I. A patient with prior clinical diagnosis of pulmonary sarcoidosis presented to care at NMH with progressive pulmonary fibrosis. A transbronchial biopsy with EBUS was performed. The radiographic pattern and biopsy results were thought to be inconsistent with sarcoidosis; a differential of indeterminate UIP v NSIP (idiopathic v IPAF) remained. We discussed sending the patient for Envisia testing.
What do we mean when we say “Envisia”?
- Envisia Genomic Classifier
- Developed using machine learning applied to bulk RNA sequencing data from lung biopsy in combination with histologically-confirmed diagnoses
- Helps differentiate UIP from non-UIP histologic patterns by transcriptomic signature
Envisia was validated in the BRAVE (Bronchial Sample Collection for a Novel Genomic Test) studies
How well can Envisia distinguish UIP from other pathology in conventional TBBx?
- Envisia identified UIP in transbronchial biopsy with a specificity of 88% and sensitivity of 70%
- Among patients who had “possible or inconsistent UIP” on HRCT, Envisia showed 81% positive predictive value for biopsy-proven UIP
Liu et al. BMJ 2022;377:e066354 https://doi.org/10.1136/bmj-2021-066354
Raghu et al. Lancet Respir Med 2019; 7: 487–96 10.1016/S2213-2600(19)30059-1
II. A patient who is undergoing evaluation for transplant had chronic hypersensitivity pneumonitis (cHP) in his differential diagnosis. We discussed the predictive value of BAL lymphocyte count given the fibrotic/chronic nature of his disease
What is the predictive value of BAL lymphocytosis in cHP?
- A 2020 ERJ systematic review and meta-analysis suggested an association between BAL lymphocytosis and fibrotic cHP
- BAL lymphocyte percentage higher in cHP (42.8%, CI 37.7-47.8) compared to IPF (10%, CI 6.9-13.1) and other IIPs
- Analysis demonstrated that a BAL lymph% cutoff >20% optimized sensitivity and specificity for cHP compared to other IIPs
- 2018 ATS/ERS/JRS/ALAT IPF diagnostic guidelines conditionally recommend BAL in patients with suspected IPF and a non-diagnostic HRCT pattern
- A meta-analysis of eight studies in the most recent guidelines found no difference in BAL lymphocyte percentage between IPF and cHP
