Inflammation is a double-edged sword in the outcome of pneumonia. On the one hand, an effective and timely inflammatory response is required to eliminate the invading respiratory pathogen. On the other, a toxic and prolonged inflammatory response may result in lung injury and poor outcomes, even in those receiving advanced medical care. This review focuses on recent understanding of the dynamics of the cytokine response, neutrophil activity, and responsiveness to cytokines and neutrophil lifespan as major elements of lung inflammation resulting in favorable or poor outcomes in lung infection primarily due to pneumococcus and influenza virus. Although some progress has been made in our understanding of the molecular mechanisms of the pneumonia inflammation axis composed of cytokines modulating neutrophil activation and neutrophil apoptosis, important questions remain to be answered. The degree of neutrophil activation, generation of reactive oxygen species, and the release of granule antimicrobial peptides play a key role in microbial pathogen clearance; however, prolonged neutrophil activation may contribute to lung injury and poor outcomes in pneumonia. Molecular markers of the mechanisms regulating neutrophil survival and apoptosis may help in the identification of novel therapeutic targets to modulate inflammation by inducing timely neutrophil apoptosis. A major task is to identify the mechanisms of dysregulation in inflammation leading to toxic responses, thereby targeting a biomarker and enabling timely therapies to modulate inflammation.

We studied antimicrobial-resistant Klebsiella pneumoniae for 1998–2010 by using data from The Surveillance Network. Susceptibility results (n = 3,132,354) demonstrated significant increases in resistance to all antimicrobial drugs studied, except tetracycline. Cross-resistance among carbapenem-resistant K. pneumoniae was lower for tetracycline and amikacin.

TFAD does not seem to be associated with the clinical outcome of patients with CAP. Early TFAD should be considered as an important marker of optimal care of patients with CAP rather than as a factor predicting outcomes.

Our study shows that clinical outcomes of HIV-infected patients with CAP are not predicted by CD4+ cell counts or HIV-RNA levels after adjusting for confounders. The management of CAP in patients with HIV infection should not be based on CD4+ cell counts or HIV-RNA levels of the HIV infection.

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