Interstitial Pneumonia

Interstitial pneumonia does not affect the alveoli but the interstitium, i.e. the narrow connective tissue layer between the alveoli and the blood vessels. It is caused by the fact that pathogens are absorbed by the alveolar macrophages - these are sedentary dendritic cells - and carried off into the supporting tissue. If this form of pneumonia has no bacterial cause, we speak of atypical pneumonia.