Sampling local respiratory tract sites for inflammation

Although host defense mechanisms protect the health of the respiratory tract, deficiencies or excessive host responses such as inflammation can create sino-nasal and pulmonary illnesses. Analysis of expectorated secretions (sputum) is traditional, but selective site specific samples (surface washing) seem more applicable for studying illnesses such as rhinitis, bronchitis, or aveolitis. Regional samples should contain representative components (cells and proteins) that ideally reflect changes in adjacent tissue; however, biopsy of contiguous mucosa and lung parenchyma is required for a comprehensive analysis that can link surface samples and tissue pathology. Clinical strategies must be flexible so that maximal information about the host can be obtained through investigation of healthy normals, volunteer-patients with latent illness that can be induced locally and observed in situ, and patients with active illness. Implicit in studying inflammation is the adaptation of new analytic methods to surface or topical samples such as nasal, bronchial and bronchoalveolar lavage (BALF). More correlations between respective components in nasal fluids, bronchial and BAL specimens seem indicated, so that more readily available samples can be used for clinical monitoring. Moreover, further correlations between bronchial and BAL cells and immunohistochemical analysis of tissue for cells are needed.