Bronchoalveolar lavage proteomics in exacerbation of bronchiectasis

Abstract

Background: The molecular pathophysiology underlying the development of bronchiectasis with exacerbation at the proteomic level has not been clarified using bronchoalveolar lavage fluid samples. This study aimed to evaluate the bronchoalveolar lavage fluid inflammatory profiles associated with exacerbation of bronchiectasis. Methods: We analyzed the bronchoalveolar lavage fluid specimens from 4 patients in the exacerbation status and 4 patients in a stable status using liquid chromatography-tandem mass spectrometry. Results: A total of 1,577 proteins were identified using proteomic analysis, with 127 differentially expressed proteins. Of 127 differentially expressed proteins, 23 proteins showed more than 2-fold differences between exacerbation and stable status groups. The exacerbation status was associated with 18 upregulated proteins (TPI1, CRP, BPI, ORM1, PTPRE, S100A9, BPY2, TPM4, ERVFC1-1, CYS1, CLEC3B, S100A8, PSAT1, NDUFA10, MDGA1, SPRR3, ALDOA, and PSMB2) and five downregulated proteins (MUC5B, HSPE1, KLK13, IGHA1, and MUC5AC). Pathway analysis revealed that the neutrophil degranulation pathway (R-HSA-6798695) was the most enriched pathway in these proteins, followed by the C-type lectin receptor pathway (R-HSA-5621481). Conclusion: The bronchoalveolar lavage fluid protein expression in patients in the exacerbation status of bronchiectasis was significantly different from that in patients in the stable status, indicating that neutrophil degranulation and C-type lectin receptor pathways are the most enriched pathways during exacerbation.