Browsing by Author "Kavuzlu, Miray"

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Anti-HLA Antibody Levels Are Associated With the Risk of Graft Failure After Allogeneic Hematopoietic Stem Cell Transplant
(2017) Basturk, Bilkay; Kasar, Mutlu; Yeral, Mahmut; Kavuzlu, Miray; 0000-0002-9580-628X; 0000-0003-3856-7005; 0000-0002-9288-942X; 0000-0002-8784-1974; 28260472; ABC-4148-2020; AAE-6201-2021; AAL-3906-2021; AAE-2689-2021; AAD-6918-2021
Objectives: Allogeneic hematopoietic stem cell trans plant provides a curative treatment for a considerable amount of hematologic diseases, and it is widely used today. Successful allogeneic stem cell transplant can be compromised by treatment-related toxicity, graft-versus-host disease, infectious complications, disease relapse, and graft failure. Primary graft failure is an important cause of hematopoietic stem cell transplant failure. Primary graft failure correlates with the level of complement-binding, donor-specific anti-HLA anti bodies prior to transplant. Material and Methods: We evaluated 15 patients who underwent hematopoietic stem cell transplant using peripheral blood stem cells in terms of graft failure and anti-HLA antibody levels before transplant. All were treated between January 2015 and June 2016. Pretreatment serum anti-HLA class I and anti-HLA class II antibody levels were measured in all patients. Results: Anti-HLA class I antibodies were present in 7 patients (46.6%) and anti-HLA class II antibodies in 8 (53.3%). All three patients who developed primary graft failure were anti-HLA-positive. Conclusions: Anti-HLA antibodies are a significant cause of graft failure. It is a situation that must be understood with caution. Our results support the considerations that allogeneic hematopoietic stem cell transplant, especially when a fully compatible sibling donor is not present, should include screening of donor-specific antibodies of alternative donors and desensitization therapy for allosensitized patients before transplant.
Böbrek nakli olan hastalarda BK virüs ve insan lökosit antijenleri (HLA) arasındaki ilişkinin araştırılması
(Başkent Üniversitesi Sağlık Bilimleri Enstitüsü, 2019) Kavuzlu, Miray; Baştürk, Bilkay
Son dönem böbrek yetmezliği (SDBY) olan hastalarda tercih edilen tedavi yöntemi böbrek naklidir. Altıncı kromozomun kısa kolu üzerinde bulunan insan lökosit antijeninin (Human Leukocyte Antigen: HLA) temel görevi antijeni T lenfositlerine sunmak ve spesifik immün cevabı başlatmaktır. HLA moleküllerinin doku ve organ nakillerindeki öneminin yanı sıra otoimmün, viral, alerjik ve nörolojik kökenli hastalıklarla da ilişkili olduğu ortaya çıkmıştır. Böbrek naklinde immün sisteminin ana hedefi, verici hücrelerinin yüzeyinde yer alan HLA molekülleridir. Ayrıca HLA’nın viral enfeksiyonlara karşı bağışıklık cevabının oluşmasında rol oynadığı bilinmektedir. BK virüs (BKV) enfeksiyonu böbrek nakli sonrası önemli problemlerden birisidir. Nakil sonrası verilen immünsüpresif tedaviler BKV gibi fırsatçı enfeksiyonlara neden olmaktadır. Çalımanın amacı böbrek nakli olan hastalarda HLA ile BKV arasında ilişki olup olmadığının araştırılmasıdır. Çalışma retrospektif olarak planlamış olup, çalışma grubundaki hastalara nakil öncesinde HLA A, B, DR doku tipleme testi çalışılmıştır. Hastalara ait EDTA’lı tam kan örneklerinden DNA izolasyonu yapıldı. Moleküler olarak PCR temelli olan SSO (Sequence Specific Oligonucleotides) ve / veya SSP (Sequence Specific Priming) yöntemi ile doku tipleme testleri çalışılmıştır. Nakil sonrasında ise hastalara BKV testi çalışıldı. Hastalara ait idrar ve / veya plazma örneklerinden DNA izolasyonu yapıldı. İzole edilen örneklerden Real-time PCR yöntemiyle kantitatif olarak BKV testi çalışılmıştır. Sonuçlar SPSS programı ile istatistiksel olarak analiz edildi. Yapılan analizlere göre HLA B*13 allelinin BKV'ye karşı koruyucu faktör, HLA DRB1*03 allelinin ise BKV'ye karşı risk faktörü olabileceği belirlendi. Analiz edilen diğer HLA alleleri ile BKV arasında ise anlamlı bir ilişki belirlenemedi. Sınıf I HLA moleküllerinin sitotoksik T hücre yardımı ile virüslere karşı etkili olduğu bilinmektedir. Bizim çalışmamızda HLA sınıf I molekülleri içerisinde yer alan HLA B*13 allelinin BKV'ye karşı koruyucu faktör olarak belirlenmesi bunu desteklemektedir. HLA sınıf II ise immün sistemin sitokin salgılayarak yardımcı olan CD4+ T hücreleri ile ilişkilidir ve hem immün sistemi uyaran hem de baskılayabilen bir rol oynar. Bizim çalışmamızda HLA DRB1*03 allelinin ise BKV’ye karşı risk faktörü olabileceği belirlendi. Bu allelin immün sistemi baskılayacı sitokin salgılayan bir sitokin salınımıyla ilişkili olduğu düşünülebilir. The best treatment modality in patients with end-stage renal disease (ESRD) is renal transplantation. The main function of the human leukocyte antigen, located on the short arm of the sixth chromosome, is to present antigens to T lymphocytes and initiate the specific immune response. In addition to the importance of human leukocyte antigen (HLA) molecules in tissue and organ transplants, autoimmune, viral, allergic and neurological diseases have been found to be related. The main target of the recipient immune system in renal transplantation is the HLA molecules on the surface of donor cells. It is also known that HLA plays a role in the development of an immune response to viral infections. BK virus (BKV) infection is one of the major problems after kidney transplantation. Immunosuppressive therapies after transplantation cause opportunistic infections such as BKV. The aim of the study was to investigate whether there is a relationship between HLA and BKV in patients with renal transplantation. The study was planned retrospectively and HLA A, B, and DR tissue typing were studied before transplantation in the study group. DNA was isolated from whole blood samples of EDTA patients. Tissue typing tests were performed by Sequence-Specific Oligonucleotides (SSO) and / or Sequence-Specific Priming (SSP) method based on PCR. After transplantation, patients were tested for BKV. DNA was isolated from urine and / or plasma samples of patients. Isolated samples were quantitatively evulated for BKV by the Real-time PCR method. Results were analyzed statistically with SPSS program. According to the analysis, it was determined that HLA B*13 allele was protective against BKV and HLA DRB1*03 allele could be risk factor against BKV. No significant relationship was found between the other HLA alleles analyzed and BKV. HLA class I molecules are known to be effective against viruses with the help of cytotoxic T cells. In our study, HLA B*13 alleles within the HLA class I molecules were identified as protective factors against BKV. HLA class II is associated with CD4+ T cells that help secrete the cytokines of the immune system and plays a role in stimulating and suppressing the immune system. Here, we demonstrated that HLA DRB1*03 allele could be a risk factor against BKV. This allele may be considered to be associated with a cytokine-secreting cytokine secretion of the immune system.
Determination of Cytokine Gene Polymorphisms in a Heart Transplant Patient Resistant to Desensitization Therapy: Case Report
(2022) Basturk, Bilkay; Kavuzlu, Miray; Khalilova, Afag; Kantaroglu, Bircan; Sezgin, Atilla; https://orcid.org/0000-0002-9288-942X; 35384819; AAE-2689-2021
Heart transplant is the best treatment option for end-stage heart failure. The major goals in solid-organ transplant are organ survivability and functionality. The effects of anti-HLA antibodies and cytokines are important for immune response. Cytokine gene polymorphisms are also effective during cytokine release. Here, we report a heart transplant recipient who was diagnosed with antibody-mediated rejection posttransplant and had an antibody response resistant to desensitization therapy. After transplant, panel reactive antibody screening and identification class I and II tests and Luminex single antigen class I and II tests were performed. Desensitization treatment included intravenous immunoglobulin, plasmapheresis, rituximab, and bortezomib. Because of these reasons, cytokine gene polymorphism tests (consistent with low, intermediate, and high expression levels for tumor necrosis factor a, transforming growth factor ss 1, interleukin 6 and 10, and interferon.) were conducted. We found polymorphic regions compatible with the high-release, proinflammatory action of tumor necrosis factor a and interleukin 6, which induced inflammation and B-cell activation, and polymorphic regions compatible with the intermediate release of the potent immunosuppres- sive effects of transforming growth factor ss 1 and interleukin 10, suggesting that the patient may not be able to effectively suppress the activation of the immune system. The influence of cytokine gene polymorphism on the formation of a resistant antibody response in a patient, despite desensitization, contributed to the proinflammatory response in which these cytokines were involved.
The Frequency of HLA-A, -B, -C,-DRB1 and-DQB1 alleles in Patients with Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia
(2023) Basturk, Bilkay; Kavuzlu, Miray; Kasar, Mutlu; 0000-0002-8784-1974; AAD-6918-2021
Golgi Stresinin foliküler T ve B hücre yüzeyinde HLA-G ekspresyonuna etkisinin araştırılması
(Başkent Üniversitesi Sağlık Bilimleri Enstitüsü, 2024) Kavuzlu, Miray; Baştürk, Bilkay
Tez çalışmasının amacı foliküler B hücresinde Brefeldin A muamelesi ile meydana getirilen Golgi stresinin MHC Sınıf-II ve non-klasik HLA-G moleküllerinin ekspresyonuna etkisinin ve foliküler B hücresinde oluşturulan bu stresinin T foliküler yardımcı (Tfh) hücrelerin yüzeyindeki ve B hücre yüzeyindeki HLA-G molekülünün ekspresyonuna etkisini araştırmaktır. Nakillerde stres altında kalan adaptif immün sistem hücrelerinin yanıtlarına ve greft doku işlevselliğine ışık tutacak bulguların elde edilmesi amaçlandı. İmmün sistem kendinden olanı ve olmayanı tanıyarak yabancı antijenleri “Major Histokompatibilite Kompleksi (MHC)” ile T hücrelerine sunar. MHC molekülleri Sınıf I, II, III ve IV olmak üzere 4 sınıfa ayrılır. Sınıf-I MHC (HLA-A, -B, -C) ve Sınıf-II MHC (HLA-DR, -DP, -DQ) moleküllerinin birincil görevi antijen sunumuna katılmaktır. Klasik olmayan Sınıf-I MHC (HLA-E, -F, -G) molekülleri ise immünomodülatör moleküllerdir. Sınıf-I MHC molekülleri CD8+ sitotoksik T hücrelere, Sınıf-II MHC molekülleri ise CD4+ yardımcı T hücrelerine antijen sunarlar. B hücreleri aktive olduktan sonra MHC Sınıf-II moleküllerinin ekspresyonlarını arttırarak antijen sunan hücre görevi görebilirler. MHC Sınıf-II peptid kompleksi CD4+ T hücrelerine antijen sunmak için hücre yüzeyine taşınır. Non-klasik Sınıf-I HLA-G molekülleri bağışıklık sisteminin modülasyonunda görev alır. HLA-G için reseptör görevi üstlenen immünglobülin benzeri transkript 2 (ILT2: Ig-Like Transcript 2) B hücreleri, T hücreleri, NK (Natural Killer) hücreleri, dendritik hücreler ve diğer bağışıklık hücreleri tarafından eksprese edilir. ILT2'nin ligandları ile etkileşimi, T ve B hücrelerinin fonksiyonunu baskılar. Alıcı (konak), greft dokuyu yüzeyinde bulunan MHC molekülleri aracılığı ile tanır. Golgi, proteinlerin ve lipidlerin alınmasında, işlenmesinde, paketlenmesi ve taşınmasında merkezi bir rol oynar. Brefeldin A Golgi için bir stres indükleyicisidir ve golgi stres yolaklarını aktive edip golginin yapısının bozulmasına neden olarak protein taşınmasını bloke eder. Bu çalışma 3 farklı kişiden alınan sekonder lenfoid doku örneklerinin (dalak örnekleri) kullanıldığı deneysel bir çalışmadır. Dalak örneklerinden manyetik boncuk yöntemi ile T hücre ve B hücre izolasyonu yapıldı. T:B hücre ko-kültürü yapılarak akım sitometri yöntemi ile 0. saat immünfenotipleme çalışması yapıldı. B hücrelerinde Brefeldin A ile muamelesi ile golgi stresi indüklendi. B hücrelerde golgi stresi immünohistokimya yöntemiyle anti-GM130 boyaması yapıldıktan sonra immünfloresan mikroskopta görüntülenmesi ve akım sitometri yöntemi ile HLA-DR ekspresyon oranının değişiminin belirlenmesi ile gösterildi. Hücre kültürü yöntemi ile T:B hücre ko-kültürü yapıldı ve steroid muamelesi uygulandı. Hücre kültüründe zamana (6/12/24. saat), golgi stresine ve steroid etkisine bağlı olarak Tfh hücreler ile foliküler B hücrelerinin hücre yüzey belirteçlerinin değişimleri akım sitometri yöntemiyle değerlendirildi. B hücrelerinde Brefeldin A muamelesi ile oluşturulan golgi stresine bağlı olarak MHC Sınıf-II molekülü (HLA-DR) ekspresyonun azaldığı, steroid muamelesiyle Tfh hücre ve B hücre yüzeyinde HLA-G ekspresyonunun arttığı saptanmıştır. The aim of thesis study is to investigate the effect of golgi stress induced by Brefeldin A treatment on the expression of MHC Class-II and non-classical HLA-G molecules in follicular B cell. We are going to investigate the impact of golgi stress of B follicular cells on HLA-G molecules expression on the cell surfaces of T follicular helper (Tfh). The immune system recognizes self and non-self antigens, and present foreign antigens to T cells through “Major Histocompatibility Complex (MHC)”. MHC have been classified into four classes: class-I, II, III and IV. The primary function of MHC Class-I (HLA-A, -B, -C) and MHC Class-II (HLA-DR, -DP, -DQ) molecules is to participate in antigen presentation. Non-classical Class-I MHC (HLA-E, -F, -G) molecules are immunomodulatory molecules. Class-I HLA molecules present antigens to CD8+ cytotoxic T cells while Class-II molecules present to CD4+ hepler T cells. After B cells are activated, it can act as antigen-presenting cells by increasing the expression of MHC Class-II molecules. The MHC Class-II peptide complex is transported to the cell surface to present antigen to CD4+ T cells. Non-classical Class-I HLA-G molecules function in the modulation of the immune system Immunoglobulin-like transcript 2 (ILT2), which acts as a receptor for HLA-G, is expressed by B cells, T cells, NK cells, dendritic cells, and other immune cells. Interaction of ILT2 with its ligands suppresses the function of T and B cells. The recipient recognizes the graft tissue with the MHC molecules on its surface. The Golgi plays a central role in the uptake, processing, packaging and transport of proteins and lipids. Brefeldin A is a stress inducer for golgi. It activates the golgi stress pathways, disrupts the structure of golgi and blocks protein transport. This is an experimental study in which secondary lymphoid tissue samples (spleen samples) from 3 different individuals were used. T cells and B cells were isolated from spleen samples by magnetic bead method. T:B cell co-culture was performed and 0. hour immunophenotyping study was performed by flow cytometry method. Golgi stress was induced in B cells by treatment with Brefeldin A. Golgi stress in B cells was demonstrated by immunohistochemistry using anti-GM130 staining followed by immunofluorescence microscopy and flow cytometry to determine the change in HLA-DR expression ratio. T:B cell co-culture was performed by cell culture method and steroid treatment was applied. Changes in cell surface markers of Tfh cells and follicular B cells depending on time (6/12/24 hours), golgi stress and steroid effect in cell culture were evaluated by flow cytometry method. In B cells isolated from secondary lymphoid organs, golgi stress induced by Brefeldin A treatment decreased the expression of HLA-DR, an MHC Class-II molecule on the cell surface. Steroid treatment increased HLA-G expression on the surface of Tfh cells and B cells.
IgG and IGG4 Positive Plasma Cell Profile in Recurrent Antibody-Mediated Rejection (AMR) of Cardiac Transplants
(2022) Terzi, Aysen; Basturk, Bilkay; Ozdemir, B. Handan; Kavuzlu, Miray; Sezgin, Atila
The Most Common HLA Alleles and Anti-HLA Antibodies to Know for Virtual Cross-Match
(2016) Basturk, Bilkay; Kantaroglu, Bircan; Kavuzlu, Miray; Kavuzlu, Miray; Sariturk, Cagla; 0000-0002-8784-1974; 0000-0002-9288-942X; 0000-0002-9288-942X; 0000-0002-4130-1059; 27805512; AAD-6918-2021; AAE-2689-2021; AAE-2689-2021; AAS-7129-2021
Objectives: Human leukocyte antigens and HLA-specific antibodies are important before and after transplant treatment. The determination of the alloantibodies before transplant is useful for the estimation of risk for antibody-mediated rejection. Virtual crossmatch uses solid-phase assay to detect anti-HLA antibodies and allows exclusion of donors with unacceptable HLA antigens. The aim of our retrospective study was to investigate HLA class I and class II alleles and panel reactive antibody and Luminex Corporation (Austin, TX, USA) single-antigen bead assay positivity frequencies in the Southeastern region of Turkey Material and Methods: Tissue typing results for HLA class I (HLA-A, HLA-B, HLA-C) and class-II (DRB1and DQB1 haplotypes) in 1756 patients and 2951 donors who were at Baskent University Adana Research and Medical Center between 2010 and 2015 for transplant were studied using sequence-specific primers and/or sequence-specific oligonucleotides. Serum samples were analyzed by Luminex bead technology for antibody detection. Results: We found that, for class I, HLA-A*02, HLA-B*35, and HLA-A*24 and, for class II, DRB*11, DRB*01, and DRB*04 were the 4 most common antigens and HLA-A02, B49, A68, B7 were the 3 most common anti-HLA antibodies, with mean fluorescence intensity values >= 2000 in our population group. Human leukocyte antigen alleles and anti-HLA antibodies were compared with each other except HLA-A*02, A2, with no correlations between allele and panel reactive antibody frequencies identified. However, there was a weak correlation between panel reactive anti body-mean fluorescence intensity scores of 5000 and above with Luminex single-antigen bead assay. Conclusions: This study is the first to conduct such a mass screening of a Turkish population. Our study results show that there is no correlation between HLA frequencies and anti-HLA antibody frequencies. However, there was a weak correlation between panel reactive antibody mean fluorescence intensity scores of 5000 and above with Luminex single-antigen bead assay. Of note, this pattern is important to know for virtual cross-match.