# Host-pathogen interaction in community-acquired pneumonia: a focus on the immune response

## TL;DR

This paper reviews how the immune system responds to community-acquired pneumonia caused by various pathogens, aiming to improve diagnosis and treatment.

## Contribution

The paper offers a detailed overview of immune responses in CAP, focusing on multiple pathogens and recent diagnostic advancements.

## Key findings

- CAP remains a major global health issue due to antibiotic resistance and diverse causative pathogens.
- The immune response to CAP varies depending on the pathogen, such as Staphylococcus aureus and SARS-CoV-2.
- Understanding immunopathogenesis could lead to better diagnostic tools and therapies for pneumonia.

## Abstract

Community-acquired pneumonia (CAP) remains one of the leading causes of morbidity and mortality worldwide, affecting individuals of all ages. Various pathogens can cause this condition, and growing antibiotic resistance makes treatment more difficult while raising the risk of severe outcomes. Despite substantial advances in diagnostics, antimicrobial therapy, and supportive care, CAP continues to represent a significant clinical and public health challenge. In this review, we provide a comprehensive overview of CAP, summarizing key aspects of its epidemiology, pathogen frequency, and recent progress in diagnostic tools and biomarkers. We also describe the innate and adaptive immune responses involved in CAP, with a particular focus on pneumonia caused by Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, respiratory syncytial virus, severe acute respiratory syndrome coronavirus 2, and Influenza A and B viruses. A deeper understanding of CAP immunopathogenesis may support the development of improved diagnostic and therapeutic approaches for pneumonia management.