Corn-induced hypersensitivity pneumonitis

Exposure assessment in hypersensitivity pneumonitis: a comprehensive review and proposed screening questionnaire

Hypersensitivity pneumonitis is an immune-mediated inflammatory lung disease characterised by the inhalation of environmental antigens leading to acute and chronic lung injury. Along with suggestive clinical and radiological findings, history and timing of suspected antigen exposure are important elements for diagnostic confidence. Unfortunately, many diagnoses remain tentative and based on vague and imprecise environmental or material exposure histories. To date, there has not been a comprehensive report highlighting the frequency and type of environmental exposure that might lead to or support a more systematic approach to antigen identification. We performed a comprehensive literature review to identify and classify causative antigens and their associated environmental contexts or source materials, with emphasis on the extent of the supportive literature for each exposure type. Eligible publications were those that reported unique inciting antigens and their respective environments or contexts. A clinical questionnaire was then proposed based on this review to better support diagnosis of hypersensitivity pneumonitis when antigen testing or other clinical and radiological variables are inconclusive or incomplete.

Pathogenesis of hypersensitivity pneumonitis

PURPOSE OF REVIEW

Hypersensitivity pneumonitis is a group of immunologically mediated diseases caused by an abnormal response to a wide variety of inhaled antigens. Its pathogenesis is complex and involves many immunological concepts. This review discusses recent advances in our understanding of the pathogenesis of hypersensitivity pneumonitis.

RECENT FINDINGS

Over the last 3 years, several studies on the pathogenesis of hypersensitivity pneumonitis have been published. New antigens have been identified. We now have a better understanding of the role of inflammatory cells and mediators, and promoting and protective factors have been suggested.

SUMMARY

Most of the mechanisms involved in the pathogenesis of hypersensitivity pneumonitis remain incompletely understood. Current and future findings will not only help our understanding of the disease and its prevention, but also improve its treatment.