Current Status of Molecular Diagnosis of Hereditary Hemolytic Anemia in Korea.

Hereditary hemolytic anemia (HHA) is considered a group of rare hematological diseases in Korea, primarily because of its unique ethnic characteristics and diagnostic challenges. Recently, the prevalence of HHA has increased in Korea, reflecting the increasing number of international marriages and increased awareness of the disease. In particular, the diagnosis of red blood cell (RBC) enzymopathy experienced a resurgence, given the advances in diagnostic techniques. In 2007, the RBC Disorder Working Party of the Korean Society of Hematology developed the Korean Standard Operating Procedure for the Diagnosis of Hereditary Hemolytic Anemia, which has been continuously updated since then. The latest Korean clinical practice guidelines for diagnosing HHA recommends performing next-generation sequencing as a preliminary step before analyzing RBC membrane proteins and enzymes. Recent breakthroughs in molecular genetic testing methods, particularly next-generation sequencing, are proving critical in identifying and providing insight into cases of HHA with previously unknown diagnoses. These innovative molecular genetic testing methods have now become important tools for the management and care planning of patients with HHA. This review aims to provide a comprehensive overview of recent advances in molecular genetic testing for the diagnosis of HHA, with particular emphasis on the Korean context.

Complication Analysis in Korean Patients With Hemophilia A From 2007 to 2019: A Nationwide Study by the Health Insurance Review and Assessment Service Database.

BACKGROUND: There has been remarkable progress in hemophilia A (HA) treatment in Korea. Viral inactivation products were developed in 1989, use of recombinant factor VIII (FVIII) concentrates started in 2002, and prophylaxis expanded thereafter. This study was conducted to identify the changes in complications in HA before and after 1989 or 2002. METHODS: The study was performed using the 2007-2019 Healthcare Big Data Hub of the Health Insurance Review and Assessment Service. RESULTS: Among 2,557 patients, 1,084 had ≥ 1 complication; 829 had joint problems, 328 had viral infections, 146 had neurologic sequelae, and 87 underwent 113 surgeries or procedures due to complications. Patients born after 1989 had a significantly lower risk of viral infections than those born before 1989; 27.1% vs. 1.4% (P < 0.001, odds ratio [OR], 0.037). Patients born after 2002 had a significantly lower risk of joint problems than those born before 2002; 36.8% vs. 24.7% (P < 0.001, OR, 0.538). Patients born after 2002 had a higher incidence of neurologic sequelae than those born before 2002; 3.7% vs. 11.1% (P < 0.001, OR, 3.210). Medical expenses for complication-associated surgeries or procedures were ₩2,957,557,005. CONCLUSION: Viral infections have significantly decreased in Korean patients with HA. The degree of reduction of joint problems was lower than we expected, because it took > 10 years to expand prophylaxis widely. Neurologic sequelae have not decreased; thus, additional efforts to decrease intracranial hemorrhage are needed. We suggest personalized dosing of FVIII and more meticulous care during childbirth to further reduce the complications.

Erratum: Correction of Affiliations in the Article "Clinical Characteristics and Treatment Outcomes in Children, Adolescents, and Young-adults with Hodgkin's Lymphoma: a KPHOG Lymphoma Working-party, Multicenter, Retrospective Study".

This corrects the article on p. e393 in vol. 35, PMID: 33258329.

Serum cytokine profiles in infants with infantile hemangiomas on oral propranolol treatment: VEGF and bFGF, potential biomarkers predicting clinical outcomes.

BACKGROUND: Oral propranolol has become first-line treatment for infantile hemangiomas (IHs). This study focused on identifying cytokines related to the biology of IH and early regression indicators of IH after propranolol treatment. METHODS: For inclusion, the patients had to be aged less than 1 year and have an IH with a largest diameter ≥2 cm. Patients were scheduled to receive 1 year of propranolol treatment. Serum cytokines involved in angiogenesis, vasculogenesis, and/or chronic inflammation were analyzed at 0, 1, and/or 12 months after treatment using Multiplex Luminex assays. RESULTS: Among the 49 evaluable patients, 33 completed the 1-year treatment: 16 showed excellent response and 12 had good response to propranolol. Significant decreases in serum MMP-2, bFGF, VEGF-α, and MCP-1 levels were observed after 1 year of treatment compared to pretreatment values. The maximal diameters of the lesions significantly correlated with pretreatment serum VEGF-α, bFGF, and MMP-9. Patients with higher bFGF and VEGF levels showed better response to propranolol at 1 year. CONCLUSION: MMP-2, VEGF-α, bFGF, and MCP-1 may involve in the biology of IH and their downregulation may be associated with involution processes of IH. Pretreatment bFGF and VEGF could be novel biomarkers for predicting response to propranolol. IMPACT: We found that decreases in the concentrations of MMP-2, bFGF, VEGF, and MCP-1 were associated with regression of the hemangioma, which indicates that one of the mechanisms of propranolol in the treatment of proliferative hemangiomas may involve downregulation of those cytokines. Patients with higher bFGF and VEGF levels showed better response to propranolol at 1 year. Importantly, serum bFGF higher than 37.07 pg/mL may predict an excellent response to propranolol. Therefore, along with the patient's age and the size and visual characteristics of the lesion, bFGF levels could help determine the viability of propranolol use in the treatment of IHs. Our study represented extensive serum profiling in IH, reporting the indicators and molecules clearly related to IH regression with propranolol treatment. The authors believe that monitoring serum cytokines, including MMP-2, bFGF, VEGF, and MCP-1, in IH patients could be important, in addition to clinical follow-up, for determining when to start and end propranolol treatment.

Treatment Outcome in Pediatric Acute Lymphoblastic Leukemia With Hyperleukocytosis in the Yeungnam Region of Korea: A Multicenter Retrospective Study.

Acute lymphoblastic leukemia (ALL) with hyperleukocytosis at diagnosis is associated with early morbidity and mortality due to complications of leukostasis. Of 535 pediatric ALL patients (January 2004 to December 2016 from the Yeungnam region of Korea), 72 (13.5%) patients with an initial white blood cell (WBC) count of ≥100×10/L were included in this study, of whom 38 patients had extreme hyperleukocytosis (WBC>200×10/L) at diagnosis. Fourteen patients (19.4%) had ≥1 early respiratory and neurologic complications during induction therapy. Relapse occurred in 8 patients (24.2%) with extreme hyperleukocytosis and in 1 patient (3.0%) with an initial WBC count of 100 to 200×10/L (P=0.012). Estimated 10-year event-free survival rate (EFS) and overall survival rate were 78.3%±8.4% and 82.6%±7.7%, respectively. The 10-year EFS was significantly lower in patients with an initial WBC count of >200×10/L than in those with an initial WBC count of 100 to 200×10/L (65.7%±13.4% vs. 91.2%±7.9%; P=0.011). The 10-year EFS and overall survival rate did not differ significantly between patients with extreme hyperleukocytosis who received hematopoietic stem cell transplantation and those who received chemotherapy. In conclusion, pediatric ALL with hyperleukocytosis can lead to early complications and mortality. Patients with initial extreme hyperleukocytosis showed significantly poorer prognosis than those with WBC counts of 100 to 200×10/L.

High anemia prevalence in Korean older adults, an advent healthcare problem: 2007-2016 KNHANES.

BACKGROUND: Anemia is associated with high morbidity and mortality in older people. However, the prevalence and characteristics of anemia in older individuals are not fully understood, and national data on these aspects in older Korean adults are lacking. This study aimed to evaluate the prevalence and characteristics of anemia in older adults using data from the Korea National Health and Nutrition Examination Survey (KNHANES), which is a nationwide cross-sectional epidemiological study conducted by the Korean Ministry of Health and Welfare. METHODS: Data from a total of 62,825 participants of the 2007-2016 KNHANES were compiled and analyzed to investigate differences in participant characteristics and potential risk factors for anemia. Differences in clinical characteristics of participants were compared across subgroups using the chi-square test for categorical variables and independent t-test for continuous variables. Univariate and multivariate analyses using logistic regression were performed to identify related clinical factors. RESULTS: The prevalence of anemia was higher in the population aged ≥65 years than in the younger population. Anemia was also more prevalent among females than among males, but this difference was not significant in people aged > 85 years. Being underweight, receiving a social allowance, living alone, and having comorbidities such as hypertension, rheumatoid arthritis, diabetes mellitus (DM), cancer, and chronic renal failure (CRF) were more common among older adults with anemia than among the population without anemia. In univariate and multivariate analyses, older age, female sex, underweight, and presence of comorbidities including rheumatoid arthritis, DM, cancer, and CRF were associated with an increased risk of anemia. CONCLUSIONS: This study revealed that age, female sex, underweight, and the presence of comorbidities such as rheumatoid arthritis, DM, cancer, and CRF were associated with an increased risk of anemia in older Korean adults. Further study on causal relationships between anemia and other variables in the older population is necessary.

Epidemiological Study of Hereditary Hemolytic Anemia in the Korean Pediatric Population during 1997-2016: a Nationwide Retrospective Cohort Study.

BACKGROUND: Hereditary hemolytic anemia (HHA) is a rare disease characterized by premature red blood cell (RBC) destruction due to intrinsic RBC defects. The RBC Disorder Working Party of the Korean Society of Hematology established and updated the standard operating procedure for making an accurate diagnosis of HHA since 2007. The aim of this study was to investigate a nationwide epidemiology of Korean HHA. METHODS: We collected the data of a newly diagnosed pediatric HHA cohort (2007-2016) and compared this cohort's characteristics with those of a previously surveyed pediatric HHA cohort (1997-2006) in Korea. Each participant's information was retrospectively collected by a questionnaire survey. RESULTS: A total of 369 children with HHA from 38 hospitals distributed in 16 of 17 districts of Korea were investigated. RBC membranopathies, hemoglobinopathies, RBC enzymopathies, and unknown etiologies accounted for 263 (71.3%), 59 (16.0%), 23 (6.2%), and 24 (6.5%) of the cases, respectively. Compared to the cohort from the previous decade, the proportions of hemoglobinopathies and RBC enzymopathies significantly increased (P < 0.001 and P = 0.008, respectively). Twenty-three of the 59 hemoglobinopathy patients had immigrant mothers, mostly from South-East Asia. CONCLUSION: In Korea, thalassemia traits have increased over the past 10 years, reflecting both increased awareness of this disease and increased international marriages. The enhanced recognition of RBC enzymopathies is due to advances in diagnostic technique; however, 6.5% of HHA patients still do not have a clear diagnosis. It is necessary to improve accessibility of diagnosing HHA.

Clinical Characteristics and Treatment Outcomes in Children, Adolescents, and Young-adults with Hodgkin's Lymphoma: a KPHOG Lymphoma Working-party, Multicenter, Retrospective Study.

BACKGROUND: Hodgkin's lymphoma (HL) constitutes 10%-20% of all malignant lymphomas and has a high cure rate (5-year survival, around 90%). Recently, interest has increased concerning preventing secondary complications (secondary cancer, endocrine disorders) in long-term survivors. We aimed to study the epidemiologic features and therapeutic outcomes of HL in children, adolescents, and young adults in Korea. METHODS: We performed a multicenter, retrospective study of 224 patients aged < 25 years diagnosed with HL at 22 participating institutes in Korea from January 2007 to August 2016. RESULTS: A higher percentage of males was diagnosed at a younger age. Nodular sclerosis histopathological HL subtype was most common, followed by mixed cellularity subtype. Eighty-one (36.2%), 101 (45.1%), and 42 (18.8%) patients were classified into low, intermediate, and high-risk groups, respectively. Doxorubicin, bleomycin, vinblastine, dacarbazine was the most common protocol (n = 102, 45.5%). Event-free survival rate was 86.0% ± 2.4%, while five-year overall survival (OS) rate was 96.1% ± 1.4%: 98.7% ± 1.3%, 97.7% ± 1.6%, and 86.5% ± 5.6% in the low, intermediate, and high-risk groups, respectively (P = 0.021). Five-year OS was worse in patients with B-symptoms, stage IV disease, high-risk, splenic involvement, extra-nodal lymphoma, and elevated lactate dehydrogenase level. In multivariate analysis, B-symptoms and extra-nodal involvement were prognostic factors for poor OS. Late complications of endocrine disorders and secondary malignancy were observed in 17 and 6 patients, respectively. CONCLUSION: This is the first study on the epidemiology and treatment outcomes of HL in children, adolescents, and young adults in Korea. Future prospective studies are indicated to develop therapies that minimize treatment toxicity while maximizing cure rates in children, adolescents, and young adults with HL.

School performance of childhood cancer survivors in Korea: A multi-institutional study on behalf of the Korean Society of Pediatric Hematology and Oncology.

OBJECTIVE: To investigate school performance of childhood cancer survivors focusing on the child's functioning, including peer relationships, school attendance, and academic achievement. METHODS: We studied 241 children from 15 institutions in Korea between 2015 and 2016. The self-reported paper-and-pencil questionnaires were used. RESULTS: Approximately 22% of the survivors suffered from lack of friends. Bullying was reported by 30% of survivors. Survivors who returned to primary school reported a higher incidence of bullying compared with survivors who returned to middle or high school (P = 0.03). The percentage of children who missed classes more than 4 days in a month was higher in survivors with brain tumors than those with other tumors (P = 0.04). Approximately 41% of children reported learning difficulty. After returning to school, 53% of the patients reported that they had lower overall mark averages than they had before. Patients who returned to high school showed the highest rate of repeating a grade and the lowest rate of achieving high academic marks. The school marks in the Korean (P = 0.03), English (P = 0.04), and physical education (P = 0.04) were worse for the children with brain tumors than for the children with other tumors. CONCLUSION: We found that 20% to 25% of survivors experienced peer-related difficulties upon returning to school. Patients who return to school, especially high school, should be provided more educational support to overcome low academic achievement. Particular concern is needed to the patients with brain tumors, who are at risk for significant academic and social difficulties and therefore may require more intensive support in school.

A case of inherited type 1 and type 2A von Willebrand disease confirmed by diagnostic exome sequencing.

A 10-year-old male and his family members visited a pediatric hematology clinic due to coagulopathy. Laboratory tests indicated von Willebrand disease (vWD) in all the family members. We conducted diagnostic exome sequencing for confirmation. The patient was confirmed to be a compound heterozygote for vWD: c.2574C > G (p.Cys858Trp) from his father (known variant of vWD type 1) and c.3390C > T (p.Pro1127_Gly1180delinsArg) from his mother (variant known to result in exon 26 skipping in vWD type 2A). He was managed with factor VIII and von Willebrand factor complex concentrate during palatoplasty due to bleeding despite pre-operative desmopressin injection. The operation was completed successfully.

Comparison of survival outcome between donor types or stem cell sources for childhood acute myeloid leukemia after allogenic hematopoietic stem cell transplantation: A multicenter retrospective study of Study Alliance of Yeungnam Pediatric Hematology-oncology.

We compared transplant outcomes between donor types and stem cell sources for childhood acute myeloid leukemia (AML). The medical records of children with AML in the Yeungnam region of Korea from January 2000 to June 2017 were reviewed. In all, 76 children with AML (male-to-female ratio = 46:30) received allogenic hematopoietic stem cell transplantation (allo-HSCT). In total, 29 patients received HSCT from either a matched-related donor or a mismatched-related donor, 32 patients received an unrelated donor, and 15 patients received umbilical cord blood. In term of stem cell sources, bone marrow was used in 15 patients and peripheral blood in 46 patients. For all HSCT cases, the 5-year overall survival (OS) was 73.1% (95% CI: 62.7-83.5) and the 5-year event-free survival (EFS) was 66.1% (95% CI: 54.5-77.7). There was no statistical difference in 5-year OS according to the donor types or stem cell sources (P = .869 and P = .911). There was no statistical difference in 5-year EFS between donor types or stem cell sources (P = .526 and P = .478). For all HSCT cases, the 5-year relapse rate was 16.1% (95% CI: 7.3-24.9) and the 5-year non-relapse mortality (NRM) was 13.3% (95% CI: 5.1-21.5). There was no statistical difference in the 5-year relapse rate according to the donor types or stem cell sources (P = .971 and P = .965). There was no statistical difference in the 5-year NRM between donor types or stem cell sources (P = .461 and P = .470).

Treatment outcome of pediatric acute lymphoblastic leukemia in Yeungnam region: Multicenter retrospective study of Study Alliance of Yeungnam Pediatric Hematology-Oncology (SAYPH).

OBJECTIVES: We aimed to evaluate treatment outcomes of pediatric acute lymphoblastic leukemia (ALL) subgroups by risk-stratification, in the Yeungnam region of Korea. METHODS: We reviewed the courses of 409 newly diagnosed ALL patients from January 2004 to December 2013 in the Yeungnam region. RESULTS: All patients were classified into three risk groups: standard risk (SR, n=212), high risk (HR, n=153) and very high risk (VHR, n=44). The mean follow-up time was 73.6 ± 39.4 months. The 7-year event-free survival (EFS) and overall survival (OS) rates were 78.7 ± 2.1% and 86.8 ± 1.8%, respectively. Significant 7-year EFS and OS rates for SR (84.0 ± 2.7%, 93.7 ± 1.8%), HR (76.5 ± 3.5%, 82.1 ± 3.3%), and VHR (60.6 ± 7.5%, 69.9 ± 7.5%) were observed (P<0.001), respectively. Relapse occurred in 52 patients, and the cumulative 7-year incidence of relapse differed according to risk groups (SR vs. HR vs. VHR=12.6% vs. 14.0% vs. 29.6%, P=0.003).For the 46 relapsed patients who were treated, the 3-year EFS and OS were 42.3 ± 8.3%and 46.4± 8.4%. Among the 44 VHR patients, EFS was not significantly different between the chemotherapy-treated patients and those received hematopoietic stem cell transplantation (P=0.533). The 7-year EFS of the hyperleukocytosis subgroup (24 cases, 14 under 10 years of age)showed a tendency for better prognosis than that of the other VHR subgroups (P=0.178). CONCLUSION: Our results revealed improved outcomes in pediatric ALL patients with risk-stratified therapy. The hyperleukocytosis subgroup without any combined chromosomal abnormalities may respond favorably to chemotherapy alone after first complete remission.

Prefixation of neutrophils for neutrophil antibody testing.

OBJECTIVE: The granulocyte immunofluorescence test based on flow cytometry is still the most commonly used method for detecting antineutrophil antibodies. We questioned whether neutrophil prefixation is necessary for this test. METHODS: Three pretreatment methods using paraformaldehyde were compared: unfixed, short-fixed (3 minutes 40 seconds), and long-fixed (10 minutes) leukocytes. The mean fluorescence intensity (MFI) of a test sample was divided by the average of negative controls, and this MFI ratio of gated neutrophils or lymphocytes was assessed for its discriminatory value based on the pretreatment method used. RESULTS: In neutrophil antibody positive (Ab+) sera (n = 7), the MFI ratio of unfixed neutrophils (1.97) was higher than that of short- (1.60, P = 0.004) or long- (1.71, P = 0.203) fixed neutrophils. In HLA Ab+ sera (n = 10), the MFI ratio of short-fixed lymphocytes (8.85) was higher than that of unfixed (6.52, P = 0.120) or long-fixed (3.86, P = 0.055) lymphocytes. In antinuclear Ab+ sera (n = 4), the MFI ratio of unfixed neutrophils (2.04) was higher than that of short- (1.23, P = 0.047) or long- (1.14, P = 0.044) fixed neutrophils. CONCLUSION: The benefit of a prefixation step depends on the diagnostic purpose. Unfixed neutrophils are more sensitive, but the prefixed neutrophils are more specific. For the diagnosis of autoimmune neutropenia of childhood, prefixation can be omitted to enhance sensitivity.

Epidemiologic and Clinical Outcomes of Pediatric Renal Tumors in Korea: A Retrospective Analysis of The Korean Pediatric Hematology and Oncology Group (KPHOG) Data.

PURPOSE: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. MATERIALS AND METHODS: From January 2001 to December 2015, data of pediatric patients (0-18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. RESULTS: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). CONCLUSION: The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

Korean Adolescent Patient with Manifestations of Lymphocyte Variant Hypereosinophilic Syndrome and Episodic Angioedema with Eosinophilia, Treated with Reslizumab.

A four-year-old female patient visited the pediatric hematologic clinic due to periodic generalized edema and eosinophilia. Laboratory assessment showed an eosinophil count of 40.02×109/L (73.6% of white blood cells). A bone marrow aspirate smear film showed no signs of malignant cells but had hypercellular marrow particles with eosinophilia (45% of all nucleated cells) and 52% of eosinophils were immature. Other laboratory tests showed an increased IgM level of 827 mg/dL, and lymphocyte phenotyping by flow cytometry revealed an aberrant CD3-CD4+ T-cell population of 27-53×109/L (1.9-3.6% of lymphocytes). Polymerase chain reaction analysis for the T-cell receptor gamma gene rearrangement showed a T-cell clonality peak. At the age of 13, allogeneic stem cell transplantation was performed, but with primary rejection. From the age of 17, she has continued receiving 3 mg/kg of reslizumab intravenously every 4 weeks for 21 months. Since reslizumab treatment was initiated, her eosinophil count remained consistently within the normal range. This is the first report describing the effective use of reslizumab in a Korean adolescent patient for the management of lymphocytic-variant hypereosinophilic syndrome (L-HES). Since the patient showed clinical manifestations of L-HES as well as episodic angioedema with eosinophilia (EAE), a continuous periodic examination is required given the higher risk of developing lymphoma or leukemia.