Mesenchymal Stem Cell Therapy in Acute Intracerebral Hemorrhage: A Dose-Escalation Safety and Tolerability Trial.

BACKGROUND: We conducted a preliminary phase I, dose-escalating, safety, and tolerability trial in the population of patients with acute intracerebral hemorrhage (ICH) by using human allogeneic bone marrow-derived mesenchymal stem/stromal cells. METHODS: Eligibility criteria included nontraumatic supratentorial hematoma less than 60 mL and Glasgow Coma Scale score greater than 5. All patients were monitored in the neurosciences intensive care unit for safety and tolerability of mesenchymal stem/stromal cell infusion and adverse events. We also explored the use of cytokines as biomarkers to assess responsiveness to the cell therapy. We screened 140 patients, enrolling 9 who met eligibility criteria into three dose groups: 0.5 million cells/kg, 1 million cells/kg, and 2 million cells/kg. RESULTS: Intravenous administration of allogeneic bone marrow-derived mesenchymal stem/stromal cells to treat patients with acute ICH is feasible and safe. CONCLUSIONS: Future larger randomized, placebo-controlled ICH studies are necessary to validate this study and establish the effectiveness of this therapeutic approach in the treatment of patients with ICH.

Trends in utilization of stored cryopreserved autologous peripheral hematopoietic cells intended for a second (or beyond) autologous hematopoietic cell transplantation in patients with multiple myeloma: a single center experience.

Due to the advent of effective novel therapies for multiple myeloma (MM), the use of cryopreserved autologous peripheral blood hematopoietic cells (APBHC) for a salvage autologous transplant (auto-HCT) is in decline. We evaluated utilization trends and costs associated with cryopreserved APBHC in patients with MM. We retrospectively evaluated the clinicopathologic data from 440 patients with MM who underwent APBHC mobilization and collection at Mayo Clinic Florida between 2010 and 2019. Based on institution-specific charges as of May 2021, the cost of 1 session of APBHC collection/apheresis was $4,680 and the cost of 1 year of APBHC cryopreservation was $4,790 per patient. Out of 347 patients who had APBHC in cryopreservation, 5 (1.4%) underwent a salvage auto-HCT and 61% of patients had ≥1 excess collection sessions for APBHC that ultimately went unused. The median cost of excess collection sessions was $4,680 per patient (range, $4,680-$32,760) and the median total cost for excess collection sessions plus costs for storage was $23,840 per patient (range, $4,680-$85,450). The sum of costs of excess collection sessions was $2,077,920 and the sum of costs of cryopreservation was $5,812,665. Institutional policies regarding universal APBHC collection and long-term storage should be reevaluated in the era of novel therapeutics.

Bone Morphogenic Protein and Mesenchymal Stem Cells to Regenerate Bone in Calvarial Defects: A Systematic Review.

BACKGROUND: The use of bone morphogenic protein and mesenchymal stem cells has shown promise in promoting bone regeneration in calvarial defects. However, a systematic review of the available literature is needed to evaluate the efficacy of this approach. METHODS: We comprehensively searched electronic databases using MeSH terms related to skull defects, bone marrow mesenchymal stem cells, and bone morphogenic proteins. Eligible studies included animal studies that used BMP therapy and mesenchymal stem cells to promote bone regeneration in calvarial defects. Reviews, conference articles, book chapters, and non-English language studies were excluded. Two independent investigators conducted the search and data extraction. RESULTS: Twenty-three studies published between 2010 and 2022 met our inclusion criteria after a full-text review of the forty-five records found in the search. Eight of the 23 studies used mice as models, while 15 used rats. The most common mesenchymal stem cell was bone marrow-derived, followed by adipose-derived. BMP-2 was the most popular. Stem cells were embedded in Scaffold (13), Transduction (7), and Transfection (3), and they were delivered BMP to cells. Each treatment used 2 × 104-1 × 107 mesenchymal stem cells, averaging 2.26 × 106. Most BMP-transduced MSC studies used lentivirus. CONCLUSIONS: This systematic review examined BMP and MSC synergy in biomaterial scaffolds or alone. BMP therapy and mesenchymal stem cells in calvarial defects, alone, or with a scaffold regenerated bone. This method treats skull defects in clinical trials. The best scaffold material, therapeutic dosage, administration method, and long-term side effects need further study.

Diabetic kidney disease induces transcriptome alterations associated with angiogenesis activity in human mesenchymal stromal cells.

BACKGROUND: Therapeutic interventions that optimize angiogenic activities may reduce rates of end-stage kidney disease, critical limb ischemia, and lower extremity amputations in individuals with diabetic kidney disease (DKD). Infusion of autologous mesenchymal stromal cells (MSC) is a promising novel therapy to rejuvenate vascular integrity. However, DKD-related factors, including hyperglycemia and uremia, might alter MSC angiogenic repair capacity in an autologous treatment approach. METHODS: To explore the angiogenic activity of MSC in DKD, the transcriptome of adipose tissue-derived MSC obtained from DKD subjects was compared to age-matched controls without diabetes or kidney impairment. Next-generation RNA sequencing (RNA-seq) was performed on MSC (DKD n = 29; Controls n = 9) to identify differentially expressed (DE; adjusted p < 0.05, |log2fold change|> 1) messenger RNA (mRNA) and microRNA (miRNA) involved in angiogenesis (GeneCards). Paracrine-mediated angiogenic repair capacity of MSC conditioned medium (MSCcm) was assessed in vitro using human umbilical vein endothelial cells incubated in high glucose and indoxyl sulfate for a hyperglycemic, uremic state. RESULTS: RNA-seq analyses revealed 133 DE mRNAs (77 upregulated and 56 down-regulated) and 208 DE miRNAs (119 up- and 89 down-regulated) in DKD-MSC versus Control-MSC. Interestingly, miRNA let-7a-5p, which regulates angiogenesis and participates in DKD pathogenesis, interacted with 5 angiogenesis-associated mRNAs (transgelin/TAGLN, thrombospondin 1/THBS1, lysyl oxidase-like 4/LOXL4, collagen 4A1/COL4A1 and collagen 8A1/COL8A1). DKD-MSCcm incubation with injured endothelial cells improved tube formation capacity, enhanced migration, reduced adhesion molecules E-selectin, vascular cell adhesion molecule 1 and intercellular adhesion molecule 1 mRNA expression in endothelial cells. Moreover, angiogenic repair effects did not differ between treatment groups (DKD-MSCcm vs. Control-MSCcm). CONCLUSIONS: MSC from individuals with DKD show angiogenic transcriptome alterations compared to age-matched controls. However, angiogenic repair potential may be preserved, supporting autologous MSC interventions to treat conditions requiring enhanced angiogenic activities such as DKD, diabetic foot ulcers, and critical limb ischemia.

How do we assess batch-to-batch consistency between extracellular vesicle products?

BACKGROUND: Extracellular vesicles (EVs) have gained interest in the field of regenerative and transfusion medicine. Specifically, current Good Manufacturing Practice (cGMP)-grade EVs produced by mesenchymal stromal cells (MSCs) are an intriguing option for cell-free therapeutics. With the development of cGMP-grade EV products, a simple and reliable method for batch-to-batch consistency is needed. STUDY DESIGN AND METHODS: The objective of this study was to validate a method to semiquantitatively assess the batch-to-batch consistency of isolated EVs. A multiplex bead-based flow cytometric assay containing 37 surface markers and 2 assay control antibody-coated capture beads was validated. Detection limits (n = 10 buffer samples), repeatability (n = 9 EV samples), and intra-observer reproducibility over 2 days (n = 10 EV batches) were assessed. A Spearman correlation matrix was used to evaluate the batch-to-batch consistency of independently isolated EV products (n = 37 surface markers). Batches with a Spearman correlation coefficient ≥0.9 and p < 0.05 were considered statistically indistinguishable from previous batches. RESULTS: This assay demonstrated robust repeatability as well as intra- and inter-assay reproducibility. In-house batches of EVs were significantly correlated (r ≥ 0.90; p ≤ 1×10-14 ). Compared with buffer, EV batches had correlation coefficients near zero (r ≤ -0.10; p ≥ 0.12). Commercially sourced EVs significantly correlated with in-house EV batches, but fell below the 90% correlation cutoff (r ≤ 0.71; p ≤ 0.0004). DISCUSSION: This time-efficient and technically simple assay offers a robust method of quality control for assessing the batch-to-batch reproducibility of cGMP-grade EV products.

Phase 1, Dose Escalation, Nonrandomized, Open-Label, Clinical Trial Evaluating the Safety and Preliminary Efficacy of Allogenic Adipose-Derived Mesenchymal Stem Cells for Recurrent Glioblastoma: A Clinical Trial Protocol.

Background and Objectives: Despite standard of care with maximal safe resection and chemoradiation, glioblastoma is the most common and aggressive type of primary brain cancer. Surgical resection provides a window of opportunity to locally treat gliomas while the patient is recovering, and before initiating concomitant chemoradiation. To assess the safety and establish the maximum tolerated dose of adipose-derived mesenchymal stem cells (AMSCs) for the treatment of recurrent glioblastoma (GBM). Secondary objectives are to assess the toxicity profile and long-term survival outcomes of patients enrolled in the trial. Additionally, biospecimens will be collected to explore the local and systemic responses to this therapy. Methods: We will conduct a phase 1, dose escalated, non-randomized, open label, clinical trial of GBM patients who are undergoing surgical resection for recurrence. Up to 18 patients will receive intra-cavitary application of AMSCs encapsulated in fibrin glue during surgical resection. All patients will be followed for up to 5 years for safety and survival data. Adverse events will be recorded using the CTCAE V5.0. Expected Outcomes: This study will explore the maximum tolerated dose (MTD) of AMSCs along with the toxicity profile of this therapy in patients with recurrent GBM. Additionally, preliminary long-term survival and progression-free survival outcome analysis will be used to power further randomized studies. Lastly, CSF and blood will be obtained throughout the treatment period to investigate circulating molecular and inflammatory tumoral/stem cell markers and explore the mechanism of action of the therapeutic intervention. Discussion: This prospective translational study will determine the initial safety and toxicity profile of local delivery of AMSCs for recurrent GBM. It will also provide additional survival metrics for future randomized trials.

Feasibility and Safety of Low-Dose Mesenchymal Stem Cell Infusion in Lung Transplant Recipients.

BACKGROUND: We have previously shown bone marrow-derived mesenchymal stem cells (MSCs) may shift immune responses toward anti-inflammatory pathways and stabilize the course of obstructive chronic lung allograft syndrome (o-CLAD) after lung transplantation. In this study, we measured the response of lower dose infusions. METHODS: We infused low-dose MSCs intravenously in 13 patients who had developed moderate-to-severe o-CLAD. Three had previously received an infusion of MSCs from a different donor and were re-dosed at 1 × 106 MSC/kg, while 5 received a first dose at 1 × 106 MSC/kg and five received an even lower dose at 0.5 × 106 MSC/kg. We recorded pulmonary function tests before and after infusion, and patients were followed clinically for 12 months. RESULTS: Infusions were well tolerated, and no significant adverse events were recorded in the first 30 days. There was significant decline (mean ± SD) in forced vital capacity (FVC) (3.49 ± 1.03 vs 3.18 ± 0.94 L, P = .03) and forced expiratory volume in 1 second (FEV1) (2.28 ± 0.86 vs 1.77 ± 0.49 L, P = .04) over the year preceding infusion. FVC (3.18 ± 0.94 vs 3.46 ± 0.99 L, P = .53) and FEV1 was not significantly changed (1.77 ± 0.49 vs 1.88 ± 0.75, P = .72) when comparing values immediately prior to infusion to those obtained 1 year after infusion, indicating a possible stabilizing effect on lung function decline due to o-CLAD. CONCLUSION: Intravenous infusions of bone marrow-derived MSCs are well tolerated in lung transplant recipients with moderate-to-severe CLAD. Low-dose MSCs appear to slow progression of CLAD in some patients.

Mesenchymal stem cell therapy for focal epilepsy: A systematic review of preclinical models and clinical studies.

Drug-resistant epilepsy (DRE) is characterized by recurrent seizures despite appropriate treatment with antiseizure medication (ASM). Due to their regenerative and immunomodulatory potential, therapies with biologics such as mesenchymal stem cells (MSCs) offer a potential therapeutic benefit for structural causes of epilepsy, such as hippocampal sclerosis. In this article, we report a systematic review of the literature evaluating the preclinical and clinical studies of MSCs for DRE. Medline, Ovid EMBASE, Scopus, and the Cochrane Databases were searched electronically from their dates of inception to November 2021 using the following keywords: (("mesenchymal") AND ("stem cell")) AND (("epilepsy") OR ("convulsion") OR ("seizures")). This review followed Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines. The initial query identified 488 studies representing 323 unique manuscripts. After application of selection criteria, 15 studies were included in this systematic review; 11 were preclinical studies and 4 were clinical studies. All preclinical studies were performed in rodents and all clinical studies were phase 1 trials. Thus far, therapy with MSCs appears to be safe for use in humans, as no severe adverse events related directly to the therapy were reported. Furthermore, MSC therapy appears to provide a statistically significant clinical benefit by reducing the seizure burden of patients, reducing the electrophysiological biomarkers of epilepsy, and improving their comorbidities, such as depression and anxiety. In addition, animal studies reveal that the therapy exerts its effect by reducing aberrant mossy fiber sprouting (reduce excitatory pathways) and increasing γ-aminobutyric acid (GABA)ergic interneurons (increase inhibitory pathways). Both preclinical and clinical studies have shown MSC therapy to be safe and preliminary effective, thus warranting further studies to investigate its therapeutic potential.

Lack of defined apheresis collection criteria in publicly available CAR-T cell clinical trial descriptions: Comprehensive review of over 600 studies.

BACKGROUND: Chimeric antigen receptor T (CAR-T) cell successes have encouraged continued clinical study. Apheresis collection of starting material for CAR-T cell therapy product manufacturing is critical but described approaches suggest variability and clinical guidelines are currently lacking. The goal of this study was to gather and assess variability in apheresis collection descriptions in publicly available CAR T-cell therapy clinical trials. STUDY DESIGN: We searched clinicaltrials.gov (a publicly available clinical trial database) for "chimeric antigen receptor T cells" on July 01, 2020 and studies accessed July 30, 2020-August 15, 2020. Data collected included date posted, study characteristics, apheresis mentions (number, location, and context), laboratory parameters and transfusion allowances. Apheresis context was analyzed using a qualitative inductive approach of grounded theory method with open coding. Text was classified into 37 context codes, grouped into 12 categories, and then consolidated into patient, procedure, product, and miscellaneous themes. RESULTS: Apheresis was mentioned 1044 times in 322 (51.9%) of 621 total studies. Laboratory parameters mentioned included white blood cells (100 studies), absolute neutrophil count (220 studies), absolute lymphocyte count (102 studies), CD3+ cell (38 studies), hemoglobin (233 studies, 54 studies specified transfusion allowance), and platelet (269 studies, 48 studies specified transfusion allowance). CONCLUSIONS: Apheresis collection of CAR-T cell products is not well-defined in clinical study descriptions and the context is inconsistent. Laboratory parameters useful for apheresis collection are variably present and do not consistently align with current practices. Further exploration, and clinical guideline development will encourage alignment of apheresis collections for CAR-T cell products.

Application of Human Adipose-Derived Stem cells for Bone Regeneration of the Skull in Humans.

BACKGROUND: Archeological archives report cranioplasty as 1 of the oldest surgical procedures; however, it was not until the last century that true advances have been made. Alternative approaches are necessary to achieve optimal closure of the defect with fewer adverse effects. We aim to evaluate the use of human adipose-derived stem cells (hADSCs) alone or seeded in scaffolds as the main treatment for cranial bone defects and to assess human patient outcomes. METHODS: A systematic review was performed by querying PubMed, Ovid MEDLINE, EMBASE, and Cumulative Index to Nursing and Allied Health Literature databases with the MeSH terms: "adipose-derived stem cells," "cranial bone defect," "stromal vascular factor," "fat grafting," as well as synonyms in combinations determined by our search strategy. We included human models that used hADSCs as primary therapy. We excluded studies in languages other than English. RESULTS: One hundred ninety-four studies were identified after removal of duplicates. Four articles that used hADSCs as the main therapy to treat calvarial defects in humans were included. One article applied the cell therapy alone, and 3 used ß-tricalcium phosphate granules as a scaffold to seed the hADSCs. CONCLUSIONS: Bone regeneration was reached in a short and intermediate period using autologous hADSCs in humans with no major adverse effects in all 4 articles included. A long-term follow-up study (6 years) exhibited late infections and reabsorption of the ß-tricalcium phosphate scaffold seeded with hADSCs.

Development and evaluation of IL-6 overexpressing mesenchymal stem cells (MSCs).

Mesenchymal stem/stromal cell (MSC) therapy has been investigated in multiple diseases and conditions. Although the mechanisms of MSC-based therapies are not fully understood, we and others have shown interleukin 6 (IL-6) to be an important factor in MSC function. IL-6 contributes to many biological events, such as immune response, neurogenesis, and bone remodeling. In our study, we tested the feasibility of engineering MSCs by IL-6 mRNA transfection (eMSCs-IL6) and evaluated the optimal time to harvest them after transfection. We then assessed the functional characteristics of eMSCs-IL6. Quantitative real-time PCR and ELISA results have shown that mature IL-6 mRNA was efficiently transfected into MSCs using a lipofectamine based method. The IL-6 mRNA and protein overexpression peaked after 1 day of transfection and the secreted IL-6 protein was sustained for at least 6 days. A short time course experiment demonstrated that 4 h after transfection was the best time point to harvest and freeze eMSCs-IL6 for future studies. In addition, eMSCs-IL6 maintained their characteristics as defined by International Society for Cell & Gene Therapy. The immunosuppressive capacity of conditioned culture medium (CCM) from eMSCs-IL6 (CCM-IL6) was significantly enhanced compared to naïve MSCs conditioned culture medium (CCM-control). Our studies established for the first time the feasibility of efficiently generating IL-6 overexpressing MSCs which have enhanced immunosuppressive capacity. This is providing a novel approach to improve the efficacy of MSCs for potential application in regenerative medicine.

IL-10 mRNA Engineered MSCs Demonstrate Enhanced Anti-Inflammation in an Acute GvHD Model.

Mesenchymal stem cells (MSCs) are used in various studies to induce immunomodulatory effects in clinical conditions associated with immune dysregulation such as graft versus host disease (GvHD). However, most of these clinical trials failed to go beyond early phase 2 studies because of limited efficacy. Various methods have been assessed to increase the potency of MSCs. IL-10 is an anti-inflammatory cytokine that is known to modulate immune responses in GvHD. In this study, we evaluated the feasibility of transfecting IL-10 mRNA to enhance MSC therapeutic potential. IL-10 mRNA engineered MSCs (eMSCs-IL10) maintained high levels of IL-10 expression even after freezing and thawing. IL-10 mRNA transfection did not appear to alter MSC intrinsic characteristics. eMSCs-IL10 significantly suppressed T cell proliferation relative to naïve MSCs in vitro. In a mouse model for GvHD, eMSCs-IL10 induced a decrease in plasma level of potent pro-inflammatory cytokines and inhibited CD4+ and CD8+ T cell proliferation in the spleen. In summary, our studies demonstrate the feasibility of potentiating MSCs to enhance their immunomodulatory effects by IL-10 mRNA transfection. The use of non-viral transfection may generate a safe and potent MSC product for treatment of clinical conditions associated with immune dysregulation such as GvHD.

Challenges and translational considerations of mesenchymal stem/stromal cell therapy for Parkinson's disease.

Parkinson's disease (PD) is the second most common neurodegenerative disease characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta and the presence of Lewy bodies, which gives rise to motor and non-motor symptoms. Unfortunately, current therapeutic strategies for PD merely treat the symptoms of the disease, only temporarily improve the patients' quality of life, and are not sufficient for completely alleviating the symptoms. Therefore, cell-based therapies have emerged as a novel promising therapeutic approach in PD treatment. Mesenchymal stem/stromal cells (MSCs) have arisen as a leading contender for cell sources due to their regenerative and immunomodulatory capabilities, limited ethical concerns, and low risk of tumor formation. Although several studies have shown that MSCs have the potential to mitigate the neurodegenerative pathology of PD, variabilities in preclinical and clinical trials have resulted in inconsistent therapeutic outcomes. In this review, we strive to highlight the sources of variability in studies using MSCs in PD therapy, including MSC sources, the use of autologous or allogenic MSCs, dose, delivery methods, patient factors, and measures of clinical outcome. Available evidence indicates that while the use of MSCs in PD has largely been promising, conditions need to be standardized so that studies can be effectively compared with one another and experimental designs can be improved upon, such that this body of science can continue to move forward.

A Combined Approach to Intracerebral Hemorrhage: Intravenous Mesenchymal Stem Cell Therapy with Minimally Invasive Hematoma Evacuation.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent stromal cells currently being tested as therapy for a variety of diseases. MSC therapy and hematoma evacuation using a minimally invasive approach are being studied separately to improve clinical outcomes after stroke. We report the first case of a patient with intracerebral hemorrhage (ICH) treated with combination MSC therapy and endoscopic hematoma evacuation. CASE REPORT: A 36-year-old woman with a past medical history of essential chronic hypertension and right lung bronchial atresia presented to the emergency department with acute neurologic decline (National Institute of Health Stroke Scale [NIHSS] score, 22). Computed tomography showed a 4.4 × 3.5 × 3.5 cm right basal ganglia hemorrhage with intraventricular extension. An external ventricular drain was placed, and she was enrolled in a Phase I clinical trial investigating intravenous MSC therapy for acute ICH. Continued neurologic deterioration due to increased intracranial pressure led to minimally invasive hematoma evacuation using the Artemis Neuro Evacuation Device (Penumbra, Inc.) on hospital day 4. Follow-up scans showed decreased density and extent of hemorrhage. She was discharged on day 41 with improved neurologic function scores (NIHSS score, 2). At 3-month follow-up, she was walking on her own, but had residual left arm and hand weakness (modified Rankin Score, 2). CONCLUSIONS: This case report suggests that the combination of MSC therapy and minimally invasive hematoma evacuation may be safe and well tolerated. Further larger randomized clinical trials are required to identify whether MSC therapy in combination with minimally invasive hematoma evacuation is safe, tolerable, and potentially improves outcomes than either alone.

Feasibility, potency, and safety of growing human mesenchymal stem cells in space for clinical application.

Growing stem cells on Earth is very challenging and limited to a few population doublings. The standard two-dimensional (2D) culture environment is an unnatural condition for cell growth. Therefore, culturing stem cells aboard the International Space Station (ISS) under a microgravity environment may provide a more natural three-dimensional environment for stem cell expansion and organ development. In this study, human-derived mesenchymal stem cells (MSCs) grown in space were evaluated to determine their potential use for future clinical applications on Earth and during long-term spaceflight. MSCs were flown in Plate Habitats for transportation to the ISS. The MSCs were imaged every 24-48 h and harvested at 7 and 14 days. Conditioned media samples were frozen at -80 °C and cells were either cryopreserved in 5% dimethyl sulfoxide, RNAprotect, or paraformaldehyde. After return to Earth, MSCs were characterized to establish their identity and cell cycle status. In addition, cell proliferation, differentiation, cytokines, and growth factors' secretion were assessed. To evaluate the risk of malignant transformation, the space-grown MSCs were subjected to chromosomal, DNA damage, and tumorigenicity assays. We found that microgravity had significant impact on the MSC capacity to secrete cytokines and growth factors. They appeared to be more potent in terms of immunosuppressive capacity compared to their identical ground control. Chromosomal, DNA damage, and tumorigenicity assays showed no evidence of malignant transformation. Therefore, it is feasible and potentially safe to grow MSCs aboard the ISS for potential future clinical applications.

Challenges of manufacturing mesenchymal stromal cell-derived extracellular vesicles in regenerative medicine.

The field of regenerative medicine has expanded greatly in the past decade, with more than 1000 current clinical trials involving mesenchymal stromal cell (MSC) treatment. Multiple recent publications have demonstrated that the beneficial effects from MSCs are not simply due to engraftment into the target organ as classically thought but rather are largely attributable to the release of paracrine factors including cytokines, growth factors and extracellular vesicles (EVs). These EVs contain miRNAs, free fatty acids and proteins that promote regeneration, proliferation and cell function and improve inflammation. Although EVs have shown promising results in animal studies, there are many obstacles to the manufacturing of EVs for clinical applications. This review discusses challenges associated with the manufacturing of clinical-grade EVs in regard to identity, purity, reproducibility, sterility, storage, potency and safety. We discuss currently employed methods and approaches for developing clinical Good Manufacturing Practices (GMP)-grade EVs and the limitations for each. We further discuss the best approaches to overcome the current hurdles in developing clinical GMP-grade EVs.

Cell-based therapy to reduce mortality from COVID-19: Systematic review and meta-analysis of human studies on acute respiratory distress syndrome.

Severe cases of COVID-19 infection, often leading to death, have been associated with variants of acute respiratory distress syndrome (ARDS). Cell therapy with mesenchymal stromal cells (MSCs) is a potential treatment for COVID-19 ARDS based on preclinical and clinical studies supporting the concept that MSCs modulate the inflammatory and remodeling processes and restore alveolo-capillary barriers. The authors performed a systematic literature review and random-effects meta-analysis to determine the potential value of MSC therapy for treating COVID-19-infected patients with ARDS. Publications in all languages from 1990 to March 31, 2020 were reviewed, yielding 2691 studies, of which nine were included. MSCs were intravenously or intratracheally administered in 117 participants, who were followed for 14 days to 5 years. All MSCs were allogeneic from bone marrow, umbilical cord, menstrual blood, adipose tissue, or unreported sources. Combined mortality showed a favorable trend but did not reach statistical significance. No related serious adverse events were reported and mild adverse events resolved spontaneously. A trend was found of improved radiographic findings, pulmonary function (lung compliance, tidal volumes, PaO2 /FiO2 ratio, alveolo-capillary injury), and inflammatory biomarker levels. No comparisons were made between MSCs of different sources.

Low baseline platelet count predicts poor response to plerixafor in patients with multiple myeloma undergoing autologous stem cell mobilization.

BACKGROUND AIMS: Baseline platelet count has been shown to be a sensitive predictor of autologous peripheral blood progenitor cell collection yield in patients with multiple myeloma mobilized with granulocyte colony-stimulating factor (G-CSF). Patients who mobilize poorly with G-CSF are often treated with plerixafor to enhance mobilization. There are no surrogate markers available to predict response to plerixafor. METHODS: We retrospectively analyzed data from 73 patients with multiple myeloma who did not have adequate mobilization with G-CSF alone and were treated with plerixafor as a rescue agent. RESULTS: We found that baseline platelet count directly correlated with peripheral blood CD34+ (PB-CD34+) count after plerixafor treatment (r = 0.36, P < 0.0001) and the number of PB-CD34+ cells collected on the first day of apheresis and inversely correlated with the number of apheresis sessions needed to collect the target number of PB-CD34+ cells (P = 0.0015). Baseline platelet count of 153 000/µL or less was associated with 90% specificity of predicting poor response to plerixafor with a sensitivity of 33%. CONCLUSIONS: Baseline platelet count is a good predictor of mobilization response to plerixafor in patients with multiple myeloma.