Analysis of polymorphisms in olive pollen allergy: IL13, IL4RA, IL5 and ADRB2 genes.
BACKGROUND
Previous results demonstrated that sensitization to specific olive pollen allergens could be related with a different clinical pattern (asthma and/or rhinitis), and that specific patterns of sensitization are regulated by different HLA class II antigens. The authors analyze the possible implication of 7 genetic polymorphisms described as asthma susceptibility genes: IL13 (C-1112T and R130Q), IL4RA (I50V, Q551R), IL5 (C-746T) and ADRB2 (Q27E and R16G) in specific olive pollen allergic sensitization.


METHODS
The authors genotyped seven polymorphisms of the IL13, IL4RA, IL5 and ADRB2 genes in 146 patients allergic to olive pollen with seasonal rhinitis/asthma and 50 controls using the polymerase chain reaction-restriction fragment length polymorphism and real-time polymerase chain reaction techniques.


RESULTS
Two polymorphisms of IL13 were associated with allergy to olive pollen: the TT genotype of IL13 C-1112T was decreased (odds ratio, OR = 0.35, p = 0.006) whereas the RQ heterozygous genotype of IL13 R130Q increased in patients allergic to olive pollen (OR = 3.12, p = 0.009). The combined analysis of two IL4RA single nucleotide polymorphisms (SNPs) (I50V and Q551R) showed an association with asthma: IL4RA V50/Q551 was associated with risk (OR = 2.48, p = 0.007) whereas the IL4RA V50R551 haplotype was associated with protection (OR = 0.31, p = 0.003).


CONCLUSIONS
The IL13 polymorphisms under study were associated with specific allergy to olive pollen: the IL13 C-1112T polymorphism as a protective factor and the IL13 R130Q polymorphism as a risk factor. Interestingly, although single polymorphisms of IL4RA are not associated with any phenotype analyzed, the interaction between IL4RA I50V/Q551R was strongly associated with the asthma phenotype. IL13 and IL4RA could be relevant markers for allergy to olive pollen and asthma development.
Servicio de Inmunología, Fundación Jiménez Díaz-CAPIO, CIBERES (ISCIII), Madrid, Spain.
Elena
E
Llanes
Joaquín
J
Quiralte
Esther
E
López
Beatriz
B
Sastre
Marina
M
Chacártegui
Victoria
V
del Pozo
Pilar
P
Palomino
Carlos
C
Lahoz
Blanca
B
Cárdaba
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D001249:Asthma / Q000097:blood / Q000235:genetics / Q000276:immunology; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D018793:Interleukin-13 / Q000097:blood / Q000235:genetics*; D053662:Interleukin-4 Receptor alpha Subunit / Q000235:genetics*; D015848:Interleukin-5 / Q000097:blood; D008297:Male; D008875:Middle Aged; D031658:Olea / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology; D020641:Polymorphism, Single Nucleotide; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D006255:Rhinitis, Allergic, Seasonal / Q000097:blood / Q000235:genetics* / Q000276:immunology; D012882:Skin Tests; D055815:Young Adult
D000485:Allergens; D018793:Interleukin-13; D053662:Interleukin-4 Receptor alpha Subunit; D015848:Interleukin-5; D010940:Plant Proteins; D018343:Receptors, Adrenergic, beta-2; D007073:Immunoglobulin E