ABSTRACT
I. Introduction Current assessment of the immunologic state of the lung allograft and recipient remains limited despite nearly three decades of experience in lung transplantation. Evaluation for cell-mediated rejection relies on transbronchial biopsy, which is invasive and subject to sampling error and inter-reader variability. Detection of chronic rejection relies on findings of airflow obstruction associated with irreversible changes of constrictive bronchiolitis. No standards exist for defining humoral rejection. Evaluation of immunosuppression is based on drug levels, toxicity, and nonspecific assessment of lymphocyte proliferation. Identification and measurement of individual biomarkers have yielded limited success in these settings. Genomic and proteomic techniques offer potential to broadly and noninvasively assess products of deoxyribonucleic acid (DNA) transcription and RNA translation using qualitative and quantitative methods. These techniques may ultimately lead to discovery of pathways and biomarkers associated with the presence or risk for primary allograft dysfunction, acute rejection, chronic rejection, and infection, as well as effect and toxicity of immunosuppressive regimens. In the following section, current genomic and proteomic techniques will be described, and evidence for potential roles in lung transplantation will be reviewed.
