Immunological characterization of pleural effusions in pediatric patients

Immunological factors in pleural effusions differed significantly from the corresponding blood samples in pediatric patients after cardiac surgery. The results suggest localized production of specific cytokines within the pleural space, while the distribution of other cytokines in pleural effusions appears to be more reflective of the systemic immune response. We found evidence that on the cellular level, the surface marker CD62L may play a key role in navigating T cells between the blood and pleural effusion. This study confirms that the pleural cavity harbors a unique lymphatic compartment, the analysis of which may be useful for both diagnostic and therapeutic purposes.