title: Ineffective erythropoiesis underlies the clinical heterogeneity of congenital dyserythropoietic anemia type II (CDA II).
abstract: BACKGROUND
  Congenital dyserythropoietic anemia type II (CDA II) is an autosomal recessive disease, and is the most common CDA. The qualitative and quantitative defects of erythropoiesis in CDA II, as estimated by the hematological and biochemical parameters at the time of diagnosis, may not reflect the heterogeneity of the disease course of each patient.
  
  
  METHODS
  Three pediatric patients with CDA II are herein presented, having an heterogeneous clinical course. In addition to bone marrow morphology, Ham test and SDS-PAGE of erythrocyte membrane protein, the present study also examined erythroid marrow activity, by measuring serum Erythropoietin (Epo), soluble Transferrin Receptors (sTfR) concentrations and Reticulocyte Production Index (RPI).
  
  
  RESULTS
  All patients demonstrated the same pattern of ineffective erythropoiesis, having increased Epo (350-389 IU/L), sTfR concentrations (6.2-7.8 mg/L) and low RPI values (0.8-1.3). Erythron expansion was expressed by RPI values nearly twofold higher than normal values in parallel to raised sTfR and high Epo production. Despite the same degree of ineffective erythropoiesis seen in all patients, the severity of the clinical course was diverse in terms of frequency and clinical relevance of transfusion needs.
  
  
  CONCLUSIONS
  An analysis of the parameters expressing ineffective erythropoiesis in CDA II can provide a better understanding of the degree of dyserythropoiesis, however it is not useful for predicting the clinical course of disease in patients, because the underlying genetic heterogeneity of this disorder remains obscure.
authors.affiliation: Department of Pediatric Hematology/Oncology, Aghia Sophia Children's Hospital, Athens, Greece.
authors.forename: Stavroula
authors.initials: S
authors.lastname: Kostaridou
authors.forename: Sophia
authors.initials: S
authors.lastname: Polychronopoulou
authors.forename: Evangelos
authors.initials: E
authors.lastname: Premetis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Papassotiriou
authors.forename: Alexandra
authors.initials: A
authors.lastname: Stamoulakatou
authors.forename: Stavros
authors.initials: S
authors.lastname: Haidas
mesh_terms: D000742:Anemia, Dyserythropoietic, Congenital / Q000097:blood / Q000235:genetics*; D002675:Child, Preschool; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000378:metabolism; D004920:Erythropoiesis; D004921:Erythropoietin / Q000097:blood; D005260:Female; D005808:Genes, Recessive; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011990:Receptors, Transferrin / Q000097:blood; D017701:Reticulocyte Count
chemical_list: D011990:Receptors, Transferrin; D004921:Erythropoietin