A93-07 Lower Airway Inflammatory Cytokines Associate With a Progressive Sarcoidosis Phenotype

Abstract Rationale Sarcoidosis is a systemic granulomatous disease most commonly affecting the lungs with variable presentation, natural history, and prognosis. We recently described distinct microbial signatures identified via 16S rRNA sequencing associated with a progressive phenotype of sarcoidosis. Progressive disease was associated with differential enrichment of lower airways with pathobiont taxa, whereas non-progressive disease was characterized by enrichment with probiotic species. Given the interplay between the host microbiome and the immune system, we hypothesized that lower airway inflammation assessed by bronchoalveolar lavage fluid (BALF) cytokine measurement may also be associated with disease progression. Methods Subjects with a confirmed or suspected diagnosis of pulmonary sarcoidosis undergoing bronchoscopy at NYU Langone Health have been recruited to a clinical registry and biorepository since 2018. We defined progressive pulmonary disease by: decline of ≥ 10% in forced vital capacity (FVC) or 15% in diffusing capacity of the lungs for carbon monoxide (DLCO) within a two-year period after bronchoscopy, chest radiograph or symptomatic worsening despite treatment, or respiratory exacerbation requiring prednisone ≥20mg daily equivalents or second-line therapy. We measured cytokines from BALF using a Luminex assay and performed unsupervised clustering analysis in R (version 4.2.1) utilizing functions from the ggplot2 package. Results 112 subjects (median age 53; IQR 46-60; 60% male; 66% white) had BAL samples obtained at time of diagnosis and at least two years of longitudinal follow-up. 30 subjects (27%) met the criteria for progressive pulmonary disease. Via unsupervised clustering analysis, we identified two distinct groups of subjects differentiated by their inflammatory milieu (Figure 1A). Cluster 1 exhibited increased levels of multiple pro-inflammatory cytokines including: TNFɑ, IFNɣ, GM-CSF, IL1b, IL2, IL4, IL5, IL6, IL7, IL-10, IL12, IL13, IL17a, IL21, IL23, MIP1b, MIP3a, ITAC, and fractalkine (p 0.05, adjusted for multiple comparisons using the Benjamini-Hochberg method). This inflammatory cluster is associated with the progressive pulmonary phenotype (Figure 1B, p = 0.02). Subjects within Cluster 1 also exhibited higher serum ACE levels (p = 0.04) and lower levels of serum PAI-1(p = 0.02). Conclusions Our findings suggest that increased levels of BALF pro-inflammatory cytokines at time of diagnosis are associated with a progressive phenotype of pulmonary sarcoidosis. This finding builds upon our prior observation of a link between lower airway enrichment with pathobiont species and the progressive phenotype. Taken together, these observations suggest a putative effect of lower airway dysbiosis on local inflammation and disease progression in pulmonary sarcoidosis. This abstract is funded by: Stony Wold-Herbert Fund