Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Professor: Elisabeth Bendstrup

Artikel link | DOI | PubMed | Journal: Am J Respir Crit Care Med I Dato: 2020 Aug

Kommentar til artiklen:

I sidste måned udkom den første internationale diagnostiske retningslinje om allergisk alveolitis (eng. hypersensitivity pneumonitis).  Retningslinjen indeholder en ny definition, der anerkender, at man ikke kan identificere det udløsende antigen hos alle patienter og gør op med det gamle paradigme om akut vs. kronisk allergisk alveolitis. Det anbefales i stedet at klassificere sygdommen som fibrotisk vs. non-fibrotisk allergisk alveolitis, idet det er tilstedeværelsen af fibrose, der er afgørende for prognose og behandlingsrespons.  Retningslinjen indeholder på linje med IPF retningslinjen anbefalinger omkring skanningsmetode, radiologiske og histopatologiske kriterier samt udredningsalgoritme. Forhåbentlig kan en internationalt anerkendt retningslinje skabe et bedre og mere ensartet diagnostisk grundlag til gavn for både patienter og fremtidig forskning.  

Abstract

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.

Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.

Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.

Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.