Intrinsic and extrinsic asthma, a shared lymphocyte abnormality.

Area of Science:

• Immunology
• Respiratory Medicine
• Pharmacology

Background:

• Asthma involves complex immune responses.
• Histamine and indomethacin are known modulators of immune function.
• Understanding lymphocyte behavior is crucial for asthma research.

Purpose of the Study:

• To investigate in vitro lymphocyte responses to Concanavalin A (Con. A) in normal subjects, and patients with extrinsic asthma, intrinsic asthma, and chronic bronchitis.
• To determine the effects of histamine and indomethacin on these cell-mediated responses.
• To identify potential common immunological mechanisms in different asthma phenotypes.

Main Methods:

• In vitro lymphocyte proliferation assays using Concanavalin A (Con. A).
• Assessment of histamine's suppressive effects on lymphocyte responses.
• Evaluation of indomethacin's ability to reverse histamine-induced suppression.
• Comparison of responses across patient groups (normal, extrinsic asthma, intrinsic asthma, chronic bronchitis).

Main Results:

• Lymphocytes from both intrinsic and extrinsic asthmatics exhibited heightened sensitivity to histamine-induced suppression of Con. A response.
• Indomethacin effectively reversed this histamine-induced suppression in asthmatic subjects.
• Lymphocytes from intrinsic and extrinsic asthmatics showed similar responses, distinct from normal subjects and chronic bronchitis patients.
• These findings suggest a shared immunological pathway in intrinsic and extrinsic asthma.

Conclusions:

• A common immunological mechanism likely underlies both intrinsic and extrinsic asthma.
• Histamine plays a significant role in suppressing lymphocyte responses in asthmatics.
• Indomethacin demonstrates potential in modulating these histamine-induced effects, offering therapeutic insights.