IntroductionThe accurate diagnosis of individual interstitial lung diseases (ILD) is often challenging, but is a critical determinant of appropriate management. If a diagnosis cannot be made after multidisciplinary team discussion (MDTD), surgical lung biopsy is the current recommended tissue sampling technique according to the most recent guidelines. Transbronchial lung cryobiopsy (TBLC) has been proposed as an alternative to surgical lung biopsy.MethodsThis prospective, multicentre, international study analysed the impact of TBLC on the diagnostic assessment of 128 patients with suspected idiopathic interstitial pneumonia by a central MDTD board (two clinicians, two radiologists, two pathologists). The level of confidence for the first-choice diagnoses were evaluated in four steps, as follows: 1) clinicoradiological data alone; 2) addition of bronchoalveolar lavage (BAL) findings; 3) addition of TBLC interpretation; and 4) surgical lung biopsy findings (if available). We evaluated the contribution of TBLC to the formulation of a confident first-choice MDTD diagnosis.ResultsTBLC led to a significant increase in the percentage of cases with confident diagnoses or provisional diagnoses with high confidence (likelihood ≥70%) from 60.2% to 81.2%. In 32 out of 52 patients nondiagnostic after BAL, TBLC provided a diagnosis with a likelihood ≥70%. The percentage of confident diagnoses (likelihood ≥90%) increased from 22.7% after BAL to 53.9% after TBLC. Pneumothoraces occurred in 16.4% of patients, and moderate or severe bleeding in 15.7% of patients. No deaths were observed within 30 days.InterpretationTBLC increases diagnostic confidence in the majority of ILD patients with an uncertain noninvasive diagnosis, with manageable side-effects. These data support the integration of TBLC into the diagnostic algorithm for ILD.