Young-Woo Jeon

Enhanced immunoregulation of mesenchymal stem cells by IL-10-producing type 1 regulatory T cells in collagen-induced arthritis

Mesenchymal stem cells (MSCs) possess immunomodulatory properties and have potential, however, there have been conflicting reports regarding their effects in rheumatoid arthritis (RA), which causes inflammation and destruction of the joints. Through a comparative analysis of regulatory T (Treg) and IL-10-producing type 1 regulatory T (Tr1) cells, we hypothesized that Tr1 cells enhance the immunoregulatory functions of MSCs, and that a combinatorial approach to cell therapy may exert synergistic immunomodulatory effects in an experimental animal model of rheumatoid arthritis (RA). A combination of MSCs and Tr1 cells prevented the development of destructive arthritis compared to single cell therapy. These therapeutic effects were associated with an increase in type II collagen (CII)-specific CD4+CD25+Foxp3+ Treg cells and inhibition of CII-specific CD4+IL-17+ T cells. We observed that Tr1 cells produce high levels of IL-10-dependent interferon (IFN)-β, which induces toll-like receptor (TLR) 3 expression in MSCs. Moreover, induction of indoleamine 2,3-dioxygenase (IDO) by TLR3 involved an autocrine IFN-β that was dependent on STAT1 signaling. Furthermore, we observed that production of IFN-β and IL-10 in Tr1 cells synergistically induces IDO in MSCs through the STAT1 pathway. These findings suggest co-administration of MSCs and Tr1 cells to be a novel therapeutic modality for clinical autoimmune diseases.

Preservation of lymphatic drainage from arm in breast cancer surgery: is it safe?.

Abstract #201 Purpose: Sentinel lymph node biopsy (SLNB) for breast cancer was introduced to prevent the high morbidity seen with Axillary lymph node dissection (ALND). Although multiple comparison studies have confirmed that SLNB consistently has lower morbidity and lymphedema rates than ALND; it is still clinically significant ranging from 0∼13%. The aim of this study was to confirm the feasibility of the technique, so called Axillary reverse mapping (ARM), and to test the hypothesis that arm lymphatics are never involved by the metastatic process of breast cancer.
 Methods: We reviewed prospectively maintained database of 129 patients who operated for primary breast cancer since June 2007. Sentinel lymph nodes (SLNs) were identified by using a radiolabeled isotope (TC99m-phytate or human serum albumin). Under general anesthesia, 2.5∼3 mL of blue dye was injected in the upper inner arm along the medial intramuscular groove of ipsilateral arm in order to locate the draining lymphatics or lymph node from the arm. We then proceeded as usual with the SLNB or ALND. During axillary procedure, we take the blue node (ARM node) and SLN (hot node), and both were sent to pathology department for frozen section analysis. If SLNs were positive, ALND was performed and axillary contents were sent to pathology. Histological results of ARM node were compared with that of the other nodes of the SLNB or ALND.
 Results: The mean age of patients was 48.3 years old (rang 27∼73). Surgeries included 41 mastectomies, 80 breast conserving surgeries and eight skin sparing mastectomies with immediate reconstruction. Of the 129 procedures, 81 were in SLNB (62.8%), 43 SLNB+ALND (33.3%), and five ALND. One hundred one of 129 (78.3%) blue ARM nodes were identified in the axilla. The average number of removed ARM node was 1.5 (range 1∼5). In 19 of 96 SLNB cases, the ARM nodes were hot, yielding 18.9% of concordance rate between ARM node and SLN. Among these 19 cases, seven ARM nodes contained metastasis. In one SLNB case, the metastatic ARM node was not hot. In all five ALND cases, ARM nodes were identified and one of five ARM nodes was positive for metastasis. Thus, ARM node metastasis rate of identified ARM node during ARM procedure was 8.9% (9/101).
 Conclusion: According to our study, it is thought that lymphatic drainage from arm share common lymphatic channel in axilla with lymphatic flow from breast. Therefore, intentional preservation of lymphatics or lymph node drained from arm during performing axillary surgery in breast cancer could be a dangerous one. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 201.

A well-tolerated regimen of 800 cGy TBI-fludarabine-busulfan-ATG for reliable engraftment after unmanipulated haploidentical peripheral blood stem cell transplantation in adult patients with acute myeloid leukemia.

Eighty adult patients with acute myeloid leukemia (AML) received peripheral blood T cell-replete HLA haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Disease status at transplantation was either first or second complete remission (CR, n = 69) or relapse/refractory (n = 11). Identical transplant-related procedures with conditioning regimen consisting of fractionated 800 cGy total body irradiation (TBI), fludarabine (30 mg/m(2)/day for 5 days), busulfan (3.2 mg/kg/day for 2 days), and antithymocyte globulin (1.25 mg/kg/day on days -4 to -1) and graft-versus-host disease (GVHD) prophylaxis with tacrolimus and methotrexate were used in all patients. Recovery of neutrophil (median, 11 days) and platelet (median, 10 days) counts was achieved in all patients with full donor chimerism (≥ 99%), and no delayed engraftment failure was observed. The cumulative incidence of grades III to IV acute GVHD and moderate to severe chronic GVHD was 11.2% and 26.3%, respectively. A donor CD8(+) and CD4(+) T cell dose above the median value was significantly associated with the incidences of grades II to IV acute GHVD and moderate to severe chronic GVHD, respectively. After a median follow-up of 28 months for survivors, the 2-year cumulative incidences of relapse (n = 20) and nonrelapse mortality (n = 10) were 26.6% and 12.2%, respectively. Although all but 1 patient in relapse/refractory status died, the 2-year overall and progression-free survival of patients in first CR was 82.5% and 75.1%, respectively. We suggest the strategy of fractionated 800 cGy TBI-based conditioning with unmanipulated peripheral blood stem cell grafts seems feasible with favorable outcomes for adult patients with AML undergoing haplo-HSCT in CR.

Feasible Outcomes of T Cell–Replete Haploidentical Stem Cell Transplantation with Reduced-Intensity Conditioning in Patients with Myelodysplastic Syndrome

Even with the recent optimization of haploidentical stem cell transplantation (SCT), its role for patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia evolving from MDS (sAML) should be validated. We analyzed the outcomes of consecutive 60 patients with MDS or sAML who received T cell-replete haploidentical SCT after reduced-intensity conditioning with fludarabine, busulfan, and rabbit antithymocyte globuline ± 800 cGy total body irradiation. Patients achieved a rapid neutrophil engraftment after a median of 12 days (range, 8 to 23) and an early immune reconstitution without high incidences of acute graft-versus-host disease (GVHD) II to IV and chronic GVHD (36.7% and 48.3%, respectively). After a median follow-up of 4 years, incidence of relapse and nonrelapse mortality and rate of overall survival and disease-free survival was 34.8%, 23.3%, 46.8%, and 41.9%, respectively. In multivariate analysis, the disease status at peak was a significant predictor for relapse (lower-risk MDS versus higher-risk MDS or sAML; hazard ratio [HR], 5.69; 95% confidence interval [CI], 1.45 to 22.29; P = .013) and disease-free survival (HR, 4.44; 95% CI, 1.14 to 17.34; P = .032). Chronic GVHD was an additional significant predictor for relapse (no versus yes; HR, 2.87; 95% CI, 1.03 to 7.51; P = .043). Our T cell-replete haploidentical SCT may be a feasible option for patients with MDS and sAML without conventional donors.

Effect of Continuous Cuff Pressure Regulator in General Anaesthesia with Laryngeal Mask Airway

Postoperative pharyngolaryngeal complications (PPLC) occur during anaesthesia due to increased cuff pressure following the insertion of laryngeal mask airways. The use of a pressure regulator to prevent PPLC was evaluated in a prospective, randomized study. Sixty patients scheduled to receive general anaesthesia were randomly assigned to two equal groups of 30, either with or without the regulator. The ‘just seal’ cuff pressure (JSCP), cuff pressure at 5-min intervals during anaesthesia, incidence of pharyngeal sore throat (PST), dysphagia, dysphonia and other complications were evaluated at 1 and 24 h postoperatively. The combined mean ± SD JSCP of both groups was 20.3 ± 3.2 mmHg. In the group with the regulator, cuff pressure was maintained at a constant level during anaesthesia. This study demonstrated that the regulator is a simple, functional device that can reduce the incidence of PST significantly at 1 h postoperatively, following general anaesthesia.

Adoptive Transfer of Treg Cells Combined with Mesenchymal Stem Cells Facilitates Repopulation of Endogenous Treg Cells in a Murine Acute GVHD Model

Therapeutic effects of combined cell therapy with mesenchymal stem cells (MSCs) and regulatory T cells (Treg cells) have recently been studied in acute graft-versus-host-disease (aGVHD) models. However, the underlying, seemingly synergistic mechanism behind combined cell therapy has not been determined. We investigated the origin of Foxp3+ Treg cells and interleukin 17 (IL-17+) cells in recipients following allogeneic bone marrow transplantation (allo-BMT) to identify the immunological effects of combined cell therapy. Treg cells were generated from eGFP-expressing C57BL/6 mice (Tregegfp cells) to distinguish the transferred Treg cells; recipients were then examined at different time points after BMT. Systemic infusion of MSCs and Treg cells improved survival and GVHD scores, effectively downregulating pro-inflammatory Th×and Th17 cells. These therapeutic effects of combined cell therapy resulted in an increased Foxp3+ Treg cell population. Compared to single cell therapy, adoptively transferred Tregegfp cells only showed prolonged survival in the combined cell therapy group on day 21 after allogeneic BMT. In addition, Foxp3+ Treg cells, generated endogenously from recipients, significantly increased. Significantly higher levels of Tregegfp cells were also detected in aGVHD target organs in the combined cell therapy group compared to the Treg cells group. Thus, our data indicate that MSCs may induce the long-term survival of transferred Treg cells, particularly in aGVHD target organs, and may increase the repopulation of endogenous Treg cells in recipients after BMT. Together, these results support the potential of combined cell therapy using MSCs and Treg cells for preventing aGVHD.

Outcome of allogeneic hematopoietic stem cell transplantation for cytogenetically normal AML and identification of high-risk subgroup using WT1 expression in association with NPM1 and FLT3-ITD mutations

According to recent guidelines, cytogenetically normal acute myeloid leukemia (CN AML) is divided into four molecular subgroups based on nucleophosmin‐1 (NPM1) and FMS‐like tyrosine kinase 3‐internal tandem duplication (FLT3‐ITD) mutations. All subgroups except for isolated NPM1mut are associated with poor prognosis. We retrospectively analyzed 223 patients with CN AML, 156 of whom were treated with standard chemotherapy. For postremission therapy, patients with available donors underwent allogeneic (allo) hematopoietic stem cell transplantation (HSCT) and the rest were treated with autologous HSCT or chemotherapy alone. We first compared the 4 conventional molecular subgroups, and then created another 4 subgroups based on WT1 expression: isolated NPM1mut, NPM1wt/FLT3‐ITD‐neg with low WT1 or high WT1, and FLT3‐ITD‐pos CN AML. We finally evaluated 89 patients who were treated with allo HSCT and achieved complete remission after standard chemotherapy. FLT3‐ITD CN AML showed the worst outcome irrespective of NPM1mut, and isolated NPM1mut CN AML showed no significant differences compared with NPM1wt/FLT3‐ITD‐neg CN AML. In contrast, two newly stratified low‐risk subgroups (NPM1wt/FLT3‐ITD‐neg with low WT1 and isolated NPM1mut CN AML) showed higher remission rates with superior overall survival (OS) compared with the other two high‐risk subgroups, which showed a higher relapse rate even after allo HSCT. Further analysis showed that higher pre‐HSCT expression of WT1 resulted in a higher relapse rate and poorer OS after allo HSCT. For CN AML, a risk‐adapted approach using allo HSCT with novel agents should be evaluated with stratification specified by WT1.

Similar outcomes of peripheral blood stem cells vs. bone marrow for human leukocyte antigen‐matched unrelated donor transplantation in adult patients with acute myeloid leukemia using risk‐adapted graft‐versus‐host disease prophylaxis

In unrelated donor allogeneic stem cell transplantation (URD‐SCT), most studies reported that peripheral blood stem cells (PBSC) resulted in higher incidence of acute and/or chronic graft‐versus‐host disease (GVHD) without survival benefits compared with bone marrow (BM). To overcome these shortcomings of PBSC, we have used a risk‐adapted GVHD prophylaxis for patients that received HLA‐matched URD‐SCT, which was adding low‐dose rabbit antithymocyte globulin (Thymoglobulin®, 1.25 mg/kg for 2 d) to conditioning in the transplants with PBSC and not BM.

Better transplant outcome with pre-transplant marrow response after hypomethylating treatment in higher-risk MDS with excess blasts

Hypomethylating treatment (HMT) has been suggested as a feasible bridge to hematopoietic stem cell transplantation (HSCT), but controversies exist around influences of HMT response on transplant outcomes. To assess the safety and influences of pre-transplant HMT focusing on debulking effects and transplant outcomes, we retrospectively analyzed consecutive HSCT-eligible patients who received HMT for higher-risk MDS with excess blasts. Of all 98 patients, 11 patients failed to proceed to HSCT and HMT-related mortality occurred in 8 patients. When excluding 9 patients who refused HSCT, 87% of scheduled HSCT (77 of 89) was performed after a median of 3 cycles (range, 1-8) of HMT. The 4-year overall survival after HMT (n = 98) and HSCT (n = 77) was 44.0% and 53.6%, respectively. Transplant outcomes were significantly different by the final response at HSCT; marrow response group (complete remission, marrow complete remission with or without hematologic improvement) showed significantly better 4-year disease-free survival compared to no marrow response group (n = 36, 87.3% vs. n = 41, 10.7%, P < 0.001). This difference between the groups was also evident in overall survival (90.9% vs. 8.6%, P < 0.001) and cumulative incidences of relapse (6.5% vs. 45.4%, P < 0.001) and treatment-related mortality (6.2% vs. 43.9%, P < 0.001). These observations indicate that pre-transplant HMT is a feasible bridging treatment in patients with excess blasts regarding high success rate of proceeding to transplantation and good survival rate. Marrow response at HSCT regardless of concomitant hematological improvement is an independent predictor of better survival, suggesting that immediate HSCT rather than continuing HMT should be performed once marrow response is achieved.

Impact of cytomegalovirus reactivation on relapse and survival in patients with acute leukemia who received allogeneic hematopoietic stem cell transplantation in first remission

Cytomegalovirus (CMV)-reactivation is associated with graft-vs-leukemia (GVL) effect by stimulating natural-killer or T-cells, which showed leukemia relapse prevention after hematopoietic stem cell transplantation (HSCT). We enrolled patients with acute myeloid leukemia (n = 197) and acute lymphoid leukemia (n = 192) who underwent allogeneic-HSCT in first remission. We measured RQ-PCR weekly to detect CMV-reactivation and preemptively used ganciclovir (GCV) when the titer increased twice consecutively, but GCV was sometimes delayed in patients without significant graft-vs-host disease (GVHD) by reducing immunosuppressive agents. In the entire group, CMV-reactivation showed poor overall survival (OS). To evaluate subsequent effects of CMV-reactivation, we excluded early relapse and deaths within 100 days, during which most of the CMV-reactivation occurred. Untreated CMV-reactivated group (n = 173) showed superior OS (83.8% vs. 61.7% vs. 74.0%, p < 0.001) with lower relapse rate (10.1% vs 22.1% vs. 25.5%, p = 0.004) compared to GCV-treated CMV-reactivated group (n = 122) and CMV-undetected group (n = 42). After excluding chronic GVHD, untreated CMV-reactivated group still showed lower relapse rate (9.4% vs. 24.1% vs. 30.2%, p = 0.006). Multivariate analysis showed adverse-risk karyotype and patients in other than untreated CMV-reactivated group were independent factors for relapse prediction. Our data showed possible GVL effect of CMV-reactivation and minimizing antiviral therapy may benefit for relapse prevention in acute leukemia.