Yu Hua Chao

Poor potential of proliferation and differentiation in bone marrow mesenchymal stem cells derived from children with severe aplastic anemia

The pathogenesis of severe aplastic anemia (SAA) has not been completely understood, and insufficiency of the hematopoietic microenvironment can be an important factor. Here, we compared the basic properties of mesenchymal stem cells (MSCs), a major component of bone marrow microenvironment, from five SAA children with those of MSCs from five controls. Although MSCs from SAA children and controls were similar in morphology and immunophenotypic profile, SAA MSCs had slower expansion rate and smaller cumulative population doubling (1.83 ± 1.21 vs 3.36 ± 0.87; p = 0.046), indicating lower proliferative capacity. After osteogenic induction, SAA MSCs showed lower alkaline phosphatase activity (optical density, 1.46 ± 0.04 vs 2.27 ± 0.32; p = 0.013), less intense von Kossa staining, and lower gene expression of core binding factor α1 (0.0015 ± 0.0005 vs 0.0056 ± 0.0017; p = 0.013). Following adipogenic induction, SAA MSCs showed less intense Oil red O staining (optical density, 0.86 ± 0.22 vs 1.73 ± 0.42; p = 0.013) and lower lipoprotein lipase expression (0.0105 ± 0.0074 vs 0.0527 ± 0.0254; p = 0.013). These findings provided evidence that defects in bone marrow MSCs of SAA children do exist.

Cotransplantation of umbilical cord-derived mesenchymal stem cells promote hematopoietic engraftment in cord blood transplantation: a pilot study.

Background Delayed hematopoietic reconstitution after cord blood transplantation (CBT) may lead to increased risk of complications and longer hospitalization. Bone marrow–derived mesenchymal stem cells (MSCs) have been found to promote engraftment after hematopoietic stem cell transplantation. However, harvesting MSCs from bone marrow involves an invasive procedure. Then again, MSCs can be easily obtained from umbilical cords without harm to the donors. Methods Umbilical cord–derived MSCs (UCMSCs) were isolated from Wharton’s jelly and then ex vivo cultured. After showing normal karyotype and negative for infectious contamination, culture-expanded UCMSCs were intravenously infused into the recipients on the day of CBT. The control patients were those receiving CBT alone. Adverse effects and efficacy of intravenous UCMSCs were evaluated. Results A total of five patients received cotransplantation of UCMSCs at the time of CBT. No serious adverse events were observed. The time to achieve neutrophil engraftment ranged from 7 to 13 days (median, 11 days) and platelet engraftment ranged from 22 to 41 days (median, 32 days). Compared with the nine patients receiving CBT alone, patients receiving cotransplantation of UCMSCs had significantly faster hematopoietic recovery of neutrophils and platelets (P=0.02 and 0.01, respectively). Conclusions This pilot study is the first report of cotransplantation of UCMSCs in CBT. Intravenous infusion of UCMSCs appeared to be a feasible and safe modality to enhance hematopoietic engraftment in patients receiving CBT. Further studies were warranted.

An Increase in CD3+CD4+CD25+ Regulatory T Cells after Administration of Umbilical Cord-Derived Mesenchymal Stem Cells during Sepsis

Sepsis remains an important cause of death worldwide, and vigorous immune responses during sepsis could be beneficial for bacterial clearance but at the price of collateral damage to self tissues. Mesenchymal stem cells (MSCs) have been found to modulate the immune system and attenuate sepsis. In the present study, MSCs derived from bone marrow and umbilical cord were used and compared. With a cecal ligation and puncture (CLP) model, the mechanisms of MSC-mediated immunoregulation during sepsis were studied by determining the changes of circulating inflammation-associated cytokine profiles and peripheral blood mononuclear cells 18 hours after CLP-induced sepsis. In vitro, bone marrow-derived MSCs (BMMSCs) and umbilical cord-derived MSCs (UCMSCs) showed a similar morphology and surface marker expression. UCMSCs had stronger potential for osteogenesis but lower for adipogenesis than BMMSCs. Compared with rats receiving PBS only after CLP, the percentage of circulating CD3+CD4+CD25+ regulatory T (Treg) cells and the ratio of Treg cells/T cells were elevated significantly in rats receiving MSCs. Further experiment regarding Treg cell function demonstrated that the immunosuppressive capacity of Treg cells from rats with CLP-induced sepsis was decreased, but could be restored by administration of MSCs. Compared with rats receiving PBS only after CLP, serum levels of interleukin-6 and tumor necrosis factor-α were significantly lower in rats receiving MSCs after CLP. There were no differences between BMMSCs and UCMSCs. In summary, this work provides the first in vivo evidence that administering BMMSCs or UCMSCs to rats with CLP-induced sepsis could increase circulating CD3+CD4+CD25+ Treg cells and Treg cells/T cells ratio, enhance Treg cell suppressive function, and decrease serum levels of interleukin-6 and tumor necrosis factor-α, suggesting the immunomodulatory association of Treg cells and MSCs during sepsis.

Human Application of Ex Vivo Expanded Umbilical Cord-Derived Mesenchymal Stem Cells: Enhance Hematopoiesis after Cord Blood Transplantation:

Delayed hematopoietic reconstitution after cord blood (CB) transplantation (CBT) needs to be overcome. Bone marrow-derived mesenchymal stem cells (BMMSCs) have been found to enhance engraftment after hematopoietic stem cell transplantation. However, getting BMMSCs involves an invasive procedure. In this study, umbilical cord-derived mesenchymal stem cells (UCMSCs) were isolated from Whartons jelly and cryopreserved in the UCMSCs bank. Compared with BMMSCs, we found that UCMSCs had superior proliferative potential. We found that NOD/SCID mice cotransplanted with CB and UCMSCs demonstrated significant human CD45+ cell engraftment compared with those transplanted with CB alone. Then, 20 patients with high-risk leukemia were prospectively randomized to either receive cotransplantation of CB and ex vivo expanded banked UCMSCs or to receive CBT alone. No serious adverse events were observed in the patients receiving UCMSC infusion. The time to undergo neutrophil engraftment and platelet engraftment was significantly shorter in the eight patients receiving cotransplantation than that in the 12 patients receiving CBT alone (p = 0.003 and p = 0.004, respectively). Thus, application of ex vivo expanded banked UCMSCs in humans appears to be feasible and safe. UCMSCs can enhance engraftment after CBT, but further studies are warranted.

Cotransplantation of umbilical cord MSCs to enhance engraftment of hematopoietic stem cells in patients with severe aplastic anemia

Cotransplantation of umbilical cord MSCs to enhance engraftment of hematopoietic stem cells in patients with severe aplastic anemia

Acute 99mTc DMSA scan predicts dilating vesicoureteral reflux in young children with a first febrile urinary tract infection: a population-based cohort study.

Objective This study aimed to examine the ability of acute 99mTc DMSA scan for predicting dilating (grades III-V) vesicoureteral reflux (VUR) after a first febrile urinary tract infection in children aged 2 years or younger. Patients and Methods All children underwent ultrasonography (US), 99mTc DMSA scan, and voiding cystourethrography. Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and receiver operating characteristic curves were performed to assess the diagnostic accuracy for predicting dilating VUR. Follow-up scan was performed at least 6 months after the acute infection to evaluate the presence of renal scarring (RS) or new scars. Results Of the 473 children analyzed (289 boys and 184 girls; median age, 5 months), 282 (59.6%) had abnormal acute 99mTc DMSA scan findings. There was VUR in 153 children (32.3%), whereas 95 (20.1%) had dilating VUR. The sensitivity and negative predictive value in predicting dilating VUR were 95.8% and 97.9%, respectively, for 99mTc DMSA and 97.9% and 98.6%, respectively, for combined US and 99mTc DMSA, whereas the positive and negative likelihood ratios were 1.90 and 0.08, respectively, for 99mTc DMSA and 1.57 and 0.06, respectively, for combined studies. On multivariate analysis, dilating VUR was a predictor for developing RS and new scars. Conclusions Our results reveal the usefulness of acute 99mTc DMSA scan for predicting dilating VUR in children with a first febrile urinary tract infection. A voiding cystourethrography is indicated in only children with abnormalities found on a 99mTc DMSA and/or a US. The presence of dilating VUR predisposes to developing RS and new scars.

The role of mesenchymal stem cells in hematopoietic stem cell transplantation: From bench to bedsides

Mesenchymal stem cells (MSCs) have been shown to be effective in the management of graft-versus-host disease (GVHD) due to their immunomodulatory effects. In addition to prevention and treatment of GVHD, many studies have demonstrated that MSCs can promote hematopoietic engraftment, accelerate lymphocyte recovery, reduce the risk of graft failure, and repair tissue damage in patients receiving hematopoietic stem cell transplantation (HSCT). Bone marrow (BM) has been considered as the traditional source of MSCs, and most of the knowledge concerning MSCs comes from BM studies. However, BM-derived MSCs have several limitations for their clinical application. Fetal-type MSCs can be isolated easier and proliferate faster in vitro as well as possessing a lower immunogenicity. Therefore, fetal-type MSCs, such as umbilical cord-derived MSCs, represent an excellent alternative source of MSCs. MSCs play multiple important roles in HSCT. Nevertheless, several issues regarding their clinical application remain to be discussed, including the safety of use in humans, the available sources and the convenience of obtaining MSCs, the quality control of in vitro-cultured MSCs and the appropriate cell passages, the optimum cell dose, and the optimum number of infusions. Furthermore, it is important to evaluate whether the rates of cancer relapse and infections increase when using MSCs for GVHD. There are still many questions regarding the clinical application of MSCs to HSCT that need to be answered, and further studies are warranted.

Role of procalcitonin in predicting dilating vesicoureteral reflux in young children hospitalized with a first febrile urinary tract infection

Objective: The aim of this article was to assess the usefulness of procalcitonin (PCT) as a marker for predicting dilating (grades III–V) vesicoureteral reflux (VUR) in young children with a first febrile urinary tract infection. Methods: Children ⩽2 years of age with a first febrile urinary tract infection were prospectively evaluated. Serum samples were tested for PCT at the time of admission to a tertiary hospital. All children underwent renal ultrasonography (US), 99mTc-dimercaptosuccinic acid renal scan, and voiding cystourethrography. The diagnostic characteristics of PCT test for acute pyelonephritis and dilating VUR were calculated. Results: Of 272 children analyzed (168 boys and 104 girls; median age, 5 months), 169 (62.1%) had acute pyelonephritis. There was VUR demonstrated in 97 (35.7%), including 70 (25.7%) with dilating VUR. The median PCT value was significantly higher in children with VUR than in those without (P < 0.001). Using a PCT cutoff value of ≥1.0 ng/mL, the sensitivity and negative predictive value for predicting dilating VUR were 94.3% and 95.4%, respectively, for PCT, and 97.1% and 97.8%, respectively, for the combined PCT and US studies, whereas the positive and negative likelihood ratios were 2.03 and 0.107, respectively, for PCT, and 1.72 and 0.067, respectively, for the combined studies. By multivariate analysis, high PCT values and abnormalities on US were independent predictors of dilating VUR. Conclusions: PCT is useful for diagnosing acute pyelonephritis and predicting dilating VUR in young children with a first febrile urinary tract infection. A voiding cystourethrography is indicated only in children with high PCT values (≥1.0 ng/mL) and/or abnormalities found on a US.

Umbilical Cord-Derived Mesenchymal Stem Cells for Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is becoming an effective therapeutic modality for a variety of diseases. Mesenchymal stem cells (MSCs) can be used to enhance hematopoietic engraftment, accelerate lymphocyte recovery, reduce the risk of graft failure, prevent and treat graft-versus-host disease, and repair tissue damage in patients receiving HSCT. Till now, most MSCs for human clinical application have been derived from bone marrow. However, acquiring bone-marrow-derived MSCs involves an invasive procedure. Umbilical cord is rich with MSCs. Compared to bone-marrow-derived MSCs, umbilical cord-derived MSCs (UCMSCs) are easier to obtain without harm to the donor and can proliferate faster. No severe adverse effects were noted in our previous clinical application of UCMSCs in HSCT. Accordingly, application of UCMSCs in humans appears to be feasible and safe. Further studies are warranted.

Diagnostic performance of procalcitonin for hospitalised children with acute pyelonephritis presenting to the paediatric emergency department

Objectives Urinary tract infection (UTI) is a common bacterial infection in children that can result in permanent renal damage. This study prospectively assessed the diagnostic performance of procalcitonin (PCT) for predicting acute pyelonephritis (APN) among children with febrile UTI presenting to the paediatric emergency department (ED). Methods Children aged ≤10 years with febrile UTI admitted to hospital from the paediatric ED were prospectively studied. Blood PCT, C reactive protein (CRP) and white blood cell (WBC) count were measured in the ED. Sensitivity, specificity, predictive values, multilevel likelihood ratios, receiver operating characteristic (ROC) curve analysis and multivariate logistic regression were used to assess quantitative variables for diagnosing APN. Results The 136 enrolled patients (56 boys and 80 girls; age range 1 month to 10 years) were divided into APN (n=87) and lower UTI (n=49) groups according to 99mTc-dimercaptosuccinic acid scan results. The cut-off value for maximum diagnostic performance of PCT was 1.3 ng/ml (sensitivity 86.2%, specificity 89.8%). By multivariate regression analysis, only PCT and CRP were retained as significant predictors of APN. Comparing ROC curves, PCT had a significantly greater area under the curve than CRP, WBC count and fever for differentiating between APN and lower UTI. Conclusions PCT has better sensitivity and specificity than CRP and WBC count for distinguishing between APN and lower UTI. PCT is a valuable marker for predicting APN in children with febrile UTI. It may be considered in the initial investigation and therapeutic strategies for children presenting to the ED.