Biomedical subjects

Fatma Dedeoglu

Publications and source records attributed to Fatma Dedeoglu.

10 recordsLinked to original sources

PubMed2026

Clinical Features and Outcome Measures Across Still Disease (Systemic Juvenile Idiopathic Arthritis and Adult-Onset Still Disease) Cohorts Worldwide: A Systematic Literature Review.

OBJECTIVE: Multinational research is essential to improve recognition and management of systemic juvenile idiopathic arthritis (sJIA). Current cohorts vary in the clinical variables and outcome measures collected. Adult-onset Still disease (AOSD) and sJIA are widely considered to comprise a single disease spectrum; however, classification criteria and clinical tools differ between groups. This systematic literature review aimed to identify clinical features and outcome measures collected across sJIA and AOSD cohorts worldwide to guide the development of a minimal dataset for Still disease. METHODS: A literature search was conducted from 2000 to 2024 using Ovid MEDLINE, Embase, and Wiley Cochrane Library (Trials). Included articles were in English and described sJIA or AOSD cohorts of ≥ 20 patients, reporting patient characteristics, clinical and laboratory features, and outcome measures. RESULTS: A total of 240 articles were included (95 sJIA, 134 AOSD, 11 mixed), from 37 countries, describing 23,136 patients. International League of Associations for Rheumatology classification was used in 77.9% of sJIA studies, whereas 98.5% of AOSD studies used Yamaguchi criteria. There was no clear consensus on the definition of macrophage activation syndrome. Race and ethnicity were only reported in 11.7% of articles. Cohorts evaluated aligned on the most commonly collected laboratory items for both AOSD and sJIA, with some agreement among clinical features, whereas disease outcome measures used to evaluate and follow disease trajectory were variable. CONCLUSION: Data reporting across sJIA and AOSD cohorts for clinical characteristics and outcome measures is widely heterogeneous. Consensus on the identification of a standardized minimal dataset for Still disease cohorts is needed to foster future collaboration and improve patient outcomes.

Humans↗

PubMed2025

Diagnostic Implications and Correlates of Plasma Adenosine Deaminase 2 Activity and ADA2 Variants.

OBJECTIVE: Deficiency of adenosine deaminase 2 (DADA2) is a monogenic autoinflammatory disease manifested as polyarteritis nodosa, stroke, and bone marrow failure. Leveraging an international cohort of 200 DADA2 cases, we aimed to characterize the diagnostic utility of a plasma ADA2 enzyme activity assay and understand the implications of residual ADA2 activity. METHODS: Data were collected from individuals who underwent ADA2 testing from 2018 to 2025. Plasma ADA2 activity was determined using an established spectrophotometric assay. ADA2 variants were analyzed in transfected cells by enzyme assay and western blotting. RESULTS: We determined that plasma ADA2 activity is 99.0% and 96.0% sensitive and 99.7% and 98.8% specific in distinguishing genetically confirmed DADA2 cases from controls and carriers, respectively. Eighteen individuals with DADA2 (9%) possessed detectable ADA2 activity, including several cases with levels seen in carriers. Residual ADA2 activity was associated with the vasculitis/inflammatory phenotype but not with disease severity. Genotype analysis revealed that 14 of 18 cases with residual plasma activity possessed at least one hypomorphic missense variant with greater than 20% residual ADA2 function when overexpressed in 293T cells, often occurring in trans with a more deleterious variant. In vitro analysis revealed that missense ADA2 variants exert variable dominant-negative effects by forming large intracellular protein aggregates via disulfide bond formation at a cysteine residue (Cys408). CONCLUSION: We confirmed the utility of plasma ADA2 activity as a diagnostic assay and showed that the inflammatory phenotype of DADA2 occurred in cases with residual activity. In vitro findings illustrate potential interactions of ADA2 variants to synergistically disrupt protein function.

Humans↗

PubMed2005

Coronary artery dilation among patients presenting with systemic-onset juvenile idiopathic arthritis.

OBJECTIVE: To evaluate coronary artery diameters among patients presenting with systemic-onset juvenile idiopathic arthritis (SoJIA). METHODS: Fifty cases of SoJIA were reviewed. At the time of initial presentation with fever, 12 patients had echocardiograms that included a complete evaluation of the coronary arteries. A single reviewer measured the diameters of the left main, proximal left anterior descending, and proximal right coronary arteries. Body surface area-adjusted z scores were calculated with respect to a normative population. RESULTS: Coronary artery dilation (z score: >2) was observed for 5 of the 12 patients with SoJIA who had echocardiograms performed at the time of presentation with fever. No patient developed a coronary artery aneurysm, and all of the coronary artery z scores normalized within 4 months. Only 2 of the 5 patients with coronary artery z scores of >2 fulfilled the clinical criteria for Kawasaki disease, the most commonly recognized cause of coronary artery dilation among children. CONCLUSIONS: Children presenting with SoJIA may have coronary artery dilation similar to that observed for children with Kawasaki disease. These data suggest that the presence of coronary artery dilation on initial echocardiograms for patients with fever does not exclude the diagnosis of SoJIA.

Arthritis, Juvenile↗

PubMed2005

TACI and BAFF-R mediate isotype switching in B cells.

The tumor necrosis factor family members BAFF and APRIL induce Ig isotype switching in human B cells. We analyzed the ability of BAFF and APRIL to induce isotype switching in murine B cells to IgG1, IgA, and IgE. APRIL and BAFF each engage two receptors, transmembrane activator and calcium-modulator and cytophilin ligand interactor (TACI) and B cell maturation antigen (BCMA), on B cells. In addition, BAFF engages a third receptor on B cells, BAFF-R. To determine the role of these receptors in isotype switching, we examined B cells from mice deficient in TACI, BCMA, and BAFF-R. The results obtained indicate that both TACI and BAFF-R are able to transduce signals that result in isotype switching.

Animals↗

PubMed2005

Vasculitis in children.

This article provides a general overview of vasculitis, situations in which the diagnosis should be considered, diagnostic methods, and therapeutic considerations. Details and treatments unique to specific vasculitides are also reviewed.

Child↗

PubMed2005

Update on pediatric vasculitis.

PURPOSE OF REVIEW: The purpose of this review is to provide an overview of the recent research and progress made in the field of pediatric vasculitis. RECENT FINDINGS: Over the past year, researchers have described several polymorphisms in Henoch-Schonlein purpura and Kawasaki Disease as well as the association between various vasculitides and infections. International and multidisciplinary efforts in Kawasaki Disease have resulted in recommendations for its diagnosis, treatment, and long-term management to improve patient care and further increase global collaboration. Researchers are investigating the role of inflammation and its role in endothelial health and atherosclerosis. Treatment regimens continue to improve, with the use of different immunosuppressive medications; however, we continue to have incomplete treatment successes. SUMMARY: Vasculitides are rare conditions with significant morbidity and mortality whose prognosis has improved with newer diagnostic modalities and treatments; however, we continue to have insufficient knowledge of vasculitides and lack unambiguous diagnostic criteria. As technology continues to progress it is clear that a single cause of these diseases may be an oversimplification: the genetic makeup of individuals, as well as various environmental exposures, are of vital importance in the pathophysiology and evolution of disease processes, as well as response to therapy. Efforts should continue to improve international multicenter collaboration and interdisciplinary efforts to help solve this ever-growing puzzle.

Bacterial Infections↗

PubMed2004

Impaired IgA class switching in APRIL-deficient mice.

The tumor necrosis factor (TNF) family member APRIL binds to the receptors BCMA on B cells and TACI on B and T cells. To investigate the role of APRIL in immunity, we generated APRIL-deficient mice. APRIL(-/-) mice have normal T and B lymphocyte development, normal T and B cell proliferation in vitro, but increased numbers of CD44(hi)CD62L(lo) CD4(+) effector/memory T cells and increased IgG responses to T-dependent antigens. Serum IgA levels were significantly decreased, and serum IgA antibody responses to mucosal immunization with TD antigens and to type 1 T-independent antigens were impaired in APRIL(-/-) mice. APRIL by itself induced IgA as well as IgG1 isotype switching in CD40-deficient IgM(+)IgD(+) sorted B cells. These results suggest that APRIL down-regulates T cell-dependent antibody responses and promotes IgA class switching.

Animals↗

PubMed2004

Induction of activation-induced cytidine deaminase gene expression by IL-4 and CD40 ligation is dependent on STAT6 and NFkappaB.

Activation-induced cytidine deaminase (AID) is an inducible gene that plays an important role in class switch recombination, somatic hypermutation and gene conversion in B cells. We examined the regulation of AID gene expression in human and mouse B cells by IL-4 and CD40 ligation. IL-4 by itself and, to a much lesser extent, CD40 ligation induced AID mRNA expression in primary B cells. The two stimuli strongly synergized in inducing AID mRNA and protein expression. IL-4 induced STAT6 binding to a site in the 5' upstream region of the AID gene, while CD40 ligation induced NFkappaB binding to two sites in that region. B cells from STAT6-/- mice failed to up-regulate AID in response to IL-4, while B cells from p50-/- mice were impaired in their ability to up-regulate AID in response to CD40 ligation and IL-4. These results suggest that signals delivered via CD40 that activate NFkappaB synergize with signals delivered via the IL-4 receptor that activate STAT6 to induce optimal AID gene expression.

Animals↗

PubMed2003

Targeted inactivation of the IL-4 receptor alpha chain I4R motif promotes allergic airway inflammation.

The insulin/interleukin-4 (IL-4) receptor (I4R) motif mediates the association of insulin receptor substrate (IRS)-2 with the interleukin-4 (IL-4)Ralpha chain and transduces mitogenic signals in response to IL-4. Its physiological functions were analyzed in mice with a germline point mutation that changed the motif's effector tyrosine residue into phenylalanine (Y500F). The Y500F mutation abrogated IRS-2 phosphorylation and impaired IL-4-induced CD4+ T lymphocyte proliferation but left unperturbed Stat6 activation, up-regulation of IL-4-responsive gene products, and Th cell differentiation under Th2 polarizing conditions. However, in vivo the Y500F mutation was associated with increased allergen-induced IgE production, airway responsiveness, tissue eosinophilia, and mucus production. These results define an important role for the I4R motif in regulating allergic inflammation.

Animals↗

PubMed2002

The binding site for TRAF2 and TRAF3 but not for TRAF6 is essential for CD40-mediated immunoglobulin class switching.

To define the role of TRAF proteins in CD40-dependent isotype switching in B cells, we introduced wild-type (WT) and mutant CD40 transgenes that lacked the binding motifs for TRAF6 (CD40deltaTRAF6), TRAF2 and TRAF3 (CD40deltaTRAF2/3), or both (CD40deltaTRAFs) into B cells of CD40(-/-) mice. The in vivo isotype switch defect in CD40(-/-) mice was fully corrected by WT and CD40deltaTRAF6, partially by CD40deltaTRAF2/3, and not at all by CD40deltaTRAFs transgenes. CD40-mediated isotype switching, proliferation, and activation of p38, JNK, and NFkappaB in B cells were normal in WT and CD40deltaTRAF6 mice, severely impaired in CD40deltaTRAF2/3, and absent in CD40deltaTRAFs mice. These results suggest that binding to TRAF2 and/or TRAF3 but not TRAF6 is essential for CD40 isotype switching and activation in B cells.

Amino Acid Motifs↗