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1.
Transfus Apher Sci ; 62(3): 103640, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36641332

ABSTRACT

BACKGROUND AND PURPOSE: Bombay and Para-Bombay phenotypes are characterized by FUT1 gene mutation and lack of H antigen expression in red blood cells. ABH antigens are not present in the body secretions of Bombay individuals, while they are expressed in the secretions of para-Bombay. The aim of this study was to investigate the molecular basis of FUT1 and FUT2 genes in Iranians with the Bombay or Para-Bombay phenotype. MATERIALS AND METHODS: ABO phenotype analysis and routine serological tests were performed on 11 people with Bombay and Para-Bombay phenotypes. The coding regions of FUT1 and FUT2 genes were amplified by PCR followed by sequencing. The ABO genotypes were also determined by sequencing exons 6 and 7 of the ABO gene. RESULTS: Serological investigations confirmed the Bombay phenotype in 8 samples and the Para-Bombay phenotype in 3 samples. Family members with the Bombay phenotype had the classic c 0.725 T > G mutation in the FUT1 gene, accompanied by deletion of the FUT2 gene. Other samples had c.653 A>G, c 0.661 C>T, c 0.652 C>G, and c.722 A>C mutations in the FUT1 while FUT2 was silenced by c 0.461 G>A. CONCLUSION: In this research, we identified two novel mutations in the FUT1 gene in individuals with the Bombay phenotype. This and previous works confirm the variety of FUT1 mutations.


Subject(s)
ABO Blood-Group System , Iran , Alleles , Genotype , Phenotype , Mutation , ABO Blood-Group System/genetics
5.
Transfus Apher Sci ; 60(6): 103271, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34535395

ABSTRACT

BACKGROUND: Transfusion is a lifesaving treatment for lots of patients. However, in chronic blood recipients such as thalassemia patients, there are high concerns about alloantibody production that affects the quality of their life. Therefore, research on risk factors of alloimmunization has been started and followed. This study aimed at the determination of correlation probability between some HLADRB1 alleles and alloimmunization in Iranian thalassemia patients. MATERIALS AND METHODS: The present study was conducted on 60 alloimmunized and 60 non-alloimmunized transfusion-dependent thalassemia patients. Antibody screening and identification tests were carried out using the tube method, and HLA-DRB1 genotyping was done using a single specific primer-polymerase chain reaction (PCRSSP). RESULTS: The results of antibody screening showed that the most prevalent alloantibodies were Anti-K (46.7 %), and followed by Anti-E (32.5 %), Anti-C (15.8 %), Anti-D (13.3 %), Anti-e (8 %), and Anti-c (5.8 %), respectively. DRB1*07:01 was detected more in non-responder patients (28.3 %). However, data analysis showed that there is no significant relationship between DRB1*07:01, *10, *13:01 frequency among responder and non-responder groups (p = 0·195, 0.648, 0.402, respectively). There was not any significant correlation between HLA-DRB1*10 and *13:01 allele and alloimmunization. There was a significant association between HLA-DRB1*12 and alloimmunization (p < 0·05, OR = 2.071, CI: 1.716-2.501). CONCLUSION: The findings of this study represented that there is a significant relationship between HLADRB1*12 and Kell and E alloantibodies. Although more developed studies on other HLA alleles are demanded, these findings can be valuable in determining important alloimmunization risk factors to better management of transfusion complications.


Subject(s)
Alleles , Blood Transfusion/methods , HLA-DRB1 Chains/genetics , Isoantibodies/blood , Thalassemia/therapy , Humans , Prognosis
8.
Mol Genet Genomic Med ; 9(7): e1701, 2021 07.
Article in English | MEDLINE | ID: mdl-33963817

ABSTRACT

OBJECTIVES: Serological methods may not be reliable for RBC antigen typing, especially in multi-transfused patients. The blood group systems provoking the most severe transfusion reactions are mainly Rh, Kell, Kidd, and Duffy. We intended to determine the genotype of these blood group system antigens among Iranian alloimmunized thalassemia patients using molecular methods and compare the results with serological phenotyping. METHODS: Two hundred patients participated in this study. Blood group phenotype and genotype were determined using the serological method and PCR-SSP, respectively. The genotypes of patients with incompatibility between phenotype and genotype were re-evaluated by RFLP-PCR and confirmed by DNA sequencing. RESULTS: Discrepancies between phenotype and genotype results were found in 132 alleles and 83 (41.5%) patients; however, there was complete accordance between the three genotyping methods. Most discrepancies were detected in Rh and Duffy systems with 47 and 45 cases, respectively, and the main discrepancy was in the FY*B/FY*B allele when serologically showed Fy(a+b+). All 39 undetermined phenotypes, due to mixed-field reactions, were resolved by molecular genotyping. CONCLUSION: Molecular genotyping is more reliable compared with the serological method, especially in multi-transfused patients. Therefore, the addition of blood group genotyping to serological assays can lead to an antigen-matched transfusion in these patients.


Subject(s)
Blood Group Antigens/genetics , Erythrocyte Transfusion/adverse effects , Genotyping Techniques/methods , Thalassemia/therapy , Transfusion Reaction/genetics , Adolescent , Adult , Blood Group Antigens/immunology , Child , Female , Genotype , Humans , Male , Middle Aged , Phenotype , Transfusion Reaction/diagnosis , Transfusion Reaction/immunology
9.
Transfus Apher Sci ; 60(3): 103124, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33839013

ABSTRACT

BACKGROUND: Rhesus (Rh) blood group system is clinically the most significant protein-based grouping system. The Rh system is of vital importance in blood transfusion, and incompatibility between the donor and recipient leads to alloimmunization. Alloimmunization is commonly seen in multiple-transfusion recipients (e.g. thalassemia patients). There are a few studies about the prevalence of Rh antigens, except for D, in Iran; and regarding the high prevalence of thalassemia in the country, in this study we have determined antigens and phenotypes of the Rh among population of regular blood donors with the aim of developing a detailed Rh databank. MATERIALS AND METHODS: This cross-sectional study randomly enrolled 3000 regular blood donors from three provinces of Sistan-Balouchestan, Khuzestan and Gilan in Iran, from September 2018 to May 2019. A fully automated system, based on hemagglutination, was used to Rh typing of blood samples. RESULTS: The prevalence of Rh antigens were as follows: D: 88.9 %; E: 30.9 %; C: 74.1 %; e: 96.2 %; and c: 72.8 %. The most common antigen and phenotype were "e" and R1r (DCcee), respectively. CONCLUSION: Due to the high rate of alloimmunization incidence against Rh blood group antigens among multiple transfusion recipients, development of regular blood donor's Rh databank can facilitate extensive matching for the Rh antigens and it likely reduces the risk of alloimmunization.


Subject(s)
Blood Transfusion/methods , Databases, Factual/standards , Rh-Hr Blood-Group System/genetics , Adult , Blood Donors , Cross-Sectional Studies , Female , Humans , Iran , Male , Phenotype
10.
Mol Genet Genomic Med ; 9(3): e1614, 2021 03.
Article in English | MEDLINE | ID: mdl-33547762

ABSTRACT

INTRODUCTION: The alloimmunization following blood transfusion can be life-threatening. The Rh alloantibodies are one of the most common causes contributing to alloimmunization. This study aimed to evaluate the rate and causes of alloimmunization and to determine the Rh phenotypes and genotypes among sickle cell disease (SCD) and sickle thalassemia (Sß). MATERIALS AND METHODS: Our study included 104 SCD and Sß patients referring to Baghaei 2 Hospital of Ahvaz in 2019 using a non-random simple sampling method. The blood samples were collected for Rh phenotypes, alloantibody screening and identification, and molecular tests. The SSP-PCR and RFLP methods with the Pst 1 enzyme were used. RESULTS: The alloimmunization rate was 9.6% and 13.2% based on immunohematological tests and medical records, respectively. The main alloantibodies (90%) were anti-Rh, and 40% of the patients had multiple alloantibodies. A significant correlation was found between gender and alloimmunization. The phenotypes of DCce (37.5%), DCcEe (24%), Dce (20.2%), and dce (5.8%) and genotypes of R1r (25%), R1R2 (20.2%), R1R1 (18.3%), and R1R0 (10.6%) were the most prevalent. The R1R2 was a frequent genotype in Sß. CONCLUSION: R0r' and R1R0 genotypes were limited to our population in Iran. Due to the differences in RH genotypes between our population and others, the blood transfusion from other ethnicities increased our total alloimmunization rate.


Subject(s)
Anemia, Sickle Cell/therapy , Rh Isoimmunization/genetics , Rh-Hr Blood-Group System/genetics , Thalassemia/therapy , Adolescent , Adult , Aged , Child , Child, Preschool , Erythrocyte Transfusion/adverse effects , Female , Genotype , Humans , Iran , Isoantibodies/blood , Male , Middle Aged , Rh Isoimmunization/immunology , Rh-Hr Blood-Group System/immunology
11.
Int J Hematol Oncol Stem Cell Res ; 15(4): 213-220, 2021 Oct 01.
Article in English | MEDLINE | ID: mdl-35291662

ABSTRACT

Background: The D antigen is a subset of Rh blood group antigens involved in the hemolytic disease of the newborn [HDFN] and hemolytic transfusion reaction [HTR]. The hybrid Rhesus box that was created after RH gene deletion, was known as a mechanism of the Rh-negative phenotype. Hybrid marker identification is used to confirm the deletion of the RHD gene and to determine zygosity. This study aims to detect this marker in Rh-negative and weak D phenotype blood donors of the southeast of Iran. Materials and Methods: The molecular analysis of the hybrid Rhesus box was performed on the 200 Rh-negative blood donors in Sistan and Baluchestan province, southeast Iran. The presence of alleles responsible for the D variants was assessed by DNA sequencing in 26 weak D phenotype donors. Results: Of the 200 Rh-negative blood samples, 198 samples were homozygous (99%), and two samples were heterozygous (1%). Heterozygous samples had RHD*01N.73 allele and the RHD*01N.18 allele. Of the 26 samples with weak D phenotype, 16 partial DLO (61%), 4 partial DBT1 (15.3%), 2 partial DV type 2 (7.7%), 1 weak D type 1, 1 weak D type 4.2.3, 1weak D type 105 and 1 RHD (S103P) (4%) were determined. Conclusion: Since RHD gene deletion is the main mechanism of the Rh-negativity in Sistan and Baluchestan provinces, a hybrid Rhesus box marker can be used in resolving RhD typing discrepancies by RHD genotyping methods.

12.
Transfus Apher Sci ; 60(1): 103006, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33229298

ABSTRACT

BACKGROUND: Serological methods are unreliable for accurate determination of blood group antigens in multi-transfused thalassemia patients. The MNS blood group system has five high-frequency antigens. Many studies demonstrated that some antibodies including anti-S, anti-s, and anti-U may cause acute and delayed transfusion reactions and hemolytic disease of the fetus and newborn. This study aimed to determine the genotype of the MNS blood group in thalassemia patients with alloantibodies by molecular methods. MATERIAL AND METHODS: In this study, 104 blood samples from thalassemia patients were collected. The blood group phenotype for M, N, S and s antigens was determined by the tube hemagglutination method. MNS blood group genotyping was performed using PCR-SSP and DNA Sequencing methods. RESULTS: All patients were genotyped with a total of 6 pairs of primers. Discrepancies between genotype and phenotype were observed in 22 patients with S/s alleles and 2 patients with M/N alleles, however, there was full accordance between the results of SSP-PCR and DNA sequencing. The frequency of MNS blood group alleles was determined as follows: 25 % MNSs, 23 % MNss, 21 % MMSs, 9% MMSS, 9% MMss, 8% NNss, 2%MNSS, and NNSS, NNSs, MM genotypes at 1% each. CONCLUSION: In conclusion, molecular genotyping is more reliable than serological methods in multiple transfusion patients and can lead to a more compatible blood unit for transfusion in these patients.


Subject(s)
Blood Group Antigens/genetics , Isoantibodies/blood , Thalassemia/physiopathology , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Genotype , Humans , Iran , Male , Middle Aged , Young Adult
13.
Indian J Hematol Blood Transfus ; 36(3): 550-555, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32647431

ABSTRACT

We aimed to determine the JK genotype in thalassemia patients from Iran using different molecular methods to compare with phenotyping results. We also aimed to standardize for the first time, the Tetra-Primer ARMS PCR method for JK genotyping. The serology method cannot correctly determine the phenotype of blood group antigens in patients with multiple blood transfusions. Peripheral blood samples were taken from two hundred alloimmunized thalassemic patients in Tehran Adult Thalassemic Clinic. The samples were tested phenotypically by routine serological methods. After DNA Extraction, SSP-PCR was performed. DNA sequencing and PCR-RFLP were used to confirm the SSP-PCR results. Discrepancies were found between the phenotype and genotype in 32 out of 200 cases. In 16 cases phenotype was determined as Jk (a + b +) but genotype was JK*A/JK*A, in 14 cases phenotype was Jk (a + b +) while the genotype showed JK*B/JK*B, 1 case had been phenotyped as Jk (a + b -) but it was genotyped as JK*A/JK*B and 1 case had been phenotyped as Jk (a - b +) but it was genotyped as JK*A/JK*B. Serological results for a few samples could not be confirmed because of mix-field agglutination. The genotyping however verified the presence of Kidd alleles. Molecular methods are a valuable tool to predict blood group phenotypes in multi-transfused patients in order to select RBC units for a perfect matching improving blood transfusion and preventing alloimmunization. Also Tetra-Primer ARMS PCR is simple and cost effective methods that could be alternative by conventional Molecular methods.

14.
Transfus Apher Sci ; 59(5): 102870, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32660892

ABSTRACT

BACKGROUND: Most prevalent weak D types in the Caucasians molecularly defined weak D types 1, 2 or 3 and can be managed safely as RhD-positive, conserving limited supplies of RhD-negative RBCs. Therefore, identification of RHD alleles prevalence in each population could improve the policies related to accuracy of RhD typing. The aim of this study was to determine the frequency of RHD variant alleles among donors and patients for the first time in Iran. MATERIALS AND METHODS: RHD genotyping was performed on 100 blood donor and patient samples with weak D phenotype. PCR-SSP and DNA sequencing were used to identify the RHD alleles. RESULTS: Molecular analysis showed only 15 samples were RHD*weak D 1(n = 13) and RHD*weak D 3(n = 2), and no cases of RHD*weak D 2 were detected. RHD*weak 15 (n = 43) was determined as the most prevalent D variants in our population and the other weak D types follows: RHD*weak 4, 5, 80 and one case of each one: RHD*weak 8, 11, 14, 100 and 105. Partial D variants also was identified in 18 samples as follows: RHD*partial DLO, DBT1, DV2, DHK and DAU-1. CONCLUSION: The results of this study highlight the specific pattern of RHD status in the Iranian population. The weak D types 15 was the most common weak D type in the Iranian population. However, the screening for weak D types 1, 2 and 3 with 15 % frequency is also necessary for accurate RhD typing and developing clinical strategy of blood transfusion in weak D patients.


Subject(s)
Blood Donors/statistics & numerical data , Rh-Hr Blood-Group System/genetics , Female , Genotype , Humans , Iran , Male
15.
Hemoglobin ; 44(1): 31-36, 2020 Jan.
Article in English | MEDLINE | ID: mdl-32400249

ABSTRACT

The best approach for prevention of alloimmunization in ß-thalassemia (ß-thal) patients is perfect matching of all red blood cell (RBC) antigens associated with clinically significant antibodies, but this is expensive and may limit the blood supply. Knowing the most common alloantibodies in transfusion-dependent ß-thal patients make it possible to establish more cost-effective matching strategies for high-risk antigens. With this in mind, we intended to determine the most common alloantibodies in different parts of Iran. A total of 480 alloimmunized ß-thal major (ß-TM) patients who were referred to the Tehran Adult Thalassemia Clinic in Tehran, Iran from all provinces between 2015 and 2017, were included in this study. Antibody screening was performed on the fresh serum of all patients. Subsequently, the specification of antibodies was identified using a panel of recognized blood group antigens. Anti-K was the most common alloantibody detected in ß-TM patients in all regions of Iran. The prevalence of this antibody reached to 37.7% in the western area, but in southeastern region, anti-E was predominant. Interestingly, the rare alloantibody anti-Kpa was detected with a high prevalence in the western region. The antibodies against E and D antigens were also encountered with high prevalence in most regions of the country. The present study demonstrated the distribution of alloantibodies in alloimmunized transfusion-dependent ß-thal patients from diverse ethnic and racial backgrounds of the Iranian population. The results of this study can be used as a basis to establish cost-effective RBC phenotyping and matching strategies for high-risk antigens in donors and chronic transfusion recipients in different regions of Iran.


Subject(s)
Blood Transfusion/methods , Erythrocytes/immunology , Hemoglobins, Abnormal/genetics , Isoantibodies/blood , beta-Globins/genetics , beta-Thalassemia/immunology , Adolescent , Adult , Aged , Autoimmunity , Blood Group Antigens/immunology , Blood Grouping and Crossmatching , Child , Child, Preschool , Erythrocytes/classification , Ethnicity , Female , Gene Expression , Hemoglobins, Abnormal/immunology , Humans , Immune Sera/chemistry , Infant , Iran/epidemiology , Male , Middle Aged , beta-Globins/deficiency , beta-Globins/immunology , beta-Thalassemia/epidemiology , beta-Thalassemia/ethnology , beta-Thalassemia/therapy
16.
Article in English | MEDLINE | ID: mdl-31533604

ABSTRACT

AIMS: Factor VIII (FVIII) replacement therapy remains a primary treatment for hemophilia A, however, the development of FVIII antibodies (inhibitors) and short half-life of the FVIII products are the major complications. Erythrocytes may prevent rapid removal of drugs from plasma. Erythrocytes are biocompatible and non-immunogenic drug delivery. In this study, in vitro activity of FVIII encapsulated by human erythrocytes was investigated. METHODS: FVIII was loaded into erythrocytes using the hypo-osmotic dialysis technique. FVIII activity assay has been analyzed using Activated Partial Thromboplastin Time (APTT). Presence of FVIII on erythrocytes was detected by western blotting and flowcytometry using specific monoclonal antibody (abcam, U.K) against FVIII. Moreover, the osmotic fragility and hematologic parameters of FVIII-loaded carrier erythrocytes were measured. RESULTS: Our results indicated that FVIII could not cross the membrane, where plenty of FVIII was found on the surface of the carrier erythrocyte. Flow cytometery results showed that 11% of the loaded carrier erythrocytes was positive for FVIII protein on their surface. The greatest activation of FVIII in both groups including lysate and non-lysate FVIII-loaded RBCs was observed on the first day, and the coagulant activity of this factor was gradually reduced on days 3 and 5. In 1:50 dilution of both groups, significant differences in FVIII activity were observed in 1:50 dilution of both groups, especially on the 5th day. CONCLUSION: This study aims to introduce erythrocytes as appropriate carriers for FVIII to prolong the dosing intervals in the effective and safe levels for a relatively longer time.


Subject(s)
Blood Coagulation/physiology , Erythrocyte Transfusion/methods , Erythrocytes/metabolism , Factor VIII/administration & dosage , Blood Coagulation Tests , Erythrocytes/chemistry , Factor VIII/chemistry , Humans
17.
Indian J Hematol Blood Transfus ; 35(1): 119-124, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30828158

ABSTRACT

D antigen is the most important and immunogenic antigen of the Rh blood group. The RhD-negative phenotype has different genetic backgrounds with variable distribution in different populations. Hybrid Rhesus box, resulting from RHD gene deletion, is used in genotyping studies of the Rh blood group as a marker to identify the RHD gene deletion. This study for the first time identified genetic mechanisms for the occurrence of RhD-negative phenotype among the Iranian population. 200 RhD-negative blood donors were randomly selected from Tehran Blood Transfusion Center. The phenotype of D, C, Ε, e and c antigens was serologically identified, and DNA was extracted from buffy coat. The molecular analysis of hybrid Rhesus box was performed by PCR-SSP and PCR-RFLP. Moreover, the presence of different exons of RHD gene was investigated by real-time PCR on extracted DNA. Hybrid Rhesus box was detected in all samples, and PCR-RFLP confirmed that 198 (99%) were homozygous for an RHD gene deletion and 2 were heterozygous for hybrid Rhesus box in which one (0.5%) had a weak D type 11 and the other one (0.5%) had a RHD-CE (2-9)-D 2 hybrid allele. Similar to Caucasians, the frequency of RHD gene deletion was high among the Iranian population studied in this investigation, so hybrid Rhesus box can be used as an efficient marker to detect RHD gene deletion in our population.

18.
Indian J Hematol Blood Transfus ; 33(4): 509-515, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29075061

ABSTRACT

DNA methylation followed by tumor suppressor gene repression plays a critical role in the leukemia development. So, DNA methyl transferase inhibitors have great importance in treatment of theses malignancies. Harmine, A beta carboline alkaloid derivative of Peganum harmala, had shown anti- proliferative effects on leukemic cell line. This study aimed to evaluate the effect of Harmine on DNMT1 (DNA methyl transferase 1) expression in a leukemic cell line. Cell proliferation and cell cycle analysis were studied in NB4 cell line after treatment with Harmine for 72 h. DNMT1 expression in treated cells was analyzed by real time PCR. Tumor suppressor gene hypometylation and reactivation was evaluated via MSP analysis and also real time PCR. Harmine reduced cell proliferation in NB4 cell line in a time and dose-dependent manner. 102 µg/ml of Harmine was increased amount of cells in G1 Phase of cell cycle (p < 0.05). Anti proliferative doses of Harmine, has suppressed DNMT1 gene in NB4 cell line. Down-regulated DNMT1 induced p15 tumor suppressor promoter hypomethylation and reactivation. Our data indicate that Harmine can be considered as a potential treatment for AML (Acute Myeloid Leukemia), and future studies are required to test the clinical efficacy of Harmine-whether used as a single agent or as an adjuvant-for AML treatment.

19.
Blood Res ; 52(1): 25-30, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28401098

ABSTRACT

BACKGROUND: Mesenchymal stem cells (MSCs) play an important role in hematopoietic stem cell (HSC) maintenance, proliferation, and apoptosis. DNA methyltransferase 1 (DNMT1) is considered an essential factor in the maintenance of HSCs in mammalian cells. Therefore, this study was conducted to evaluate the mRNA expression level of DNMT1 during cord blood (CB)-HSC ex vivo expansion with MSCs. METHODS: Ex vivo cultures of CB-HSCs were performed in three culture conditions for 7 days: cytokines, cytokines with MSCs, and only MSCs. Total and viable cell numbers were counted after 5 and 7 days using trypan blue stain, and the stem cell percentage was then evaluated by flow cytometry. Moreover, in vitro colony-forming unit assay was carried out to detect clonogenic potential of HSCs at days 0 and 7 using MethoCult H4434. Finally, DNMT1 mRNA expression level was evaluated by real-time polymerase chain reaction. RESULTS: Maximum CB-CD34+ cell expansion was observed on day 7 in all the three cultures. After 7 days, ex vivo expansion of CB-CD34+ cells indicated a significant decrease in DNMT1 expression in the cytokine cultures, whereas in the two co-culture conditions DNMT1 expression was increased. A significant difference between the number of CD34+ and CD34- cells in the cytokine co-culture system was observed. CONCLUSION: These data indicated that an elevated expression of DNMT1 is associated with increased expansion and proliferation of HSCs co-cultured with human MSCs. Hence, DNMT1 may be a potential factor in the maintenance of expanded HSCs co-cultured with human MSCs.

20.
Indian J Hematol Blood Transfus ; 32(1): 67-77, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26855509

ABSTRACT

Expansion of umbilical cord blood-derived CD34(+) cells can potentially provide them in numbers sufficient for clinical applications in adult humans. In this study apoptosis rate of expanded cells, mRNA expression and promoter methylation status of DAPK1 were evaluated during cord blood hematopoietic stem cell (CB-HSC) ex vivo expansion using cytokines and a co-culture system with mesenchymal stromal cells (MSCs). Ex vivo cultures of CB-HSCs were performed in three culture conditions for 14 days: cytokines with MSCs feeder layer, cytokines without MSCs feeder layer and co-culture with MSCs feeder layer without cytokine. Total number of cells, CD34(+) cells and colony forming unit assay were performed during expansion. Flow cytometric analysis by propidium iodide was performed to detection of apoptosis rate in expanded cells. Methylation status of the DAPK1 gene promoter was analyzed using methylation specific PCR, and DAPK1 mRNA expression was evaluated by real time-PCR. Maximum CB-CD34(+) cells expansion was observed in day 10 of expansion. The highest apoptosis rate was observed in cytokine culture without feeder layer that showed significant difference with co-culture condition. The data showed that ex vivo expansion of CD34(+) cells in all three culture conditions after 10 days resulted in, significant increased expression of DAPK1, also a significant difference between co-culture without cytokine and two other cytokine culture was observed (p < 0.01). DAPK1gene promoter of expanded CD34(+) cells at days 5, 10 and 14 of culture remained in unmethylated form similar to fresh CD34(+) cells. Expression of DAPK1 in hematopoietic cells was increased during 10 days expansion of CD34(+) cells. Also no methylation of DAPK1 promoter was observed; otherwise it would be capable of initiating some leukemic cell progression or disruption in hematopoietic regeneration.

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