Caplans syndrome pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sharmi Biswas, M.B.B.S

Caplan Syndrome is known as Rheumatoid pneumoconiosis. In patients with rheumatoid arthritis, lungs show increased immune response to the foreign materials. In coal miners with RA, exposure to silica causes the release of different cytokines as interleukin-1,granulocyte colony stimulating factor and tumor necrosis factor-alpha by monocytes and macrophages. Lymphocytes get activated by the cytokines and leading to hyperactive autoimmune response.

• It is understood that syndrome is the result of alteration of immune response in the patients with Rheumatoid arthritis.^[1]
• There is an increased immune response to foreign materials in the lungs.Silica initiates hyperactive immune responses in the coal miners with Rheumatoid arthritis
• Macrophages engulf silica particles, causing inflammation which eventually activate the firbroblasts.
• Due to having apoptotic capacity, engulfed silica destroy the macrophages and again get taken up by another macrophage. This continued process activates chronic immune response and fibrosis.

• No genetic association is found in Caplan Syndrome.

Conditions associated with [disease name] include:

• Rheumatoid Arthritis ^[1]
• Silicosis
• Asbestosis

Some people who have been exposed to the dust have severe lung scarring that makes it difficult for their lungs to carry oxygen to the bloodstream (called progressive massive fibrosis). People with rheumatoid arthritis do not seem more likely to have this complication of scarring.

Persons with rheumatoid arthritis are more likely to develop larger areas of inflammation and scarring in response to coal dust.

Microscopic features of Caplan syndrome are

• Central necrotic area with various amounts of collagen tissue. ^{[2] [3]}
• Few nuclei might be found in the central necrotic area.
• Outside of the necrotic area there are alternate layers of black coal dust and necrotic tissue.
• Surrounding the dust ring, there is a zone of inflammation containing granulocytes, macrophages, and giant cells. Macrophages might contain some dust particles.
• Outside of the inflammatory zone, there are some palisading cells.