Case Report: Co-existence of sarcoidosis and Takayasu arteritis

Integrative single-cell analysis of cardiac and pulmonary sarcoidosis using publicly available cardiac and bronchoalveolar lavage fluid sequencing datasets

Introduction

Cardiac presentation of autoimmune sarcoidosis, known as cardiac sarcoidosis (CS), is a poorly understood disease with high mortality and low diagnosis rate. While CS is an immunological syndrome, little is known about how cardiac parenchymal and stromal cells mediate its pathogenesis. Moreover, while most current sarcoidosis research is based on research in pulmonary sarcoidosis (PS), it remains unclear how much both presentations of sarcoidosis overlap. To tackle these concerns, we leveraged publicly available sarcoidosis transcriptomic datasets.

Methods

Two publicly available bronchoalveolar lavage single-cell RNA sequencing datasets were integrated to analyze PS relative to control. Additionally, two publicly available cardiac single-nucleus RNA sequencing datasets were integrated to analyze CS relative to control. Following integration, we ran cell-cell communication, transcription factor, and differential expression analyses on parenchymal, stromal, and immune subsets identified in our analysis.

Results

Our analysis revealed that there was an expansion of stromal and immune cells in PS and CS. We also observed upregulation of Th17.1 and attenuated activation transcriptional profiles in the immune cells of CS and PS relative to control. Additionally, we found upregulation of pro-inflammatory and pro-fibrotic transcriptional profiles in the cardiac stromal cells of CS relative to control. We also found that cardiomyocytes exhibited upregulated cardiac stress and proliferation transcriptional profiles in CS relative to control.

Conclusions

Our integrative transcriptomic analysis shows that despite tissue-specific differences, there are shared transcriptional trends between CS and PS. It also shows that stromal and parenchymal populations exhibit transcriptional trends that could explain their pathogenic role in CS.

Vasculitis in Patients With Sarcoidosis: A Single-Institution Case Series of 17 Patients

OBJECTIVES

Vasculitis in patients with sarcoidosis is rare and can affect any sized blood vessel. Limited information describing this association is available.

METHODS

A single-institution medical records review study was performed reviewing all patients with a diagnosis code for sarcoidosis and vasculitis between January 1, 1998, and December 31, 2019. Data were abstracted regarding diagnosis, treatment, and outcomes from medical records. Patients were diagnosed with vasculitis based on biopsy and/or arterial imaging. Comparison between patients presenting with large and/or medium vessel vasculitis (L/MVV) versus patients with only small vessel vasculitis (SVV) was performed.

RESULTS

Seventeen patients were identified during the study period. Nine patients (56% female) had L/MVV, and 8 (50% female) had SVV. Sarcoidosis preceded vasculitis in 4 (44%) L/MVV and 3 (38%) SVV. The mean ± SD age at sarcoidosis diagnosis was 53.2 ± 17.8 and 51.9 ± 11.4 years, and the mean ± SD age at vasculitis diagnosis was 57.4 ± 19.6 and 59.0 ± 13.4 years in L/MVV and SVV, respectively. Number of organ systems involved by sarcoidosis was similar (median [interquartile range], 3 [1-4] L/MVV vs 2.5 [1.75-3.25] SVV). The mean length of follow-up was 11.5 ± 12.8 in L/MVV and 13.1 ± 14.3 years in SVV. Complete response to therapy for vasculitis was observed in 8 of 9 with L/MVV and 7 of 8 with SVV. Four patients with SVV were able to stop all immunosuppression as compared with only 1 patient with L/MVV at the last follow-up.

CONCLUSIONS

This series observed a comparable number of patients with L/MVV and SVV. Although a variety of treatments were used, most patients achieved remission regardless of vessel size affected. Clinicians should be aware of the overlap between sarcoidosis and vasculitis.