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Dive into the research topics where H. Haluk Akar is active.

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Featured researches published by H. Haluk Akar.


Journal of Clinical Immunology | 2014

Atypical Severe Combined Immunodeficiency Caused by a Novel Homozygous Mutation In Rag1 Gene in a Girl who Presented with Pyoderma Gangrenosum: A Case Report and Literature Review

Turkan Patiroglu; H. Haluk Akar; Kimberly Gilmour; M. Akif Ozdemir; Shahnaz Bibi; Frances Henriquez; Siobhan O. Burns; Ekrem Unal

Severe combined immunodeficiency (SCID) is a heterogeneous group of inherited defects involving the development of T- and/or B-lymphocytes. We report a female with atypical severe combined immunodeficiency caused by a novel homozygous mutation at cDNA position 2290 (c.2290C > T) in exon 2 of the RAG1 gene. The patient presented with bronchopneumonia, pyoderma gangrenosum (PG), pancytopenia and splenomegaly. She presented to us with pancytopenia and splenomegaly at the age of 11. Her condition was complicated by PG on left lower ankle at the age of 12. She experienced bronchopneumonia at the age of 15. She was diagnosed with RAG1 deficiency at the age of 16. Her immunological presentation included leucopenia and diminished number of B cells.


Clinical Immunology | 2015

Silent brain infarcts in two patients with zeta chain-associated protein 70 kDa (ZAP70) deficiency

H. Haluk Akar; Turkan Patiroglu; Başak Nur Akyıldız; Nazan Ülgen Tekerek; M. Sait Doğan; Selim Doganay; Mirjam van der Burg; Ruhan Dusunsel

Zeta-chain associated protein 70 kDa deficiency (ZAP70) is a form of severe combined immunodeficiency (SCID). It is caused by defects in the signaling pathways associated with T-lymphocyte activation. ZAP70 deficiency is characterized by a marked reduction in peripheral CD8+ T-cells. In this report, we described two patients with ZAP70 deficiency who presented with recurrent infections, lung tuberculosis (TBC), congenital nephrotic syndrome (CNS), and silent brain infarcts (SBIs) as a common feature. The first patient initially presented with recurrent infections and TBC as in a classic SCID patient. At the age of 4, he was interned with febrile seizure. Cranial magnetic resonance imaging (MRI) showed SBIs. The second patient, an 8-month-old boy, presented with congenital nephrotic syndrome caused by cytomegalovirus (CMV) and he had also SBIs.


European journal of microbiology and immunology | 2014

X-linked severe combined immunodeficiency due to a novel mutation complicated with hemophagocytic lymphohistiocytosis and presented with invagination: A case report

Turkan Patiroglu; H. Haluk Akar; Mirjam van den Burg; Ekrem Unal; Başak Nur Akyıldız; Nazan Ülgen Tekerek; Ebru Yilmaz

Severe combined immunodeficiency (SCID) is an inherited disease with profoundly defective T cells, B cells, and natural killer (NK) cells. X-linked SCID (X-SCID) is its most common form. In this report, we describe a 4-month-old male with X-SCID who presented invagination and also showed hemophagocytic lymphohistiocytosis (HLH). The patient was admitted to our hospital with fever, cough, vomiting, monoliasis, and hepatosplenomegaly in postoperative period at the age of 3 months. The laboratory finding revealed no detectable T cells and hypogammaglobulinemia despite normal B-cell counts. Diagnosis of X-SCID was established by DNA analysis of the interleukin (IL)-2 receptor gamma chain gene (IL2RG); namely, we detected the novel mutation in the splice-site of exon 5 (c.595-1G>T). The patient died due to infection at the age of 4 months. Also, this case is the first report that describes the patient with X-SCID with presented invagination.


Asia Pacific Allergy | 2015

The association of forced expiratory volume in one second and forced expiratory flow at 50% of the vital capacity, peak expiratory flow parameters, and blood eosinophil counts in exercise-induced bronchospasm in children with mild asthma.

H. Haluk Akar; Fulya Tahan; Hatice Eke Gungor

Background Exercise-induced bronchoconstriction (EIB), which describes acute airway narrowing that occurs as a result of exercise, is associated with eosinophilic airway inflammation, bronchial hyperresponsiveness. The forced expiratory volume in one second (FEV1) is the most commonly used spirometric test in the diagnosis of EIB in exercise challenge in asthma. Other parameters such as forced expiratory flow at 50% of the vital capacity (FEF50%) and peak expiratory flow (PEF) are used less often in the diagnosis of EIB. Objective The purpose of this study is to evaluate the association of FEV1 and FEF50%, PEF parameters, blood eosinophil counts in EIB in children with mild asthma. Methods Sixty-seven children (male: 39, female: 28) with mild asthma were included in this study. Pulmonary functions were assessed before and at 1, 5, 10, 15, and 20 minutes after exercise. The values of spirometric FEV1, FEF50%, PEF, and blood eosinophil counts were evaluated in EIB in children with mild asthma. Results There was a positive correlation between FEV1 with FEF50% and PEF values (p<0.05; FEF50%, r=0.68; PEF, r=0.65). Also, a positive correlation was found between blood eosinophil counts and the values of spirometric FEV1, FEF50%, and PEF (p<0.05; FEV1, r=0.54; FEF50%, r=0.42; PEF, r=0.26). In addition to these correlations, in the exercise negative group for FEV1, the FEF50% and PEF values decreased more than the cutoff values in 3, and 2 patients, respectively. Conclusion According to the presented study, eosinophil may play a major role in the severity of EIB in mild asthma. FEF50% and PEF values can decrease in response to exercise without changes in FEV1 in mild asthmatic patients.


Allergologia Et Immunopathologia | 2015

Exhaled breath condensate annexin A5 levels in exercise-induced bronchoconstriction in asthma: A preliminary study

Fulya Tahan; H. Haluk Akar; Berkay Saraymen

BACKGROUND AND OBJECTIVE The pathogenesis of exercise-induced bronchoconstriction (EIB) in asthma is incompletely understood. The role of exhaled breath condensate (EBC) annexin A5, which is an anti-inflammatory mediator, has not been investigated. The purpose of this study is to evaluate EBC annexin A5 levels in EIB in asthmatic children. METHODS Two groups of children were enrolled in this study: asthmatic children with positive (n=11) and negative (n=7) responses to exercise. The levels of pre- and post-exercise EBC annexin A5 were determined with using enzyme-linked immunosorbent assay (ELISA). RESULTS We observed significant higher pre-exercise EBC annexin A5 levels in the challenge test negative children than in the challenge test positive children (p<0.05). No significant difference was observed in the post-exercise EBC annexin A5 levels between the groups (p>0.05). Also, no significant difference was observed between pre- and post-exercise EBC annexin A5 levels within each group (p>0.05). There was an inverse correlation between annexin A5 levels and a reduction in forced expiratory volume at one second percent (FEV1%) (p=0.009, r=-0.598). CONCLUSIONS Our preliminary study showed that EBC annexin A5 may have a possible preventive role in EIB in asthma. Annexin A5 and related compounds may provide novel therapeutic approaches to the treatment of EIB in asthma.


Acta Microbiologica Et Immunologica Hungarica | 2015

Autosomal recessive hyper IgM syndrome associated with activation-induced cytidine deaminase gene in three Turkish siblings presented with tuberculosis lymphadenitis - Case report.

Turkan Patiroglu; H. Haluk Akar; Mirjam van der Burg; Ekrem Unal

The hyper-immunoglobulin M (HIGM) syndrome is a heterogeneous group of genetic disorders characterized by recurrent infections, decreased serum levels of immunoglobulin G (IgG) and IgA, and normal/increased serum levels of IgM. Herein, we describe three Turkish siblings with HIGM syndrome who had a homozygous missense mutation (c.70C>T, p.Arg24Trp) in the activation-induced cytidine deaminase gene which results in autosomal recessive HIGM syndrome. Two of the siblings, sibling 1 and sibling 3, presented with cervical deep abscess and cervical tuberculosis lymphadenitis, respectively.


European journal of microbiology and immunology | 2014

A selective IgA deficiency in a boy who presented recurrent parotitis.

H. Haluk Akar; Turkan Patiroglu; L. Duman

Recurrent parotitis is a non-obstructive, non-suppurative inflammatory disease which is characterized by unilateral or bilateral parotid gland swelling attacks. It is also known as juvenile recurrent parotitis. Although the etiology is unknown, congenital malformations of the ductus, genetic predisposition, infections, allergies, autoimmune diseases, and some immune deficiencies are blamed. Here, we present a case report of recurrent parotitis with selective immunoglobulin A deficiency in a six-year-old boy. The patient was presented to us with a new episode of swelling of left parotid region. In the last 2 years, the patient suffered from recurrent parotitis which lasted for approximately 5 days in ten individual episodes.


Turkish Journal of Hematology | 2016

The Frequency of HLA-A, HLA-B, and HLA-DRB1 Alleles in Patients with Acute Lymphoblastic Leukemia in the Turkish Population: A Case-Control Study

Turkan Patiroglu; H. Haluk Akar

We studied the frequencies of human leukocyte antigen alleles (A, B, and DRB1) in 90 patients with acute lymphoblastic leukemia (ALL) and then compared them with 126 controls in this study. Although the frequencies of the A*03 allele, the DRB1*03 allele, the DRB1*04 allele, the A*02/B*35/DRB1*13 haplotype, and homozygosity of A*02 were higher in patients (p=0.006, p=0.003, p=0.002, p=0.01, and p=0.02, respectively), the frequencies of the A*23, B*13, B*40, and DRB1*13 alleles were lower (p=0.002, p=0.07, p=0.002, and p=0.003, respectively) in patients than controls. The frequencies of the DRB1*04 and DRB1*07 alleles were higher in patients in the high-risk group and standard-risk group, respectively (p=0.009 and p=0.007, respectively). This study indicated that the frequency of the A*03 allele, the DRB1*03 allele, the DRB1*04 allele, the A*02/B*35/DRB1*13 haplotype, and A*02 homozygosity may play a predisposing role in patients with ALL in the Turkish population. The frequency of the DRB1*04 and DRB1*07 alleles may also be associated with high risk and standard risk in patients with ALL, respectively.


Central European Journal of Immunology | 2016

Combined immunodeficiencies: Twenty years experience from a single center in Turkey

H. Haluk Akar; Turkan Patiroglu; Michael S. Hershfield; Mirjam van der Burg

Combined immunodeficiencies (CIDs) include a group of inherited monogenic disorders. CIDs are characterized by defective cellular and humoral immunities that lead to severe infections. CIDs can be classified according to immunologic phenotypes as T–B–NK– CID, T–B–NK+ CID, T–B+NK– CID and T–B+NK+ CID. In a 20-year period, from 1994 to 2014, a total of 40 CID patients were diagnosed at the Pediatric Immunology of Erciyes University Medical Faculty in Kayseri, Turkey. The gender ratio (F/M) was 3/5. The median age at the onset of symptoms was 2 months (range, 15 days – 15 years). Of the 14 T–B–NK– CIDs, 6, 2 (siblings), 1, 1 and 4 had a mutation in the ADA, PNP, Artemis, RAG1 genes and unknown genetic diagnosis respectively. Of the 15 T–B–NK+ CIDs, 3, 2 (siblings) and 10 had a mutation in the RAG1, XLF/Cernunnos genes and unknown genetic diagnosis respectively. Of the 9 T–B+NK– CIDs, 2 siblings, 1, 1 and 5 had a mutation in the ZAP70, IL2RG, DOCK8 genes and unknown genetic diagnosis respectively. Of the 2 T–B+NK+ CIDs, 2 had a mutation in the MAGT1 and ZAP70 genes respectively. Of the 40 CIDs, 26 (65%) were died and 14 (35%) are alive. Eight patients received HSCT (hematopoietic stem cell transplantation) with 62.5% survival rate. As a result, patients presented with severe infections in the first months of life have to be examined for CIDs. Shortening time of diagnosis would increase chance of HSCT as life-saving treatment in the CID patients.


Nutricion Hospitalaria | 2015

THE INFLUENCE OF HLA-DQ2 HETERODIMERS ON THE CLINICAL FEATURES AND LABORATORY OF PATIENTS WITH CELIAC DISEASE.

H. Haluk Akar; Mikdat Yıldız; Eylem Sevinç; S. Sökücü

BACKGROUND AND AIM the essential genetic marker related with celiac disease (CD) is the HLA-DQ2 molecule encoded by the DQA1*0501 and DQB1*0201 genes. The aim of this study is to evaluate effect of these alleles on the clinical, serological and histological features of Turkish children with celiac disease. MATERIAL AND METHODS we divided 36 celiac patients to 4 groups according to their HLA-DQ2 genotype based on the presence or absence of DQA1*0501 and DQB1*0201 alleles. Group 1: 4 patients had no HLA-DQ2A1*0501 and DQ2B1*0201 alleles, Group 2: 12 patients had at least one of these alleles with heterozygous status, Group 3: 12 patients had both alleles with heterozygous status, Group 4: 8 patients had both alleles with homozygous status. We compared groups according to the clinical, serological, histological, and biochemical features. RESULTS there was no statistical significance among the groups for age, body mass index (BMI), weight for height, and onset of symptoms. However, both in groups 3 and 4 compared with groups 1 and 2, minor differences were observed for BMI and anti-gliadin antibody (AGA) without statistical significance. According to the anti-endomysial antibody (EMA), Marsh scores, clinical presentations, hematological and biochemical values, there was no statistical significance among groups without constipation that observed higher rate in the 4th group without statistically significance. Hypothyroidism was detected in one patient (25%) in the lowest genetic load group (Group 1) with statistically significance (p < 0.046). CONCLUSION in this study, small differences found among groups were not elucidated the impact of HLADQ2 A1*0501 and DQ2B1*0201 alleles on the clinical, serological and laboratory manifestations of celiac patients. Further studies are needed to assess the effect of reported HLA alleles and other genetic polymorphisms on CD outcomes in children.

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Mirjam van der Burg

Erasmus University Rotterdam

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