Usefulness of gene expression profiling of bronchoalveolar lavage cells in acute lung allograft rejection.Weigt, S. S., et al.
Journal of Heart & Lung Transplantation 2019; 38(8): 845-855.
The aim of this study was to investigate whether the gene expression profiling of bronchoalveolar lavage (BAL) cell pellet (CP) could be used as a replacement for biopsy and provide information on the mechanisms of chronic lung allograft dysfunction (CLAD).
Subjects randomly split 70:30 to a training set or a testing set.
219 lung transplant recipients.
The outcomes of interest included the analysis of differential gene expression during acute cellular rejection (ACR), analysis of functional annotation and pathway enrichment with ACR, and the development and performance of an acute cellular rejection classifier.
This study investigated gene expression in the BAL samples from lung transplant recipients, looking for gene expression profiles that reflect cellular rejection. The aim was to identify a gene profile that could be used as a diagnostic marker for ACR, avoiding the need for transbronchial biopsy. The authors found differential expression of genes in the T-cell immune response and created a 4-gene model that was able to predict presence of ACR with an AUC of 0.72, sensitivity of 60% and specificity of 82%. Whilst perhaps not sensitive and specific enough to replace transbronchial biopsy in its current form, this approach does show some promise for a less-invasive mechanism for detecting ACR. More information is needed on the temporal changes in the gene profile - the present samples were taken at the time of confirmed rejection, and it would be important to know how early in the rejection process these changes can be detected. This would require a prospective longitudinal study.