Putative association of SMAPIL polymorphisms with risk of aspirin intolerance in asthmatics

Unraveling the genetic basis of aspirin hypersensitivity in asthma beyond arachidonate pathways

Although aspirin-exacerbated respiratory disease (AERD) has attracted a great deal of attention because of its association with severe asthma, it remains widely under-diagnosed in the asthmatic population. Oral aspirin challenge is the best method of diagnosing AERD, but this is a time-consuming procedure with serious complications in some cases. Thus, development of non-invasive methods for easy diagnosis is necessary to prevent unexpected complications of aspirin use in susceptible patients. For the past decade, many studies have attempted to elucidate the genetic variants responsible for risk of AERD. Several approaches have been applied in these genetic studies. To date, a limited number of biologically plausible candidate genes in the arachidonate and immune and inflammatory pathways have been studied. Recently, a genome-wide association study was performed. In this review, the results of these studies are summarized, and their limitations discussed. In addition to the genetic variants, changes in methylation patterns on CpG sites have recently been identified in a target tissue of aspirin hypersensitivity. Finally, perspectives on application of new genomic technologies are introduced; these will aid our understanding of the genetic pathogenesis of aspirin hypersensitivity in asthma.

Differential gene expression profile in PBMCs from subjects with AERD and ATA: a gene marker for AERD

Aspirin-exacerbated respiratory disease (AERD) is associated with severe asthma and aspirin can cause asthma to worsen, often in the form of a severe and sudden attack. The oral aspirin challenge is the gold standard to confirm the diagnosis of AERD, but it is time consuming and produces serious complications in some cases. Therefore, more efficient and practical method is needed to predict AERD patients. The aim of the present study was to identify AERD-related gene expression in peripheral blood mononuclear cells (PBMCs) and examine the diagnostic potential of these candidate gene(s) for predicting AERD. To do this, RNAs from 24 subjects with AERD and 18 subjects with aspirin-tolerant asthma (ATA) were subjected to microarray analysis of ~34,560 genes. In total, 10 genes were selected as candidate gene markers by applying p ≤ 0.001(t test) and ≥8-fold change, and to correct for multiple comparisons, the false discovery rate analyses were performed. By applying multiple logistic regression analysis, among possible 1,023 models (2(10)-1), a model consisting of CNKSR3, SPTBN2, and IMPACT was selected as candidate set, because this set showed the best AUC (0.98) with 88 % sensitivity and 89 % specificity. For validation, mRNA levels by real-time PCR on PBMCs from two population sets in a gene-chip study and another replication sample, 20 AERD, 20 ATA, and 8 normal controls, were significantly different between groups with 100 % sensitivity and 100 % specificity in each of the two population sets. However, IMPACT gene did not differentiate between AERD and normal controls. The set of the two genes (CNKSR3 and SPTBN2) showed the best AUC (0.96) with 88 % sensitivity and 94 % specificity in a gene-chip study sample. In addition, this set showed perfect discriminative power with AUC (1.0, 100 % sensitivity and 100 % specificity) in each of the two population sets: the gene-chip samples and the replication samples. It also showed perfect discrimination for AERD from NC (AUC: 1.0) and ATA from NC (AUC: 1.0). In conclusion, we developed the two gene markers (CNKSR3 and SPTBN2) of PBMC which differentiate between AERD and ATA with a perfect discriminative power. These gene markers may be an efficient and practical method for predicting AERD.