[Diagnostic value of transbronchial lung biopsy in pulmonary alveolar proteinosis]

To evaluate the diagnostic value and limits of transbronchial lung biopsy (TBLB) in pulmonary alveolar proteinosis (PAP).

The complete hospital data from Second Xiangya Hospital, Central South University, between June, 2006 and December, 2012, were analyzed retrospectively in 25 patients with PAP (who were diagnosed pathologically by TBLB or not by TBLB) and in 4 patients with other disease (who were misdiagnosed by TBLB).

Among the 25 patients with PAP, 14 patients were confirmed by TBLB in the fi rst time [TBLB positive rate in the first time was 56% (14/25)]; 6 patients who were misdiagnosed by TBLB in the fi rst time were confirmed by TBLB in the second time [the positive rate in the second time was 24% (6/25)]. Th e total positive rate was 80% (20/25). Th e total negative rate was 20% (5/25). Five patients with PAP, who showed negative results in TBLB analysis, were confirmed by the typical CT as well as the whole lung lavage. In addition, 4 patients with other diseases were misdiagnosed as PAP by TBLB.

TBLB is a very good diagnosis method. But the negative results in the first time cannot exclude PAP. TBLB should be repeated if conditions allow. If clinical manifestation and CT results are typical, it can be used for diagnosis of PAP combined with the positive results from bronchoalveolar lavage fluid check. However, for non-typical cases, it needs TBLB pathological diagnosis.