Farhad Shahsavar; Nader Tajik; Kobra-Zinat Entezami; Masoomeh Fallah Radjabzadeh; Behnam Asadifar; Kamran Alimoghaddam; Mohammadreza Ostadali Dahaghi; Arash Jalali; Andisheh Ghashghaie; Ardeshir Ghavamzadeh
Volume 7, Issue 1 , March 2010, , Pages 8-17
Abstract
Background: Interaction between killer cell immunoglobulin-like receptors (KIR) and human leukocyte antigen (HLA) class I molecules is important for regulation of natural killer (NK) cell function. Objective: The aim of this study was to investigate the impact of compound KIR-HLA genotype on susceptibility ...
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Background: Interaction between killer cell immunoglobulin-like receptors (KIR) and human leukocyte antigen (HLA) class I molecules is important for regulation of natural killer (NK) cell function. Objective: The aim of this study was to investigate the impact of compound KIR-HLA genotype on susceptibility to acute leukemia. Methods: Cohorts of Iranian patients with acute myeloid leukemia (AML; n=40) and acute lymphoid leukemia (ALL; n=38) were genotyped for seventeen KIR genes and their three major HLA class I ligand groups (C1, C2, Bw4) by a combined polymerase chain reaction–sequence-specific primers (PCR-SSP) assay. The results were compared with those of 200 healthy control individuals. Results: We found a significantly decreased frequency of KIR2DS3 in AML patients compared to control group (12.5% vs. 38%, odds ratio=0.23, p=0.0018). Also, the KIR3DS1 was less common in AML group than controls (27.5% vs. 44.5%, p=0.0465, not significant after correction). Other analyses including KIR genotypes, distribution and balance of inhibitory and activating KIR+HLA combinations, and co-inheritance of activating KIR genes with inhibitory KIR+HLA pairs were not significantly different between leukemia patients and the control group. However, in AML patients a trend toward less activating and more inhibitory KIR-HLA state was observed. Interestingly, this situation was not found in ALL patients and inhibition enhancement through increase of HLA ligands and inhibi-tory combinations was the main feature in this group. Conclusion: Our findings may suggest a mechanism for escape of leukemic cells from NK cell immunity.
Tahereh Mousavi; Parisa Farnia; Nader Tajik; Mahbubeh Soofi
Volume 7, Issue 1 , March 2010, , Pages 49-56
Abstract
Background: Protective immune responses induced in the majority of people infected with Mycobacterium tuberculosis enable them to control TB infection. Objective: The aim of this study was to investigate CD56 and CD16 positive peripheral blood mononu-clear cells (PBMCs) and leukocyte subsets from multi-drug ...
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Background: Protective immune responses induced in the majority of people infected with Mycobacterium tuberculosis enable them to control TB infection. Objective: The aim of this study was to investigate CD56 and CD16 positive peripheral blood mononu-clear cells (PBMCs) and leukocyte subsets from multi-drug resistant pulmonary tuber-culosis (MDR-TB), and compare them with nonresistant (NR) TB patients and healthy controls. Methods: 13 MDR-tuberculosis patients, 20 NR-TB individuals and 40 healthy subjects were included. Peripheral blood mononuclear cells were double stained with fluorochrome conjugated antibodies against CD56 and CD16 cell surface markers. The phenotype of positive cells was then analyzed by flow cytometry and the percent-ages of CD56+ CD16+, CD56- CD16+, CD56dimCD16+/-, and CD56brightCD16+/- subsets were calculated. Results: There was a significant decline in the percentage of CD56+CD16+ lymphocytes in both MDR and NR-TB patients compared with healthy controls. We also observed lower proportions of CD56dim/brightCD16+ in addition to higher percentages of CD56dim/brightCD16- subsets in all TB patients (p≤0.05). In MDR-TB, our findings demonstrated a distinct phenotypic feature with increased levels of CD56brightCD16- in comparison with both NR-TB and healthy subjects. Conclusion: Considering the function of CD56/CD16 expressing cells in TB, we suggest that pheno-typic characteristics of PBMCs in MDR-TB may correlate with their status of drug re-sistance and probably with their high mortality rates.
Nader Tajik; Tohid Kazemi; Aliakbar Delbandi; Ahad Ghods; Alireza Salek Moghaddam
Volume 3, Issue 4 , December 2006, , Pages 150-156
Abstract
Background: In addition to Human Leukocyte Antigens (HLA) compatibility, gene polymorphisms in cytokines might also be important in the quality of allogeneic immune response. Objective: To evaluate the influence of HLA-DR matching and a number of cytokine gene polymorphisms on acute rejection after living-unrelated ...
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Background: In addition to Human Leukocyte Antigens (HLA) compatibility, gene polymorphisms in cytokines might also be important in the quality of allogeneic immune response. Objective: To evaluate the influence of HLA-DR matching and a number of cytokine gene polymorphisms on acute rejection after living-unrelated donor (LURD) kidney transplantation. Methods: A total of 42 renal transplants performed at Hashemi Nejad Kidney Hospital (Tehran/Iran) and followed up for 3 months post-transplantation were included. Using PCR-SSP, HLA-DR alleles (DR1- 18) of recipients and donors and gene polymorphisms in TNF-a, TGF-b1, IL-10, IL- 6, and IFN-g of recipients were determined. Results: Acute rejection was observed in 11(26.2%) of renal recipients. The frequency of one and two HLA-DR mismatches in rejector group was 2(18.2%) and 9(81.8%) and in non-rejector group was 13(41.9%) and 17(54.8%), respectively. HLA-DR incompatibility was not significantly higher in rejector (1.82 0.40) compared with non-rejector (1.52 0.57) recipients (P=0.069) and more than half of non-rejectors had completely mismatched HLA-DR antigens with donors. Polymorphisms associated with the mentioned cytokines had no correlation with acute rejection. Conclusion: The predictive value of HLA-DR mismatching for acute rejection is not as prominent in LURD kidney transplantation as in the cadaveric one. In addition, we failed to demonstrate an association between combined cytokine genotypes and HLA-DR matching with acute rejection. Further and more detailed immunogenetic investigations are required in order to have a better prediction of the transplant outcome.
Behrouz Nikbin; Nader Tajik; Ali Saraji; Gholam Reza Pourmand; Fatemeh Talebian; Abdurasul Mehrsai; Ali Akbar Amirzargar
Volume 1, Issue 3 , December 2004, , Pages 162-168
Abstract
Background: The Presence of donor leukocytes in recipients of organ allograft has been shown even several years after transplantation. However, it remains unclear whether this donor cell microchimerism plays an effective role in allograft acceptance or is simply a consequence of immunosuppressive conditions ...
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Background: The Presence of donor leukocytes in recipients of organ allograft has been shown even several years after transplantation. However, it remains unclear whether this donor cell microchimerism plays an effective role in allograft acceptance or is simply a consequence of immunosuppressive conditions in recipients. Objective: To study microchimerism in a group of kidney transplant recipients. Methods: In this study, the Peripheral Blood Microchimerism (PBM) after renal transplantation was retrospectively evaluated in 32 male-to-female recipients of living (unrelated) and cadaveric donor renal transplants. Using a Nested Polymerase Chain Reaction (Nested-PCR) amplification specific for SRY region of the Y chromosome, microchimerism was detected with a sensitivity of 1:1000000. Recipients were classified and compared according to the presence of PBM, acute and chronic rejection episodes, type of allotransplant, recipient and donor age at transplantation, previous male labor or blood transfusion, allograft function (serum creatinine level), and body mass index. Results: Among 32 recipients, 7 (21.9) were positive for PBM in multiple testing at different post-transplantation times. All microchimeric recipients had received kidney from living-unrelated donors. No significant difference was observed with regard to other parameters mentioned above. In addition, acute rejection rate in the microchimeric group was 3 (42%) versus 4 (16%) in the nonmicrochimeric recipients (not significant). Conclusion: Our results demonstrate better establishment of microchimerism after living donor kidney transplantation. However, concerning the true effect of microchimerism after renal transplantation doubt still persists; and it seems that microchimerism alone has no major protective role in renal allograft survival.
