BACKGROUND: Characterization of the ABO blood group at the phenotype and genotype levels is clinically essential for transfusion, forensics, and population studies. This study elucidated ABO phenotypes and genotypes, and performed an evaluation of their distribution in individuals from the western region of Saudi Arabia. METHODS: One-hundred and seven samples underwent standard serological techniques for ABO blood group phenotype analysis. ABO alleles and genotypes were identified using multiplex polymerase chain reaction, and electrophoretic analysis was performed to evaluate the highly polymorphic ABO locus. RESULTS: A phenotype distribution of 37.4%, 30.8%, 24.3%, and 7.5% was found for blood groups O, A, B, and AB respectively in our study cohort. Genotype analysis identified 10 genotype combinations with the O01/O02 and A102/O02 genotypes being the most frequent with frequencies of 33.6% and 14.95%, respectively. Common genotypes such as A101/A101, A101/A102, A101/B101, B101/B101, and O01/O01 were not detected. Similarly, the rare genotypes, cis-AB01/O02, cis-AB01/O01, and cis-AB01/A102 were not found in our cohort. The most frequently observed allele was O02 (35.98%) followed by the A102 allele (17.76%). Furthermore, our findings are discussed in reference to ABO allele and genotype frequencies found in other ethnic groups. CONCLUSION: The study has a significant implication on the management of blood bank and transfusion services in Saudi Arabian patients.
ABO Blood-Group System ; Alleles ; Blood Banks ; Blood Group Antigens ; Cohort Studies ; Ethnic Groups ; Genotype* ; Humans ; Multiplex Polymerase Chain Reaction ; Phenotype ; Saudi Arabia*

BACKGROUND: In Korea, the prevalence of anemia and iron deficiency anemia (IDA) among older infants and young children remains high. To detect IDA early and to reduce its adverse impact, we assessed the characteristics of infants and young children who had IDA or were at risk of developing IDA, or who exhibited characteristics associated with severe anemia. METHODS: Among the 1,782 IDA-affected children aged 6 months to 18 years who visited the hospital, we retrospectively analyzed the medical records and laboratory data of 1,330 IDA-affected children aged 6–23 months who were diagnosed between 1996 and 2013. We excluded patients with a C-reactive protein level ≥5 mg/dL. RESULTS: IDA was predominant in boys (2.14:1) during infancy and early childhood. The peak IDA incidence was noted among infants aged 9–12 months. Only 7% patients exhibited symptoms of IDA, while 23.6% patients with severe IDA demonstrated classic symptoms/signs of IDA. Low birth weight (LBW) infants with IDA demonstrated low adherence to iron supplementation. In a multivariate analysis, prolonged breastfeeding without iron fortification (odds ratio [OR] 5.70), and a LBW (OR 6.49) were identified as risk factors of severe anemia. CONCLUSION: LBW infants need more attention in order to increase their adherence to iron supplementation. For the early detection of IDA, nutritional status of all infants, and iron batteries of high-risk infants (LBW infants, infants with prolonged breastfeeding, picky eaters, and/or infants with the presence of IDA symptoms) should be evaluated at their health screening visits.
Anemia ; Anemia, Iron-Deficiency* ; Breast Feeding ; C-Reactive Protein ; Child ; Humans ; Incidence ; Infant* ; Infant, Low Birth Weight ; Infant, Newborn ; Iron* ; Korea ; Mass Screening ; Medical Records ; Multivariate Analysis ; Nutritional Status ; Prevalence ; Retrospective Studies ; Risk Factors

BACKGROUND: Immune thrombocytopenia (ITP) is the most common cause of acquired childhood thrombocytopenia and is characterized by increased immune-mediated destruction of circulating thrombocytes. Oxidative damage may be involved in ITP pathogenesis; paraoxonase (PON) and arylesterase (ARE) enzymes are closely associated with the cellular antioxidant system. We investigated the effect of short-term high-dose methylprednisolone (HDMP) treatment on the total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), and PON and ARE enzymatic activity in children with acute ITP. METHODS: Thirty children with acute ITP constituted the study group and 30 healthy children constituted the control group. Children with acute ITP were treated with HDMP: 30 mg/kg for 3 days, then 20 mg/kg for 4 days. The TOS, TAC, OSI, PON, and ARE levels were determined before and after 7 days of HDMP treatment. RESULTS: The TAC level (P<0.001), and PON (P<0.001) and ARE (P=0.001) activities were lower and the TOS (P=0.003) and OSI (P<0.001) levels were higher in children with acute ITP than those in healthy children in the control group. We also observed statistically significant increases in the TAC (P<0.01), PON (P<0.001) and ARE levels (P=0.001) and decreases in the TOS (P<0.05) and OSI levels (P<0.05) with 7 days of HDMP treatment compared to their values before treatment. CONCLUSION: Our study demonstrated increased oxidative stress (OSI and TOC) and decreased antioxidant capacity (TAC), PON, and ARE in ITP patients and that steroid treatment could be effective in reducing the oxidative stress.
Aryldialkylphosphatase ; Blood Platelets ; Child* ; Humans ; Methylprednisolone* ; Oxidative Stress* ; Purpura, Thrombocytopenic, Idiopathic* ; Thrombocytopenia

BACKGROUND: Kasabach-Merritt syndrome (KMS) is a rare but life-threatening illness. The purpose of this study is to report our single-center experience with KMS. METHODS: We reviewed the medical records of 13 patients who were diagnosed with KMS between 1997 and 2012 at Samsung Medical Center. Treatment response was defined as follows: 1) hematologic complete response (HCR) – platelet count >130×10⁹/L without transfusion; 2) clinical complete response (CCR) – complete tumor disappearance or small residual vascular tumor displaying lack of proliferation for at least 6 months after treatment discontinuation. RESULTS: Participants included 7 male and 6 female patients. The median initial hemoglobin levels and platelet counts were 9.7 g/dL (range, 6.6–11.6 g/dL) and 11×10⁹/L (range, 3–38×10⁹/L), respectively. Twelve patients received corticosteroid and interferon-alpha as initial treatment, and the remaining patient received propranolol instead of corticosteroid. Two patients with unsatisfactory response to the initial treatment received weekly vincristine. Successful discontinuation of medication was possible at a median of 301 days (range, 137–579) in all patients except one who was lost to follow-up. The median times to achieve HCR and CCR were 157 days and 332 days, respectively. The probabilities of achieving HCR and CCR were 77% and 54% at 1 year, and 88% and 86% at 2.5 years, respectively. CONCLUSION: The prognosis of KMS in our cohort was excellent. Our data suggest that individualized treatment adaptation according to response may be very important for the successful treatment of patients with KMS.
Cohort Studies ; Female ; Humans ; Interferon-alpha ; Kasabach-Merritt Syndrome* ; Lost to Follow-Up ; Male ; Medical Records ; Platelet Count ; Prognosis ; Propranolol ; Vincristine

BACKGROUND: Although intravenous acyclovir therapy is recommended for varicella zoster virus (VZV) infection in immunocompromised children, the clinical characteristics and outcomes of VZV infection in the acyclovir era have rarely been reported. METHODS: The medical records of children diagnosed with varicella or herpes zoster virus, who had underlying hematologic malignancies, were retrospectively reviewed, and the clinical characteristics and outcomes of VZV infection were evaluated. RESULTS: Seventy-six episodes of VZV infection (herpes zoster in 57 and varicella in 19) were identified in 73 children. The median age of children with VZV infection was 11 years (range, 1-17), and 35 (46.1%) episodes occurred in boys. Acute lymphoblastic leukemia was the most common underlying malignancy (57.9%), and 90.8% of the episodes occurred during complete remission of the underlying malignancy. Acyclovir was administered for a median of 10 days (range, 4-97). Severe VZV infection occurred in 16 (21.1%) episodes. Although the finding was not statistically significant, a previous history of hematopoietic cell transplantation (HCT) appeared to be associated with the development of more severe episodes of herpes zoster (P=0.075). CONCLUSION: Clinical characteristics of VZV infection in immunocompromised children were not significantly different from those without it, and clinical outcomes improved after the introduction of acyclovir therapy. However, risk factors for severe VZV infection require further investigation in a larger population and a prospective setting.
Acyclovir* ; Cell Transplantation ; Chickenpox* ; Child* ; Hematologic Neoplasms* ; Herpes Zoster ; Herpesvirus 3, Human* ; Humans ; Leukemia ; Lymphoma ; Medical Records ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Prospective Studies ; Retrospective Studies ; Risk Factors ; Transplants

BACKGROUND: This retrospective study aimed to characterize and analyze the outcome of therapy-related myeloid neoplasms (t-MNs) in children and adolescents. METHODS: The medical records of 16 patients under 21 years of age at the time of t-MN diagnosis were reviewed. RESULTS: The median patient age was 11.5 years (range, 1.6–20.4 yr). Twelve patients had therapy-related acute myeloid leukemia, 3 patients had myelodysplastic syndrome, and 1 patient had chronic myelomonocytic leukemia. The median latency period was 29 months (range, 11–68 mo). Fourteen patients had cytogenetic aberrations, 8 of whom had an 11q23 abnormality. Of the 13 patients treated with curative intent, 12 patients received myeloid-type induction therapy that led to complete remission (CR) in 8 patients. Nine patients underwent allogeneic transplantation; 4 patients did not undergo transplantation due to chemotherapy-related toxic death (N=3) or parental refusal (N=1). The 5-year overall survival and event-free survival of the 13 patients treated with a curative intent were 46.2% and 30.8%, respectively. For the 9 patients who underwent allogeneic transplantation, the 5-year event-free survival was 66.7%. CONCLUSION: A significant proportion of young patients with t-MNs can experience long-term survival, and allogeneic transplantation plays a key role for attaining cure in these patients.
Adolescent* ; Child* ; Chromosome Aberrations ; Diagnosis ; Disease-Free Survival ; Humans ; Latency Period (Psychology) ; Leukemia, Myeloid, Acute ; Leukemia, Myelomonocytic, Chronic ; Medical Records ; Myelodysplastic Syndromes ; Parents ; Retrospective Studies ; Transplantation, Homologous

BACKGROUND: Different criteria have been used to diagnose mixed-phenotype acute leukemia (MPAL), which has impacted the number of individuals diagnosed with this pathology. Better outcomes have been reported when using acute lymphoblastic leukemia (ALL)-type chemotherapy in the treatment of MPAL. METHODS: We compared the outcome of 4 groups of patients with MPAL. Group 1 included patients diagnosed using the 2008/2016 World Health Organization (WHO) classification; group 2 included patients diagnosed using the European Group for the Immunological Characterization of Leukemias (EGIL) criteria; group 3 included patients diagnosed using either the EGIL or the 2008/2016 WHO criteria; and group 4 was comprised of patients diagnosed with MPAL using the EGIL classification only. RESULTS: We found a significantly worse disease-free survival (groups 1-4) and overall survival (OS) (groups 2 and 3) when comparing MPAL patients to other acute leukemia (AL) patients. A significantly better OS was obtained in patients (groups 2-4) treated with ALL-type chemotherapy compared to acute myeloid leukemia (AML)-type regimens. CONCLUSION: In light of these results, and because a trend (P=0.06) was found with regard to a better OS in group 4 when compared to other AL patients, an argument can be made that the 2008/2016 WHO classification is underpowered to diagnose all MPAL cases, potentially resulting in the suboptimal treatment of some individuals with AL.
Classification* ; Disease-Free Survival ; Drug Therapy ; Humans ; Leukemia* ; Leukemia, Myeloid, Acute ; Pathology ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; World Health Organization

Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are clonal myeloid disorders characterized by hematopoietic insufficiency. As MDS and AML are considered to originate from genetic and molecular defects of hematopoietic stem and progenitor cells (HSPC), the main focus of research in this field has focused on the characterization of these cells. Recently, the contribution of BM microenvironment to the pathogenesis of myeloid malignancies, in particular MDS and AML has gained more interest. This is based on a better understanding of its physiological role in the regulation of hematopoiesis. Additionally, it was demonstrated as a ‘proof of principle’ that genetic disruption of cells of the mesenchymal or osteoblastic lineage can induce MDS, MPS or AML in mice. In this review, we summarize the current knowledge about the contribution of the BM microenvironment, in particular mesenchymal stromal cells (MSC) to the pathogenesis of AML and MDS. Furthermore, potential models integrating the BM microenvironment into the pathophysiology of these myeloid disorders are discussed. Finally, strategies to therapeutically exploit this knowledge and to interfere with the crosstalk between clonal hematopoietic cells and altered stem cell niches are introduced.
Animals ; Hematopoiesis ; Leukemia, Myeloid, Acute ; Mesenchymal Stromal Cells* ; Mice ; Myelodysplastic Syndromes ; Osteoblasts ; Stem Cell Niche ; Stem Cells

No abstract available.
Escherichia coli* ; Escherichia* ; Multiple Myeloma* ; Osteomyelitis*

No abstract available.
Cytogenetics* ; Humans ; Leukemia*