Novel variants in Krueppel like factor 1 that cause persistence of fetal hemoglobin in In(Lu) individuals

Beta-hemoglobinopathies become prominent after birth due to a switch from γ-globin to the mutated β-globin. Haploinsufficiency for the erythroid specific indispensable transcription factor Krueppel-like factor 1 (KLF1) is associated with high persistence of fetal hemoglobin (HPFH). The In(Lu) phenotype, characterized by low to undetectable Lutheran blood group expression is caused by mutations within KLF1 gene. Here we screened a blood donor cohort of 55 Lutheran weak or negative donors for KLF1 variants and evaluated their effect on KLF1 target gene expression. To discriminate between weak and negative Lutheran expression, a flow cytometry (FCM) assay was developed to detect Lu antigen expression. The Lu(a−b−) (negative) donor group, showing a significant decreased CD44 (Indian blood group) expression, also showed increased HbF and HbA2 levels, with one individual expressing HbF as high as 5%. KLF1 exons and promoter sequencing revealed variants in 80% of the Lutheran negative donors. Thirteen different variants plus one high frequency SNP (c.304 T > C) were identified of which 6 were novel. In primary erythroblasts, knockdown of endogenous KLF1 resulted in decreased CD44, Lu and increased HbF expression, while KLF1 over-expressing cells were comparable to wild type (WT). In line with the pleiotropic effects of KLF1 during erythropoiesis, distinct KLF1 mutants expressed in erythroblasts display different abilities to rescue CD44 and Lu expression and/or to affect fetal (HbF) or adult (HbA) hemoglobin expression. With this study we identified novel KLF1 variants to be include into blood group typing analysis. In addition, we provide further insights into the regulation of genes by KLF1.

A Para-Bombay Blood Group Case Associated with a Novel FUT1 Mutation c.361G>A

<b><i>Background:</i></b> Here we report a case of para-Bombay phenotype due to a novel mutation <i>FUT1</i> c.361G&#x3e;A p.(Ala121Thr) and a nonfunctional allele <i>FUT1</i>*<i>01N.13</i>(c.881_882delTT) which showed a discrepancy in the routine ABO blood group typing. <b><i>Materials and Methods:</i></b> The ABO phenotype and the Lewis blood group were typed with serological methods. The ABH antigens in saliva were determined by a hemagglutination inhibition test. The CDS region of <i>ABO, FUT1</i>and <i>FUT2</i> were amplified with polymerase chain reaction and then directly sequenced. The novel mutation was confirmed by cloning and sequencing. Three-dimensional (3-D) structural analysis of the mutant and wild-type Fut1 were performed by the Chimera software. <b><i>Results:</i></b> A, B and H antigens were not detected on the surface of red blood cells (RBCs) by the serological technique, and the B and H blood group substances were detected in the saliva, while the Lewis phenotype was Le(a–b+). Sequencing and cloning analysis showed the presence of a novel <i>FUT1</i> mutation c.361G&#x3e;A and a nonfunctional allele <i>FUT1</i>*<i>01N.13</i>(c.881_882delTT). The ABO genotype was <i>ABO</i>*<i>B.01/ABO</i>*<i>O.01.01</i>. The in silico analysis showed that the mutation p.(Ala121Thr) of <i>FUT1</i>did not change the 3-D structure of the whole enzyme but caused a certain amplitude of turnover in the loop region where Ala121 was located. <b><i>Conclusions:</i></b> A novel <i>FUT1</i> allele (<i>FUT1</i>*c.361G&#x3e;A) was identified in a Chinese individual with para-Bombay B phenotype. The <i>FUT1</i>c.361G&#x3e;A mutation may significantly downregulate the expression of H antigens on RBCs by damaging the enzyme conformation.

Ethical Issues and Management of Fetal Hemolytic Anemia Caused by Anti-Rh17 in a Multipara with Rare –D– Phenotype

<b><i>Background:</i></b> The development of allo-anti-Rh17 (anti-Hr0) in a –D– phenotype whose red blood cells (RBCs) lack CcEe antigens is most likely triggered by transfusion, transplantation, or pregnancy. Gene conversion is the predominating factor in generating RHD-CE-D and RHCE-D-CE hybrids like –D–. <b><i>Methods:</i></b> We report here immunohematological and obstetrical data from 2 of the 5 pregnancies of a 24-year-old woman presenting with the –D– phenotype with anti-Rh17. Blood group typing, antibody screening, antibody differentiation, direct antiglobulin test (DAT), and antibody titers were performed by routine gel technology and tube testing. Additionally, molecular genetic analysis was performed. Fetal surveillance was done by sonographic evaluation of the fetal middle cerebral artery peak systolic velocity (MCA-PSV). <b><i>Results:</i></b> Blood group typing showed O, C-c-D+E-e- and the DAT was negative. DNA sequencing revealed homozygosity for an <i>RHCE-D(3–9)-CE</i> null allele. Anti-Rh17 titers in the fourth pregnancy remained between 1:8 and 1:128, and no signs for a fetal anemia were observed. However, in the fifth pregnancy, the antibody titers increased up to 1:4,096. Signs of moderate fetal anemia were detected and cesarean section was performed at 34 + 6 weeks of gestation. The newborn presented with hemolytic anemia (cord blood hemoglobin [Hb] = 8.5 mg/dL). She received 2 compatible (small) packed RBC concentrates, phototherapy, and intravenous immunoglobulins. <b><i>Conclusion:</i></b> Our case shows that the risk for hemolytic complications increases with the number of pregnancies of sensitized women. Only people who also lack CcEe antigens are compatible as donors. The role of such rare donors as lifesavers, their freedom, and voluntariness conflict with the urgent need for compatible blood.

Enhancement the Agglutination of Erythrocytes in Blood Typing Test by Acousto-Optic Technique

A proposed modern technique for determination the blood group typing by monitoring the agglutination of red blood cells using acousto-optical technique and digital camera. The method based on analysis the digital image of the agglutination process by MATLAB software. We present an overview of two acousto-optic sensing approaches; the first demonstrates the cuvette approach while the second is the microscope slide approach. The cuvette approach digital image analyzing depends on the green channel distribution of the original image and count the brighten pixels, while the microscope slide approach passes through series of algorithms started with grayscale filter and end with edge detection it counts the different color pixels. The experimental result shown that it is possible to enhance the determination of blood group typing by using acousto-optical technique in both cases of using isohemagglutinating sera as well as the crossmatch test in a short time and high efficiency compared with the traditional methods.