Assessment of CTLA-4 Gene Expression Levels on CD8+ T Cells in Renal Transplant Patients and Relation with Serum sCTLA-4 Levels.

CTLA-4 (Cytotoxic T Lymphocyte Antigen-4) is an immune regulator molecule that is expressed on a variety of immune cells, including CD4+ and CD8+ T cells. After realizing the significance of this regulator molecule, researchers began to concentrate on its activation or inhibition in cancer. Even though there have been some studies on organ transplantation and autoimmunity, the role of the CTLA-4 molecule in renal transplantation has not been demonstrated. The goal of this study was to see how CTLA-4 gene expression and serum sCTLA-4 levels affected renal transplant patients. Peripheral blood samples were collected before and 1-3 months after renal transplantation from 29 recipients. CD8+ T lymphocytes were separated using magnetic beads and purity of the cells controlled by Flow cytometry. CTLA-4 mRNA levels were determined by Real-Time PCR while serum sCTLA-4 levels were assessed by ELISA. 55% of the patient had decreased level of CTLA-4 mRNA after transplantation when compared to pre-transplantation levels. Moreover 61% of the patient had lower serum sCTLA-4 levels after transplantation. sCTLA-4 levels were decreased 11% of the patients with rejection episode after transplantation when compared to stabile patients (5%). Kidney rejection is a complicated process influenced by numerous unknown factors. Several parameters should be evaluated together to precise rejection episodes or graft dysfunctions. Further research focused on the other immune checkpoint regulator molecules could give an opportunity to have an idea about the effect of these molecules on renal transplantation.

Delayed Graft Function in Kidney Transplantation: Risk Factors and Impact on Early Graft Function.

CONTEXT: Although kidney transplantations are routinely performed at many centers in Turkey, the incidence and risk factors associated with delayed graft function (DGF) here have not yet been well defined. OBJECTIVE: The aim of this study is to evaluate the incidence and risk factors of DGF and its impact on early graft function. DESIGN: The medical charts of 154 adult patients who underwent deceased donor kidney transplantation between 2000 and 2014 in a single center were reviewed retrospectively. SETTING: Delayed graft function-related risk factors for donors, recipients, and the transplant surgery itself were analyzed, and their relation with graft function was evaluated. MAIN OUTCOMES MEASURES: The median recipient age was 39 years. The median cold ischemia time (CIT) was 840 minutes (14 hours). The incidence of DGF and acute rejection were 57.8% and 8.4%, respectively. Higher serum creatinine levels at 3, 6, and 12 months were observed in patients with DGF compared to other patients without DGF (P < .05). Patients with DGF had poor graft function (glomerular filtration rate ≤ 50) at 3 and 6 months (P < .05), but these correlations were not seen at 12 months (P = not significant). RESULTS: This study showed that DGF was a common and serious problem associated with poor graft functions at 3, 6, and 12 months after transplantation. Extra effort to shorten CIT as an independent risk factor for DGF could have protective effect on graft functions.

Single antigen flow beads for identification of human leukocyte antigen antibody specificities in hypersensitized patients with chronic renal failure.

AIMS OF THIS STUDY: Aims of this study were to identify class I and class II antibodies in highly sensitized patients by flow cytometry single antigen bead (FC-SAB) assay and to evaluate according to donor HLA type in order to increase their kidney transplantation chance. MATERIAL AND METHODS: We analyzed 60 hypersensitive patients of 351 individuals, who applied to our laboratory for PRA test in November 2013-December 2014. Flow cytometric PRA screening and single antigen bead commercial kits were used for these analyses. RESULTS: In our study group, 19 (31.7%) of these patients were male while 41 (68.3%) patients were female. The most common acceptable antigens were A*02 (10.11%), HLA-A*23 (10.11%), HLA-B*38 (8.79%) and HLA-DRB1*03 (7.83%) in hypersensitive patients. The highest antibody reactivity on SAB was observed against HLA-A*25, HLA-B*45, HLA-DRB1*04 and HLA-DRB1*08 antigens. CONCLUSIONS: The determination of these acceptable and unacceptable antigens may increase their transplantation chance. Pre-transplant HLA antibody identifications provide prognostic information with respect to the determination of patients who are at increased risk of graft loss.

The predictive value of stimulation index calculated by modified mixed lymphocyte culture in the detection of GVHD following hematopoietic stem cell transplantation.

OBJECTIVE: Mixed lymphocyte culture (MLC) is one of the routine tests performed prior to hematopoietic stem cell transplantation (HSCT) as a predictive assay for assessing the quality of donor matching and graft-versus-host disease (GVHD). The stimulation index is one of the formulas of the MLC test, and it is used for evaluation of matching between donor and recipient. Modified MLC (mMLC) test is produced by adding various cytokines to the MLC test, and increased sensitivity has been reported with this modification. METHODS: The importance of the stimulation index values in MLC and mMLC tests was evaluated in 59 patients who received HSCs from human leukocyte antigen-identical sibling donors. In the mMLC test, cytokines were added as interleukin (IL)-2, IL-2 + IL-4 and IL-2 + interferon (IFN)-gamma + tumor necrosis factor (TNF)-alpha. Stimulation index values in mMLC test were compared with stimulation index values in MLC test. RESULTS: Twenty-three (39%) patients developed GVHD. When evaluated in terms of stimulation index >1 patients, in MLC, 55% of the patients developed GVHD (p=0.229), whereas these values were 75% in the IL-2 added mMLC test (p=0.035), 100% in the IL-2 + IL-4 added mMLC test (p=0.076) and 85.7% in the IL-2 + IFN-gamma + TNF-alpha added mMLC test (p=0.015). CONCLUSION: mMLC increased the sensitivity of the test. The relation between the positive results and evidence of GVHD after transplantation was found significant.

Cytotoxic effects of leaf, stem and root extracts of Nerium oleander on leukemia cell lines and role of the p-glycoprotein in this effect.

Nerium oleander (No), is a toxic plant. In recent studies, it was determined that the extracts of this plant are effective to treat some types of cancer, but these studies are limited and do not include human leukemia. In the present study, firstly we aimed to investigate in vitro the cytotoxic effects of No on the HL60 and K562 leukemia cell lines. The cells were incubated with six different concentrations of each three extracts. MTT assay was employed as a cytotoxicity test. It was observed that concentrations of 1000, 500 and 50 microg/ml from each extract possess marked antileukemic effects. No leaf and root extracts were seen to be more cytotoxic than the stem extract according to LC50. Secondly, in order to understand the role of P-gp in cytotoxicity, P-gp levels of K562 resistant and sensitive cells were measured by flow cytometry before treatment extracts, and then, the cells were incubated with No leaf, stem and root extracts in 500 microg/ml concentrations overnight. After incubation, measurements showed decreased levels of P-gp in the cells. Hence, it is possible to think contributes to their cytotoxic effects that inhibiting of the P-gp pump by No extracts on leukemia cell lines.