Mesenchymal Stromal/Stem Cell Therapy Improves Salivary Flow Rate in Radiation-Induced Salivary Gland Hypofunction in Preclinical in vivo Models: A Systematic Review and Meta-Analysis.

BACKGROUND: Mesenchymal stromal/stem cells (MSCs) have been suggested for salivary gland (SG) restoration following radio-induced salivary gland damage. This study aimed to determine the safety and effectiveness of MSC therapy on radio-induced SG damage and hypofunction in preclinical in vivo studies. METHODS: PubMed and EMBASE were systematically searched for preclinical in vivo interventional studies evaluating efficacy and safety of MSC treatment following radio-induced salivary gland damage published before 10th of January 2022. The primary endpoint was salivary flow rate (SFR) evaluated in a meta-analysis. The study protocol was published and registered on PROSPERO ( www.crd.ac.uk/prospero ), registration number CRD42021227336. RESULTS: A total of 16 preclinical in vivo studies were included for qualitative analysis (858 experimental animals) and 13 in the meta-analysis (404 experimental animals). MSCs originated from bone marrow (four studies), adipose tissue (10 studies) and salivary gland tissue (two studies) and were administered intravenously (three studies), intra-glandularly (11 studies) or subcutaneously (one study). No serious adverse events were reported. The overall effect on SFR was significantly increased with a standardized mean difference (SMD) of 6.99 (95% CI: 2.55-11.42). Studies reported improvements in acinar tissue, vascular areas and paracrine factors. CONCLUSION: In conclusion, this systematic review and meta-analysis showed a significant effect of MSC therapy for restoring SG functioning and regenerating SG tissue following radiotherapy in preclinical in vivo studies without serious adverse events. MSC therapy holds significant therapeutic potential in the treatment of radio-induced xerostomia, but comprehensive, randomized, clinical trials in humans are required to ascertain their efficacy in a clinical setting.

Cosmetic Breast Augmentation with Autologous Ex Vivo-Expanded Adipose-Derived Mesenchymal Stem/Stromal Cell (Stemform®)-Enriched Fat Grafts: A Study of the First Twenty-Two Real-World Patients.

BACKGROUND: Fat grafting is commonly utilized in breast surgery, and since it was first described, clinicians and researchers have stridden towards improvement of graft retention. Current advancements include adding adipose-derived mesenchymal stem/stromal cells (MSC(AT)s), which have demonstrated promise for improved graft retention. OBJECTIVES: This study reports outcomes for the first twenty-two patients undergoing breast augmentation (Stemform BA) or artificial implant replacement (Stemform AIR) with MSC(AT)-enriched fat in a real-world setting. METHODS: Autologous MSC(AT)s were isolated and expanded ex vivo, then mixed with lipoaspirate and injected as enriched fat for Stemform BA and AIR. The breast volume was measured preoperatively and at 3 and 12 months postoperative using a 3D Infinity Dual-Lens Camera and LifeVizApp software. Additionally, independent plastic surgeons evaluated clinical images, and patient satisfaction was obtained at equal time points. RESULTS: Twenty-two patients were included. All completed 3 and 12 months clinical follow-up and 3 months volume measurements. Nineteen patients completed 12 months volume measurements. The median fat graft retention at 12 months was 95.7% (IQR = 82.44-103.12%) for Stemform BA patients and 113.0% (IQR = 94.8-131.2%) for Stemform AIR patients. The Stemform BA patients had a median breast enlargement of 172.0% (IQR = 156.7-241.0%). The implant replacement volume of Stemform AIR patients was 102% (IQR = 85.1-130.3%). The patient reported 92.8% and 100% would elect to repeat treatment if they had the opportunity for Stemform BA and Stemform AIR, respectively. CONCLUSION: Breast augmentation and breast implant replacement patients receiving ex vivo-expanded MSC(AT)-enriched fat grafts had high graft retention and patient satisfaction scores. The paper confirms the clinical efficacy of using ex vivo-expanded MSC(AT)s. Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Donor Lymphocyte Infusion Is a Feasible Way to Improve Survival in Patients with Acute Myeloid Leukemia and Myelodysplastic Syndromes Who Relapse after Allogeneic Stem Cell Transplantation.

INTRODUCTION: Donor lymphocyte infusion (DLI) is used to induce remission in patients who relapse after allogeneic stem cell transplantation (allo-HSCT). During the last decade, the hypomethylating agent Azacitidine has been used together with DLI for a synergistic graft-versus-leukemia (GVL) effect. Here we report results of DLI/Azacitidine treatment from a retrospective single-center study. METHODS: 50 AML/MDS patients treated for relapse after allo-HSCT between 2001 and 2020 with DLI at the Department of Hematology, at Rigshospitalet, Copenhagen University Hospital were included for analyses. A subgroup of patients who obtained complete remission (CR) after reinduction chemotherapy, received DLI in combination with low-dose (32 mg/m2) Azacitidine. RESULTS: Overall survival in all patients after DLI treatment was 59% at 2 years and 20% at 5 years. Relapse-free survival in patients in CR prior to DLI was 32% after 2 years and 7% after 5 years. In the DLI+low-dose-Azacitidine group, 5-years relapse-free survival was 40%. CONCLUSION: DLI remains an effective treatment in post-transplant relapse leaving one fifth of patients long-term survivors. Our results support the concomitant use of low-dose Azacitidine in the future use of DLI in order to enhance the GVL effect of donor lymphocytes.

Efficacy of mesenchymal stem cell-delivery using perpendicular multi-needle injections to the skin: Evaluation of post-ejection cellular health and dermal delivery.

AIM: Mesenchymal stem cell (MSC)-therapy is increasingly being evaluated in clinical trials. Dermal delivery is not only time consuming but also unreliable, potentially hampering the therapeutic result. Therefore, qualification of cell delivery protocols is essential. This study evaluated a clinically relevant automated multi-needle injection method for cutaneous MSC-therapy, allowing the skin to be readily and timely treated, by assessing both the cellular health post-ejection and dermal delivery. METHODS: Following dispensation through the injector (31 G needles: 9- or 5-pin) the cellular health and potency (perceived- and long-term (12 h) viability, recovery, metabolism, adherence, proliferation and IDO1-expression) of adipose-derived stem cells (10-20-50 ×106 cells/ml) were assessed in vitro in addition to dermal delivery of solution in human skin. RESULTS: No significant detrimental effect on the perceived cell viability, recovery, metabolism, adherence or IDO1-expression of either cell concentration was observed. However, the overall long-term viability and proliferation decreased significantly regardless of cell concentration, nonetheless marginally. An injection depth above 1.0 mm resulted in all needles piercing the skin with dermal delivery from up to 89% needles and minimal reflux to the skin surface, and the results were confirmed by ultrasound and histology. CONCLUSION: The automated injector is capable of delivering dermal cell-doses with an acceptable cell quality.

Intraglandular mesenchymal stem cell treatment induces changes in the salivary proteome of irradiated patients.

BACKGROUND: Hyposalivation and xerostomia (dry mouth), are the leading site-effects to treatment of head and neck cancer. Currently, there are no effective therapies to alleviate radiation-induced hyposalivation. Adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) have shown potential for restoring salivary gland function. However, the mode of action is unknown. The purpose of the present study was therefore to characterize the effect of AT-MSC therapy on the salivary proteome in previously irradiated head and neck cancer patients. METHODS: Whole saliva was collected from patients with radiation-induced salivary gland hypofunction (n = 8) at baseline, and 120 days after AT-MSC treatment, and from healthy controls (n = 10). The salivary proteome was characterized with mass spectrometry based proteomics, and data was compared within the AT-MSC group (baseline versus day 120) and between AT-MSC group and healthy controls. Significance levels between groups were determined by using double-sided t-test, and visualized by means of principal component analysis, volcano plots and cluster analysis. RESULTS: Here we show that 140 human proteins are significantly differentially expressed in saliva from patients with radiation-induced hypofunction versus healthy controls. AT-MSC treatment induce a significant impact on the salivary proteome, as 99 proteins are differentially expressed at baseline vs. 120 days after treatment. However, AT-MSC treatment does not restore healthy conditions, as 212 proteins are significantly differentially expressed in saliva 120 days after AT-MSCs treatment, as compared to healthy controls. CONCLUSION: The results indicate an increase in proteins related to tissue regeneration in AT-MSCs treated patients. Our study demonstrates the impact of AT-MSCs on the salivary proteome, thereby providing insight into the potential mode of action of this novel treatment approach.

Currently, there are no effective treatments to ease dry mouth, which is a leading long-term side effect of radiation treatment for head and neck cancer. However, treatment with stem cells has shown potential for restoring function of the salivary glands, which are damaged due to radiation. We compared proteins in saliva of previously radiation-treated patients with healthy non-irradiated persons and found differences in the levels of 140 proteins. After stem cell treatment of irradiated patients, we found changes in the salivary content of proteins related to tissue regeneration. Our study demonstrates the impact of stem cell treatment on proteins in saliva, thereby providing insight into the potential mode of action of this treatment approach for patients with radiation-induced dry mouth. Consequently, this could potentially help to improve treatment of dry mouth in the future.

Mesenchymal stromal/stem cell therapy for radiation-induced salivary gland hypofunction in animal models: a protocol for a systematic review and meta-analysis.

BACKGROUND: Salivary gland (SG) hypofunction (objectively reduced saliva flow rate) and xerostomia (subjective sensation of dry mouth) are common and burdensome side effects of radiotherapy to the head and neck region. Currently, only sparse symptomatic treatment is available to ease the discomfort of xerostomia. The objective of this study is to assess the effect of mesenchymal stem cell (MSC) therapy on SG function after radiation-induced injury. METHODS: This systematic review will include animal intervention studies assessing efficacy and safety of MSCs in treating radiation-induced SG hypofunction. The primary outcome is the effect of MSC administration on salivary flow rates (SFR), by comparing treated groups to control groups when available. Secondary outcomes are morphological and immunohistochemical effects as well as safety of MSC treatment. Electronic searches in MEDLINE (PubMed) and Embase databases will be constructed and validated according to the peer review of electronic search strategies (PRESS) and assessed by two independent researchers. Data from eligible studies will be extracted, pooled, and analyzed using random-effects models. Risk of bias will be evaluated with the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk of bias tool. DISCUSSION: Thus far, critical appraisal of MSC therapy as an effective treatment for SG hypofunction caused solely by radiation injury has not been conducted. A summary of the existing literature on preclinical studies concerning this issue can provide valuable information about effectiveness, mode of action, and safety, allowing further optimization of preclinical and clinical trials. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021227336.

Intraglandular Off-the-Shelf Allogeneic Mesenchymal Stem Cell Treatment in Patients with Radiation-Induced Xerostomia: A Safety Study (MESRIX-II).

No effective therapy exists for the most common long-term side effect of radiation therapy for head and neck cancer (HNC)-xerostomia. The objective was to evaluate safety and provide proof of concept for efficacy of allogeneic adipose tissue-derived mesenchymal stem/stromal cells (AT-MSCs) injected into the major salivary glands of irradiated patients. This open-label, first-in-human, phase 1b, and single-center trial was conducted with repeated measurements days 0, 1, 5, and 30 and 4 months. Eligible patients with objective and subjective signs of radiation-induced salivary gland damage after treatment of oropharyngeal squamous cell carcinoma stages I-II (UICC 8) were enrolled. Twenty-five million cryopreserved AT-MSCs were injected into each submandibular and 50 million AT-MSCs into each parotid gland. Data were collected on adverse events, unstimulated and stimulated whole saliva (UWS and SWS) flow rates and saliva composition, patient-reported outcomes (EORTC QLQ-H&N35 and Xerostomia Questionnaire [XQ]), blood samples and salivary gland scintigraphy. Data were analyzed using repeated measures linear mixed models. Ten patients (7 men, 3 women, 59.5 years [range: 45-70]) were treated in 4 glands. No treatment-related serious adverse events occurred. During 4 months, UWS flow rate increased from 0.13 mL/minute at baseline to 0.18 mL/minute with a change of 0.06 (P = .0009) mL/minute. SWS flow rate increased from 0.66 mL/minute at baseline to 0.75 mL/minute with a change of 0.09 (P = .017) mL/minute. XQ summary score decreased by 22.6 units (P = .0004), EORTC QLQ-H&N35 dry mouth domains decreased by 26.7 (P = .0013), sticky saliva 23.3 (P = .0015), and swallowing 10.0 (P = .0016). Our trial suggests treatment of the major salivary glands with allogenic AT-MSCs is safe, warranting confirmation in larger trials.

Long-term Safety of Treatment with Autologous Mesenchymal Stem Cells in Patients with Radiation-Induced Xerostomia: Primary Results of the MESRIX Phase I/II Randomized Trial.

PURPOSE: Mesenchymal stem/stromal cell therapy may reduce radiation-induced xerostomia. We investigated the long-term safety of autologous adipose tissue-derived mesenchymal stem/stromal cell (ASC) injections into the submandibular glands. EXPERIMENTAL DESIGN: An investigator-initiated, randomized, single-center, placebo-controlled trial. Previous patients with oropharyngeal squamous cell carcinoma with radiation-induced xerostomia were randomly (1:1) allocated to receive a 2.8 million ASCs/cm3 injection or placebo in both submandibular glands and followed for a minimum of 2 years. The primary endpoint was number of serious adverse events (SAE). Secondary endpoints included whole saliva flow rates and xerostomia-related symptoms. Data analysis was based on the intention-to-treat population using repeated measures mixed-effects linear models. RESULTS: Thirty-three patients were randomized; 30 patients were treated (ASC group, n = 15; placebo group, n = 15). Long-term safety data were collected from all 30 patients. During follow-up, 6 of 15 (40%) of the ASC-treated patients versus 5 of 15 (33%) of the placebo patients experienced an SAE; no SAEs appeared to be treatment related. Unstimulated whole saliva flow rate increased to 0.20 and 0.16 mL/minute in the ASC and placebo group, respectively, yielding a 0.05 mL/minute (95% confidence interval: 0.00-0.10; P = 0.051) difference between groups. Patient-reported xerostomia symptoms diminished according to a decreased xerostomia questionnaire summary score of 35.0 and 45.1, respectively [-10.1 (-18.1 to -2.2); P = 0.013]. Three of the visual analog scale xerostomia measures indicated clinical benefit following use of ASC. CONCLUSIONS: Our data show that ASC therapy is safe with a clinically relevant effect on xerostomia-related symptoms. Confirmation in larger randomized controlled trials is warranted.

Application of a deep learning-based image analysis and live-cell imaging system for quantifying adipogenic differentiation kinetics of adipose-derived stem/stromal cells.

Quantitative methods for assessing differentiative potency of adipose-derived stem/stromal cells may lead to improved clinical application of this multipotent stem cell, by advancing our understanding of specific processes such as adipogenic differentiation. Conventional cell staining methods are used to determine the formation of adipose areas during adipogenesis as a qualitative representation of adipogenic potency. Staining methods such as oil-red-O are quantifiable using absorbance measurements, but these assays are time and material consuming. Detection methods for cell characteristics using advanced image analysis by machine learning are emerging. Here, live-cell imaging was combined with a deep learning-based detection tool to quantify the presence of adipose areas and lipid droplet formation during adipogenic differentiation of adipose-derived stem/stromal cells. Different detection masks quantified adipose area and lipid droplet formation at different time points indicating kinetics of adipogenesis and showed differences between individual donors. Whereas CEBPA and PPARG expression seems to precede the increase in adipose area and lipid droplets, it might be able to predict expression of ADIPOQ. The applied method is a proof of concept, demonstrating that deep learning methods can be used to investigate adipogenic differentiation and kinetics in vitro using specific detection masks based on algorithm produced from annotation of image data.

Platelet and Red Blood Cell Transfusions and Risk of Acute Graft-versus-Host Disease after Myeloablative Allogeneic Hematopoietic Cell Transplantation.

Transfusion therapy is a critical part of supportive care early after allogeneic hematopoietic cell transplantation (allo-HCT). Platelet and RBC transfusions elicit immunomodulatory effects in the recipient, but if this impacts the risk of acute graft-versus-host disease (aGVHD) has only been scarcely investigated. We investigated if platelet and RBC transfusions were associated with the development of aGVHD following myeloablative allo-HCT in a cohort of 664 patients who underwent transplantation between 2000 and 2019. Data were further analyzed for the impact of blood donor age and sex and blood product storage time. Exploratory analyses were conducted to assess correlations between transfusion burden and plasma biomarkers of inflammation and endothelial activation and damage. Between day 0 and day +13, each patient received a median of 7 (IQR, 5 to 10) platelet transfusions and 3 (IQR, 2 to 6) RBC transfusions (Spearman's ρ = 0.49). The cumulative sums of platelet and RBC transfusions, respectively, received from day 0 to day +13 were associated with subsequent grade II-IV aGVHD in multivariable landmark Cox models (platelets: adjusted hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.06 to 1.51; RBCs: adjusted HR, 1.41; 95% CI, 1.09 to 1.82; both per 5 units; 184 events). For both platelet and RBC transfusions, we did not find support for a difference in the risk of aGVHD according to age or sex of the blood donor. Transfusion of RBCs with a storage time longer than the median of 8 days was inversely associated with aGVHD (HR per 5 units, 0.54; 95% CI, 0.30 to 0.96); however, when using an RBC storage time of ≥14 days as a cutoff, there was no longer evidence for an association with aGVHD (HR, 1.03 per 5 units; 95% CI, 0.53 to 2.00). For platelets, there was no clear association between storage time and the risk of aGVHD. The transfusion burdens of platelets and RBCs were positively correlated with plasma levels of TNF-α, IL-6, and soluble thrombomodulin at day +14. In conclusion, platelet and RBC transfusions in the first 2 weeks after myeloablative allo-HCT were associated with subsequent development of grade II-IV aGVHD. We did not find evidence of an impact of blood donor age or sex or blood product storage time on the risk of aGVHD. Our findings support restrictive transfusion strategies in allo-HCT recipients.

DMSO (Me2SO) concentrations of 1-2% in combination with pentaisomaltose are effective for cryopreservation of T cells.

T cell based treatments in the setting of allogenic haematopoietic stem cell transplantation (HSCT) have been used for decades. In addition, the use of chimeric antigen receptor (CAR) T cells has been introduced as a promising cancer immunotherapy. A prerequisite for many of these treatments is the ability to cryopreserve the cells safely and efficiently. In the present study, we compared freezing media combinations containing pentaisomaltose and 1-2 % DMSO (PIM1 and PIM2, respectively) to 10 % DMSO and commercially available cryosolutions (CS2 and CS10, Cryostor® containing 2 and 10 % DMSO, respectively) for cryopreservation of T cells. T cells isolated from buffy coats from healthy donors were cryopreserved with different freezing media and analysed for 1) viability immediately post-thaw and the following 24 h, 2) recovery, 3) proliferative potential and 4) migration towards a gradient of SDF-1α. The results showed that PIM2 was superior to 10 % DMSO and comparable to CS10 when assessing viability. Furthermore, the results indicated that the T cells cryopreserved with 10 % DMSO showed the lowest proliferative potential. The expression levels of CXCR3, CXCR4 and VLA-4 were similar in T cells independent of the freezing media used; however, T cells cryopreserved with PIM2 demonstrated the highest migratory potential. In summary, the combination of pentaisomaltose and 1-2 % DMSO improves the cryoprotective properties compared to 10 % DMSO while achieving comparable results with CS10 and even showing improved migration towards SDF-1α. Thus, our results show promising potential for pentaisomaltose in combination with low amounts of DMSO for the cryopreservation of T cells.

Granulocyte Colony-Stimulating Factor Effectively Mobilizes TCR γδ and NK Cells Providing an Allograft Potentially Enhanced for the Graft-Versus-Leukemia Effect for Allogeneic Stem Cell Transplantation.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a potential cure for patients with hematological malignancies but substantial risks of recurrence of the malignant disease remain. TCR γδ and NK cells are perceived as potent innate effector cells in HSCT and have been associated with post-transplant protection from relapse in clinical studies. Immunocompetent cells from the donor are crucial for patient outcomes and peripheral blood stem cells (PBSC) are being increasingly applied as graft source. G-CSF is the preferential mobilizing agent in healthy donors for PBSC grafts, yet effects of G-CSF on TCR γδ and NK cells are scarcely uncovered and could influence the graft composition and potency of these cells. Therefore, we analyzed T and NK cell subsets and activation markers in peripheral blood samples of 49 donors before and after G-CSF mobilization and-for a subset of donors-also in the corresponding graft samples using multicolor flowcytometry with staining for CD3, CD4, CD8, TCRαß, TCRγδ, Vδ1, Vδ2, HLA-DR, CD45RA, CD197, CD45RO, HLA-DR, CD16, CD56, and CD314. We found that TCR γδ cells were mobilized and harvested with an efficiency corresponding that of TCR αß cells. For TCR γδ as well as for TCR αß cells, G-CSF preferentially mobilized naïve and terminally differentiated effector (TEMRA) cells over memory cells. In the TCR γδ cell compartment, G-CSF preferentially mobilized cells of the nonVδ2 types and increased the fraction of HLA-DR positive TCR γδ cells. For NK cells, mobilization by G-CSF was increased compared to that of T cells, yet NK cells appeared to be less efficiently harvested than T cells. In the NK cell compartment, G-CSF-stimulation preserved the proportion of CD56dim NK effector cells which have been associated with relapse protection. The expression of the activating receptor NKG2D implied in anti-leukemic responses, was significantly increased in both CD56dim and CD56bright NK cells after G-CSF stimulation. These results indicate differentiated mobilization and altering properties of G-CSF which could improve the effects of donor TCR γδ and NK cells in the processes of graft-versus-leukemia for relapse prevention after HSCT.

Mesenchymal stem cell therapy of acute thermal burns: A systematic review of the effect on inflammation and wound healing.

AIM: Mesenchymal stem cell (MSC) therapies are emerging as a promising strategy to promote tissue repair, and may extend their utility to burn care. This comprehensive review of the extant literature, evaluated all in vivo studies, to elucidate the potential protective and therapeutic effect of MSCs in acute thermal skin burns. METHODS: PubMed was systematically searched, according to PRISMA guidelines, and all relevant preclinical and clinical studies were included according to pre-specified eligibility criteria. RESULTS: Forty-two studies were included in a qualitative synthesis, of which three were human and 39 were animal studies. The preclinical studies showed that MSCs can significantly reduce inflammation, burn wound progression and accelerate healing rate of acute burns. The underlying mechanisms are complex and not fully understood but paracrine modulators, such as immunomodulatory, antioxidative and trophic factors, seem to play important roles. Allogeneic MSC therapy has proved feasible in humans, and could allow for prompt treatment of acute burns in a clinical setting. CONCLUSION: MSC therapy show positive results, regarding improved burn wound healing and immunologic response. However, most findings are based on small animal studies. Randomized clinical trials are warranted to investigate the regenerative effects in human burns before translating the findings into clinical practice.

[Treatment of monogenic disorders with viral transduced haematopoietic stem cells].

Infusion of ex vivo transduced haematopoietic stem cells (HSC) has emerged as a promising new treatment of certain monogenetic disorders. Since early clinical studies on patients with severe combined immune deficiency were halted due to de novo leukaemia, the technology has matured. Thus, treatment of transfusion-dependent thalassaemia and adenosine deaminase deficient severe combined immunodeficiency by using lentiviral vectors for gene correction of autologous HSC can induce expression of the deficient protein and thus potentially cure the patients. The review summarises recent advances allowing for clinical implementation of the treatment in Denmark.

Mesenchymal Stem Cell Therapy for Osteoradionecrosis of the Mandible: a Systematic Review of Preclinical and Human Studies.

BACKGROUND: Osteoradionecrosis (ORN) of the mandible is a severe complication of radiotherapy for head and neck cancer and is arduously difficult to manage. Current treatment options carry risks with some patients remaining incurable. Mesenchymal stromal/stem cell (MSC) therapy has shown promising results supporting osteogenesis and regeneration of radiotherapy-damaged tissues. The aim of this study was to systematically review the literature on the safety and efficacy of MSCs in treating ORN. METHODS: A systematic search was performed on MEDLINE, Embase, Cochranes Library online databases, and clinicaltrials.gov to identify preclinical and clinical studies examining the effect of MSCs on osseous healing of ORN. The preclinical studies were assessed according to the SYRCLEs guidelines and risk of bias tool. RESULTS: Six studies (n = 142) from 5 countries were eligible for analysis. Of these four were preclinical studies and two clinical case studies. Preclinical studies found MSC treatment to be safe, demonstrating bone restorative effects and improved soft tissue regeneration. In the clinical cases, healing of bone and soft tissue was reported with no serious adverse events. CONCLUSION: The evidence from the included studies suggests that MSCs may have beneficial regenerative effects on the healing of ORN. None of the studies reported adverse events with the use of MSCs. More carefully controlled studies with well-identified cells are however needed to demonstrate the efficacy of MSCs in a clinical setting. Graphical abstract.

Ex vivo-expanded autologous adipose tissue-derived stromal cells ensure enhanced fat graft retention in breast augmentation: A randomized controlled clinical trial.

Autologous fat grafting and implant surgery are used for volume restoration in plastic surgery. With the aim of producing a treatment superior to current solutions, we report a randomized, controlled, data assessor-blinded clinical trial comparing fat grafts enriched with ex vivo-expanded autologous adipose-derived stromal cells (ASCs) to nonenriched fat grafts in breast augmentation. The intervention group received ASC-enriched fat grafts (≥20 × 106 viable ex vivo-expanded ASCs per milliliter fat), and the control group received conventional nonenriched fat grafts. Volume retention was measured by magnetic resonance imaging, and clinical photographs were taken simultaneously for outcome evaluation. ASC-enriched fat grafts had significantly higher retention rates (mean = 80.2%) compared with conventional fat grafts (mean = 45.1%). Clinical photos showed statistically significant superior results in the intervention group, assessed by independent clinical experts. These results improve the prospects for using culture-expanded ASCs in both reconstructive and cosmetic volume restoration and make the procedure an attractive alternative to conventional fat grafting and implants. This study is registered at www.ClinicalTrials.gov, number H-16046960.

Improved Relapse-Free Survival in Patients With High Natural Killer Cell Doses in Grafts and During Early Immune Reconstitution After Allogeneic Stem Cell Transplantation.

Mature immunocompetent cells from the stem cell graft as well as early robust immune reconstitution are essential for the graft-vs. -tumor (GVT) effect to eliminate residual malignant cells after allogeneic hematopoietic stem cell transplantation (HSCT). In this prospective study we characterized graft composition of T- and NK cell subsets in 88 recipients of peripheral blood stem cell grafts with multicolor flowcytometry. Our primary aim was to analyze the impact of graft composition on immune reconstitution and clinical outcomes after transplantation. Patients transplanted with graft NK cell doses above the median value of 27 × 106/kg had significantly increased relapse-free-survival compared to patients transplanted with lower doses, HR 2.12 (95% CI 1.01-4.45, p = 0.04) Peripheral blood concentrations of NK cells obtained from donors before G-CSF mobilization were significantly correlated to graft NK cell doses (Spearman's ρ 0.53, p = 0.03). The dose of transplanted NK cells/kg correlated significantly with NK cell concentrations in patients early after transplantation (Spearman's ρ 0.26, p = 0.02, and ρ = 0.35, p = 0.001 for days 28 and 56, respectively). Early immune reconstitution above median values of NK cells was significantly associated with improved relapse-free survival (HR 2.84 [95% CI 1.29-6.28], p = 0.01, and HR 4.19 [95% CI 1.68-10.4], p = 0.002, for day 28 and 56, respectively). Early concentrations above the median value of the mature effector CD56dim NK cell subset were significantly associated with decreased relapse incidences at 1 year, 7% (95% CI 1.8-17) vs. 28% (95% CI 15-42), p = 0.04, and 7% (95% CI 1.8-18) vs. 26% (95% CI 14-40) %, p = 0.03, for days 28 and 56, respectively. The results suggest a protective effect of high doses of NK cells in grafts and during early immune reconstitution and support the perception of NK cells as innate effector cells with anti-tumor effects in the setting of allogeneic stem cell transplantation.