Bibliographic updates

The Monthly Choice
April 2015
Prof. Claude MOLINA - Dr Jacques GAYRAUD

Genetics and Allergy in 2015

1. Gene expression in bronchial epithelium and Clinical Phenotypes of asthmatic disease.
2. Filaggrin gene and food allergy.
3. Exhaled biomarkers and Gene expression at pre-school age improve Asthma prediction at 6 years age.                              
4. Probiotics and risks of Eczema and Atopy
5. GWAS of short-acting β2-agonists : A novel significant locus

1.   Gene expression in bronchial epithelium and Clinical Phenotypes of asthmatic disease.
BD Modena et al, AJRCCM : 2014 12 1363-1372
TS Hallstrand S. Agharib, AJRCCM 2014 and 1333 to 1335

Theme: Asthma – Genetics & Allergy
Key words: Asthma phenotypes – Bronchial epithelium – Asthma biomarkers.

The molecular basis of Asthma phenotypes remains poorly understood.  The authors show that bronchial epithelial cell gene expression, as related to the asthma biomarker FeNO, can identify distinct asthma  phenotypes with gene transcription characteristics (such Th2-high Asthma defined by 3 genes) also   suggesting the presence of novel gene  pathways relevant to these phenotypes.

2.   Filaggrin gene and  food allergy                         
CD Van Gicke Allergy 2015 & al, Allergy: 2015 70  461-464

Theme: Food Allergy – Genetics & Allergy
Key words: Filagrin – Food allergy

Of 155 children reactive to food allergy, diagnosed by DDBFC, 33 had  at least one variant  of  Filaggrin gene loss of function. Among them, 29 were clinically reactive to at least one food, (odd-ratio 4,9) corresponding to a relative risk of 1,5 , compared to carriers of wild-type allele (it will be needed to refine the model for each specific food).  
In another research: GWAS identifies peanut allergy specific loci.   (X.Hong et al: Nature communications 2015  6 24 feb. n°6304). A GWAS in 1315 children and 1444 parents in Chicago Food Allergy Study,   identifies specific loci in the HLA-DR and DQ region at 6p21.32. These associations were replicated in participants of European ancestry and show evidence of epigenetic mediation. According to the authors, this study suggests that the HLA-DR and DQ region probably poses significant genetic risk for peanut allergy.

3.   Exhaled biomarkers and Gene expression at pre-school age improve Asthma prediction at 6 years age.
EM.M. Klaassen et al   AJRCCM  2015 191  2  201-207

Theme: Asthma – Genetics & Allergy
Key words: Exhaled biomarkers – VOC - Asthma gene expression – Asthma prediction

Information on exhaled VOCs combined with possibly expression of inflammatory genes,  at pre-school age, enhance     a correct asthma diagnosis at 6 years, in around 90% of children with wheeze.

4.   Probiotics and risks of Eczema and Atopy
G.Marlow et al  Ped.All.Imm Mars 2015 accepted article

Theme: Eczema – Genetics & Allergy
Key words: Eczema – Probiotics - Atopy
                 
The aim of this study was to investigate differential effects of 2 probiotics: Lactobacillus rhamnosus HN001 and Bifidobacterium animalis HN019  on  the TLR genes, in a high risk infant population (331 children of European ancestry).                                                     
26 TLR SNPs interacted with HN001, resulting in significantly reduced risk of eczema, eczema severity and atopy. Only 2 reacted with HN019.    
In conclusion: TLR genotypes may be positively affected by probiotic supplementation   HN001 had a much  stronger effect than HN019.         

5.   GWAS of short-acting β2-agonists : A novel significant locus
E. Israël et al, AJRCCM: 2015  March 1 191  5 530-535

Theme: Asthma – Pharmacogenetics
Key words: Short acting 2agonists
 
In a phenotypic and genotypic analysis of 724 subjects, a  GWAS of acute bronchodilator response to inhaled β2 agonists was performed. 444.088 SNP were examined and the top 50 was replicated in a population of 444 asthmatics. 4 SNP reached statistical significance on the genetic region of chromosome 2 near ASB 3 gene region associated with smooth  muscle proliferation, suggesting influence of smooth muscle relaxation that occurs in asthma. This is an example of a pharmacogenetic study predictive for an individual responsiveness to β2 agonists leading towards a personalized medicine.  

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Last updated 14 July 2015