Aspirin intolerant asthma (AIA) is frequently characterized as an aspirin (ASA)-exacerbated respiratory disease (AERD). It is a clinical syndrome associated with chronic severe inflammation in the upper and lower airways resulting in chronic rhinitis, sinusitis, recurrent polyposis, and asthma. AERD generally develops secondary to abnormalities in inflammatory mediators and arachidonic acid biosynthesis expression. Upper and lower airway eosinophil infiltration is a key feature of AERD; however, the exact mechanisms of such chronic eosinophilic inflammation are not fully understood. Cysteinyl leukotriene over-production may be a key factor in the induction of eosinophilic activation. Genetic studies have suggested a role for variability of genes in disease susceptibility and response to medication. Potential genetic biomarkers contributing to the AERD phenotype include HLA-DPB1*301, LTC4S, ALOX5, CYSLT, PGE2, TBXA2R, TBX21, MS4A2, IL10 -1082A > G, ACE -262A > T, and CRTH2 -466T > C; the four-locus SNP set was composed of B2ADR 46A > G, CCR3 -520T > G, CysLTR1 -634C > T, and FCER1B -109T > C. Management of AERD is an important issue. Aspirin ingestion may result in significant morbidity and mortality, and patients must be advised regarding aspirin risk. Leukotriene receptor antagonists (LTRA) that inhibit leukotriene pathways have an established role in long-term AERD management and rhinosinusitis. Aspirin desensitization may be required for the relief of upper and lower airway symptoms in AERD patients. Future research should focus on identification of biomarkers for a comprehensive diagnostic approach.

Elevated levels of circulating CD4(+) CRTh2(+) T cells are a feature of severe asthma, despite high-dose corticosteroids. Tracking the systemic level of these cells may help identify type 2 severe asthmatics at risk of exacerbation.

The FCER1G-237A>G and FCERIA-344C>T polymorphisms may contribute to the development of AIA in a Korean population.

PurposeAspirin-intolerant asthma (AIA) is characterized by moderate to severe asthma that is aggravated by aspirin or other non-steroidal anti-inflammatory drugs. Affected patients frequently have chronic rhinosinusitis and nasal polyposis due to persistent upper and lower airway inflammation with marked eosinophilia. IL-13 plays a crucial role in the development of allergic asthma by inducing airway eosinophilia and hyper-reactivity and it has been correlated with an increased eosinophil count.MethodsTwo promoter polymorphisms of the IL-13 gene (-1510 A>C and -1055C>T) and one coding nonsynonymus Arg110Gln (110G>A) polymorphism were genotyped using primer extension methods in 162 patients with AIA, 301 patients with aspirin-tolerant asthma (ATA), and 430 normal healthy controls (NC).ResultsThere was no significant difference in the genotype, allele, and haplotype frequencies of the three polymorphisms among the three groups. AIA patients with the AA genotype -1510A>C (P=0.012) and CC genotype -1055C>T (P<0.001) had a significantly higher frequency of rhinosinusitis, as compared to those with the minor alleles of these two single nucleotide polymorphisms. AIA patients with the GG genotype had a higher peripheral eosinophil count (P=0.025) and a higher serum eotaxin-1 level (P=0.044), as compared to patients with the AA genotype IL-13 Arg110Gln (110G>A).ConclusionsThese findings suggest that the IL-13 polymorphisms at -1510A>C and 1055C>T are associated with the development of rhinosinusitis in AIA patients. IL-13 Arg110Gln may be associated with an increased eosinophil count and eotaxin-1 level and could increase eosinophilic inflammation in the upper and lower airways of patients with AIA.

The CRTH2 -466T>C polymorphism increases serum and cellular eotaxin-2 production through lowered CRTH2 expression, leading to eosinophilic infiltration in AERD patients.