Background: Late prognosis of Community-Acquired Pneumonia (CAP) patients is related to cardiovascular events. Persistence of inflammation-related markers, defined by high circulatory levels of interleukin 6 and 10 (IL-6/IL-10), is associated with a higher post-event mortality rate for CAP patients. However, association between these markers and other components of the immune response, and the risk of cardiovascular events, has not been adequately explored. The main objectives of this study are: 1) to quantify the incidence of cardiovascular disease, in the year post-dating their hospital admittance due to CAP and, 2) to describe the distribution patterns of a wide spectrum of inflammatory markers upon admittance to and release from hospital, and to determine their relationship with the incidence of cardiovascular disease.
Methods/design: A cohort prospective study. All patients diagnosed and hospitalized with CAP will be candidates for inclusion. The study will take place in the Universitary Hospital La Princesa, Spain, during two years. Two samples of blood will be taken from each patient: the first upon admittance and the second one prior to release, in order to analyse various immune agents. The main determinants are: pro-adrenomedullin, copeptin, IL-1, IL-6, TNF-α, IL-17, IFN-γ, IL-10 and TGF-β, E-Selectin, ICAM-1, VCAM-1 and subpopulations of peripheral T lymphocytes (T regulator, Th1 and Th17), together with other clinical and analytical variables. Follow up will start at admittance and finish a year after discharge, registering incidence of death and cardiovascular events. The main objective is to establish the predictive power of different inflammatory markers in the prognosis of CAP, in the short and long term, and their relationship with cardiovascular disease.
Discussion: The level of some inflammatory markers (IL-6/IL-10) has been proposed as a means to differentiate the degree of severity of CAP, but their association with cardiovascular risk is not well established. In this study we aim to define new inflammatory markers associated with cardiovascular disease that could be helpful for the prognosis of CAP patients, by describing the distribution of a wide spectrum of inflammatory mediators and analyzing their association with the incidence of cardiovascular disease and mortality one year after release from hospital.