Immunosuppressive therapy versus alternative donor hematopoietic stem cell transplantation for children with severe aplastic anemia who lack an HLA-matched familial donor

We compared the outcomes of immunosuppressive treatment (IST) with those of alternative donor hematopoietic stem cell transplantation (HSCT) in children and adolescents with severe aplastic anemia (SAA). The medical records of 42 patients with SAA who received frontline IST (N=19) or frontline HSCT with an alternative donor (N=23) between 1998 and 2012 were analyzed retrospectively. Six patients responded in the frontline IST group, whereas 11 underwent salvage HSCT after IST failure. Twenty-one of 23 patients who underwent frontline HSCT survived without treatment failure. The estimated failure-free survival rate of the frontline HSCT group was higher than that of the frontline IST group (91.3% vs 30.7% respectively, P<0.001). Six of 11 patients who underwent salvage HSCT experienced event-free survival (EFS). The estimated EFS of the frontline HSCT group was higher than that of the salvage HSCT group (91.3% vs 50.9% respectively, P=0.015). The outcome of alternative donor HSCT was better than commonly reported rates, especially in patients who underwent frontline HSCT. These results suggest that frontline alternative donor HSCT may be a better treatment option than IST for children and adolescents with SAA who lack a human leukocyte Ag-matched familial donor.

Efficacy and safety of micafungin for the prophylaxis of invasive fungal infection during neutropenia in children and adolescents undergoing allogeneic hematopoietic SCT

The objective of this study was to evaluate the efficacy and safety of micafungin for the prevention of invasive fungal infection (IFI) during the neutropenic phase of allogeneic hematopoietic SCT (allo-HSCT) in children and adolescents. This was a prospective, multicenter, open-label, single-arm study. Micafungin was administered i.v. at a dose of 1 mg/kg/day (max 50 mg) from the beginning of conditioning until neutrophil engraftment. Treatment success was defined as the absence of proven, probable, possible or suspected IFI through to 4 weeks after therapy. From April 2010 to December 2011, 155 patients were enrolled from 11 institutions in Korea, and 147 patients were analyzed. Of the 147 patients, 121 (82.3%) completed the protocol without premature interruption. Of the 132 patients in whom micafungin efficacy could be evaluated, treatment success was achieved in 119 patients (90.2%). There was no proven fungal infection in any patient. The number of patients with probable, possible and suspected IFI was two, two and nine, respectively. Thirty-five patients (23.8%) experienced 109 adverse events (AEs) possibly related to micafungin. No patients experienced grade IV AEs. Two patients (1.4%) discontinued micafungin administration due to adverse effects. None of the deaths were related to the study drug.

Quality of functional haematopoietic stem/progenitor cells from cryopreserved human umbilical cord blood

BACKGROUND AND OBJECTIVES

Transplantation of cryopreserved umbilical cord blood (UCB) can be used to treat a multitude of haematologic and immunological diseases. In this study, we examined the quality of UCB cryopreserved for 2 (group I), 4 (group II) and 6 (group III) years.

METHODS

The following parameters and procedures were used to test individual units of cryopreserved UCB: the number of total nucleated cells (TNC), cell viability, CFU-GM assay, T-cell activation in vitro and haematopoietic stem cell engraftment in NOD/SCID mice in vivo.

RESULTS

The TNC recovery rates for groups I, II and III were 106·2 ± 6·17%, 96·69 ± 6·39% and 100·38 ± 5·27%, respectively, and the mean percentages of viable cells after thawing were 86·88%, 86·38% and 87·43%. When TNC were plated at 5 × 10(3), the number of CFU-GM was 13·6 (group I), 13·8 (group II), 14·2 (group III) and 14·7 (fresh UCB). We confirmed that the huCD4(+) and huCD8(+) T cells within cryopreserved UCB are functionally responsive by assessment of activated huCD25(+) cells. Moreover, the percentage of huCD45(+) cells in the bone marrow was 4·32 ± 1·29% (group I), 4·48 ± 1·11% (group II), 4·40% ± 1·12% (group III) and 4·50% ± 0·66% (fresh UCB), and that in the peripheral blood was 14·69 ± 3·08% (group I), 15·24 ± 4·05% (group II), 15·74 ± 3·43% (group III) and 17·48 ± 3·74% (fresh UCB) in NOD/SCID mice infused with isolated huCD34(+) cells.

CONCLUSION

These results indicated that cryopreserved UCB units efficiently retrieve in functionally competent form and are suitable for transplantation.

Genetic variants of AICDA/CASP14 associated with childhood brain tumor

We conducted a hospital-based case-control study in Korea to investigate whether apoptosis- and cell cycle control-related genes are associated with childhood brain tumor. Incident brain tumor cases (N = 70) and non-cancer controls (N = 140), frequency-matched by age and gender, were selected from 3 teaching hospitals in Seoul between 2003 and 2006. Tag single nucleotide polymorphisms (SNPs) (N = 297) in 30 genes related to apoptosis and cell cycle control were selected using a pairwise linkage-disequilibrium-based algorithm. Five tag SNPs in 2 genes (AICDA and CASP14) remained significant after adjusted multiple tests. The most significant association with childhood brain tumor risk was for IVS1-401G>C in the AICDA gene [odds ratio (OR) = 2.8; 95% confidence interval (95%CI) = 1.25-6.46]; the polymorphism *9276A>C of CASP14 was associated with decreased brain tumor risk (OR = 0.4; 95%CI = 0.19-0.95). We concluded that genetic polymorphisms in AICDA and CASP14 are associated with risk for brain tumor in Korean children.

Evaluation of overnight storage conditions for autologous peripheral blood stem cell products: comparison of three different conditions

BACKGROUND

Overnight (ON) storage of peripheral blood stem cell (PBSC) occurs frequently in clinical settings. However, there are no standard guidelines for optimal storage conditions of freshly harvested PBSC. The aim of this study was to investigate the influence of storage temperatures on the quality of autologous PBSC and establish optimal storage conditions before cryopreservation.

METHODS

A retrospective analysis was performed on 260 PBSC harvests according to pre-cryopreservation conditions: immediate processing or ON storage at room temperature (RT). For direct comparison, 30 autologous PBSC products were collected prospectively and prepared under three different pre-cryopreservation conditions: immediate processing, ON storage at 4°C and ON storage at RT. The recovery of CD34(+) cells, post-thaw CFU-GM count and viability were analysed.

RESULTS

Retrospective analysis revealed that post-thaw CFU-GM count was significantly lower when PBSC were stored ON at RT compared to when immediately processed (136·4 vs. 409·6/μl). Prospective analysis showed a mean recovery of CD34(+) cells of 65·5 ± 25·1%, 70·5 ± 27·4% and 35·9 ± 25·1% for immediate processing, ON storage at 4°C and ON storage at RT, respectively. Similarly, mean viability and CFU-GM counts were significantly reduced when stored ON at RT compared to when immediately processed or stored ON at 4°C (60·4 ± 25·6 vs. 84·1 ± 12·9 vs. 82·7 ± 12·6%, 15·7 ± 25·7 vs. 398·5 ± 906·2 vs. 350·0 ± 847·9/μl, respectively).

CONCLUSIONS

ON storage of autologous PBSC at RT significantly decreased the quality of HPCs. These data indicate that ON storage of autologous PBSC at 4°C would be the most reasonable approach for maintaining the quality of HPCs when immediate processing is not possible.

Correlation between the immature characteristics of umbilical cord blood-derived mesenchymal stem cells and engraftment of hematopoietic stem cells in NOD/SCID mice

Umbilical cord blood (UCB)-derived mesenchymal stem cells (MSC) facilitate the engraftment of human (h) hematopoietic stem cells when transplanted simultaneously in animal and human studies. However, the type of MSCs that preferentially enhance the engraftment of HSCs is unknown. Recent studies have shown that MSCs derived from a single source are heterogeneous in terms of cell size, morphology, proliferation rate, and differentiation potential. This study was designed to investigate the properties of UCB-MSCs, which influence the engraftment of hHSCs in a NOD/SCID mouse model. We categorized MSCs as being the most effective (UCB-352 MSCs) or the least effective (UCB-156 MSCs) at promoting the homing and engraftment of HSCs, and compared the characteristics of these 2 MSC populations. We observed that the 2 populations showed differences in characteristics typical of immature MSCs, and related to proliferation potential. We showed that UCB-352 MSCs, which proliferate quickly, preferentially enhanced the engraftment of HSCs in NOD/SCID mice. In addition, we observed differences in the pattern of both PODXL and Oct4 expression, and in the levels of cytokines such as SDF-1 and SCF using flow cytometry and membrane arrays. The more effective UCB-352 MSCs expressed higher levels of PODXL and Oct4, which were associated with immaturity, than did the UCB-156 MSCs. Furthermore, UCB-352 cells secreted greater levels of SDF-1 and SCF, both of which are required for hematopoiesis. We propose that the proliferation potential of UCB-MSCs, coupled with their immature characteristics, may serve as a novel standard to promote the homing and engraftment of HSCs.

Kinetics of the removal of iron pyrite from coal by microbial catalysis

Different strains of Thiobacillus ferrooxidans and Thiobacillus thiooxidans were used to catalyze the oxidative dissolution of iron pyrite, FeS(2), in nine different coal samples. Kinetic variables and parametric factors that were determined to have a pronounced effect on the rate and extent of oxidative dissolution at a fixed Po(2) were: the bacterial strain, the nitrogen/phosphorus molar ratio, the partial pressure of CO(2), the coal source, and the total reactive surface area of FeS(2). The overall rate of leaching, which exhibited a first-order dependence on the total surface area of FeS(2), was analyzed mathematically in terms of the sum of a biochemical rate, nu(1), and a chemical rate, nu(2). Results of this study show that bacterial desulfurization (90 to 98%) of coal samples which are relatively high in pyritic sulfur can be achieved within a time-frame of 8 to 12 days when pulp densities are </=20% and particle sizes are </=74 mum. The most effective strains of T. ferrooxidans were those that were isolated from natural systems, and T. ferrooxidans ATCC 19859 was the most effective pure strain. The most effective nutrient media contained relatively low phosphate concentrations, with an optimal N/P molar ratio of 90:1. These results suggest that minimal nutrient additions may be required for a commercial desulfurization process.

Hepatic veno-occlusive disease in children after hematopoietic stem cell transplantation: incidence, risk factors, and outcome

Four hundred and sixty-seven hematopoietic stem cell transplantations (HSCTs) (217 autologous and 250 allogeneic HSCT) were performed in 374 children at four pediatric HSCT centers in Korea from January 2005 to December 2007. Among 467 transplants, veno-occlusive disease (VOD) developed in 72 transplants (15.4%) at a median of 10 days after HSCT. Multivariate analysis showed that BU or TBI-containing regimen (P=0.002), VOD prophylaxis without lipo-prostaglandin E1 (PGE1) (P=0.012), number of previous HSCT (P=0.014), and pretransplant serum ferritin (P=0.018) were independent risk factors for developing VOD. Mean serum ferritin levels were significantly higher in HSCT with VOD (2109.6+/-2842.5 ng/ml) than in HSCT without VOD (1315.9+/-1094.4 ng/ml) (P<0.001). The relative risk of death within 100 days of HSCT in transplants with VOD compared with transplants without VOD was 3.39 (confidence interval: 1.78-6.45). Our results suggest that lipo-PGE1 might have a protective effect against the development of VOD, and pretransplant serum ferritin could act as a risk factor for VOD. A larger prospective study is needed to confirm a possible role of lipo-PGE1 and iron chelation therapy in reducing the incidence of VOD.

Tandem high-dose chemotherapy and autologous stem cell rescue in patients over 1 year of age with stage 4 neuroblastoma

From June 1997 to August 2005, 52 consecutive newly diagnosed stage 4 neuroblastoma patients over 1 year of age were assigned to receive tandem high-dose chemotherapy and autologous stem cell rescue (HDCT/ASCR) as consolidation therapy. Fifty of the 52 patients underwent a first HDCT/ASCR and 44 patients underwent a second HDCT/ASCR. Eight patients (15.4%) died from treatment-related toxicity (seven during the second HDCT/ASCR). Total body irradiation (TBI) in the first HDCT/ASCR and a shorter interval (< 12 weeks) between the first and second HDCT/ASCR were associated with a higher rate of treatment-related death in the second HDCT/ASCR (P = 0.032 and 0.095, respectively). The tumor relapsed or progressed in 11 patients, and 33 patients remained event free with a median follow-up of 53 months (range 19-117) from diagnosis. The 5-year event-free survival (EFS) (+/- 95% confidence interval) for all 52 patients was 62.1+/-13.7%. The application of TBI and local radiotherapy, and a longer interval between the first and second HDCT/ASCR were independently associated with a better EFS (P = 0.026, 0.007 and 0.020, respectively). However, further studies will be needed to decrease the toxic death rate in the second HDCT/ASCR while reducing the relapse rate.

The impact of post-thaw colony-forming units-granulocyte/macrophage on engraftment following unrelated cord blood transplantation in pediatric recipients

We retrospectively reviewed the engraftment kinetics following unrelated cord blood transplantation (CBT) in association with the post-thaw colony-forming units-granulocyte/macrophage (CFU-GM) number along with the numbers of total nucleated cells (TNC), CD34(+) cells and CD3(+) cells. A total of 71 cord blood units prepared for 53 patients (double-unit CBT in 18 patients) were evaluated. Either the number of infused CFU-GM or CD34(+) cells was significantly lower in patients who failed to achieve engraftment (P=0.028 and 0.005, respectively). Post-thaw CFU-GM, TNC and CD34(+) cells correlated with the speed of neutrophil engraftment (P=0.004, 0.037 and 0.004, respectively), whereas only CFU-GM showed a significant correlation with platelet engraftment (r=-0.385, P=0.024). In double-unit transplants, the number of CFU-GM was the only significant factor predicting engraftment of the predominating unit (P=0.006). We conclude that the post-thaw CFU-GM number is a reliable predictor of rapid engraftment after CBT as well as of the predominating unit in double-unit transplants. Thus, it would be important to perform post-thaw CFU-GM assay on cryopreserved aliquots from several candidate cord blood units in advance before CBT to avoid selecting the unit that might possess a low clonogenic potential.

Assessment of converting from intravenous to oral administration of cyclosporin A in pediatric allogeneic hematopoietic stem cell transplant recipients

We studied the administration method during a transition period from continuous intravenous (i.v.) infusion to oral administration of cyclosporin A (CsA). Thirty-two pediatric hematopoietic stem cell transplant (HSCT) recipients, between the ages of 8 months and 15.6 years (median 7.1 years) participated in this study. The pharmacokinetic properties of CsA was evaluated during the transition period from i.v. to oral CsA. The daily oral dose of CsA was three times higher than the i.v. dose. Oral dosing began immediately after the continuous infusion was discontinued. Whole-blood CsA concentrations were measured by a monoclonal fluorescence polarization immunoassay (FPIA). The mean+/-s.d. value of bioavailability (F), maximum concentration (C(max)), half-life (t(1/2)) of CsA were 43.1+/-14.4%, 1135.3+/-340.6 ng/ml and 3.1+/-1.2 h, respectively. Mean clearance (CL)+/-s.d. was 480.9+/-103.7, 414.9+/-137.1 and 320+/-51.8 ml/h/kg in patients <20, 20-40 and >40 kg of body weight, respectively. The CsA CL of younger children was significantly greater than for older children (P=0.044). CsA trough levels were maintained within the therapeutic range throughout the transition period. Therefore, our findings suggest that the immediate administration of an oral formulation, after discontinuation of the continuous infusion, would be practical and effective for routine clinical use.

The effect of Epstein-Barr virus status on clinical outcome in Hodgkin's lymphoma

The association of Epstein-Barr virus (EBV) with Hodgkin's lymphoma (HL) has been investigated over the last few years. The impact of EBV on clinical outcome is still controversial, however. In this study, we investigated the effect of EBV status on clinical outcome of HL patients. Between January 1986 and September 2004, fifty-six patients, diagnosed as having HL, were included in the analysis. Clinical data were reviewed retrospectively from the patients' records. Tissues from 56 patients were analyzed for the presence of EBV using the in situ hybridization (ISH) for EBV-encoded RNA (EBER) and immunohistochemistry for latent membrane protein (LMP)1. EBV infection was identified in 41.1% of cases by EBER ISH, 26.8% by LMP1 expression, and 26.8% by LMP1 and EBER ISH. EBER-positive HL were significantly more frequent in mixed cellularity (MC) subtype (P=0.014) and advanced stage (P=0.034). There was a trend toward shorter overall survival in EBER-positive patients without statistical significance (P=0.238). LMP1 expression also correlated with MC subtype (P=0.006) and advanced stage (P=0.007), although it did not significantly influence the survival outcome. In subgroup analysis, both EBER and LMP1 positivities were associated with longer progression-free survival in patients with age <25 years old (P=0.045). Reverse trends were shown in patients > or =25 years old. In this study, we demonstrated that the impact of tumor EBV status on prognosis may be age dependent and young patients with latent EBV infection have favorable prognosis.

Successive double high-dose chemotherapy with peripheral blood stem cell rescue collected during a single leukapheresis round in patients with high-risk pediatric solid tumors: a pilot study in a single center

In total, 18 of 26 double high-dose chemotherapies (HDCT) in pediatric solid tumors were rescued with peripheral blood stem cells collected during a single leukapheresis round (single-harvest group, SHG). In the remaining eight HDCT, additional leukapheresis were necessary after the first HDCT (HDCT1) to rescue the second HDCT (HDCT2) (double-harvest group, DHG). Stem cell collection after HDCT1 was inefficient and delayed in patients who had received prior chemotherapy before HDCT1. The interval between HDCT1 and HDCT2 was shorter in SHG than in DHG (median 62.5 days vs 178.5 days, P-value=0.002). Hematologic recovery in HDCT2 was delayed compared to HDCT1. However, there was no difference in hematologic recovery between SHG and DHG. A high rate of treatment-related mortality (TRM) was recorded during HDCT2, but there was no evidence that the shorter interval caused a higher rate of TRM (P-value=0.454). The probability of disease-free survival at 2 years after HDCT2 in the SHG and DHG were 66.7 and 25.0%, respectively (P-value=0.031). Therefore, to administer the second HDCT earlier in double HDCT, and thus to improve the survival of patients with high-risk solid tumors, the single-harvest approach is recommended rather than the double-harvest approach.

Erythrocyte thiopurine methyltransferase activity in a Korean population

Thiopurine methyltransferase (TPMT) is the enzyme responsible for the S-methylation of thiopurine drugs. The enzyme, present in human red blood cells (RBC), is known to exhibit genetic polymorphism and interethnic differences in its activity have been demonstrated. We have studied the role of TPMT polymorphism in Koreans and compared enzyme activity between this and other ethnic groups. In a population of 360 unrelated healthy Korean subjects TPMT activity showed a large interindividual variation ranging from 3.2 to 22.9 nmol ml-1 packed RBC h-1 with a median value of 12.0 and mode of 11.0 nmol ml-1 packed RBC h-1. The enzyme activity was higher in male subjects than that in female (median values; 12.2 vs 11.2, 95% confidence interval of the difference; -2.1, 4.0 nmol ml-1 packed RBC h-1). All subjects had detectable TPMT activity, but contrary to previous reports in other ethnic groups, this was distributed unimodally. The median RBC TPMT activity was very similar to values found in Caucasian populations, higher than in Floridian blacks and lower than that of a Norwegian Saami population.

Incidence estimation of leukemia among Koreans

This study was undertaken in order to estimate the incidence of leukemia among Koreans. Medical records were studied of patients with diagnoses of either ICD-9 038 (septicemia), or 204-208 (leukemias), or 284 (aplastic anemia), or 289 (other diseases of the blood and blood-forming organs) in the claims sent in by medical care institutions throughout the country to the Korea Medical Insurance Corporation (KMIC) during the period from January 1, 1986 to December 31, 1987. These records were abstracted in order to identify and confirm new cases of leukemia among the beneficiaries of KMIC, which covers about 10% of the whole Korean population. Using these data from the KMIC, the incidence rates of leukemia among Koreans were estimated as of July 1st, 1986 to June 30, 1987. The crude incidence rate of all types of leukemia among Koreans is estimated to be 3.45 (95% CI; 0.77-9.55) and 2.29 (95% CI; 0.28-7.81) per 100,000 in males and females, respectively. The cumulative rate for the age span 0-64 is 0.25% in males and 0.18% in females, and for the age span 0-74, 0.35% in males and 0.23% in females. The adjusted rates for the standard world population are 3.90 and 2.48 per 100,000 in males and females, respectively. The relative frequencies by type are 51.5% for AML, 21.6% for ALL, 20.2% for CML, and only 1.5% for CLL. The incidence patterns of various types of leukemia, of which this is the first report in Korea, are analyzed and presented.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence estimation of thyroid cancer among Koreans

The medical records of inpatients with diagnoses of either ICD-9 193(malignant neoplasm of the thyroid gland) or 226(benign neoplasm of the thyroid gland) in the claims sent in by medical care institutions throughout the country, to the Korea Medical Insurance Corporation (KMIC) during the period from January 1, 1986 to December 31, 1987 were abstracted. These records were abstracted in order to identify and confirm new cases of thyroid cancer among the beneficiaries of the KMIC. Using these data, the incidence rate of thyroid cancer among Koreans was estimated as of July 1, 1986 through June 30, 1987. The crude rates were estimated to be 0.76(95% Cl: 0.63-0.87) and 3.87(95% Cl: 3.60-4.14) per 100,000 in males and females, respectively, and the cumulative rates for the age spans 0-64 and 0-74 in males were 0.06% and 1.10%, respectively. In females, those were equally 0.35%. The age-adjusted rate for the world population was 0.93 per 100,000 in males, which is one of the lowest levels in the world. However, the adjusted rate in females was 3.96 per 100,000, which is an average level and very similar to that of the Chinese in Singapore and Shanghai. A similar tendency was shown in the case of the truncated rates for the age group of 35-64, which was 1.91 per 100,000 in males and 8.82 per 100,000 in females.