Skin test hypersensitivity for childhood asthma in Istanbul during a period of 16 years

BACKGROUND

For diagnosis of allergic disorders, besides history and physical examination, many in vivo and in vitro laboratory tests are used. Skin prick test (SPT) is an easily performed and valuable test in children. Our aim was to evaluate the SPT results of asthmatic children according to age and gender, in Istanbul and its neighborhood, followed for a period of 16 years.

MATERIAL AND METHODS

Consecutive 5080 asthmatic children, aged 1 to 18 years, admitted to Pediatric Allergy Policlinics of Istanbul University Cerrahpasa Medicine Faculty from 1987 to 2003, were screened retrospectively for 10 frequently exposed allergens.

RESULTS

3086 cases (61 %) had SPT reactivity for one and/or for multiple allergens; the SPT reactivity percentages of the exposed allergens was 50 % (2554 cases) for house dust mites DP, 49 % (2462 cases) for house dust mites DF, 15 % (784 cases) for cat dander, 10 % (525 cases) for dog dander, 4 % (228 cases) for lamb wool, 10 % (504 cases) for wheat, 3 % (162 cases) for egg white, 6 % (345 cases) for hazelnut pollen, 6 % (318 cases) for Candida Albicans, 6 % (326 cases) for Aspergillus Fumigatus.

CONCLUSION

While house dust mites were determined as the predominant allergen for each age groups in this study, allergy against cat dander was the third important allergen in sequence, as cat is a domestic pet which is frequently kept at home in Turkey.

Childhood asthma perception in Turkey under real-life environment (CAPTURE) study

Successful management of asthma requires good communication between patients and the healthcare team. The background and expectations of a patient inevitably influence the success of any partnership. A questionnaire-based survey was performed to obtain data on the perception of the impact of asthma in daily life among children (age-range 6-14 years) and adolescents (age-range 15-20 years). A total of 756 patients (384 children, 372 adolescents) were randomly selected from 11 Turkish cities and interviewed face-to-face. Of the total study population, 71.3% received regular follow-up and 75.9% currently took asthma medication. Almost 50% reported that asthma affected their lives significantly. Even though half of the patients had symptoms at least once a week, one-third were not receiving regular prophylactic treatment. Exercise produced asthma symptoms in 45.5% of children and 27.4% of adolescents. The finding that asthma continues to be a major health problem clearly indicates an urgent need for further management programs in Turkey.

Cystic fibrosis mutations and associated haplotypes in Turkish cystic fibrosis patients

Identification of mutations causing cystic fibrosis (CF) in the Turkish population is essential for assessment of the molecular basis of CF in Turkey and the development of strategies for prenatal diagnosis and genetic counseling. Here, we present an updated report of mutations found in the Turkish CF population from an extensive screening study of the entire coding region, including exon-intron boundaries and the promoter region. Cases for which mutations could not be identified were also screened for previously defined large alterations and (TG)mTn-M470V loci. This study revealed a total of 27 different mutations accounting for almost 60% of disease genes in the Turkish population. In this study, we also identified the haplotypes associated with 17 mutations and those associated with unknown mutations. The mutation spectrum of CF in Turkey and its associated haplotypes indicated the presence of a major Mediterranean component in the contemporary Turkish population.

In a novel form of IFN-gamma receptor 1 deficiency, cell surface receptors fail to bind IFN-gamma

Complete IFN-gamma receptor ligand-binding chain (IFNgammaR1) deficiency is a life-threatening autosomal recessive immune disorder. Affected children invariably die of mycobacterial infection, unless bone marrow transplantation is undertaken. Pathogenic IFNGR1 mutations identified to date include nonsense and splice mutations and frameshift deletions and insertions. All result in a premature stop codon upstream from the segment encoding the transmembrane domain, precluding cell surface expression of the receptors. We report herein two sporadic and two familial cases of a novel form of complete IFNgammaR1 deficiency in which normal numbers of receptors are detected at the cell surface. Two in-frame deletions and two missense IFNGR1 mutations were identified in the segment encoding the extracellular ligand-binding domain of the receptor. Eight independent IFNgammaR1-specific mAb's, including seven blocking antibodies, gave recognition patterns that differed between patients, suggesting that different epitopes were altered by the mutations. No specific binding of (125)I-IFN-gamma to cells was observed in any patient, however, and the cells failed to respond to IFN-gamma. The mutations therefore cause complete IFNgammaR1 deficiency by disrupting the IFN-gamma-binding site without affecting surface expression. The detection of surface IFNgammaR1 molecules by specific antibodies, including blocking antibodies, does not exclude a diagnosis of complete IFNgammaR1 deficiency.

Analysis of the CFTR gene in Turkish cystic fibrosis patients: identification of three novel mutations (3172delAC, P1013L and M1028I)

In order to determine the spectrum of cystic fibrosis (CF) mutations in the Turkish population, a complete coding region of the cystic fibrosis transmembrane conductance regulator (CFTR) gene including exon-intron boundaries, on 122 unrelated CF chromosomes from 73 Turkish CF families was analysed by denaturing gradient gel electrophoresis and multiplex heteroduplex analysis on MDE gel matrix. In addition to 15 previously reported mutations and 12 polymorphisms, three novel mutations, namely 3172delAC, P1013L and M1028I, were detected. DeltaF508 was found to be present on 18.8% of CF chromosomes. The second most common mutation was 1677delTA, with a frequency of 7.3%, followed by G542X and 2183AA-->G mutations, with frequencies of 4.9%. These four most common mutations in Turkish CF population account for approximately 36% of mutations. This study could only detect 52.5% of disease-causing mutations in this population; 47.5% of CF alleles remain to be identified, reflecting the high molecular heterogeneity of the Turkish population.