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ÖZEN, AHMET OĞUZHAN

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ÖZEN

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AHMET OĞUZHAN

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2015 - 201922020 - 20211
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Author: AYDINER, ELİF × Subject: autoimmunity ×

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    Potentially Beneficial Effect of Hydroxychloroquine in a Patient with a Novel Mutation in Protein Kinase C delta Deficiency
    (SPRINGER/PLENUM PUBLISHERS, 2015) ÖZEN, AHMET OĞUZHAN; Kiykim, Ayca; Ogulur, Ismail; Baris, Safa; Salzer, Elisabeth; Karakoc-Aydiner, Elif; Ozen, Ahmet Oguzhan; Garncarz, Wojciech; Hirschmugl, Tatjana; Krolo, Ana; Yucelten, Ayse Deniz; Boztug, Kaan; Barlan, Isil B.
    Protein kinase C delta (PRKCD) has essential functions in controlling B-cell proliferation and apoptosis, development of B-cell tolerance and NK-cell cytolitic activity. Human PRKCD deficiency was recently identified to be causative for an autoimmune lymphoproliferative syndrome like disorder with significant B-cell proliferation particularly of immature B cells. Here we report a child with a novel mutation in PRKCD gene who presented with CMV infection and an early onset SLE-like disorder which was successfully treated with hydroxychloroquine.
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    Hematopoietic Stem Cell Transplantation in Patients with Heterozygous STAT1 Gain-of-Function Mutation
    (SPRINGER/PLENUM PUBLISHERS, 2019-01) ÖZEN, AHMET OĞUZHAN; 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.
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    Stepwise Reversal of Immune Dysregulation Due to STAT1 Gain-of-Function Mutation Following Ruxolitinib Bridge Therapy and Transplantation
    (SPRINGER/PLENUM PUBLISHERS, 2021) ÖZEN, AHMET OĞUZHAN; Kayaoglu, Basak; Kasap, Nurhan; Yilmaz, Naz Surucu; Charbonnier, Louis Marie; Geckin, Busranur; Akcay, Arzu; Eltan, Sevgi Bilgic; Ozturk, Gulyuz; Ozen, Ahmet; Karakoc-Aydiner, Elif; Chatila, Talal A.; Gursel, Mayda; Baris, Safa
    Purpose Patients with heterozygous gain-of-function (GOF) mutations in STAT1 frequently exhibit chronic mucocutaneous candidiasis (CMC), immunodeficiency and autoimmune manifestations. Several treatment options including targeted therapies and hematopoietic stem cell transplantation (HSCT) are available for STAT1 GOF patients but modalities and outcomes are not well established. Herein, we aimed to unravel the effect of ruxolitinib as a bridge therapy in a patient with sporadic STAT1 T385M mutation to manage infections and other disease manifestations. Methods Peripheral blood mononuclear cells were isolated from the patient prior to, during ruxolitinib treatment and 6 months after HSCT. IFN-beta-induced STAT1 phosphorylation/dephosphorylation levels and PMA/ionomycin-stimulated intracellular IL-17A/IFN-gamma production in CD4(+) T cells were evaluated. Differentially expressed genes between healthy controls and the patient prior to, during ruxolitinib treatment and post-transplantation were investigated using Nanostring nCounter Profiling Panel. Results Ruxolitinib provided favorable responses by controlling candidiasis and autoimmune hemolytic anemia in the patient. Dysregulation in STAT1 phosphorylation kinetics improved with ruxolitinib treatment and was completely normalized after transplantation. T(H)17 deficiency persisted after ruxolitinib treatment, but normalized following HSCT. Consistent with the impairment in JAK/STAT signaling, multiple immune related pathways were found to be dysregulated in the patient. At baseline, genes related to type I IFN-related pathways, antigen processing, T-cell and B-cell functions were upregulated, while NK-cell function and cytotoxicity related genes were downregulated. Dysregulated gene expression was partially improved with ruxolitinib treatment and normalized after transplantation. Conclusion Our findings suggest that improved disease management and immune dysregulatory profile can be achieved with ruxolitinib treatment before transplantation and this would be beneficial to reduce the risk of adverse outcome of HSCT.