Young Shil Park

Epidemiology and clinical long-term outcome of childhood aplastic anemia in Korea for 15 years: retrospective study of the Korean Society of Pediatric Hematology Oncology (KSPHO).

Purpose Aplastic anemia (AA) is a rare hematologic disease characterized by pancytopenia and hypocellular marrow. The Korean Society of Pediatric Hematology Oncology investigated retrospectively the incidence, survival, and transfusion independency according to treatment strategies in AA. Methods All the questionnaires were sent to members for medical records. We collected and analyzed 702 available data. Results The male and female ratio was 1.2, and the median age at diagnosis was 9.3 years. The annual incidence of Korean children with AA was 5.16 per million per year. Constitutional anemia was diagnosed in 44 children. In acquired AA, causes were identified in 39 children. Severe AA (SAA) at initial diagnosis was more common than nonsevere AA. The overall survival was 47.8% with supportive care, 68.1% with immunosuppressive therapy (IST), and 81.8% with hematopoietic stem cell transplantation. In IST, response rate was 65.7%, and relapse rate after response was 54.4% within a median of 23.0 months. The factors with overall survival were severity of disease in supportive care, severity and response in IST, donor type, graft failure, and posttransplant events in hematopoietic stem cell transplantation. Conclusions Long-term outcome in AA was dependent on treatment strategies. These Korean results may help research and prospective international clinical trials for childhood AA.

The efficacy of bypassing agents in surgery of hemophilia patients with inhibitors.

Background Inhibitory antibodies to factor VIII (FVIII) or IX (FIX) are important issues when managing patients with hemophilia A or B. Advances in bypassing agents such as recombinant activated FVII (rFVIIa) and activated prothrombin complex concentrates (APCC) have enabled the aggressive management of hemophilia with inhibitors during emergency or elective surgery. This study provides an updated evaluation of the safety and effectiveness of bypassing agents in treating perioperative bleeding. Methods We reviewed the records of hemophilia patients with inhibitors who underwent surgery between May 2008 and July 2014 using bypassing agents or high-dose FVIII concentrates at a single center. Results In total, 36 surgeries (24 orthopedic, 12 other) were conducted in 18 hemophilia patients with inhibitors. The median inhibitor titer at surgery was 14 (range, 0.7-1,900) Bethesda units. Most patients had high-responding inhibitors. In total, 25 patients received APCC, 9 with rFVIIa initially. In most cases, bleeding stopped or was well controlled; however, bleeding in 6 patients was controlled using sequential bypassing therapy. Hemostatic efficacy of bypassing agents in various surgeries, based on the final patient outcome, was 94.4% (34/36). Among 5 emergency surgeries, 2 deaths occurred. Conclusion Good control of hemostasis can be achieved using bypassing agents in hemophilia patients with inhibitors who are undergoing surgery. Thorough planning is needed before elective surgery and more active and aggressive management may be needed for emergency surgery. Use of bypassing agents can facilitate safe and successful surgeries in hemophilia patients with inhibitors.

Sequential therapy with activated prothrombin complex concentrates and recombinant activated factor VII to treat unresponsive bleeding in patients with hemophilia and inhibitors: a single center experience

Background Currently, the greatest challenge in hemophilia treatment is managing hemophilia patients with inhibitors. The two main bypassing agents that are used to treat hemophilia patients with inhibitors are activated prothrombin complex concentrates (APCC) and recombinant factor VIIa (rFVIIa). Hemophilia patients with inhibitors can develop bleeding episodes, that are refractory to monotherapy with either APCC or rFVIIa and thus are often difficult to manage. Methods This report describes a retrospective chart review of four hospitalized patients with severe hemophilia and inhibitors who were treated with sequential therapy of APCC and rFVIIa for refractory bleeding. Sequential therapy was defined as the administration of both rFVIIa and APCC within 12 h. Results In 5 episodes experienced by 4 patients with inhibitors, bleeding was not controlled by single bypass treatment, but it was controlled when two agents were sequentially administered. Sequential therapy was administered by alternating one APCC dose to 1 to 2 rFVIIa doses, with dosing intervals ranging from 3 to 6 h. All bleeding episodes were controlled within 12 to 24 h. Sequential therapy was discontinued after 2 to 5 days. No adverse clinical events, such as thrombosis, were observed. Conclusion Sequential therapy with APCC and rFVIIa was efficacious without adverse events; however, attention on thrombosis is needed. In addition, a prospective clinical trial is needed to provide further evidence for this treatment.

Immune tolerance induction in patients with severe hemophilia A with inhibitors

Background Inhibitory antibodies to factor VIII (FVIII) are an important complication when managing patients with hemophilia A. Immune tolerance induction (ITI) has been regarded as a useful method for eradicating inhibitors. We report the results of a retrospective study in Korean patients with hemophilia A who underwent ITI. Methods We reviewed the records of patients with hemophilia A with inhibitors who underwent ITI from March 2004 to December 2014. ITI was started with FVIII concentrates at 100 IU/kg, 3 times per week. The dose of FVIII was reduced according to the inhibitor titer and recovery of FVIII. Inhibitor elimination was defined as the time taken to achieve a negative inhibitor assay with no anamnestic response and normal FVIII recovery and/or normal half-life. Results In total, 17 patients with severe hemophilia A were evaluated. Complete tolerance was achieved in 14 of 17 patients (83%). The mean peak inhibitor titer before ITI was 38.4 BU/mL. The mean treatment duration was 26.2 months. The mean duration between inhibitor detection and ITI was 5.1 years in the complete tolerance group and 10.8 years in the partial tolerance and failed group. Conclusion This study shows that ITI can be an effective and well-tolerated method for eradicating inhibitors. Possible influencing factors for ITI success were age at the start of ITI treatment and duration after inhibitor detection. More research to provide further insight about other factors and conditions is needed.

Surgery in patients with congenital factor VII deficiency: A single center experience

Background Congenital factor VII (FVII) deficiency is a rare hemorrhagic disorder that can cause excessive bleeding during and after surgery in affected patients. The recombinant form of activated factor VII (rFVIIa, NovoSeven® from Novo Nordisk, Bagsvaerd, Denmark), which was developed as a second-generation bypassing agent, has recently been used in the management of bleeding for patients with congenital FVII deficiency. Methods We reviewed the results of 8 surgical procedures in 5 patients with congenital FVII deficiency at the Kyung Hee University Hospital, Gangdong, Seoul, Korea, between January 2008 and June 2010. We administrated rFVIIa preoperatively in six patients and postoperatively in five patients. Results Between January 2008 and June 2010 at our center, 8 operations were performed successfully and no complications were observed in the 5 patients with congenital FVII deficiency. The median level of FVII activity was 2% (range, 0.6-7%). Four orthopedic procedures, 1 tonsillectomy, and 3 dental extractions were performed. The median duration of hospitalization was 8.5 days (range, 0-15 days). rFVIIa was administered at all procedures, except the dental extraction that was performed using only antifibrinolytic agents without any replacement. No bleeding or thrombogenic complications were observed in any case. Conclusion Patients with congenital FVII deficiency who require surgery can be treated efficiently and safely with rFVIIa or antifibrinolytic agents. rFVIIa was well tolerated and maintained effective hemostasis and showed good clinical outcome after the major surgery.

Allogeneic hematopoietic stem cell transplantation in congenital hemoglobinopathies with myeloablative conditioning and rabbit anti-thymocyte globulin

Background Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for β-thalassemia major (TM) and sickle cell disease (SCD) in children. Graft-versus-host disease (GVHD) and treatment-related mortality (TRM) remain significant challenges to improving survival after HSCT. Here, we analyzed the outcome of TM and SCD patients, who received allogeneic HSCT with myeloablative conditioning at our institution. Methods Twenty-two patients (15 TM, 7 SCD), with a median age of 9 years (range, 1.6–16.9), underwent allogeneic HSCT using busulfan, cyclophosphamide and rabbit anti-thymocyte globulin-based conditioning. Cells were derived from either the bone marrow (8 patients), or peripheral blood stem cells (14 patients). The majority of patients received HSCT from a matched sibling donor (N=18). GVHD prophylaxis included cyclosporine and short course methotrexate. Results All patients achieved donor engraftment. Two SCD patients died from TRM-related grade IV gut GVHD (N=1) or severe bronchiolitis obliterans (BO) (N=1). Cumulative incidence of acute and chronic GVHD was 36.4% and 32.7%, respectively. Veno-occlusive disease (VOD) occurred in 8 patients (36.4%), but resolved in all instances. Epstein-Barr virus (EBV)-related post-transplantation lymphoproliferative disease (PTLD) occurred in 1 patient. The overall survival (OS) was 90.9% (TM 100%, SCD 71.4%), with all patients achieving transfusion independence, while 8 achieved complete donor chimerism. Conclusion Busulfan, cyclophosphamide, and ATG-based conditioning for HSCT of TM and SCD patients did not result in graft failure, although modifications may be required to reduce VOD incidence. Further changes to donor type and cell source prioritization are necessary to minimize TRM and morbidity caused by GVHD.

Availability of angiography and therapeutic embolization for the treatment of acute bleeding in patients with hemophilia.

Clotting factor replacement therapy alone is often inadequate for acute bleeding in hemophilia patients, and surgery for such patients poses significant clinical challenges. Arterial angiographic intervention is used to control bleeding in local blood vessels. In the present study, we examined the clinical course and prognosis of hemophilia patients with bleeding who had undergone angiography, and evaluated the validity of diagnostic angiography and therapeutic embolization in these patients. Angiography was performed in five hemophilia patients, who experienced bleeding that was difficult to control even after treatment with clotting factor replacement or bypassing agent therapy. Of these patients, four were confirmed to have continued bleeding, and angiographic embolization was performed using clotting factor concentrates or bypassing agents. However, one patient developed uncontrollable bleeding at the puncture site, which eventually led to the patient’s death. Thus, angiography and therapeutic embolization may be the preferred procedures for the treatment of hemorrhagic complications, refractory to treatment with clotting factor concentrates or bypassing agents. Further comprehensive, multidisciplinary team studies are needed to develop effective strategies to reduce hemorrhagic complications.

Comparison of growth and pubertal progression in wild type female rats with different bedding types

Purpose Endocrine-disrupting chemicals interfere with the endocrine system and therefore affect growth and pubertal progression. The study aim was to compare the growth and pubertal progression in wild-type female rats with different bedding types. Methods Twenty 5-week-old female wild-type Sprague Dawley rats were randomly assigned to two groups with different bedding types: one group received wood shaving bedding, while a second group received corncob bedding. We determined crown-rump length and body weight as anthropometric measurements and assessed the serum growth hormone (GH) and estradiol levels. The gh1 mRNA expression levels were compared using quantitative real time transcription polymerase chain reaction. The estrous cycle was evaluated by vaginal smear. Results The anthropometric measurements were not significantly different between the two groups. The mean relative expression of the gh1 gene was lower in the corncob bedding group than that in the wood shaving group (P=0.768). Meanwhile serum GH and estradiol were increased in the wood shaving bedding group; however this difference was not statistically significant. The time to first estrus and the length of the estrous cycle were increased in the corncob bedding group; the proportion of normal estrous cycles was also decreased. These findings indicate irregularities in the estrous cycle. Conclusion Endocrine-disrupting chemicals in corncob bedding might be associated with time to first estrus and length of the estrous cycle. Therefore, the type of bedding should be considered as a factor affecting pubertal progression in rodents.