What is the nature of the antibody-antigen interaction in rheumatoid arthritis?

 Complex formation

Explanation:

Rheumatoid Arthritis is the condition in which the body's own immune system reacts with the own cells of the body considering as antigen.

The rheumatoid factor are the auto-anbodies that is produced from the immune system of the body.These antibodies binds to the Fc region of the IgG molecules.

There is a formation of complex that consists of the auto antibody and self antigen. This is the nature of interaction in case of rheumatoid arthritis.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]