Browsing by Author "Ozturk, Gulyuz"

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Different Kinetics and Risk Factors for Isolated Extramedullary Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Acute Leukemia
(ELSEVIER SCIENCE INC, 2021-01-01) Hazar, Volkan; Ozturk, Gulyuz; Yalcin, Koray; Uygun, Vedat; Aksoylar, Serap; Kupesiz, A.; Bozkaya, Ikbal Ok; Karagun, Barbaros Sahin; Bozkurt, Ceyhun; Ileri, Talia; Atay, Didem; Kocak, Ulker; Karasu, Gulsun Tezcan; Yesilipek, Akif; Gokce, Muge; Kansoy, Savas; Kintrup, Gulen Tuysuz; Karakukcu, Musa; Okur, Fatma Visal; Ertem, Mehmet; Kaya, Zuhre; Gursel, Orhan; Yaman, Yontem; Ozbek, Namik; Antmen, Bulent; Tufekci, Ozlem; Albayrak, Canan; Aksoy, Basak Adakli; Sezgin, Gulay; Albayrak, Davut; Evim, Melike Sezgin; Zengin, Emine; Pekpak, Esra; Transpl, Turkish Pediat Bone Marrow
Relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the most frequent cause of post-transplantation mortality. Isolated extramedullary (EM) relapse (iEMR) after HSCT is relatively rare and not well characterized, particularly in pediatric patients. We retrospectively analyzed 1527 consecutive pediatric patients with acute leukemia after allo-HSCT to study the incidence, risk factors, and outcome of iEMR compared with systemic relapse. The 5 -year cumulative incidence of systemic relapse (either bone marrow {[}BM] only or BM combined with EMR) was 24.8\%, and that of iEMR was 5.5\%. The onset of relapse after allo-HSCT was significantly longer in EM sites than in BM sites (7.19 and 5.58 months, respectively
Hematopoietic Stem Cell Transplantation in Patients with Heterozygous STAT1 Gain-of-Function Mutation
(SPRINGER/PLENUM PUBLISHERS, 2019-01-01) Kiykim, Ayca; Charbonnier, Louis Marie; Akcay, Arzu; Karakoc-Aydiner, Elif; Ozen, Ahmet; Ozturk, Gulyuz; Chatila, Talal A.; Baris, Safa
PurposeHuman signal transducer and activator of transcription 1 (STAT1) gain-of-function (GOF) mutations present with a broad range of manifestations ranging from chronic mucocutaneous candidiasis and autoimmunity to combined immunodeficiency (CID). So far, there is very limited experience with hematopoietic stem cell transplantation (HSCT) as a therapeutic modality in this disorder. Here, we describe two patients with heterozygous STAT1 GOF mutations mimicking CID who were treated with HSCT.MethodsData on the HSC sources, conditioning regimen, graft-versus-host disease (GvHD) and antimicrobial prophylaxis, and the post-transplant course including engraftment, GvHD, transplant-related complications, infections, chimerism, and survival were evaluated. Pre- and post-transplant immunological studies included enumeration of circulating interferon gamma (IFN-)- and interleukin 17 (IL-17)-expressing CD4(+) T cells and analysis of IFN--induced STAT1 phosphorylation in patient 1 (P1)'s T cells.ResultsP1 was transplanted with cord blood from an HLA-identical sibling, and P2 with bone marrow from a fully matched unrelated donor using a reduced toxicity conditioning regimen. While P1 completely recovered from her disease, P2 suffered from systemic CMV disease and secondary graft failure and died due to severe pulmonary involvement and hemorrhage. The dysregulated IFN- production, suppressed IL-17 response, and enhanced STAT1 phosphorylation previously found in the CD4(+) T cells of P1 were normalized following transplantation.ConclusionHSCT could be an alternative and curative therapeutic option for selected STAT1 GOF mutant patients with progressive life-threatening disease unresponsive to conventional therapy. Morbidity and mortality-causing complications included secondary graft failure, infections, and bleeding.
Mesenchymal Stem Cell Treatment for Steroid Refractory Graft-versus-Host Disease in Children: A Pilot and First Study from Turkey
(HINDAWI LTD, 2016-01-01) Erbey, Fatih; Atay, Didem; Akcay, Arzu; Ovali, Ercument; Ozturk, Gulyuz
This study evaluated the efficacy of mesenchymal stem cells (MSCs) from bone marrow of a third-party donor for refractory aGVHD. We report the first experience using MSCs to treat refractory aGVHD in 33 pediatric patients undergoing allogeneic HSCT from Turkey. Totally, 68 doses of bone marrow derived MSCs were infused. The median dose of MSC was 1.18 x 10(6) cells per kg body weight. Overall, complete response (CR) was documented in 18 patients, partial response (PR) was documented in 7 patients, and no response (NR) was documented in 8 patients. The 2-year estimated probability of overall survival (OS) for patients achieving CR and PR/NR was 63.8\% and 29.4\%, respectively (p = 0.0002). While the cumulative incidence of transplant related mortality (TRM) at day 100 after first MSC infusion was 46.6\% in PR/NR patients, there was no any TRM at day 100 after first MSC infusion in CR patients (p = 0.001). Twelve patients developed chronic GVHD (cGVHD)
Stem cell transplantation for congenital dyserythropoietic anemia: an analysis from the European Society for Blood and Marrow Transplantation
(FERRATA STORTI FOUNDATION, 2019-01-01) Miano, Maurizio; Eikema, Dirk-Jan; Aljurf, Mahmoud; van't Veer, Pieter J.; Ozturk, Gulyuz; Wolfl, Matthias; Smiers, Frans; Schulz, Angsar; Socie, Gerard; Vettenranta, Kim; Diaz de Heredia, Cristina; Zecca, Marco; Maertens, Johan; Rovira, Montserrat; Sierra, Jorge; Uckan-Cetinkaya, Duygu; Skorobogatova, Elena; Antmen, Ali Bulent; Dalle, Jean-Hugues; Markiewicz, Miroslaw; Hamladji, Rose Marie; Kitra-Roussou, Vassiliki; La Nasa, Giorgio; Krivan, Gergely; Al-Seiraihy, Amal; Giardino, Stefano; Risitano, Antonio Maria; de Latour, Regis Peffault; Dufour, Carlo
Sustained hyperferritinemia in a child with macrophage activation syndrome secondary to systemic juvenile idiopathic arthritis - perforinopathy: case based review
(TURKISH J PEDIATRICS, 2018-01-01) Cakan, Mustafa; Aktay-Ayaz, Nuray; Gemici, Hakan; Annayev, Agageldi; Citak, Agop; Akcay, Arzu; Ozturk, Gulyuz
Systemic juvenile idiopathic arthritis is a subtype of juvenile idiopathic arthritis and characterized by arthritis and many systemic features like fever, rash, hepatosplenomegaly, lymphadenopathy and serositis. Macrophage activation syndrome is the most dreadful complication of systemic juvenile idiopathic arthritis and can cause mortality and morbidity if not recognized and treated early and aggressively. Hemophagocytic lymphohistiocytosis (HLH) is characterized by diminished or absent activities of natural killer cells and cytotoxic T lymphocytes leading to cytokine storm and uncontrolled activation of T cells and macrophages. Primary (familial) HLH is a group of autosomal recessive disorders caused by mutations in the perforin and other related genes and distinctive for onset during early infancy and high rate of mortality. Secondary HLH may be caused by infectious, oncologic and rheumatologic disorders. The term Perforinopathy is used to describe cases with classical familial HLH and also for cases with familial HLH gene mutations but not following a classical familial HLH course. Herein we report a case of chronic perforinopathy in which clinical symptoms started with systemic juvenile idiopathic arthritis and severe macrophage activation syndrome that needed plasma exchange and extracorporeal membrane oxygenation during acute period and ongoing interleukin-1 blockage for sustained hyperferritinemia.
Thrombolysis with Systemic Recombinant Tissue Plasminogen Activator in Children: A Multicenter Retrospective Study
(GALENOS YAYINCILIK, 2021-01-01) Zengin, Emine; Sarper, Nazan; Erdem, Arzu Yazal; Al, Isik Odaman; Evim, Melike Sezgin; Yarali, Nese; Belen, Burcu; Akcay, Arzu; Yildirim, Aysen Turedi; Karapinar, Tuba Hilkay; Gunes, Adalet Meral; Gelen, Sema Aylan; Oren, Hale; Olcay, Lale; Baytan, Birol; Gulen, Huseyin; Ozturk, Gulyuz; Orhan, Mehmet Fatih; Oymak, Yesim; Akpinar, Sibel; Tufekci, Ozlem; Albayrak, Meryem; Gunen, Burcak Tatli; Canpolat, Aylin; Ozbek, Namik
Objective: This study aimed to evaluate systemic thrombolysis experiences with recombinant tissue plasminogen activator (rtPA). Materials and Methods: Retrospective data were collected from 13 Turkish pediatric hematology centers. The dose and duration of rtPA treatment, concomitant anticoagulant treatment, complete clot resolution (CCR), partial clot resolution (PCR), and bleeding complications were evaluated. Low-dose (LD) rtPA treatment was defined as 0.01-0.06 mg/kg/h and high-dose (HD) rtPA as 0.1-0.5 mg/kg/h. Results: Between 2005 and 2019, 55 thrombotic episodes of 54 pediatric patients with a median age of 5 years (range: 1 day to 17.75 years) were evaluated. These patients had intracardiac thrombosis (n=16), deep vein thrombosis (DVT) (n=15), non-stroke arterial thrombosis (n=14), pulmonary thromboembolism (PE) (n=6), and stroke (n=4). The duration from thrombus detection to rtPA initiation was a median of 12 h (range: 2-504 h) and it was significantly longer in cases of DVT and PE compared to stroke, non-stroke arterial thrombosis, and intracardiac thrombosis (p=0.024). In 63.6\% of the episodes, heparin was initiated before rtPA treatment. LD and HD rtPA were administered in 22 and 33 of the episodes, respectively. Concomitant anticoagulation was used in 90\% and 36\% of the episodes with LD and HD rtPA, respectively (p=0.0001). Median total duration of LD and HD rtPA infusions was 30 h (range: 2-120 h) and 18 h (2-120 h), respectively (p=0.044). Non-fatal major and minor bleeding rates were 12.5\% and 16.7\% for LD and 3.2\% and 25.8\% for HD rtPA, respectively. At the end of the rtPA infusions, CCR and PCR were achieved in 32.7\% and 49.0\% of the episodes, respectively. The most successful site for thrombolysis was intracardiac thrombosis. HD versus LD rtPA administration was not correlated with CCR/PCR or bleeding (p>0.05). Conclusion: Systemic thrombolytic therapy may save lives and organs effectively if it is used at the right indications and the right times in children with high-risk thrombosis by experienced hematologists with close monitoring of recanalization and bleeding.