Time filter

Source Type

Polin H.,Red Cross | Polin H.,Ludwig Boltzmann Institute for Experimental and Clinical Traumatology | Pelc-Klopotowska M.,Institute of Hematology and Transfusion Medicine | Danzer M.,Red Cross | And 11 more authors.
Transfusion | Year: 2016

BACKGROUND The Rhesus (Rh) complex consists of a core comprising the Rh proteins (RhD/RhCE) and the Rh-associated glycoprotein (RhAG) with accessory chains (GPB, LW, CD47). Molecular defects of the RHAG gene may cause a regulator Rhnull phenotype without Rh antigen expression or a Rhmod phenotype with decreased Rh antigen expression. STUDY DESIGN AND METHODS Blood samples of a donor with strongly diminished Rh antigens and five family members were analyzed by serological phenotyping, flow cytometry, molecular testing, and gene expression analysis of Rh complex candidate genes. RESULTS RHAG sequencing identified a missense mutation, c.241G>C (p.Gly81Arg) and a splice site mutation, c.640 + 3del14, among the cohort. Compound heterozygosity of these novel alleles identified in the propositus and two siblings gave rise to a strongly diminished expression of RhAG, Rh, and CD47 antigens on the RBC surface. CONCLUSION The Rhmod phenotype was caused by a novel RHAG splice site mutation in association with a non-functional allele. The primary depression of RhAG is most likely due to posttranslational events that affect the interaction and processing of the RhAG glycoprotein and gave rise to a secondary depression of RhD, RhCE, and CD47, the major members of the Rh complex. © 2016 AABB.

Singh D.K.,Guru Teg Bahadur Hospital | Singh B.,Regional Blood Transfusion Center | Rusia U.,Guru Teg Bahadur Hospital
Transfusion and Apheresis Science | Year: 2011

Aims and objectives: To evaluate the magnitude of red cell alloimmunization in regularly transfused patients with thalassemia major and analyse factors responsible for development of antibodies. Materials and methods: This cross sectional study was conducted on 116 thalassemics receiving regular transfusions. All the patients underwent antibody screening. Patients with positive antibody screen were further tested for antibody identification. The data was analysed to find out the frequency, pattern and factors influencing red cell alloimmunization secondary to multiple transfusions. Results: Mean age of the patients was 14years (range 1.5-27years). Red cell alloantibodies were found in 11 patients (9.48%). In four (36%) patients first transfusion was given before 6months of age and in seven (64%) patients, first transfusion was given after two years of age. The interval between consecutive transfusions varied from 18 to 35days. The most common antibody was Anti-E found in 4 (36.4%) patients, followed by Anti-K (three patients, 27.2%), Anti-Kp a (two patients, 18.2%) and Anti-C w (two patients, 18.2%). The interval from first transfusion to antibody development varied from 1.5 to 14years. None of the eight out of 116 patients, who underwent splenectomy showed any antibody development. Conclusions: The rate of red cell alloimmunization was found to be 9.48% in thalassemics receiving regular transfusions. The incidence of alloantibody development was higher if first transfusion was received at more than 2 years of age. Early institution of red cell transfusions and Rh and Kell phenotyping followed by provision of matched blood could prevent alloimmunization. © 2011 Elsevier Ltd.

Kriebardis A.G.,Technological Educational Institute of Athens | Foudoulaki-Paparizos L.E.,Regional Blood Transfusion Center | Dzieciatkowska M.,University of Colorado at Denver | Wither M.J.,University of Colorado at Denver | And 3 more authors.
Free Radical Biology and Medicine | Year: 2016

Storage of packed red blood cells (RBCs) is associated with progressive accumulation of lesions, mostly triggered by energy and oxidative stresses, which potentially compromise the effectiveness of the transfusion therapy. Concerns arise as to whether glucose 6-phosphate dehydrogenase deficient subjects (G6PD-), ∼5% of the population in the Mediterranean area, should be accepted as routine donors in the light of the increased oxidative stress their RBCs suffer from. To address this question, we first performed morphology (scanning electron microscopy), physiology and omics (proteomics and metabolomics) analyses on stored RBCs from healthy or G6PD- donors. We then used an in vitro model of transfusion to simulate transfusion outcomes involving G6PD- donors or recipients, by reconstituting G6PD- stored or fresh blood with fresh or stored blood from healthy volunteers, respectively, at body temperature. We found that G6PD- cells store well in relation to energy, calcium and morphology related parameters, though at the expenses of a compromised anti-oxidant system. Additional stimuli, mimicking post-transfusion conditions (37 °C, reconstitution with fresh healthy blood, incubation with oxidants) promoted hemolysis and oxidative lesions in stored G6PD- cells in comparison to controls. On the other hand, stored healthy RBC units showed better oxidative parameters and lower removal signaling when reconstituted with G6PD- fresh blood compared to control. Although the measured parameters of stored RBCs from the G6PD deficient donors appeared to be acceptable, the results from the in vitro model of transfusion suggest that G6PD- RBCs could be more susceptible to hemolysis and oxidative stresses post-transfusion. On the other hand, their chronic exposure to oxidative stress might make them good recipients, as they better tolerate exposure to oxidatively damaged long stored healthy RBCs. © 2016 Elsevier Inc. All rights reserved.

Pahuja S.,Regional Blood Transfusion Center | Pujani M.,Lady Hardinge Medical College | Gupta S.K.,Lady Hardinge Medical College | Chandra J.,Lady Hardinge Medical College | Jain M.,Lady Hardinge Medical College
Hematology | Year: 2010

Transfusion therapy in thalassemia is a double edged sword, on the one hand, it is a major life saving modality, while on the other hand, it can lead to complications such as alloimmunization. The rates of alloimmunization have been variably reported across the world; however, there is a paucity of such literature among Indian thalassemics. We studied the frequency of alloimmunization and autoimmunization among 211 multitransfused thalassemics of Indian origin. All the patients have been receiving blood matched for ABO and Rh(D) antigens only. Direct antiglobulin test was performed on all patients to detect autoantibody while antibody screening (using 3-cell panel) and antibody identification (11-cell panel) were carried out to detect the presence of alloantibody. The frequency of alloimmunization was 3•79% and that of autoimmunization was 0•47%. The alloantibodies identified were anti-E, anti-K, anti-D, anti-Kpa, anti-Cw, anti-c and anti-Jk a. In the present study, no significant association was observed between splenectomy and the development of alloantibodies as well as between age at initiation of transfusion and alloimmunization. To conclude, there is a need to formulate a balanced and cost-effective approach for transfusion management of thalassemics to minimize alloimmunization and autoimmunization. © 2010 Maney Publishing.

Kriebardis A.G.,Technological Educational Institute of Athens | Voulgaridou A.I.,Apostle Paul Educational Institution | Stamoulis K.E.,Hellenic National Blood Center Acharnes | Stamoulis K.E.,Regional Blood Transfusion Center | Foudoulaki-Paparizos L.E.,Regional Blood Transfusion Center
Transfusion | Year: 2016

BACKGROUND Previous studies have shown that baseline hematologic characteristics concerning or influencing red blood cell (RBC) properties might affect storage lesion development in individual donors. This study was conducted to evaluate whether variation in hemolysis, microparticle accumulation, phosphatidylserine (PS) exposure, and other storage lesion-associated variables might be a function of the prestorage hematologic and biologic profiles of the donor. STUDY DESIGN AND METHODS Ten eligible, regular blood donors were paired and studied before donation (fresh blood) and during storage of RBCs in standard blood banking conditions. Plasma and cellular characteristics and modifications were evaluated by standard laboratory and biochemical or biologic analyses as well as by statistical and network analysis tools. RESULTS Nitrate/nitrite and other bioactive factors exhibited high interdonor variability, which further increased during storage in a donor-specific manner. Storage lesion evaluators, including RBC fragility and PS exposure, fluctuated throughout the storage period in proportion to their values in fresh blood. Donors' levels of phosphatidylserine exposure and hemoglobin F correlated with stored cells' mean cell (RBC) Hb concentration, oxidative stress markers, and cellular fragility. DISCUSSION Storage lesion indicators change in an orderly fashion, namely, by following donor-related prestorage attributes. These correlations are illustrated for the first time in "prestorage versus storage" biologic networks, which might help determine the best candidates for in vivo biomarkers of storage quality and provide deeper insight into the apparently complex donor variation effect on the RBC storage lesion. © 2016 AABB.

Discover hidden collaborations