Nak-Gyun Chung

Allele frequencies of 15 STR loci using AmpF/STR Identifiler kit in a Korean population

The genetic variations for 15 short tandem repeat (STR) loci D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA were performed on 231 unrelated Korean population using commercially available AmpF/STR Identifiler kit.

Reduced-intensity conditioning allogeneic stem cell transplantation is a potential therapeutic approach for adults with high-risk acute lymphoblastic leukemia in remission: results of a prospective phase 2 study

The aim of this prospective study was to investigate the feasibility of reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (SCT) in 37 adults with high-risk acute lymphoblastic leukemia (ALL) in first (n=30) or second (n=7) complete remission (CR). All patients were treated with fludarabine (150 mg/m2) and melphalan (140 mg/m2) followed by transplantation from matched sibling (n=27) or unrelated (n=10) donors. The indications for reduced-intensity conditioning allogeneic SCT (RIC-SCT) were as follows: (1) ⩾50 years, 16 (43.2%) and (2) decreased organ function or active infections, 21 (56.8%). Graft-versus-host disease (GVHD) prophylaxis consisted of calcineurin inhibitor (cyclosporine for sibling and tacrolimus for unrelated transplants) and methotrexate. The cumulative incidence of acute (grades II–IV) and chronic GVHD was 43.2 and 65.6%, respectively. After a median follow-up of 36 months for surviving transplants, the 3-year relapse, non-relapse mortality, disease-free survival and overall survival rates were 19.7, 17.7, 62.6 and 64.1%, respectively. Transplants in first CR showed better transplantation outcomes than those in second CR. The potential of antileukemic activity of chronic GVHD was also found. This study suggests that RIC-SCT is a potential therapeutic approach for adults with high-risk ALL in remission who are ineligible for myeloablative transplantation.

Impact of minimal residual disease kinetics during imatinib-based treatment on transplantation outcome in Philadelphia chromosome-positive acute lymphoblastic leukemia

We conducted a systemic evaluation to describe the effect of minimal residual disease (MRD) kinetics on long-term allogeneic transplantation outcome by analyzing 95 adult transplants with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) who received first-line two courses of imatinib-based chemotherapy (median follow-up 5 years). MRD monitoring was centrally evaluated by real-time quantitative PCR (4.5 log sensitivity). After the first course of imatinib-based chemotherapy, 33 patients (34.7%) achieved at least major molecular response. On the basis of MRD kinetics by the end of two courses of imatinib-based chemotherapy, we stratified entire patients into four subgroups: early-stable molecular responders (EMRs, n=33), late molecular responders (LMRs, n=35), intermediate molecular responders (IMRs, n=9) and poor molecular responders (PMRs, n=18). Multivariate analysis showed that the most powerful factor affecting long-term transplantation outcome was MRD kinetics. Compared with EMRs, IMRs or PMRs had significantly higher risk of treatment failure in terms of relapse and disease-free survival (DFS). LMRs had a tendency toward a lower DFS. Quantitative monitoring of MRD kinetics during the first-line imatinib-based chemotherapy course is useful in identifying subgroups of Ph-positive ALL transplants at a high risk of relapse.

The extent of minimal residual disease reduction after the first 4‐week imatinib therapy determines outcome of allogeneic stem cell transplantation in adults with Philadelphia chromosome‐positive acute lymphoblastic leukemia

Previously, the authors demonstrated the positive impact of imatinib on the outcome of allogeneic stem cell transplantation in adults with Philadelphia chromosome‐positive acute lymphoblastic leukemia (Ph‐positive ALL). Here, the authors analyzed for risk factors that affect transplantation outcome, and they focused particularly on the prognostic relevance of minimal residual disease level at each treatment stage.

Treatment of BK virus-associated hemorrhagic cystitis in pediatric hematopoietic stem cell transplant recipients with cidofovir: a single-center experience

BK virus (BKV)‐associated hemorrhagic cystitis (BKV‐HC) is a severe complication after hematopoietic stem cell transplantation (HSCT). Cidofovir (CDV) has emerged as an effective agent for the treatment of BKV nephropathy, but its use for BKV‐HC in pediatric HSCT recipients has not yet been established as a standard therapy.

Clinical features, genetics, and outcome of pediatric patients with hemophagocytic lymphohistiocytosis in Korea: report of a nationwide survey from Korea Histiocytosis Working Party

We analyzed a nationwide registry of pediatric patients with hemophagocytic lymphohistiocytosis (HLH) in Korea to assess the clinical and genetic features and treatment outcomes in pediatric HLH.

Pretransplant imatinib can improve the outcome of nonmyeloablative stem cell transplantation without increasing the morbidity in Philadelphia chromosome-positive chronic myeloid leukemia.

Pretransplant imatinib can improve the outcome of nonmyeloablative stem cell transplantation without increasing the morbidity in Philadelphia chromosome-positive chronic myeloid leukemia

Donor-specific differences in long-term outcomes of myeloablative transplantation in adults with Philadelphia-negative acute lymphoblastic leukemia

We analyzed long-term outcomes of myeloablative stem cell transplantation (SCT) in 292 adults with Philadelphia (Ph)-negative acute lymphoblastic leukemia (ALL). Donors were related (RD; n=132), unrelated (URD; n=68; 30 well-matched (WM), 19 partially matched (PM), 19 mismatched (MM)) and autologous (AUTO; n=92). After a median follow-up of 85 months, the risk of relapse was higher for AUTO-SCT than for RD-SCT (P<0.001). MM-URD-SCT yielded higher risk of non-relapse mortality than RD-SCT (P=0.010). As a result, disease-free survival (DFS) at 5 years was inferior using AUTO (46.1%; P=0.010) or MM-URD (26.3%; P=0.036), whereas DFS from other donor sources was approximately equivalent (53.5% for RD, 63.3% for WM-URD and 57.0% for PM-URD). Other factors associated with poorer DFS included SCT beyond first complete remission (CR), older age and adverse cytogenetics. In a pairwise comparison of outcomes between RD-SCT and AUTO-SCT for patients in first CR, the inferiority of AUTO-SCT was observed, particularly in high-risk patients. Conversely, in standard-risk patients, AUTO-SCT yielded comparable outcomes to RD-SCT. SCT using RD, WM-URD or PM-URD may be considered the best donor sources for adult high-risk Ph-negative ALL.

Gastrointestinal Complications Following Hematopoietic Stem Cell Transplantation in Children

Gastrointestinal system involvement is one of the principal complications seen in the recipients of hematopoietic stem cell transplantation (HSCT), and it is also a major cause of morbidity and death in these patients. The major gastrointestinal complications include typhlitis (neutropenic enterocolitis), pseudomembranous enterocolitis, viral enteritis, graft-versus-host disease, benign pneumatosis intestinalis, intestinal thrombotic microangiopathy, and post-transplantation lymphoproliferative disease. As these patients present with nonspecific abdominal symptoms, evaluation with using such imaging modalities as ultrasonography and CT is essential in order to assess the extent of gastrointestinal involvement and to diagnose these complications. We present here a pictorial review of the imaging features and other factors involved in the diagnosis of these gastrointestinal complications in pediatric HSCT recipients.

High Levels of B Cell Activating Factor During the Peritransplantation Period Are Associated with a Reduced Incidence of Acute Graft-versus-Host Disease following Myeloablative Allogeneic Stem Cell Transplantation

B cell activating factor (BAFF), also known as B cell survival and activation factor, is associated with autoimmune disease and chronic graft-versus-host disease (cGVHD). T cells are known to be modulated by soluble BAFF (sBAFF). Considering the possible association of sBAFF with T cell as well as B cell function, sBAFF during the peritransplantation period may affect the development of acute GVHD (aGVHD). To test this hypothesis, we evaluated 45 patients who had undergone myeloablative (MA) allogeneic stem cell transplantation (SCT) for hematologic malignancy. Serum sBAFF levels were measured before conditioning and on day 0, day +7, and day +14. Thirty-three of the 45 patients (cumulative incidence, 73%) developed aGVHD between 16 days and 98 days posttransplantation. Repeated-measures analysis of variance revealed significantly lower sBAFF levels during the peritransplantation period in patients with aGVHD than in those without aGVHD (P=.001). Receiver operating characteristic curve analysis revealed that sBAFF levels at every time point were available for the prediction of aGVHD development, and that patients with a sBAFF level >43 pg/mL at each time point (which could ensure 75% sensitivity and 73%-82% specificity for the prediction of aGVHD at every time point) had a significantly lower cumulative incidence of aGVHD. This study is the first to demonstrate that sBAFF level during the peritransplantation period not only may be predictive of aGVHD, but also may have a protective effect against aGVHD in humans. Further investigation is needed to confirm our findings.