免疫生物学杂志

Vascular endothelial growth factor (VEGF) genes regulate proliferation of vascular endothelial cells, hence, are essential for both physiological and pathological angiogenesis. The aim of the present study was to examine the association between three common VEGF single nucleotide polymorphisms (-583 T/C, -1154 G/A, and 936 C/T) and the risk of RSA in Saudi women. A total of 200 women; 100 with RSA-patient matched with 100 controls were enrolled sequentially. Genotyping was conducted using TaqMan assay in order to detect single nucleotide polymorphism (SNPs) in DNA extracts from blood samples. Results showed that the +936C/T allele of VEGF gene is not associated with increased risk of RSA. On the other hand, polymorphisms within -583T/C and -1154G/A of the promotor region were significantly associated with increased RSA risk. Based on these it can be concluded that polymorphisms of VEGF are associated with increased risk of RSA in Saudi women. Hence VEGF gene polymorphism can be a useful biomarker to predict susceptibility to RSA.

This study was designed to determine the extent of exposure of individuals to the avian influenza viruses by evaluating their humoral and cell-mediated immune response. Therefore blood samples were collected from three cohorts i.e. poultry related personals, healthy individuals and flu patients. Serum and PBMC analysis provided the information about humoral and cell-mediated immune responses respectively. The serum samples were examined for the presence of antibodies against indigenous avian influenza strains by using vaccines i.e. avian influenza (H5) monovalent vaccine, avian influenza (H7+H9) bivalent vaccine and commercially available four human international brands of Bird/Swine influenza vaccines i.e. Aventis 2008/2009, Vaxigrip 2009/2010, Agripal 2009/2010 and Vaxigrip 2010/2011 by Dot-Blot assay. In parallel the lymphocytes were isolated from the collected blood of these cohorts and cell mediated immune response was determined by ELI-spot assay and HLA subtyping. The ELI-spot assay of 50 samples of lymphocytes revealed the positive spot for Influenza virus subtype H9. 90% and 70% of the lymphocytes were positive for influenza virus subtype H7 and H5 respectively. Interestingly, it has been concluded from the results that all those individuals who were having antibodies against H5, H7 and H9 were also positive for ELI-spot assay and they never being immunized against influenza viral strains. Whereas HLA results in chicken hawkers and flu patients revealed that MHC Class II alleles are majorly involved in the susceptibility and resistance to influenza infections. Results indicated that majority of the individuals were heterozygous at all HLA Loci, homozygous individuals at MHC Class II loci showed a highly significant association with influenza viral infection. Whereas the Homozygosis at HLA-class I loci A and B had no effect on the rate of disease progression. Such immunogenetical studies will help to develop an enhanced mechanistic understanding of the immune response to seasonal flu responses as well.

Objective: Absolute and percentage CD4+ T-lymphocytes counts are useful in monitoring people living with HIV. In spite of point-of-care development, CD4 testing in some laboratories of resources-limited countries still use flow cytometers from many manufacturers. We evaluated three flow cytometers (FACSCOUNT CD4/CD4%, GUAVA Auto CD4/CD4%, CYFLOW Counter® CD4/CD4%) and brought out choice criteria according to laboratory resources. Methods: CD4 percent and absolute count obtained with 180 HIV-infected patients (adults and children) with evaluated platforms (FACSCOUNT CD4/CD4%, GUAVA Auto CD4/CD4%, CYFLOW Counter CD4/CD4%) were compared with those provided by FACSCalibur TruCount®. Agreement was analyzed using Bland-Altman analysis. We also carried out a Comparative analysis of technical and operational characteristics to identify strengths and weaknesses of each tested cytometer. Results: The median CD4 percentage and absolute count obtained with FACSCOUNT and CYFLOW were similar to those of FACSCALIBUR. By contrast, GUAVA showed higher values. Bland-Altman analysis did not show measurement error. However, GUAVA and CYFLOW gave a relative high bias with mean difference respectively -69 and +27CD4 cells/μl. The overall bias of CD4 percentage were >5% for the evaluated cytometers. There was a good interclass agreement (Kappa ≥ 0.78) and good measurement precision (coefficient of variation <10%) with the 3 cytometers. Only FACSCOUNT showed good stability (CV<5%) even for stained and unstained samples within 24 and 48 hours after blood collection. FACSCOUNT, GUAVA and CYFLOW have good technical performances. Conclusion: Though we found differences in their operational characteristics, it appears very important to know how to use these kinds of cytometers before making a choice for peripheral laboratory in limited-resources countries.