Tülay Kiliçaslan Ayna

Effect of Cyclosporin A and Tacrolimus on Sister Chromatid Exchange Frequency in Renal Transplant Patients

Long-term use of Cyclosporin A (CsA) and Tacrolimus is known to yield serious untoward side effects including nephrotoxicity, neurotoxicity, and malignant tumor formation. Sister chromatid exchange (SCE) is used to assess the genotoxic potential of various agents. A total of 37 postrenal transplant patients receiving either CsA (n = 20) or Tacrolimus (n = 17) were included in this study. The genotoxic effects of CsA and Tacrolimus were assessed by determination of SCE frequency. In patients receiving CsA, SCE frequency was increased significantly compared to that in the control group (p = 0.001), whereas Tacrolimus did not yield such a significant change (p = 0.801). SCE frequency was not correlated with drug dosage (p > 0.05). Our results indicate that the use of CsA, but not Tacrolimus 506, is associated with an increased genotoxic effect in postrenal transplant patients.

Long-Term Effects of Antibodies against Human Leukocyte Antigens Detected by Flow Cytometry in the First Year after Renal Transplantation.

OBJECTIVE In this study, we aimed to investigate the incidence, dynamics and profiles of human leukocyte antigen (HLA)-directed antibodies developed after transplantation and their impact on graft rejection and outcome in kidney recipients. STUDY DESIGN Prospective follow-up study. MATERIAL AND METHODS A total of 56 kidney recipients were monitored at 1(st), 6(th) and 12(th) months for the development of anti-HLA antibodies using bead based flow-cytometry assays (Flow PRA tests). RESULTS In 21 (37.5%) patients, panel reactive antibodies (PRA) was positive after transplantation, however, in 35 (62.5%) patients PRA was found negative. Twelve (57.1%) patients with post-transplantation HLA-reactive antibodies [PRA (+)] and 8 (22.9%) patients with no detectable alloantibodies [PRA (-)] were developed allograft rejection (p=0.010). In the PRA positive patient group the rates of early period infection and delayed graft function (DGF) were higher than the PRA negative patient group. Serum creatinine levels of PRA positive group at 6. and 12. months after transplantation were significantly higher than the PRA negative group (p=0.015 and p=0.048, respectively). The rejection rates of patients who had class I and II HLA antibodies were significantly higher than the patients who had either class I or II HLA antibodies (p=0.011). Acute rejection rates were significantly higher in patients who had class I and II HLA antibodies at the first month (p=0.007). CONCLUSION Higher occurrence of rejection episodes in PRA positive group may show the importance of anti-HLA antibody monitoring using Flow-PRA after renal transplantation as a prognostic marker in terms of graft survival.

Flow Cytometric Evaluation of Pregnancy-Induced Anti-Donor Immunization

BACKGROUND Living donor kidneys from spouses and children (from offspring to parents) are currently considered to be important organ sources. However, pregnancy-induced alloimmunization may provoke acute rejection episodes after kidney transplantation. being flow cytometry cross-match (FCXM) we studied donor-specific antibodies (DSAs) in the sera of recipients planned for living kidney transplantation from their spouse or children. When the FCXM was positive, we confirmed the existence of anti-human leukocyte antigen (HLA) antibodies using flow cytometry panel-reactive antibody (flow-PRA). PATIENTS AND METHODS Between March 2005 and November 2010, we tested 85 pretransplantation sera from renal transplant recipients for DSAs. The recipients included 37 wives (group I) and 48 husbands (group II). FCXM-positive sera were tested using a flow-PRA screening method using HLA class I and class II antigen-coated beads. The mean recipient age was 48.1 ± 9.8 (range, 28-69) years and the mean donor age was 45.1 ± 11.1 (range, 23-69 years). RESULTS Among group I were 18 (48.6%) FCXM-positive cross-matches; for group II, 5 (10.4%) cases (P = .001). Sensitized patients were 37.9% FCXM-positive, whereas nonsensitized patients were 3.7% positive (P = .001). FCXM-positive patients were re-evaluated for anti-HLA antibodies using flow-PRA. Seventeen of 18 group I tests (94.4%) were FCXM-positive, whereas 3 of 5 (60%) were positive among group II. CONCLUSIONS We concluded that flow cytometry-based cross-match and PRA techniques can be used to detect anti-HLA antibodies using spousal or children donors for kidney transplantation.

Böbrek Nakli Olan Hastalarda Nakil Sonrasında Oluşan Anti-HLA Antikorlarının Saptanması ve Çeşitli Parametrelerle İlişkisinin Değerlendirilmesi

Amac: Bu calismada Izmir Tepecik Egitim ve Arastirma Hastanesi’nde kadavra veya canli donorden bobrek nakli olmus hastalarin nakil sonrasinda periyodik olarak toplanan serum orneklerinde grefte karsi gelisen immunolojik cevabin ve ilgili faktorlerle arasindaki iliskisinin degerlendirilmesi amaclanmistir. Gerec ve Yontem: 31 hasta serumunun anti-HLA antikor tarama ve tanimlama testleri flow sitometrik yontemle yapilmistir. Bu serum ornekleri, hastanemizde nakilden sonra periyodik olarak (1. gun, 1. hafta, 2. hafta, 4. hafta, 12. hafta, 24. hafta ve 52. hafta) toplanmistir. Butun orneklere tarama testi yapilirken, sadece PRA pozitif olan serum orneklerine anti-HLA antikor tipini belirlemek amaciyla tanimlama testi uygulanmistir. Butun prosedurler uretici firmanin talimatlarina gore yapilmistir. Diger parametreler Pearson korelasyon testiyle istatistiksel oalrak degerlendirilmistir. Bulgular: Nakilden sonra 52. haftadan sonra hastalarin sirasiyla %12,9 ile %6,45’i anti-HLA sinif I ve II antikorlari bakimindan pozitif bulunmustur. Hastalarda 1. gun, 1., 2., 4. ve 12. haftalarda mismatch antijenlere karsi antikor olusumu gozlenmemistir. Bir hastada antikorlar 24. haftadan itibaren olusmustur. Yapilan korelasyon analizlerinde hastalarin nakil sonrasi son kreatinin degerleriyle donor yaslari ve GFR degerleriyle hasta yaslari arasinda istatistiksel olarak anlamli sonuclar elde edilmistir (sirasiyla p 0.05). Sonuc: Nakil oncesinde kan transfuzyonu olan bir hastada 12. haftada anti-HLA antikoru olustugu gorulmustur. 5 hastada 24. haftadan sonra antikor olusmustur. Dolayisiyla nakil sonrasi 12. haftadan itibaren rutinde yapilacak anti-HLA antikoru tarama testleri tedavi protokolu icin onemli olabilir.

BÖBREK NAKLİ BEKLEME LİSTESİNDEKİ HASTALARDA ANTİ-HLA ANTİKORLARININ TANIMLANMASI

Amac: Kronik bobrek yetmezliginin kesin tedavisinin bobrek nakli oldugu bilinmektedir. Bu yuzden bobrek nakil bekleme listesindeki hastalarin nakil sansini dusuren veya nakil sonrasi rejeksiyona sebep olabilen anti-HLA antikorlarinin profillerinin cok iyi belirlenmesi gerekmektedir. Anti-HLA antikorlarinin panel reaktif tarama ve tanimlama testlerinin sonuclarina gore uygun donor secilebilmekte, yuksek oranda duyarlilasmis hastalarin bile nakil sansi arttirilabilmektedir. Bu calismanin amaci, panel reaktif sinif I ve sinif II antikor tarama test sonuclari pozitif olan kronik bobrek yetmezligi tanisi konulan hastalarin antikorlarini tanimlayarak profillerini ortaya koymaktadir. Gerec ve Yontemler: Kronik bobrek yetmezligi tanisi ile laboratuvarimiza basvuran ve panel reaktif antikor tarama test sonuclari pozitif cikan 150 hastanin serum ornekleri antikor tiplerinin tanimlanmasi icin kullanildi. 54 hasta yuksek oranda duyarlilasmis olarak degerlendirildi. 96 hastanin antikor profilleri Luminex’e dayali yontemle tanimlandi. Lifecodes CI/II ID Kitleri kullanildi ve calisma proseduru firmanin talimatlarina gore gerceklestirildi. Bulgular: En fazla tespit edilen sinif I anti-HLA antikorlari A2 (%11,6), B7 (%5,2), sinif II anti-HLA antikorlari ise DR4 ve DR7 (%9,9) oldugu belirlendi. Ayrica kadinlarda en cok DR4 (%12,4), erkeklerde ise DR11 (%9,7) tespit edildi. Hem kadin hem de erkek hastalarda en sik tespit edilen sinif I antikoru ise A2 olarak tanimlandi (sirasiyla %11,5 ve %12,9). Sonuc: Elde edilen sonuclar, toplumdaki antijen frekanslariyla ilgili calismalarin sonuclariyla karsilastirildiginda, birbirilerine paralel oldugu belirlendi. Fakat calismamizda yuksek oranda tanimlanan bazi antikorlarin (A33, A68, B7, DR9, DR10, DR8, DR17, DQ9, DR1) toplumda nadir gorulen antijenlere karsi gelistirildigi tespit edildi. Bu HLA antijenlerinin digerlerine gore daha antijenik olabileceginin goz onunde bulundurulmasi gerektigini dusunmekteyiz.

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.