Induction of bystander tolerance and immune deviation after Fel d 1 peptide immunotherapy.

BACKGROUND: Treatment of patients with cat allergy with peptides derived from Fel d 1 (the major cat allergen) ameliorated symptoms of cat allergy in phase 2 clinical trials. OBJECTIVE: We sought to demonstrate that the tolerance induced by Fel d 1 peptide immunotherapy can be exploited to reduce allergic responses to a second allergen, ovalbumin (OVA), in mice sensitized dually to OVA and Fel d 1. METHODS: Induction of tolerance to OVA was achieved through simultaneous exposure to both allergens after peptide treatment. Functional tolerance to each allergen was assessed in a model of allergic airways disease in which treated mice were protected from eosinophilia, goblet cell hyperplasia, and TH2 cell infiltration. RESULTS: Suppression of allergic responses to cat allergen challenge was associated with significant increases in numbers of CD4+CD25+Foxp3+ T cells, IL-10+ cells, and CD19+IL-10+ B cells, whereas the response to OVA was associated with a marked reduction in numbers of TH2 cytokine-secreting T cells and less prominent changes in outcomes associated with immune regulation. CONCLUSIONS: These observations suggest that immune tolerance induced by peptide immunotherapy can be used experimentally to treat an allergic response to another allergen and that the molecular mechanisms underlying induction of tolerance to a treatment-specific allergen and a bystander allergen might be different.

A real-world retrospective analysis of the management of metastatic castrate-resistant prostate cancer in Ontario, Canada from 2010 - 2018.

PURPOSE: We sought to quantify mCRPC patient treatment patterns and survival across multiple lines of therapy after prior androgen-receptor-axis-targeted therapy (ARAT) failure. METHODS: Individuals diagnosed with prostate cancer between 2010 and 2018 were identified in the Ontario Cancer Registry (OCR). An algorithm was created to identify patients with mCRPC that was aligned to Prostate Cancer Clinical Trials Working Group 3 criteria (PCWG3) and validated with Canadian clinical experts. In the mCRPC setting, treatment patterns were assessed by line of therapy, and survival was calculated from treatment initiation until death or lost to follow-up. RESULTS: 64,484 men were diagnosed withprostate cancer in Ontario between 2010 and 2018with 5,588 men assessed to have mCRPC and 2,970 (53%) of those received first-line systemic treatment. Across the first-, second- and third-line of therapy, ARATs (abiraterone and enzalutamide) were the most used therapies. Survival for mCRPC patients treated with ARATs in first-, second- and third-line were 13.0 (95% CI, 11.6 - 14.5), 11.5 (95% CI, 10.1 - 13.4) and 8.9 (95% CI, 7.4 - 10.2) months, respectively. Survival for mCRPC patients treated with taxanes in first, second- and third-line were 16.7 (95% CI, 14.8 - 18.0), 11.3 (95% CI, 10.1 - 12.5) and 7.8 (95% CI, 6.5 - 10.6) months, respectively. No statistical difference in overall survival was found between taxanes and ARATs. CONCLUSION: In this analysis of a large retrospective cohort of Canadian men with mCRPC, we found that survival in patients treated with ARATs and taxanes was fairly similar across all lines of therapy. Importantly, this trend was maintained in ARAT-exposed patients, where sequential ARAT and taxanes offered similar survival. These data may help inform optimal sequencing of therapies in mCRPC.

An Update on Lymphocyte Subtypes in Asthma and Airway Disease.

Inflammation is a hallmark of many airway diseases. Improved understanding of the cellular and molecular mechanisms of airway disease will facilitate the transition in our understanding from phenotypes to endotypes, thereby improving our ability to target treatments based on pathophysiologic characteristics. For example, allergic asthma has long been considered to be driven by an allergen-specific T helper 2 response. However, clinical and mechanistic studies have begun to shed light on the role of other cell subsets in the pathogenesis and regulation of lung inflammation. In this review, we discuss the importance of different lymphocyte subsets to asthma and other airway diseases, while highlighting the growing evidence that asthma is a syndrome that incorporates many immune phenotypes.