Mustafa Yavuz Köker

Clinical, functional, and genetic characterization of chronic granulomatous disease in 89 Turkish patients

BACKGROUND Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disorder of phagocytes resulting in impaired killing of bacteria and fungi. A mutation in one of the 4 genes encoding the components p22(phox), p47(phox), p67(phox), and p40(phox) of the leukocyte nicotinamide dinucleotide phosphate reduced (NADPH) oxidase leads to autosomal recessive (AR) CGD. A mutation in the CYBB gene encoding gp91(phox) leads to X-linked recessive CGD. OBJECTIVE The aim of this study is to show the correlation between clinical, functional, and genetic data of patients with CGD from Turkey. METHODS We report here the results of 89 patients with CGD from 73 Turkish families in a multicenter study. RESULTS Most of the families (55%) have an AR genotype, and 38% have an X-linked genotype; patients from 5 families with a suspected AR genotype (7%) were not fully characterized. We compared patients with CGD according to the severity of NADPH oxidase deficiency of neutrophils. Patients with A22(0), A67(0) or X91(0) phenotypes with a stimulation index of 1.5 or less have early clinical presentation and younger age at diagnosis (mean, 3.2 years). However, in p47(phox)-deficient cases and in 5 other AR cases with high residual oxidase activity (stimulation index ≥ 3), later and less severe clinical presentation and older age at diagnosis (mean, 7.1 years) were found. Pulmonary involvement was the most common clinical feature, followed by lymphadenitis and abscesses. CONCLUSION Later and less severe clinical presentation and older age at diagnosis are related to the residual NADPH oxidase activity of neutrophils and not to the mode of inheritance. CGD caused by A22(0) and A67(0) subtypes manifests as severe as the X91(0) subtype.

Six different CYBA mutations including three novel mutations in ten families from Turkey, resulting in autosomal recessive chronic granulomatous disease

Background  One of the rarest forms of autosomal recessive chronic granulomatous disease (AR‐CGD) is attributable to mutations in the CYBA gene, which encodes the alpha polypeptide of cytochrome b558, (also known as p22‐phox), a key transmembrane protein in the phagocyte NADPH oxidase system. This gene is localized on chromosome 16q24, encompasses 8·5 kb and contains six exons.

Skewing of X-chromosome inactivation in three generations of carriers with X-linked chronic granulomatous disease within one family

Background  Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by impairment of intracellular microbicidal activity of phagocytes. Mutations in one of the four known NADPH‐oxidase components preclude generation of superoxide and related antimicrobial oxidants, leading to the phenotype of CGD. Defects in gp91‐phox, encoded by CYBB, lead to X‐linked CGD, responsible for approximately 70% of all CGD cases. The aim of the study was to evaluate the hypothesis that age‐related skewing of X‐chromosome inactivation, as described in several CGD families, is caused by preferential survival of bone marrow clones with an inactive NADPH oxidase.

Four different NCF2 mutations in six families from Turkey and an overview of NCF2 gene mutations

Background  One of the rarest forms of autosomal recessive chronic granulomatous disease (AR‐CGD) is attributable to mutations in the NCF2 gene, which encodes the polypeptide p67phox, a key cytoplasmic protein in the phagocyte NADPH oxidase system. NCF2 is localized on chromosome 1q25, encompasses 40 kb and contains 16 exons.

Performance of Galactomannan Antigen, Beta-d-Glucan, and Aspergillus-Lateral-Flow Device for the Diagnosis of Invasive Aspergillosis

Aspergillus lateral-flow device (LFD) was recently introduced as a practical tool for the diagnosis of invasive aspergillosis (IA). We investigated the performance of Aspergillus-LFD as a point-of-care test for the diagnosis of IA. Serum samples were collected twice weekly from patients who received intensive chemotherapy for acute leukemia, or recepients of allogeneic stem cell transplantation. Aspergillus galactomannan (GM) antigen, 1,3-beta-d-glucan and Aspergillus-LFD tests were carried out according to manufacturers’ recommendations. GM testing was repeated with a modified procedure which was proven to increase the sensitivity. Aspergillus-LFD was performed without applying any pretreatment procedure to allow the kit to fit as a point-of-care test. Fungal infections were categorized according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria. A total of 75 neutropenia episodes in 64 patients were prospectively followed between February 2012 and January 2013. Probable IA was diagnosed in 11 patients, probable pulmonary fungal disease was diagnosed in one patient, and rhinocerebral aspergillosis was diagnosed in one patient. Fungemia was detected in two patients. Aspergillus-LFD was positive in serum of a patient with probable IA and in the bronchoalveolar lavage fluid of an other patient with probable IA. Aspergillus-LFD was false positive in serum of two patients. Although there was no radiological finding of IA or documented fungemia, fever resolved after empirical caspofungin therapy in one of these patients. The sensitivity of Aspergillus-LFD as a point-of-care test without any pretreatment of serum sample is low.

The association of endothelial progenitor cell markers with arteriovenous fistula maturation in hemodialysis patients

AbstractAimsArteriovenous fistula (AVF) failure is one of the most important clinical problems in end-stage renal disease. Endothelial progenitor cells (EPCs) have a role on vascular angiogenesis and endothelialization. We aimed to investigate the association markers of EPCs on AVF maturation by measuring the surface expressions of CD34, CD309 and CD133 on the monocytes.MethodsThis prospective observational study was conducted in 54 voluntary patients with end-stage renal disease who were admitted for their first renal replacement therapy and were available for AVF creation. Venography was performed in all patients before AVF creation. Six patients were excluded due to inadequate veins after venographic imaging, and also seven patients were excluded due to postoperative thrombosis. The blood samples were analyzed a day before the fistula operation, and the expressions of CD34, CD133 and CD309 on the surface of monocytes were measured.ResultsPatients were divided into two groups after the evaluation of AVF maturation, as the mature group and the failure group. The CD309 expression level on the monocytes was 338.00 (35.00–479.00) in the mature group; however, it was 36.00 (5.50–237.00) (p 0.031) in the failure group. Multiple logistic regression analyses showed that both BMI and the mean fluorescence intensity level of CD309 expression on monocytes independently predicted AVF maturation.ConclusionsThe presence of DM and increased BMI negatively correlated with AVF maturation. High intensity of CD309 expression on monocytes was observed in patients with successful AVF maturation.

Comparison of ELISA and flow cytometry for measurement of interleukin-1 beta, interleukin-6 and tumor necrosis factor-α

Abstract Background Although majority of the previous studies have shown a good correlation between enzyme linked immuno sorbent assay (ELISA) and flow cytometry in terms of cytokines, two laboratory methods usually were compared with the regression analysis and correlation in the literature. This study aimed at comparing the ELISA and flow cytometry assay for measuring cytokines by using two different statistical methods, regression analysis and Bland-Altman plot. Materials and methods Fifty patients, diagnosed with hypercholesterolemia and expecting high level serum cytokines, and 30 healthy volunteers, expecting normal level serum cytokines, were enrolled in the study. The interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured using ELISA, and compared with obtained levels using flow cytometric method. Results Although regression analysis showed that the two methods are compatible with measurements of IL-1β, IL-6 and TNF-α, they tended to show dissimilarity with measurements of IL-1β and TNF-α based on Bland-Altman graphs. Conclusion According to Bland-Altman plot, our results providing evidence of ELISA and flow cytometry assays were compatible with each other for IL-1β and IL-6 measurements compared to TNF-α measurement. However, our study has a small number of participants, hence this study need to be confirmed by investigations involving more participants.

Embriyonik Kök Hücreler ve İndüklenmiş Pluripotent Kök Hücreler

Embriyonik kök hücreler embriyonik blastosistlerin iç hücre kitlesinde yerleşen hücrelerden implantasyon öncesi evrede elde edilirler. Bu hücreler kendini sonsuz bir şekilde yenileyebilen ve çok sayıda farklı hücreye dönüşme (pluripotent) kabiliyetine sahip olan hücrelerdir. Bu özellikleri nedeni ile birçok dejeneratif ve genetik hastalığın tedavisinde kullanılabileceği düşünülmektedir. İnsan embriyonik kök hücreleri ile çalışmanın; etik, politik ve dini tartışmalar nedeniyle zorlaşması ve bilimsel araştırmalarda kullanımının sınırlandırılması araştırmacıları yeni arayışlara itmiştir. Japon araştırmacılar Yamanaka ve ark. 2006 yılında dört transkripsiyon faktörünü kullanarak (Oct 3⁄4, Sox-2, Klf-4, c-Myc) (OSKM faktörleri) fare ve insandan elde edilen fibroblast hücrelerini yeniden programlayarak indüklenmiş pluripotent kök (İPK) hücre elde etmeyi başarmış ve kök hücre araştırmalarında yeni bir dönemi başlatmışlardır. Elde edilen İPK hücrelerin embriyonik kök hücre ile aynı işlevlere sahip olması nedeniyle kök hücre araştırmalarında yeni bir ufuk açılmıştır. Özellikle kişiye ve hastalığa özel İPK hücre elde edilebilmesi, ilaç araştırmaları için laboratuvarda hastalık modellemesinin yapılabilmesini sağlayarak hücre düzeyinde araştırmalar için yeni bir alan açmıştır. ABSTRACT

Research update for articles published in EJCI in 2009: RESEARCH UPDATE FOR ARTICLES PUBLISHED IN EJCI IN 2009

Eur J Clin Invest 2011; 41 (11): 1149–1163