Autologous Peripheral Blood Mononuclear Cells in Diabetic Foot Patients With No-option Critical Limb Ischemia

Study Overview
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Brief Summary
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The objective of this trial is to determine whether PBMNCs in diabetic patients with critical, non revascularizable limb ischemia can prevent major amputation and affect mortality and healing.

Detailed Description
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This is an interventional study with historical control group carried out to assess as primary outcome major amputations, overall mortality, number of healed patients in group of patients who received repetitive intra-muscular implant of PBMNCs (3 times; 4-week interval) in comparison to a historical internal control group with a 1:1 case-control ratio. Secondary outcomes are TCPO2, healing time and rest pain. No-option critical limb ischaemia is defined by evidence of no run-off pedal vessels, failure after several percutaneous intervention and no longer possible re-intervention, failure after infra-genicular bypass grafting, no-walking capacity with severe comorbidities unfit for surgical or endovascular procedures. Inclusion criteria are: a) ulcers with inadequate perfusion, as indicated by a transcutaneous oxygen pressure value (TcpO2) <30 mmHg; b) ulcers with grade I or II or III and stage C as defined by the Texas University Classification System or W1,2,3 - I 3 - FI 0,1 as defined by the WiFI Classification System c) not eligible for angioplasty or vascular surgery or following failed revascularization; d) possibility to save foot support. Exclusion criteria are: a) lesion site above the tibial-tarsal joint; b) moderate or severe infection according by the WiFI classification system; c) NYHA class IV; d) Anemia (Hb<8g/dl); e) coagulation disorder/thrombocytopenia (PLT< 50,000 per microliter); f) active cancer/leukemia or lymphoma hematological disease. Standard of care in both groups includes: diabetes control maximization by the diabetologist, comprehensive foot assessment by the nurse together with the diabetologist, including determination of vibration perception threshold, 10-g monofilament test and TcpO2 measurement, dressings, off-loading and systemic therapy according to the IWGDF guidelines . Informed consent for participation in the study during the progress of the clinical trial is obtained from all subjects. Concentration of PB-MNCs autologous cell therapy is produced by a filtration-based point-of-care device with the intended for use intra-operatively, from 120 mL of anticoagulated blood. All the procedures are performed in operatory room with anaesthesiologic support (propofol and/or peripheral block). Blood withdrawal (120 ml) is collected through a peripheral venous access, than loaded and gravity filtration is allowed in about 10 minutes. During filtration, MNCs are captured in the filter while plasma, platelets (PLTs) and red blood cells (RBCs) are not retained. After appropriate surgical debridement of the wound bed multiple perilesional and intramuscular injections of PBMNC cells suspension (0.2-0.3cc in boluses) are injected along the relevant axis below the knee, at intervals of 1-2 cm and to a mean depth of 1.5-2 cm, using a 21G needle. This procedure is repeated on each patient for three times, at intervals of 30-45 days from each other. Foot-sparing surgery, the removal of all the unviable tissue and the reconstruction of the foot to allow a functional deambulation,is performed at the same time of the last implant in the patients with increased TcpO2 value above 30 mmHg. Between the implants, diabetologists together with nurses evaluated changing in pain, infection signs, wound size, demarcation of the necrosis, granulation tissue formation, perilesional tissue trophism and TcpO2 value to optimize standard of care. After the first treatment, a two years follow-up is registered, with evaluation at 1-3-6-12-18-24 months. A baseline assessment is carried out, in order to estimate any differences among cases and controls before the treatment. Statistical evaluation includes non-parametric tests (Mann-Whitney U test for independent samples for continuous variables and Cochrane chi-square test for discrete variables), evaluation of Relative Risk (RR), Absolute Risk Reduction (ARR), Relative Risk Reduction (RRR) and Number Needed to Treat (NNT), multivariate survival analysis (Kaplan-Meier's survival analysis model).

Official Title
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Autologous Peripheral Blood Mononuclear Cells for Limb Salvage in Diabetic Foot Patients With No-option Critical Limb Ischemia

Conditions
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Critical Limb Ischemia, Diabetic Foot

Intervention / Treatment
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* Device: Pall Celeris System, point of care device for human cell therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ulcers with inadequate perfusion, as indicated by a transcutaneous oxygen pressure value (TcpO2) <30 mmHg; ulcers with grade I or II or III and stage C as defined by the Texas University Classification System or W1,2,3 - I 3 - FI 0,1 as defined by the WiFI Classification System not eligible for angioplasty or vascular surgery or following failed revascularization; possibility to save foot support. Exclusion Criteria: lesion site above the tibial-tarsal joint; moderate or severe infection according by the WiFI classification system; NYHA class IV; d) Anemia (Hb<8g/dl); coagulation disorder/thrombocytopenia (PLT< 50,000 per microliter); active cancer/leukemia or lymphoma hematological disease.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: We would enroll a cohort of 38 consecutive diabetic patients with CLI in charge at the Diabetic Foot Unit of the San Donato Hospital in Arezzo or referred from other Italian hospitals, who have no option for revascularization or are not further eligible for revascularization according to ESVS ESC 2017 criteria to undergo PB-MNC implantation. Furthermore, an historical control group, with a 1:1 case-control ratio, will be collected backwards from our records, when PBMNCs cellular therapy was not available in our center, with same no-option CLI diagnosis.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: A-PBMNC therapy<br>Patients in A-PBMNC therapy are treated with wound bed multiple perilesional and intramuscular injections of PBMNC cells suspension (0.2-0.3cc in boluses). This procedure is repeated on each patient for three times, at intervals of 30-45 days from each other. | Device: Pall Celeris System, point of care device for human cell therapy<br>* Concentration of PB-MNCs autologous cell therapy was produced by a filtration-based point-of-care device. All the procedures were performed in operatory room with anaesthesiologic support (propofol and/or peripheral block). Blood withdrawal (120 ml) was collected through a peripheral venous access. Blood was loaded, and gravity filtration was allowed to proceed until the upstream side of the filter had no remaining blood; filtration last about 10 minutes. During filtration, MNCs were captured in the filter while plasma, platelets (PLTs) and red blood cells (RBCs) were not retained. Immediately concentrate solution is injected in the perilesional area and intramuscular in the foot and the leg (0.2-0.3cc in boluses) below the knee, at intervals of 1-2 cm and to a mean depth of 1.5-2 cm, using a 21G needle. This procedure is repeated on each patient for three times, at intervals of 30-45 days from each other.<br>|
| No Intervention: No A-PBMNC therapy<br>Patients in No A-PBMNC therapy receive only supportive treatment including wound care and pain killer drug. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amputation-free survival at 1 month | rate of non amputated limb 1 month after the intervention | 1 month | 
| Amputation-free survival at 3 months | rate of non amputated limb 3 months after the intervention | 3 months | 
| Amputation-free survival at 6 months | rate of non amputated limb 6 months after the intervention | 6 months | 
| Amputation-free survival at 12 months | rate of non amputated limb 12 months after the intervention | 12 months | 
| Amputation-free survival at 18 months | rate of non amputated limb 18 months after the intervention | 18 months | 
| Amputation-free survival at 24 months | rate of non amputated limb 24 months after the intervention | 24 months | 
| risk of death at 1 month | rate of dead subjects 1 month after the intervention | 1 month | 
| risk of death at 3 months | rate of dead subjects 3 months after the intervention | 3 months | 
| risk of death at 6 months | rate of dead subjects 6 months after the intervention | 6 months | 
| risk of death at 12 months | rate of dead subjects 12 months after the intervention | 12 months | 
| risk of death at 18 months | rate of dead subjects 18 months after the intervention | 18 months | 
| risk of death at 24 months | rate of dead subjects 24 months after the intervention | 24 months | 
| probability of healing at 1 month | rate of healed subjects 1 month after the intervention | 1 month | 
| probability of healing at 3 months | rate of healed subjects 3 months after the intervention | 3 months | 
| probability of healing at 6 months | rate of healed subjects 6 months after the intervention | 6 months | 
| probability of healing at 12 months | rate of healed subjects 12 months after the intervention | 12 months | 
| probability of healing at 18 months | rate of healed subjects 18 months after the intervention | 18 months | 
| probability of healing at 24 months | rate of healed subjects 24 months after the intervention | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| transcutaneous oxygen measurement (TcPO2) variation | comparison of TcPO2 at the second follow up (3 months after intervention) with the baseline measure | 0-3 months | 
| Healing time | time to reach complete epithelialization | within 24 months | 
| rest pain | comparison of rest pain measured by a numeric rating scale (NRS) min 0 - max 10, where 10 is the worst pain the patient has felt | 0-1-3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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autologous peripheral blood mononuclear cell, diabetic foot