Imaging Mass Cytometry Immune Profiling of Hunner Lesions in a Convenience Sample of Patients With Interstitial Cystitis/Bladder Pain Syndrome.

Abstract

A comprehensive spatial immune profile of Hunner lesions (HLs) in interstitial cystitis/bladder pain syndrome (IC/BPS) is absent from the literature. Here, we leveraged imaging mass cytometry, a multiplex imaging platform, with novel computational pipelines to evaluate the immune in situ microenvironment of HL-IC/BPS. Formalin-fixed paraffin-embedded HL tissue samples retrospectively collected from 10 patients with HL-IC/BPS were stained using a cocktail of 20-metal conjugated antibodies designed to profile both the innate and adaptive immune system. Imaging data were acquired using the Hyperion Imaging System. Data were visualized and processed using computational machine learning pipelines to resolve general immune complexity and spatial relationships in HL. More than 174,000 cells were analyzed across these 10 patient samples. On average, macrophages were the most abundant cell type found in HL-IC/BPS, followed by CD4⁺ T cells, CD8⁺ T cells, and B cells. We observed distinct spatial neighborhoods of macrophage subtypes including tissue repair-like CD163⁺ macrophages and activated granzyme B⁺ macrophages within lesions. Computational analysis also demonstrated quantifiable methods to differentiate HL-IC/BPS patients based on differences in immune cell agglomeration within a lesion. Here, we demonstrate the use of highly multiplexed imaging in combination with novel analysis pipelines as a feasible method to understand the spatial organization of HLs. This pilot study suggests that these methods will be useful to prospectively characterize and evaluate the local immune microenvironment in HL-IC/BPS and could uncover mechanisms of disease pathogenesis.