Oncological Outcomes and Patterns of Recurrence after the Surgical Resection of an Invasive Intraductal Papillary Mucinous Neoplasm versus Primary Pancreatic Ductal Adenocarcinoma: An Analysis from the German Cancer Registry Group of the Society of German Tumor Centers.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMNs) are premalignant cystic neoplasms of the pancreas (CNPs), which can progress to invasive IPMN and pancreatic cancer. The available literature has shown controversial results regarding prognosis and clinical outcomes after the resection of invasive IPMN. AIMS: This study aims to characterize the oncologic outcomes and metastatic progression pattern after the resection of non-metastatic invasive IPMN. METHODS: Data were obtained from 24 clinical cancer registries participating in the German Cancer Registry Group of the Society of German Tumor Centers (ADT). Patients with invasive IPMN (n = 217) as well as PDAC (n = 5794) between 2000 and 2021 were included and compared regarding oncological outcomes. RESULTS: Invasive IPMN was significantly smaller in size (p < 0.001) and of a lower tumor grade (p < 0.001), with fewer lymph node metastases (p < 0.001), lymphangiosis (p < 0.001), and consequently a higher R0 resection rate (88 vs. 74%) compared to PDAC. Moreover, invasive IPMN was associated with fewer local (11 vs. 15%) and distant recurrences (29 vs. 46%) and metastasized more frequently in the lungs only (26% vs. 14%). Invasive IPMN was associated with a longer median OS (29 vs. 19 months) and DFS (31 vs. 15 months) compared to PDAC and stayed independently prognostic in multivariable analyses. These survival differences were most pronounced in early tumor stages. Interestingly, postoperative chemotherapy was not associated with improved overall survival in surgically resected invasive IPMN. CONCLUSIONS: Invasive IPMN is a rare pancreatic entity with increasing incidence in Germany. It is associated with favorable histopathological features at the time of resection and longer OS and DFS compared to PDAC, particularly before the locoregional spread has occurred. Invasive IPMNs are associated with lung-only metastasis. The benefit of postoperative chemotherapy after the resection of invasive IPMN remains uncertain.

C5aR1 activation in mice controls inflammatory eosinophil recruitment and functions in allergic asthma.

BACKGROUND: Pulmonary eosinophils comprise at least two distinct populations of resident eosinophils (rEOS) and inflammatory eosinophils (iEOS), the latter recruited in response to pulmonary inflammation. Here, we determined the impact of complement activation on rEOS and iEOS trafficking and function in two models of pulmonary inflammation. METHODS: BALB/c wild-type and C5ar1-/- mice were exposed to different allergens or IL-33. Eosinophil populations in the airways, lung, or mediastinal lymph nodes (mLN) were characterized by FACS or immunohistochemistry. rEOS and iEOS functions were determined in vivo and in vitro. RESULTS: HDM and IL-33 exposure induced a strong accumulation of iEOS but not rEOS in the airways, lungs, and mLNs. rEOS and iEOS expressed C3/C5 and C5aR1, which were significantly higher in iEOS. Initial pulmonary trafficking of iEOS was markedly reduced in C5ar1-/- mice and associated with less IL-5 production from ILC2 cells. Functionally, adoptively transferred pulmonary iEOS from WT but not from C5ar1-/- mice-induced airway hyperresponsiveness (AHR), which was associated with significantly reduced C5ar1-/- iEOS degranulation. Pulmonary iEOS but not rEOS were frequently associated with T cells in lung tissue. After HDM or IL-33 exposure, iEOS but not rEOS were found in mLNs, which were significantly reduced in C5ar1-/- mice. C5ar1-/- iEOS expressed less costimulatory molecules, associated with a decreased potency to drive antigen-specific T cell proliferation and differentiation into memory T cells. CONCLUSIONS: We uncovered novel roles for C5aR1 in iEOS trafficking and activation, which affects key aspects of allergic inflammation such as AHR, ILC2, and T cell activation.

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.

Short-term high-fat diet feeding protects from the development of experimental allergic asthma in mice.

BACKGROUND: A close association between obesity and asthma has been described. The nature of this association remains elusive, especially with respect to allergic asthma. Controversial findings exist regarding the impact of short-term high-fat diet (HFD) feeding on the development of allergic asthma. OBJECTIVE: To delineate the impact of short-term HFD feeding on the development of experimental allergic asthma. METHODS: Female C57BL/6JRJ mice were fed with a short-term HFD or chow diet (CD) for 12 weeks. Allergic asthma was induced by intraperitoneal OVA/alum sensitization followed by repeated OVA airway challenges. We determined airway hyperresponsiveness (AHR) and pulmonary inflammation by histologic and flow cytometric analysis of immune cells. Furthermore, we assessed the impact of HFD on dendritic cell (DC)-mediated activation of T cells. RESULTS: Female mice showed a mild increase in body weight accompanied by mild metabolic alterations. Upon OVA challenge, CD-fed mice developed strong AHR and airway inflammation, which were markedly reduced in HFD-fed mice. Mucus production was similar in both treatment groups. OVA-induced increases in DC and CD4+ T-cell recruitment to the lungs were significantly attenuated in HFD-fed mice. MHC-II expression and CD40 expression in pulmonary CD11b+ DCs were markedly lower in HFD-fed compared to CD-fed mice, which was associated in vivo with a decreased T helper (Th) 1/17 differentiation and Treg formation without impacting Th2 differentiation. CONCLUSIONS/CLINICAL RELEVANCE: These findings suggest that short-term HFD feeding attenuates the development of AHR, airway inflammation, pulmonary DC recruitment and MHC-II/CD40 expression leading to diminished Th1/17 but unchanged Th2 differentiation. Thus, short-term HFD feeding and associated metabolic alterations may have protective effects in allergic asthma development.