of a relatively large AICLI cohort in our center during a long-term follow-up period. From May 2009 to August 2020, 181 patients with AICLI received peripheral blood mononuclear cells (PBMNCs) or purified CD34+ cells (PCCs) transplantation. The main outcomes included recurrence and new lesions. Patient demographic data, ischemic limb characteristics, interventional characteristics, etc., were identified and analyzed. A logistic multivariable regression was performed to identify the independent risk factors for recurrence by a stepwise selection of variables. One hundred forty-eight patients were enrolled in this study. The mean follow-up period was 62.3 ± 37.4 months (range 12-144 months). The 5- and 10-year recurrence-free rates were 88.5% (95% confidence interval [CI] 3.1%-82.6%) and 71.7% (95% CI 7.6%-58.2%), respectively. The 5- and 10-year new lesion-free rates were 93.2% (95% CI 2.2%-89.0%) and 91.7% (95% CI 2.7%-86.6%), respectively. The finding of multiple limbs involved (OR 1.322 95% CI 1.123-12.549, P = .036) and ischemia relief period ≥5 months (OR 3.367 95% CI 1.112-10.192, P = .032) were demonstrated to be independent risk factors for recurrence in patients with AICLI who underwent cell transplantation. For patients with AICLI who responded to cell transplantation, the durability of this therapy was satisfactory, with 5- and 10-year recurrence-free rates of 88.5% and 71.7%, respectively. Multiple limbs involved at admission and ischemia relief period ≥5 months were demonstrated to be independent risk factors for recurrence after transplantation.

A systematic review of patient-reported outcome measures patients with chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) causes significant morbidity with profound negative effects on health-related quality of life. As the prevalence of peripheral artery disease and diabetes continue to rise in our aging population, the public health impact of CLTI has escalated. Patient-reported outcome measures (PROMs) have become common and important measures for clinical evaluation in both clinical care and research. PROMs are important for the measurement of clinical effectiveness and cost effectiveness and for shared decision-making on treatment options. However, the PROMs used to describe the experience of patients with CLTI are heterogeneous, incomplete, and lack specific applicability to the underlying disease processes and diverse populations. For example, certain PROMs exist for patients with extremity wounds, and other PROMs exist for patients with pain, and still others exist for patients with vascular disease. Despite this multiplicity of tools, no single PROM encompasses all of the components necessary to describe the experiences of patients with CLTI. This significant unmet need is evident from both published reports and contemporary large-scale clinical trials in the field. In this systematic review, we review the current use of PROMs for patients with CLTI in clinical practice and in research trials and highlight the gaps that need to be addressed to develop a unifying PROM instrument for CLTI.

Current Status of Angiogenic Cell Therapy and Related Strategies Applied in Critical Limb Ischemia

Critical limb ischemia (CLI) constitutes the most severe form of peripheral arterial disease (PAD), it is characterized by progressive blockade of arterial vessels, commonly correlated to atherosclerosis. Currently, revascularization strategies (bypass grafting, angioplasty) remain the first option for CLI patients, although less than 45% of them are eligible for surgical intervention mainly due to associated comorbidities. Moreover, patients usually require amputation in the short-term. Angiogenic cell therapy has arisen as a promising alternative for these "no-option" patients, with many studies demonstrating the potential of stem cells to enhance revascularization by promoting vessel formation and blood flow recovery in ischemic tissues. Herein, we provide an overview of studies focused on the use of angiogenic cell therapies in CLI in the last years, from approaches testing different cell types in animal/pre-clinical models of CLI, to the clinical trials currently under evaluation. Furthermore, recent alternatives related to stem cell therapies such as the use of secretomes, exosomes, or even microRNA, will be also described.