African Journal of Thoracic and Critical Care Medicine (Dec 2022)

Criteria for progressive fibrotic hypersensitivity pneumonitis in a Portuguese patient cohort

  • E Seixas,
  • M Ferreira,
  • P Serra,
  • R Aguiar,
  • I Cunha,
  • P G Ferreira

DOI
https://doi.org/10.7196/AJTCCM.2022.v28i4.250

Abstract

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Background. Hypersensitivity pneumonitis is a syndrome caused by sensitisation to inhaled antigens that leads to an abnormal immune response in the airways and lung parenchyma. Some patients previously diagnosed with certain types of fibrotic interstitial lung diseases, including fibrotic HP, are susceptible to develop a progressive fibrosing phenotype, despite initial state- of-the-art management. Objectives. To characterise a cohort of patients with a multidisciplinary diagnosis of chronic f-HP, who were followed up in an ILD outpatient clinic of a hospital in Portugal, and to assess the prevalence of PF-ILD criteria in these patients.Methods. Data were collected from all patients with a definite or provisional diagnosis of f-HP after a multidisciplinary team discussion. Patients were followed up between December 2014 and July 2019. Data included clinical characteristics, high-resolution chest tomography disease patterns, lung function tests, bronchoalveolar lavage and further immunological work-up, biopsy reports, all ILD multidisciplinary team records and diagnostic confidence levels. Patients were assessed according to PF-ILD criteria as defined in the INBUILD trial. Results. We identified 83 patients with an MTD of HP, who had been followed up for at least 12 months. Of these, 63 (75.9%) were diagnosed with f-HP. Of the 63 f-HP patients, 33.3% (n=21) fulfilled the predefined criteria for PF-HP: 66.7% had a relative decline of ≥10% forced vital capacity; 5% a relative decline of 5 - 9% FVC, with worsening symptoms or increased fibrosis on HRCT; and 23.8% had worsening respiratory symptoms with radiological progression. Conclusion. This single-centre cohort study demonstrated that a third of f-HP patients presented with PF-ILD, as determined by progression during initial standard-of-care treatment. A usual interstitial pneumonia (UIP)/UIP-like pattern was present in >70% of patients with f-HP, and two-thirds of these patients had an FVC decline of ≥10%.

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