Long-Term Loss of Response in Proton Pump Inhibitor-Responsive Esophageal Eosinophilia Is Uncommon and Influenced by CYP2C19 Genotype and Rhinoconjunctivitis.

OBJECTIVES: Proton pump inhibitor-responsive esophageal eosinophilia (PPI-REE) is diagnosed in at least one-third of patients with suspected eosinophilic esophagitis (EoE). We aimed to evaluate the durability and factors influencing long-term efficacy of PPI therapy. METHODS: Retrospective multicenter cohort study of patients with PPI-REE who had at least 12 months of follow-up. PPI therapy was tapered to the lowest dose, which maintained clinical remission. Primary outcomes were the proportion of patients with loss of histological response (<15 eos/HPF) and predictors of loss of response. CYP2C19 polymorphisms were determined from blood samples in a subset of patients. RESULTS: Seventy-five PPI-REE patients were included (mean follow-up 26 months (12-85)), of whom fifty-five (73%) had sustained histological remission on low-dose PPI therapy. Loss of response was significantly higher in those patients with a CYP2C19 rapid metabolizer genotype (36% vs. 6%, P = 0.01) and with rhinoconjunctivitis (40% vs. 13%, P = 0.007). On the multivariate analysis, a CYP2C19 rapid metabolizer genotype (odds ratio (OR) 12.5; 95% confidence interval (CI): 1.3-115.9) and rhinoconjunctivitis (OR 8.6; 95% CI: 1.5-48.7) were independent predictors of loss of response. Among relapsing patients, eosinophilia was limited to the distal esophagus in 14/20 (70%). Nine of ten relapsers, with distal eosinophilia, all showing a CYP2C19 rapid metabolizer genotype, regained histological remission after PPI dose intensification. CONCLUSIONS: Most PPI-REE patients remain in long-term remission on low-dose PPI therapy. CYP2C19 rapid metabolizer genotypes and rhinoconjunctivitis were independent predictors of loss of response to PPI, but patients frequently responded to PPI dose escalation.

Functional relevance of NLRP3 inflammasome-mediated interleukin (IL)-1ß during acute allergic airway inflammation.

Overall asthmatic symptoms can be controlled with diverse therapeutic agents. However, certain symptomatic individuals remain at risk for serious morbidity and mortality, which prompts the identification of novel therapeutic targets and treatment strategies. Thus, using an adjuvant-free T helper type 2 (Th2) murine model, we have deciphered the role of interleukin (IL)-1 signalling during allergic airway inflammation (AAI). Because functional IL-1ß depends on inflammasome activation we first studied asthmatic manifestations in specific inflammasome-deficient [NACHT, LRR and PYD domains-containing protein 3 (NLRP3(-/-) ) and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC(-/-) )] and IL-1 receptor type 1(-/-) (IL-1R1(-/-) ) mice on the BALB/c background. To verify the onset of disease we assessed cellular infiltration in the bronchial regions, lung pathology, airway hyperresponsiveness and ovalbumin (OVA)-specific immune responses. In the absence of NLRP3 inflammasome-mediated IL-1ß release all symptoms of AAI were reduced, except OVA-specific immunoglobulin levels. To address whether manipulating IL-1 signalling reduced asthmatic development, we administered the IL-1R antagonist anakinra (Kineret®) during critical immunological time-points: sensitization or challenge. Amelioration of asthmatic symptoms was only observed when anakinra was administered during OVA challenge. Our findings indicate that blocking IL-1 signalling could be a potential complementary therapy for allergic airway inflammation.

Transcriptional explorations of CAPN3 identify novel splicing mutations, a large-sized genomic deletion and evidence for messenger RNA decay.

Mutations in the gene encoding calpain-3 (CAPN3) cause autosomal recessive limb-girdle muscular dystrophy type 2A (LGMD2A) and idiopathic eosinophilic myositis. Accurate diagnosis and genetic counselling are based on the identification of disease-causing mutations on both alleles of CAPN3 in the patients. In the present study, we used transcriptional analysis as a complementary approach for patients suspected of being affected with LGMD2A, in whom initial denaturing high-performance liquid chromatography genomic mutation screening evidenced no or only one CAPN3 mutation obviously considered as disease causing. This allowed to identify and characterize cDNA deletions. Further genomic analysis allowed to determine the origin of these deletions, either as splicing defects caused by intronic mutations or as an internal multi-exonic deletion. In particular, we report two novel CAPN3 mutations (c.1745 + 4_1745 + 7delAGTG in IVS13 and c.2185-16A>G in IVS20) and a recurrent large-sized genomic deletion including exons 2-8 for which genomic breakpoints have been characterized. In addition, our results indicate nonsense-mediated messenger RNA decay as a mechanism for under-expression of CAPN3 associated to some specific variations.

Microarray analysis of allergic fungal sinusitis and eosinophilic mucin rhinosinusitis.

OBJECTIVE: Our goal was to determine and compare the differential gene expression in allergic fungal sinusitis (AFS) and eosinophilic mucin rhinosinusitis (EMRS). STUDY DESIGN AND SETTING: We conducted a complementary DNA microarray analysis of prospectively gathered tissue from a tertiary rhinology practice. RESULTS: Compared to normal subjects, 38 genes or potential genes were differentially expressed in AFS patients, while 10 genes were differentially expressed in EMRS patients. Four genes differentially expressed in EMRS were not differentially expressed in AFS: cathepsin B, sialyltransferase 1, GM2 ganglioside activator protein, and S100 calcium binding protein. These genes mediate lysosomal activity and are known to have differential expression in inflammatory and neoplastic states. CONCLUSIONS: EMRS and AFS show some similarities in gene expression profiles using microarray analysis. Significant differences in gene expression in both EMRS and AFS patients compared with normal subjects provide early clues to the pathophysiology of EMRS and AFS. SIGNIFICANCE: This study demonstrates that complementary DNA microarray analysis is a feasible tool for studying different disease subclassifications and is the first to study these subclasses in chronic rhinosinusitis.

Increase in IL-8, IL-10, IL-13, and RANTES mRNA levels (in situ hybridization) in the nasal mucosa after nasal allergen provocation.

BACKGROUND: Allergic inflammation is regulated by the local production and release of several cytokines. OBJECTIVES: This study was designed to assess the changes in mRNA cytokine-positive cells after allergen provocation and to compare these cytokines with tissue eosinophilia as a marker of allergic inflammation. METHODS: A grass pollen allergen provocation study was conducted in autumn, out of the hay fever season. Nasal mucosal biopsy specimens were taken before provocation and 1 hour, 24 hours, and 1 week after allergen provocation. Eosinophils and mRNA-positive cells (in situ hybridization for IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, IFN-gamma, RANTES, and TNF-alpha) were assessed in the biopsy specimens. RESULTS: After allergen provocation, an increase in cell number was found for eosinophils and cells expressing mRNA for the chemokines IL-8 and RANTES and for the TH2 cytokines IL-10 and IL-13. Significant correlations were found between eosinophils and RANTES and eosinophils and IFN-gamma in the early phase and between eosinophils and IL-5 and eosinophils and RANTES in the late phase. The increase in eosinophils and IL-10 and IL-13 mRNA-positive cells could still be observed 1 week after allergen provocation. CONCLUSIONS: Nasal allergen provocation induced significant tissue eosinophilia and a significant increase in IL-8, IL-13, and RANTES mRNA-positive cells. A significant increase in eosinophils and IL-10 and IL-13 mRNA-positive cells compared with baseline can still be observed 1 week after a single allergen provocation.