Yu-Mei Liao

Improved efficacy and tolerability of oral deferasirox by twice-daily dosing for patients with transfusion-dependent β-thalassemia†

Deferasirox is an oral iron‐chelating agent taken once‐daily by patients with transfusion‐dependent iron overload. However, some patients are unresponsive or unable to tolerate once‐daily deferasirox. The current study evaluated whether twice‐daily deferasirox treatment showed increased efficacy or tolerability in unresponsive or intolerant patients.

Survival of motor neuron protein downregulates miR-9 expression in patients with spinal muscular atrophy

Spinal muscular atrophy (SMA) is a lethal hereditary disease caused by homozygous absence of the survival of the motor neuron (SMN) 1 gene (SMN1), and it is the leading genetic cause of infant mortality. The severity of SMA is directly correlated with SMN protein levels in affected patients; however, the cellular regulatory mechanisms for SMN protein expression are not completely understood. In this study, we investigated the regulatory effects between SMN expression and miR‐9a, a downstream noncoding small RNA. Using an inducible SMN short hairpin RNA interference (shRNAi) system in NSC 34 and human skin fibroblast cells, cellular miR‐9 levels and SMN protein repression were time‐dependently upregulated. Conversely, cellular miR‐9 levels decreased when HeLa cells were transfected with SMN protein fused with green fluorescent protein. In SMA‐like mice spinal cords and human primary skin fibroblasts isolated from patients with different degrees of SMA, human SMN exhibited a disease severity‐dependent decrease, whereas cellular miR‐9 levels increased. These results clearly suggested that cellular SMN proteins regulated miR‐9 expression and that miR‐9 expression was related to SMA severity. Thus, miR‐9 may be a marker for SMA prognosis.

Immune tolerance induction therapy for patients with hemophilia A and FVIII inhibitors particularly using low-dose regimens†

Inhibitory antibodies against infused clotting factor VIII concentrates (FVIII) developed in 20–30% of patients with hemophilia A. Bypass therapy may control the bleeds in patients with FVIII inhibitors, however, immune tolerance induction (ITI) therapy is the only proven modality for eradicating FVIII inhibitors. Since the cost of high‐dose (200 IU/kg) ITI is extremely expansive, we conducted this study to identify whether low‐dose ITI can be an alternative strategy besides high‐dose ITI or bypass therapy.

Wntless (GPR177) expression correlates with poor prognosis in B-cell precursor acute lymphoblastic leukemia via Wnt signaling

B-cell precursor acute lymphoblastic leukemia (BCP ALL) is the most common childhood leukemia, with a cure rate of 80%. Nevertheless, disease relapse is the most important prognostic factor for the disease outcome. We aimed to elucidate the role of Wnt secretion-regulating protein, Wntless (Wls)/GPR177, on disease outcome in pediatric patients with BCP ALL, and assess its pathogenetic role in the regulation of the disease. Wls expression was characterized and correlated with Wnt pathway signaling in the bone marrow leukemia cells isolated from 44 pediatric patients with BCP ALL. The overexpression of Wls was detected in leukemia cells and was significantly correlated with the disease relapse and poor survival in the patients. The high expression of Wls also correlated with the Wnt expression and consequent downstream signaling activation, which was shown to provide essential proliferation, transformation and anti-apoptotic activity during leukemogenesis. These results indicated that Wls played an essential role in disease relapse and poor survival in patients with BCP ALL. Therefore, Wls may provide a potential future therapeutic target, particularly for patients who do not respond to existing therapies and suffer relapse.

Control of Oxidative Stress and Generation of Induced Pluripotent Stem Cell-like Cells by Jun Dimerization Protein 2

We report here that the Jun dimerization protein 2 (JDP2) plays a critical role as a cofactor for the transcription factors nuclear factor-erythroid 2-related factor 2 (Nrf2) and MafK in the regulation of the antioxidants and production of reactive oxygen species (ROS). JDP2 associates with Nrf2 and MafK (Nrf2-MafK) to increase the transcription of antioxidant response element-dependent genes. Oxidative-stress-inducing reagent led to an increase in the intracellular accumulation of ROS and cell proliferation in Jdp2 knock-out mouse embryonic fibroblasts. In Jdp2-Cre mice mated with reporter mice, the expression of JDP2 was restricted to granule cells in the brain cerebellum. The induced pluripotent stem cells (iPSC)-like cells were generated from DAOY medulloblastoma cell by introduction of JDP2, and the defined factor OCT4. iPSC-like cells expressed stem cell-like characteristics including alkaline phosphatase activity and some stem cell markers. However, such iPSC-like cells also proliferated rapidly, became neoplastic, and potentiated cell malignancy at a later stage in SCID mice. This study suggests that medulloblastoma cells can be reprogrammed successfully by JDP2 and OCT4 to become iPSC-like cells. These cells will be helpful for studying the generation of cancer stem cells and ROS homeostasis.

Efficient detection of factor IX mutations by denaturing high-performance liquid chromatography in Taiwanese hemophilia B patients, and the identification of two novel mutations

Hemophilia B (HB) is an X‐linked recessive disorder characterized by mutations in the clotting factor IX (FIX) gene that result in FIX deficiency. Previous studies have shown a wide variation of FIX gene mutations in HB. Although the quality of life in HB has greatly improved mainly because of prophylactic replacement therapy with FIX concentrates, there exists a significant burden on affected families and the medical care system. Accurate detection of FIX gene mutations is critical for genetic counseling and disease prevention in HB. In this study, we used denaturing high‐performance liquid chromatography (DHPLC), which has proved to be a highly informative and practical means of detecting mutations, for the molecular diagnosis of our patients with HB. Ten Taiwanese families affected by HB were enrolled. We used the DHPLC technique followed by direct sequencing of suspected segments to detect FIX gene mutations. In all, 11 FIX gene mutations (8 point mutations, 2 small deletions/insertions, and 1 large deletion), including two novel mutations (exon6 c.687–695, del 9 mer and c.460–461, ins T) were found. According to the HB pedigrees, 25% and 75% of our patients were defined as familial and sporadic HB cases, respectively. We show that DHPLC is a highly sensitive and cost‐effective method for FIX gene analysis and can be used as a convenient system for disease prevention.

Seroprevalence and clinical characteristics of viral hepatitis in transfusion-dependent thalassemia and hemophilia patients

Background/Aims Transfusion dependent subjects are at a great risk of viral hepatitis infection. We aimed to evaluate the prevalence and factors associated with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection among transfusion-dependent patients in Taiwan. Methods A total of 140 patients (67 thalassemic patients, 70 hemophilic patients, two patients with hereditary spherocytosis and one patient with von Willebrand disease) were prospectively enrolled to evaluate the prevalence and factors associated with viral hepatitis and spontaneous HCV clearance. All patients were tested for HBV and HCV serology and virology. Two consecutive serum samples, at least 1 year apart, were collected to clarify HCV seroclearance. Results The seropositivity rate of hepatitis B surface antigen (HBsAg), HCV antibody (anti-HCV), and both HBsAg/anti-HCV were 6.4%, 45.7% and 5%, respectively. Logistic regression analysis of factors associated with anti-HCV seropositivity included age (odds ratio/95% confidence interval [OR/CI]: 1.12/1.07–1.18, P<0.001), serum alanine aminotransferase (ALT) (OR/CI: 1.04/1.02–1.06, P<0.001) and platelet counts (OR/CI: 0.995/0.991–0.998, P = 0.002). Age was the only factor independently associated with HBsAg seropositivity (OR/CI: 1.08/1.02–1.14.4, P = 0.007). Compared to patients born before 1992, the seroprevalence of HCV among thalassemic patients decreased dramatically in those born after 1992 (46.0% vs. 11.8%, p = 0.012). The seroprevalence of HCV among hemophilic patients also decreased significantly when comparing patients born before 1987 to those born after 1987 (79.5% vs. 11.5%, p<0.001). Similarly, the seroprevalence of HBV decreased significantly in the post-vaccination cohort compared to its counterpart (13.1%, vs. 1.3%, p = 0.005). The spontaneous clearance of HCV was observed in 25.4% (15/59) of patients, and ALT was the only factor associated with it (OR/CI 0.98/0.96–1.00, P = 0.02). Conclusions Both HBV and HCV infections are prevalent among transfusion-dependent thalassemic and hemophilic patients in Taiwan. Nevertheless, seroprevalence decreased significantly and dramatically for HCV after universal blood screening and for HBV after implementation of a universal mass vaccination program.

Soluble vascular cell adhesion molecular-1 is a potential biological indicator of hemophilic arthropathy

AbstractHemophilic arthropathy is the most common chronic complication in patients with hemophilia. The pathogenesis of hemophilic arthropathy involves the inflammatory processes associated with rheumatoid arthritis (RA). Determining the severity and/or progression of joint damage is crucial when evaluating the effect of treatment modalities. Identifying reliable biomarkers in the peripheral blood of patients with hemophilic arthropathy may be beneficial in clinical practice. Circulating soluble vascular cell adhesion molecule-1 (sVCAM-1), E-selectin, and P-selectin levels are elevated in patients with RA. Our study investigated whether these soluble adhesion molecules can be used as biological indicators in the course of joint damage in patients with hemophilia A.Patients with hemophilia A (mild, moderate, and severe) were enrolled. The plasma levels of sVCAM-1, E-selectin, and P-selectin in patients with hemophilia A and control were measured using specific enzyme-linked immunosorbent assay kits. Joint damages were evaluated using Pettersson scores.No statistically significant differences were observed in E-selectin and P-selectin levels between patients and controls. The sVCAM-1 level was significantly higher in patients with hemophilia A than in controls. The differences remained significant in patients with severe hemophilia A but not in patients with mild or moderate hemophilia A. The degree of hemophilic arthropathy was evaluated using Pettersson scores, and a score higher than 5 indicated marked arthropathy. Patients with more than 1 joint with marked arthropathy showed significantly higher sVCAM-1 levels.sVCAM-1 levels in patients with hemophilia A are associated with the severity of hemophilic arthropathy.

Metabolic pathways related to oxidative stress in patients with hemoglobin h disease and iron overload.

Iron overload is a major complication in patients with hemoglobin H (Hb H) disease and causes damage of tissues.

Successful Large-volume Leukapheresis for Hematopoietic Stem Cell Collection in a Very-low- weight Brain Tumor Infant with Coagulopathy

Peripheral apheresis has become a safe procedure to collect hematopoietic stem cells, even in pediatric patients and donors. However, the apheresis procedure for small and sick children is more complicated due to difficult venous access, relatively large extracorporeal volume, toxicity of citrate, and unstable hemostasis. We report a small and sick child with refractory medulloblastoma, impaired liver function, and coagulopathy after several major cycles of cisplatin-based chemotherapy. She successfully received large-volume leukapheresis for hematopoietic stem cell collection, although the patient experienced severe coagulopathy during the procedures. Health care providers should be alert to this potential risk.