Pathogenesis of Hypersensitivity Pneumonitis 

Please read and agree to the disclaimer before watching this video.
. Hypersensitivity pneumonitis is alveolitis due to inhaled extrinsic allergens of known type.
It is a restrictive disease. It is an allergic reaction at the respiratory zone or smaller airways of the lungs.
In this video, Dr. Mobeen Syed discusses the pathogenesis of hypersensitivity pneumonitis.
It is a mixture of type-III and type-IV hypersensitivity reactions.
Hypersensitivity pneumonitis is classified as acute, subacute (intermittent), or chronic progressive.
Acute hypersensitivity pneumonitis occurs primarily via a type III hypersensitivity reaction. Most patients show evidence of specific antibodies in their serum, and bronchoalveolar-lavage studies may demonstrate high levels of pro-inflammatory chemokines.
Subacute and chronic forms of hypersensitivity pneumonitis are supposed to transition more towards type IV, T-cell mediated, hypersensitivity reactions. Antigen-presenting cells (dendritic cells and alveolar macrophages) present antigens to CD4+ Th1 and Th17 cells. It triggers an inflammatory cascade with the release of many factors, including interferon (IFN)‒γ, tumor necrosis factor (TNF), interleukin (IL)‒17, and IL-22. The milieu of cytokines and chemokines ultimately results in sustained infiltration of mononuclear cells, macrophages, and fibroblasts.
It results in the pattern of noncaseating granulomas.
The following topics have discussed in the video:
Hypersensitivity pneumonitis
Pathogenesis of hypersensitivity pneumonitis ...
Disclaimer:
This video is not intended to provide assessment, diagnosis, treatment, or medical advice; it also does not constitute provision of healthcare services. The content provided in this video is for informational and educational purposes only.
Please consult with a physician or healthcare professional regarding any medical or mental health related diagnosis or treatment. No information in this video should ever be considered as a substitute for advice from a healthcare professional. ...
Disclaimer:
This video is not intended to provide assessment, diagnosis, treatment, or medical advice; it also does not constitute provision of healthcare services. The content provided in this video is for informational and educational purposes only.
Please consult with a physician or healthcare professional regarding any medical or mental health related diagnosis or treatment. No information in this video should ever be considered as a substitute for advice from a healthcare professional.