COL4A3 is degraded in allergic asthma and degradation predicts response to anti-IgE therapy.

BACKGROUND: Asthma is a heterogeneous syndrome substantiating the urgent requirement for endotype-specific biomarkers. Dysbalance of fibrosis and fibrolysis in asthmatic lung tissue leads to reduced levels of the inflammation-protective collagen 4 (COL4A3). OBJECTIVE: To delineate the degradation of COL4A3 in allergic airway inflammation and evaluate the resultant product as a biomarker for anti-IgE therapy response. METHODS: The serological COL4A3 degradation marker C4Ma3 (Nordic Bioscience, Denmark) and serum cytokines were measured in the ALLIANCE cohort (paediatric cases/controls: n=134/n=35; adult cases/controls: n=149/n=31). Exacerbation of allergic airway disease in mice was induced by sensitising to ovalbumin (OVA), challenge with OVA aerosol and instillation of poly(cytidylic-inosinic). Fulacimstat (chymase inhibitor; Bayer) was used to determine the role of mast cell chymase in COL4A3 degradation. Patients with cystic fibrosis (n=14) and cystic fibrosis with allergic bronchopulmonary aspergillosis (ABPA; n=9) as well as patients with severe allergic uncontrolled asthma (n=19) were tested for COL4A3 degradation. Omalizumab (anti-IgE) treatment was assessed using the Asthma Control Test. RESULTS: Serum levels of C4Ma3 were increased in asthma in adults and children alike and linked to a more severe, exacerbating allergic asthma phenotype. In an experimental asthma mouse model, C4Ma3 was dependent on mast cell chymase. Serum C4Ma3 was significantly elevated in cystic fibrosis plus ABPA and at baseline predicted the success of the anti-IgE therapy in allergic, uncontrolled asthmatics (diagnostic OR 31.5). CONCLUSION: C4Ma3 levels depend on lung mast cell chymase and are increased in a severe, exacerbating allergic asthma phenotype. C4Ma3 may serve as a novel biomarker to predict anti-IgE therapy response

Distinct "asthma" phenotypes of four mouse strains correlate with different responses to house dust mite (HDM) allergens

Background: Asthma is a heterogeneous disease comprising different phenotypes. The corresponding “endotypes” are currently insufficiently understood thus hampering the development of personalized treatments. As a first step in this direction, models for experimental asthma reflecting different asthma phenotypes and endotypes need to be developed. Thus, we aimed to develop a murine model for the investigation of different responses to single Der p allergens. Method: Female mice of four different strains were obtained from Jackson Laboratory. Experimental asthma was induced by intranasal administration of 20 μg HDM extract (D. pteronyssinus extract, Greer, USA) three times weekly/ three weeks. Asthma phenotypes were evaluated by lung function measurements, histology, gene expression, immune cell infiltration, cytokine levels in broncho‐alveolar lavage (BAL) and total and allergen specific IgE in sera. Results: Higher airway resistance, elevated levels of BAL cell and eosinophil numbers, increased levels of IgE in sera and goblet cell hyperplasia were observed in all HDM treated animals in contrast to PBS‐treated controls. Initial tests measuring single anti‐Der p‐IgE reactivities (Der p 1, Der p 2, Der p 7, Der p 20, Der p 21, Der p 23) revealed distinct sensitization patterns for the different strains. The gene expression levels of MUC5B (fold‐change to control A/J: 7.5; BALB/cJ: 3.5; C57Bl/6J: 4.1; C3H/HeJ: 8.5) and CCL11(foldchange to control A/J: 72.7; BALB/cJ: 8.1; C57Bl/6J: 21.1; C3H/HeJ: 21.1) showed differences among the four strains. Combining all these results allowed us to characterize distinct “asthma” phenotypes, ranging from low eosinophilic, Th2 low (“low susceptible”) over an “intermediate susceptible” Th17 high to a mainly eosinophilic, Th2‐dominated phenotype with pronounced changes in lung histology (“high susceptible”). Conclusion: Applying the same HDM treatment in four different mouse strains resulted in distinct asthma phenotypes and showed for the very first time different sensitization patterns. In future studies, we will investigate the mechanisms underlying these different responses to different single Der p allergens and if possible investigate these in human asthma patients as well

Serological neo-epitope extracellular matrix related markers reflecting collagen or elastin degradation are elevated in a mouse model of allergic asthma exacerbation

Asthma is a chronic inflammatory disease, characterized by symptoms including increased mucus production, reversible airway obstruction and lung inflammation: all of which are exaggerated during asthma exacerbations. Extracellular matrix remodeling is associated with the release of ECM protein fragments (neo-epitopes) to the circulation. We sought to investigate the relationship between serological assessment of ECM remodeling markers (neo-epitopes) and the level of symptoms in a mouse model of exacerbated asthma. The hypothesis was, that an increase in ECM remodeling would be observed as a consequence of airway inflammation during exacerbations. Balb/C mice were sensitized to ovalbumin (OVA) (i.p.), acute exacerbations were provoked by i.n. instillation of poly-cytidylic-inosinic acid. Markers of matrix metalloproteinase (MMP) degraded collagen type I (C1M), type III (C3M), type IV (C4M), elastin (ELM7), and laminin (LAMa5) were assessed in serum. Analysis-software: JMP13 (SAS). Serum levels of C1M and LAMa5 individually correlated with bronchoalveolar lavage cells (BAL). Furthermore, the increase of airway resistance (C4M rs = -0.42, p <0.01; C1M, rs -0.55, p <0.001), the absolute airway resistance (C1M, rs = -0.51, p <0.001) and the dynamic compliance (C1M, rs = -0.47, p <0.01), were correlated with the ECM remodeling markers. Additionally, C1M showed a distinct correlation with the amount of mucus producing cells (Pearson coefficient 0.60, p = 0.0006). These data suggest, that serological neo-epitope markers may be valuable tools for objectively assessing the extent of airway remodeling especially during disease aggravation

Prediction of the lower serum anti-Müllerian hormone threshold for ovarian stimulation prior to in-vitro fertilization using the Elecsys® AMH assay: a prospective observational study

Abstract Background In assisted reproductive technology, prediction of treatment failure remains a great challenge. The development of more sensitive assays for measuring anti-Müllerian hormone (AMH) has allowed for the possibility to investigate if a lower threshold of AMH can be established predicting very limited or no response to maximal ovarian stimulation. Methods A prospective observational multicenter study of 107 women, < 40 years of age with regular menstrual cycle and serum AMH levels ≤ 12 pmol/L, treated with 300 IU/day of HP-hMG in a GnRH-antagonist protocol. AMH was measured before treatment start using the Elecsys® AMH assay by Roche Diagnostics. The ability of AMH to predict follicular development and ovarian response was assessed by receiver operating characteristics (ROC). Furthermore, the relationship between AMH at start of stimulation and cycle outcome was investigated using multivariate logistic regression analysis. Results Five out of 107 cycles (4.7%) were cancelled due to lack of follicular development and 60/107 (56%) women did not reach the classical hCG criteria for ovulation induction (≥ 3 follicles of ≥17 mm). An AMH threshold of 4 pmol/L predicted failure to reach the classical hCG criteria with 89% specificity and 53% sensitivity and an area under the curve (AUC) of 0.76 (95% CI 0.66–0.85). AMH predicted cycle cancellation due to lack of follicular development, using a cut-off value of 1.5 pmol/L, with a specificity of 96% and sensitivity of 80% (AUC = 0.92, 95% CI 0.79–1.00). A single-unit increase in AMH was associated with a 29% decrease in odds of failure to reach the classical hCG criteria (OR 0.71 95% CI 0.59–0.85, p < 0.01). The lowest AMH value compatible with a live birth was 1.3 pmol/L. Conclusions Among women with a limited ovarian reserve, pre-treatment serum AMH levels significantly predicted failure to reach the classical hCG triggering criteria and predicted lack of follicular development using a new sensitive assay, but AMH was not suitable for withholding fertility treatment, as even very low levels were associated with live births. Trial registration Not relevan