Polymorphisms in the promoter region of the serotonin reuptake transporter (SERT) gene may underlie the disturbance in gut function in patients with irritable bowel syndrome (IBS). Association studies of SERT polymorphisms and IBS have shown diverse results among different countries, which might be due to racial and subject composition differences. The aim of this study was to assess the potential association between SERT polymorphisms and IBS in Koreans. A total of 190 IBS patients, who met the Rome II criteria, and 437 healthy controls were subjected to genotyping. SERT polymorphisms differed in the IBS and control groups (P = 0.014). The SERT deletion/deletion genotype occurred with greater frequency in the diarrhoea-predominant IBS group than in the controls. A strong genotypic association was observed between the SERT deletion/deletion genotype and diarrhoea-predominant IBS (P = 0.012). None of the clinical symptoms analysed was significantly associated with the SERT genotypes. The frequency of the SERT insertion/insertion genotype was much lower than that of the other two genotypes. A significant association was observed between the SERT polymorphism and IBS, especially diarrhoea-predominant IBS, suggesting that the SERT gene is a potential candidate gene involved in IBS in Korea.

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 ¼ 0.002), VOD prophylaxis without lipo-prostaglandin E1 (PGE1) (P ¼ 0.012), number of previous HSCT (P ¼ 0.014), and pretransplant serum ferritin (P ¼ 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) (Po0.001). 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.

Graft failure (GF) is a significant complication after allogeneic hematopoietic stem cell transplantation (HCT) and is associated with a high mortality rate. We performed re-transplantation using haploidentical-related donors to rescue children with early GF. Between 2008 and 2013, 10 patients received re-transplantation from haploidentical family donors. The median age at HCT was 13.5 years and the median time between transplantations was 52.5 days. Conditioning regimen with fludarabine and CY was used in seven patients, and TBI was added in three patients. All 10 patients received T-cell-depleted grafts using CD3 or CD3/CD19 MoAb. The median numbers of CD34 þ and CD3 þ cells were 5.52 Â 10 6 /kg and 1.08 Â 10 6 /kg, respectively. For GVHD prophylaxis, mycophenolate mofetil (MMF) and tacrolimus or MMF and CYA were used. All 10 patients achieved a sustained neutrophil engraftment and maintained a complete donor chimerism at the time of analysis (median 23 months, range 6-62 months). Nine of 10 patients were alive, and one patient with moyamoya disease with AML died of encephalopathy 7 months post transplant. This study suggests that fludarabine-and CY-based conditioning with T-cell-depleted haploidentical HCT is a feasible option to rescue pediatric patients with primary GF. Keywords: pediatric; graft failure; haploidentical hematopoietic stem cell transplantation INTRODUCTION Graft failure (GF) after allogeneic hematopoietic stem cell transplantation (HCT) is associated with a high mortality. The overall frequency of GF under myeloablative conditioning has been reported to be o5%. Meanwhile, it reaches around 10% for haploidentical HCT (HHCT) and umbilical cord blood transplantation (UCBT).1-3 Following GF, a second transplantation offers the best opportunity for long-term, disease-free survival for these patients. However, the best conditioning regimen and the optimal stem cell source for salvage transplantation are yet to be determined, and achieving stable engraftment is often difficult with engraftment rates as low as 30%.4 Waki et al. 5 reported the results of salvage UCBT. Although more than half of the patients achieved neutrophil engraftment, transplant-related mortality (TRM) at day 100 was 45, and 60% of the deaths were related to infectious complications, with the probability of 1-year OS at 33%. On the other hand, second transplantation using haploidenticalrelated donors showed more favorable results. 6,7 We performed salvage transplantation using T-cell-depleted grafts from haploidentical-related donors to rescue children and adolescents with early GF after initial transplantation, and in this study, we report the results.