PD-1 expression on CD8+ T cells regulates their differentiation within lung allografts and is critical for tolerance induction

Immunological requirements for rejection and tolerance induction differ between various organs. While memory CD8⁺ T cells are considered a barrier to immunosuppression-mediated acceptance of most tissues and organs, tolerance induction after lung transplantation is critically dependent on central memory CD8⁺ T lymphocytes. Here we demonstrate that costimulation blockade-mediated tolerance after lung transplantation is dependent on programmed cell death 1 (PD-1) expression on CD8⁺ T cells. In the absence of PD-1 expression, CD8⁺ T cells form prolonged interactions with graft-infiltrating CD11c⁺ cells; their differentiation is skewed towards an effector memory phenotype and grafts are rejected acutely. These findings extend the notion that requirements for tolerance induction after lung transplantation differ from other organs. Thus, immunosuppressive strategies for lung transplant recipients need to be tailored based on the unique immunological properties of this organ.

Efficacy and cost effectiveness of rapid on site examination (ROSE) in management of patients with mediastinal lymphadenopathies

BACKGROUND

The diagnostic and staging approach for the mediastinal lymphadenopathies, with or whithout pulmonary lesions endoscopically visible, is based on transbronchial needle aspiration (TBNA) during fiberoptic bronchoscopy and on mediastinoscopy. One important factor impacting on TBNA sensitivity is the rapid on site cytological examination (ROSE).

AIM

The aim of this study was to evaluate the economic impact of TBNA and TBNA + ROSE, in the diagnosis of these lesions.

PATIENTS AND METHODS

120 patients, affected by mediastinal lymphadenopathies suspected for lung cancer, underwent TBNA during fiberoptic bronchoscopy: 60 patients without ROSE (group A) and other 60 with ROSE (group B). Whenever needle aspirations failed to provide diagnosis, the patient underwent mediastinoscopy. The economic impact of the diagnostic process was performed.

RESULTS

In group A, 39 patients (65%) obtained a diagnosis with TBNA while 21 patients (35%) required mediastinoscopy. In group B, 48 patients (80%) obtained a diagnosis with TBNA + ROSE, while 12 patients (20%) required mediastinoscopy. With regards to the costs of the procedures performed in the diagnostic process, the use of TBNA with ROSE as first diagnostic approach has saved a considerable amount of euros (19,413) compared to the use of TBNA without ROSE and the combined procedure increased (p < 0.02; chi square test) the sensitivity of TBNA by 15%.

CONCLUSIONS

ROSE significantly impacts on the diagnostic yield, as well as on the overall management costs of patients with mediastinal lymphadenopathy, suspected for lung cancer.