Genetic analysis of CFH and MCP in Egyptian patients with immune-complex proliferative glomerulonephritis.

Glomerulonephritis (GN) is a complex disease with intricate underlying pathogenic mechanisms. The possible role of underlying complement dysregulation is not fully elucidated in some GN subsets, especially in the setting of autoimmunity or infection. In the current study, diagnosed cases of lupus nephritis (LN) and post-infectious GN (PIGN) were recruited for molecular genetic analysis and targeted next-generation DNA sequencing was performed for two main complement regulating genes: in the fluid phase; CFH, and on tissue surfaces; MCP. Three heterozygous pathogenic variants in CFH (Q172*, W701*, and W1096*) and one likely pathogenic heterozygous variant in MCP (C223R) have been identified in four of the studied LN cases. Additionally, among the several detected variants of uncertain significance, one novel variant (CFH:F614S) was identified in 74% of the studied LN cases and in 65% of the studied PIGN cases. This variant was detected for the first time in the Egyptian population. These findings suggest that subtle mutations may be present in complement regulating genes in patients with immune-complex mediated category of GN that may add to the disease pathogenesis. These findings also call for further studies to delineate the impact of these gene variants on the protein function, the disease course, and outcome.

L-Selectin P213S and Integrin Alpha 2 C807T Genetic Polymorphisms in Pediatric Sickle Cell Disease Patients.

Sickle cell disease (SCD) is an autosomal recessive hemoglobinopathy characterized by increased cellular adhesiveness. Vaso-occlusion (VOC) is the most prevalent disease complication of SCD that could be altered by genetic factors. L-Selectin and integrin alpha 2 (ITGA2) are 2 adhesion molecules linked to vasculopathy and inflammation. The current study aimed at detecting the prevalence of genetic variants of L-selectin and ITGA2 as possible molecular modulators and novel therapeutic targets in a cohort of pediatric SCD patients. Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism technique for 100 SCD patients and 100 age and gender-matched unrelated healthy controls. The homomutant genotype of ITGA2 C807T was significantly higher in SCD patients compared with controls (P=0.001) and confirmed almost a 3-fold increased risk of moderate and severe attacks of VOC. There are significant adverse effects caused by the polymorphisms of ITGA2, and hence Egyptian SCD patients could benefit from the targeted therapies specifically against ITGA2 to ameliorate the severe course of the disease and improve the quality of life. However, further studies of genotypes and expression levels of these adhesion molecules during the attacks of VOC are recommended.

Studying the effect of adding growth factors to the autologous melanocyte keratinocyte suspension in segmental vitiligo.

Addition of different growth factors to the medium used in autologous melanocyte-keratinocyte transplantation procedure (MKTP) was reported in the literature. The aim of the current study was comparison of response to MKTP in segmental vitiligo (SV) with and without adding growth factors to the suspension medium. Eighteen cases with SV were randomly divided into two groups. In group A: Ham F12 medium was used for suspension and in group B: 5 ng/mL recombinant basic fibroblast growth factor (bFGF) and 25 mg/500 mL 3'5' cyclic adenosine monophosphate (cAMP) were added to the medium. All cases received NB-UVB twice weekly for 24 weeks. The area of vitiligo lesions was measured before and after therapy by point-counting technique and complications were recorded. Excellent response (90%-100% repigmentation) occurred in 5/9 cases (56%) in group A and 7/9 cases (78%) in group B (with growth factors). A significant decrease in the area of treated lesions before and after therapy was found in both groups A and B (P = .0012 and .0004, respectively), however, a higher percentage of reduction in area of vitiligo was seen in group B cases (70% in group A vs 90% in group B; P value: .028). Marginal halo was seen in five cases in group A and six in group B. In conclusion addition of bFGF and cAMP to MKTP medium improved the results of the procedure. It could be considered if economically feasible.

Breast cancer resistance protein (BCRP) gene expression in a cohort of adult Egyptian patients with acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML), an aggressive clonal disease, is genetically heterozygous. The prognostic role of expression of Breast Cancer Resistance Protein (BCRP) gene, which behaves as a multidrug transporter, in adult AML is ambiguous. OBJECTIVE: The objective is to assess the level of mRNA expression of BCRP gene in newly diagnosed cytogenetically normal adult Egyptian AML patients; and to clarify its potential influence and association between therapeutic responsiveness and disease free survival. METHODS: The BCRP gene expression was evaluated by quantifying its mRNA using real time RT-PCR in fifty newly diagnosed cytogenetically normal adult AML patients and 20 healthy normal controls. The expression was evaluated in relation to clinical and prognostic factors, response to treatment and the survival rate. RESULTS: BCRP mRNA was over expressed in adult AML patients compared to controls. This study showed a positive statistical correlation between BCRP gene expression and the percent of CD34 expression. Statistical analysis did not reveal any association between BCRP expression level and chemotherapeutic responsiveness or disease free survival rate. CONCLUSION: The significance of BCRP gene expression and its function in AML is very complicated, therefore more standardized clinical studies are needed.

Effect of Procedural-Related Variables on Melanocyte-Keratinocyte Suspension Transplantation in Nonsegmental Stable Vitiligo: A Clinical and Immunocytochemical Study.

BACKGROUND: Melanocyte-keratinocyte suspension (M-K susp) is gaining popularity for vitiligo treatment. Few studies have addressed procedure-related variables. OBJECTIVE: To assess the effect of different M-K susp procedure-related variables on the clinical outcome in stable vitiligo. METHODS: This prospective multicenter comparative study included 40 cases with nonsegmental stable vitiligo. Donor site was either a skin graft in noncultured epidermal cell suspension (NCECS) or hair follicle units in outer root sheath hair follicle suspension (ORSHFS). Recipient site was prepared by either cryoblebbing or CO2 laser resurfacing. Cell counts and viability were recorded in the cell suspensions. Tissue melanocytes and keratinocytes were examined by melan-A and cytokeratin, respectively. Assessment of repigmentation was performed 18 months after the procedure. RESULTS: Thirty-seven subjects completed the study. Cell count was significantly lower in the ORSHFS compared with NCECS with no significant difference in the repigmentation outcome. On comparing techniques of recipient site preparation, homogenicity was better in the CO2 group. Elbows and knees responded better to CO2 resurfacing, whereas distal fingers responded better to combination of cryoblebbing with NCECS. CONCLUSION: Using different techniques in M-K susp produces comparable results. However, the distal fingers showed better results using combination of donor NCECS and recipient cryoblebs.

Association of DNA Methyltransferase 3B Promotor Polymorphism With Childhood Chronic Immune Thrombocytopenia.

BACKGROUND: DNA methylation is an epigenetic process that refers to chromatin-based mechanisms in the regulation of gene expression without DNA alternation. It is mediated by DNA methyltransferases (DNMTs). The DNA methyltransferase 3B (DNMT3B) gene contains a C-to-T single nucleotide polymorphism (SNP; rs2424913) in the Promotor region, 149 base pairs from the transcription start site, which is reported to significantly increase the Promotor activity. OBJECTIVE: To investigate the prevalance of rs2424913 single nucleotide polymorphism located in the DNMT3B gene Promotor. METHODS: In the present study, we investigated the prevalence of rs2424913 single nucleotide polymorphism located in DNMT3B gene Promotor by restriction fragment length polymorphism (PCR-RFLP) in Egyptian pediatric chronic immune thrombocytopenia (ITP) patients and controls. RESULTS: The homozygous genotype (TT) was significantly higher in our patient and conferred almost 3-fold increased risk of chronic ITP when compared to controls. CONCLUSION: The present study shows that DNMT3B rs2424913 promotor polymorphism represents a genetic risk factor that may play an important role in understanding the pathogenesis of chronic ITP.

Prevalence of Hepatitis C among Egyptian Children with Sickle Cell Disease and the Role of IL28b Gene Polymorphisms in Spontaneous Viral Clearance.

BACKGROUND AND OBJECTIVES: Hepatitis C virus (HCV) is a major health problem in Egypt with its prevalence estimated to be 14.7% among the general population in 2008. Patients receiving frequent blood transfusions like those with sickle cell disease (SCD) are more exposed to the risk of acquiring HCV. IL28B gene polymorphisms have been associated with spontaneous HCV clearance. This study aims to determine the prevalence of HCV infection among children with SCD and to investigate the relation between IL28B gene polymorphisms and spontaneous HCV clearance. METHODS: Seventy SCD patients were screened for HCV antibody. HCV-positive patients were tested for the level of HCV RNA using quantitative real-time PCR. IL28B polymorphisms (rs 12979860 SNP and rs 12980275 SNP) were detected using TaqMan QRT-PCR and sequence-specific primers PCR respectively. RESULTS: Sixteen patients (23%) were HCV antibody positive, 9 of them (56.3%) had undetectable HCV RNA in serum, and 7 (43.7%) had persistent viremia. Genotypes CC/CT/TT of rs12979860 were found in 30 (42.9%), 29 (41.4%) and 11 (15.7%) patients and rs12980275 AA/AG/GG were found in 8 (11.4%), 59 (84.3%) and 3 (4.3%) patients. There was no significant difference in the frequency of IL28B (rs 12979860 and rs12980275) genotypes among HCV patients who cleared the virus and those with persistent viremia (p=0.308 and 0.724 respectively). CONCLUSION: Egyptian SCD patients have a high prevalence of HCV. Multi-transfused patients still exposed to the risk of transmission of HCV. IL28B gene polymorphismsare not associated with spontaneous clearance of HCV in this cohort of Egyptian children with SCD.

Diagnostic values of CD64, C-reactive protein and procalcitonin in ventilator-associated pneumonia in adult trauma patients: a pilot study.

BACKGROUND: Ventilator-associated pneumonia (VAP) is one of the most common nosocomial infections; however, its diagnosis remains difficult to establish in the critical care setting. We investigated the potential role of neutrophil CD64 (nCD64) expression as an early marker for the diagnosis of VAP. METHODS: Forty-nine consecutive patients with clinically suspected VAP were prospectively included in a single-center study. The levels of nCD64, C-reactive protein (CRP), and serum procalcitonin (PCT) were analyzed for diagnostic evaluation at the time of intubation (baseline), at day 0 (time of diagnosis), and at day 3. The receiver operating characteristic curves were analyzed to identify the ideal cutoff values. RESULTS: VAP was confirmed in 36 of 49 cases. In patients with and without VAP, the median levels (interquartile range, IQR) of nCD64 did not differ either at baseline [2.4 (IQR, 1.8-3.1) and 2.6 (IQR, 2.3-3.2), respectively; p=0.3] or at day 0 [2 (IQR, 2.5-3.0) and 2.6 (IQR, 2.4-2.9), respectively; p=0.8]. CRP showed the largest area under the curve (AUC) at day 3. The optimum cutoff value for CRP according to the maximum Youden index was 133 mg/dL. This cutoff value had 69% sensitivity and 76% specificity for predicting VAP; the AUC was 0.73 (95% CI, 0.59-0.85). The nCD64 and PCT values could not discriminate between the VAP and non-VAP groups either at day 0 or day 3. CONCLUSIONS: The results of this pilot study suggest that neutrophil CD64 measurement has a poor role in facilitating the diagnosis of VAP and thus may not be practically recommended to guide the administration of antibiotics when VAP is suspected.

Interleukin 28B polymorphisms and therapy response in Egyptian hepatitis C genotype-4 patients.

Hepatitis C infection represents a major health problem in Egypt; only 20% of patients undergo spontaneous clearance of the virus and around 25% of all patients progress to develop cirrhosis. More than 90% of Egyptian patients have hepatitis C virus (HCV) genotype-4. Combined pegylated interferon and oral ribavirin are the current standard therapies for HCV-4. The aim of the work is to evaluate the predictive power of the rs12979860 IL28B SNP and rs12980275 IL28B SNP for treatment response in Egyptian patients infected with HCV genotype 4. One hundred eleven HCV patients receiving combined treatment were studied for rs12979860 and rs12980275 polymorphisms by the restriction fragment length polymorphism technique. The rs12979860 CC and rs12979860 AA genotypes were significantly associated with sustained virological response (p=0.001). Our results suggest that studying IL28B polymorphisms contribute to proper prediction of response to standard therapies in Egyptian patients, optimizing cost effectiveness, and minimizing unneeded adverse effect of therapy.

Association between matrix metalloproteinase 2 (MMP2) promoter polymorphisms and the susceptibility to non-Hodgkin's lymphoma in Egyptians.

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases capable of extracellular matrix degradation. MMP2 is the key molecule that control invasion, tumor growth, and metastasis, and has been associated with poor prognosis in several tumors. Several epidemiological studies have focused on the associations between MMP2 promoter polymorphisms and cancer susceptibility; however, little is known about their role in hematological malignancies. The present study aimed to investigate the association of MMP2 -735C/T and -1306C/T promoter polymorphisms with B-NHL susceptibility and their clinicopathological characteristics. The study included 100 B-NHL patients and 100 healthy controls. Genotyping of MMP2 -735C/T and MMP2 -1306C/T was done by polymerase chain reaction restricted fragment length polymorphism (PCR-RFLP) technique. MMP2 -735C/T heteromutant genotype (CT) was detected in 23 % of patients, and the homomutant genotype (TT) was detected in 7 % of patients. The polymorphic allele, T allele, was associated with susceptibility to B-NHL (OR = 2.8:95 %CI = 1.48-5.28). For MMP2 -1306C/T, the frequencies of the polymorphic variants were 5 % for the heteromutant genotype (CT) and 3 % for the homomutant genotype (TT). The polymorphic allele, T allele, conferred almost fourfold increased risk of B-NHL (OR = 3.8, 95 %CI = 1.05-13.9), and the risk elevated to be almost eight folds when confined to diffuse large B-cell lymphoma (DLBCL) (OR = 7.9, 95 %CI = 1.67-32.27). MMP2 -735C/T polymorphic genotypes were correlated with advanced clinical stages of the disease (stages III and IV). In conclusion, the study revealed that the variant alleles of MMP2 -735C/T and MMP2 -1306C/T can be considered as molecular risk factors for B-NHL among Egyptians.

Association of cytotoxic T-lymphocyte antigen 4 genetic polymorphism, hepatitis C viral infection and B-cell non-Hodgkin lymphoma: an Egyptian study.

Abstract Genetic and environmental factors are involved in the pathogenesis of non-Hodgkin lymphoma (NHL). The present study aimed to investigate the association between cytotoxic T-lymphocyte antigen 4 (CTLA-4) genetic polymorphism, hepatitis C virus (HCV) infection and B-cell NHL risk in Egypt. Genotyping of CTLA-4 single nucleotide polymorphisms (SNPs) was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay for 181 adult patients with B-NHL and 200 controls. Our study revealed that CTLA-4 + 49 A/G polymorphism conferred increased risk of B-NHL (odds ratio [OR] = 1.7, 95% confidence interval [CI] = 1.36-2.565). The prevalence of HCV infection in individuals harboring the mutant genotype + 49 A/G and - 318 C/T SNPs was higher in patients with B-NHL and was associated with increased risk of B-NHL (OR = 2.79, 95% CI = 1.24-6.93 for + 49 A/G and OR = 3.9, 95% CI = 1.01-15.98 for - 318 C/T). In conclusion, some SNPs of CTLA-4 are genetic risk factors for B-NHL. Moreover, this study identified an association of CTLA-4 + 49 A/G and - 318 C/T promoter polymorphisms with HCV infection.

Cannabinoid CB2 receptor gene (CNR2) polymorphism is associated with chronic childhood immune thrombocytopenia in Egypt.

Immune thrombocytopenia (ITP) is a heterogeneous autoimmune disorder characterized by thrombocytopenia with or without mucocutaneous bleeding manifestations. ITP patients have significant defects in immune self-tolerance: autoreactive T-lymphocyte clones are capable of directly damaging platelets and possibly megakaryocytes and are likely to proliferate under the influence of Th lymphocytes. The CB2 receptor is thought to be the principal cannabinoid receptor that mediates immune modulation by endocannabinoid. The later has shown a complex range of immunomodulatory effects, primarily suppressive effects on leukocytes and immune functions, including modulation of Th cell development, chemotaxis and cytokine secretion. In this study, we investigated the association between cannabinoid CB2 receptor gene (CNR2) Q63R polymorphism and the susceptibility to childhood ITP in Egyptian population. CNR2 genotyping in ITP patients revealed that 41% of patients had the QR(AA/GG) heterotype and 49% had the RR(AA/AA) homotype. There was a significantly higher frequency of homomutant genotype (RR) in ITP patients than in controls, which conferred more than two-fold increased risk of ITP among Egyptian children [odds ratio (OR) 2.352, 95% confidence interval (CI) 1.313-4.215]. There was a significant statistical difference in the distribution of CNR2 Q63R genotypes between chronic ITP patients group and the control groups. The homomutant genotype carried nearly three-fold increased risk for chronic ITP (OR 2.701, 95% CI 1.462-5.009). In conclusion, CNR2 Q63R polymorphism may represent a novel genetic risk factor in the pathophysiology of chronicity development of ITP in Egyptian children.

The association between hepatitis C virus infection, genetic polymorphisms of oxidative stress genes and B-cell non-Hodgkin's lymphoma risk in Egypt.

Hepatitis C virus (HCV) has been postulated to be an etiological agent for lymphoid malignancies. Polymorphisms in oxidative stress genes as; superoxide dismutase (SOD2), glutathione peroxidase (GPX1), catalase (CAT), myeloperoxidase (MPO) and nitric oxide synthase (NOS2) may influence non-Hodgkin's lymphoma (NHL) risk. HCV screening and polymorphisms in these five genes coding for antioxidant enzymes were studied in 100 Egyptian patients with B cell-NHL and 100 controls to clarify the association between HCV infection, oxidative stress genes polymorphisms and B cell-NHL risk. A significantly higher prevalence of HCV infection was detected among NHL patients relative to controls and this carried a 14-fold increased NHL risk (odds ratio (OR)=14.3, 95% confidence interval (CI)=5.4-38.3, p<0.0001). GPX1 and MPO genetic polymorphisms conveyed increase in B-NHL risk (OR=3.3, 95% CI=1.4-7.4, p=0.004 and OR=4.4, 95% CI=1.3-14.2, p=0.009 respectively). Further analyses stratified by HCV infection revealed that concomitant HCV infection and GPX1 gene polymorphism had a synergetic effect on NHL risk with an OR of 15 (95%CI=2.2-69.6, p<0.0001). In addition, combined HCV infection and MPO gene polymorphisms had a pronounced NHL risk (OR=9.2, 95%CI=2.5-33.9, p<0.0001). SOD2, CAT and NOS2 genetic polymorphisms were not found to confer increased NHL risk. This study revealed that HCV infection is a risk factor for NHL in Egypt. Polymorphisms in GPX1 and MPO genes may influence NHL risk in HCV infected Egyptian patients. Larger scale studies are warranted to establish this genetic susceptibility for NHL.

Frequency of expression of RHAMM/CD168 in Egyptian patients with CML.

RHAMM/CD168 is a cell surface receptor for hyaluronan, a glycoaminoglycan that plays a fundamental role in cell growth, differentiation and motility. It is one of the leukemia-associated antigens (LAA) identified in patients with myeloid leukemias. WE AIMED: at studying the frequency of expression of RHAMM/CD168 in Egyptian patients with CML, both in chronic phase and accelerated/blastic phase, as a potential target structure for cellular immunotherapies, and to compare it with available western records. PATIENTS AND METHODS: RHAMM expression was tested by RT-PCR in peripheral blood mononuclear cells of 60 CML patients divided into 2 groups, group A: 44 chronic phase CML patients, group B: 16 accelerated/ blastic phase patients as well as 15 healthy volunteers. OUR RESULTS: Demonstrated that 14/44 (31.8%) of chronic CML patients showed positive RHAMM expression in contrast to 15/16 ( 93.7%) in the accelerated/blastic phase patients. Moreover within the chronic phase patients the RHAMM positive patients had a significantly higher level of bcr-abl/abl ratio. This highlighted the contribution of RHAMM expression with CML disease progression. CONCLUSION: Our work demonstrated a similar proportion of RHAMM expression in both Egyptian and western CML patients. This may pave the way for subsequent studies suggesting the concomitant use of RHAMM R3 peptide vaccination with conventional CML therapy especially in accelerated phase, in order to achieve complete molecular remission for our patient.

Evaluation of bone marrow in 143 lymphomas: the relative frequency and pattern of involvement, secondary myelopathies, pitfalls and diagnostic validity.

UNLABELLED: The aim of the present study is to assess the frequency of bone marrow (BM) involvement by both bone marrow aspirate and biopsy (BMA and BMB, respectively) procedures in established cases of lymphomas at initial presentation, and to study the relative frequency of marrow disease in relation to lymphoma types, patterns of infiltration and the 2ry associated changes, as well as the diagnostic challenges. Moreover, the diagnostic validity of BMA is tested taking the results of the BMB as the true test results, in order to determine the role of each procedure in the diagnostic approach of marrow infiltration. PATIENTS AND METHOD: This is a retrospective study carried out on 143 nonconsecutive Egyptian patients with lymphomas obtained from a private series during the years 2005 to 2008. Criteria of inclusion included the availability of full medical records and material (medical and pathological), patient consent, nodal disease with no therapy prior to BM sampling, except in 7 patients who had another 2nd BMB following therapy. BMA and BMB were performed as part of the routine workup for diagnosis and staging of lymphoma. The patients had a male to female sex ratio of 2.6:1 and a wide age range from 4 to 74 years. RESULTS: In the present series, 64 cases out of the 143 lymphoma patients studied (44.8%) had a BM disease. Involvement was mostly bilateral (80%). Patients older than 40 years showed higher incidence of bone marrow involvement. There was complete concordance (100%) between both diagnostic procedures in the detection of 76 marrow disease-free lymphoma patients. BMA showed no false positive results and a low rate of deference that makes of it an ideal screening test. Three deferred smears of CLL for BMB diagnosis were all positive for involvement. However, in a total number of 64 BMB positive patients, aspirates could only identify lymphoma involvement in 42 lymphoma patients and missed 22 patients with a BM disease, with an overall sensitivity rate of 65.6%. BMB had a high diagnostic viability and is an easily applied reproducible procedure for diagnosis of BM involvement based on a more detailed informative analysis of both architectural and individual cytomorphologic changes. CONCLUSION: The relatively high level of BM involvement in Egyptian lymphoma patients was directly proportional to high-risk factors. The diagnostic validity of BMB is higher than that of BMA. However, BMA serves as a good positive test in screening lymphomas for marrow disease. A negative BMA does not exclude involvement. Thus, smears should be taken as a complimentary procedure.

Evaluation of MIB-1 and p53 overexpression as risk factors in large cell non-Hodgkin lymphoma in adults.

BACKGROUND: Improvement of current results of therapy for large cell non-Hodgkin lymphoma patients can be achieved by optimization of initial treatment or application of risk-adapted therapy. The international prognostic index ( IPI), introduced to identify high-risk patients, was recently criticized because it was based on clinical risk factors only, ignoring important tumor molecular risk factors and it fails to identify a sector of high-risk patients, who ultimately relapse. OBJECTIVE: The aim of this study is to evaluate the value of two tumor biomarkers:MIB-1 and p53 as potential risk factors in diffuse large cell lymphoma. MIB-1 measures tumor cell proliferation, whereas p53 is related to tumor progression and response to chemotherapy. PATIENTS AND METHODS: The study was done on 69 adult patients with diffuse large cell NHL ( 58 B-phenotype and 11 T-phenotype). Clinical risk assessment was determined by the IPI and patients with a score of 3 or more were considered high-risk. Expression of MIB-1 and p53 was determined by immunohistochemistry and nuclear staining was quantitated by image analysis. Immunoexpression was considered high for MIB-1 nuclear count 50% and p53 counts 20%. Evaluation included both response to chemotherapy ( mostly CHOP), as well as 2- year overall survival analysis. RESULTS: The IPI was the only clinical variable which had a significant impact on survival. Overexpression of both MIB-1 and p53 was associated with poor response to treatment, as well as unfavorable survival. Combined risk factor analysis revealed that only MIB-1 was an independent variable. MIB-1 could also identify some high-risk patients previously categorized in the IPI lowrisk group. CONCLUSIONS: MIB-1 is an independent biologic risk factor for large cell NHL. In order to optimize risk assessment of these patients, it is recommended to construct a new prognostic index by adding MIB-1 overexpression to the other clinical factors of standard IPI. This may allow better identification of high-risk patients and help to guide planning of effective initial treatment. Key Words:NHL - MIB-1 - p53 - CHOP - Risk factors.

Ex vivo expansion of stem cells: defining optimum conditions using various cytokines.

With the increasing information on the number, quality, and characteristics of hematopoietic stem cells (HSC) in umbilical cord and placental blood, this material has been found to be efficacious as an alternative source of HSC for transplantation in children. In this study, we sought to define the optimal conditions for ex vivo expansion of cord blood (CB) stem cells. These conditions include: the combinations and concentrations of hematopoietic growth factors (stem cell factor [SCF], granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin [IL]-3, thrombopoietin [Tpo], IL-6 and Fms-like tyrosine kinase 3 ligand [Flt-3L]), the duration of culture, and the effect of serum supplementation. In this study, 2 protocols were applied for ex vivo expansion of CB stem cells. In protocol I, 20 CB samples were expanded in a static, serum-added, liquid culture for 7 and 11 days using 5 cytokine cocktails. In protocol II, 10 CB samples were expanded for 7 days using cytokines of cocktail 1, with and without IL-6 and Flt-3L, in serum-added and serum-free culture media. This protocol was intended to verify the effect of IL-6, Flt-3L, and the role of serum supplementation in short-term liquid culture. From the present study, it can be concluded that cocktail 1 is the cocktail of choice for ex vivo expansion of CB stem cells in serum-free, liquid culture expanded for 7 days. We can also conclude that culture expanded for 7 days is better than 11 days, as the fold expansion of CD34+ cells was not significantly increased or even decreased in some of the cocktails used. Moreover, the percent of CD95+ cells (apoptotic cells) was significantly increased on day 11 compared to day 7 in the cocktails tested.