What is believed to cause tissue injury in systemic rheumatic disorders such as systemic lupus erythematosus?

The mechanism believed to cause tissue injury in systemic rheumatic disorders like systemic lupus erythematosus primarily involves the deposition of immune complexes. In these conditions, the body produces autoantibodies against various self-antigens, leading to the formation of immune complexes. These complexes can deposit in different tissues, such as the kidneys, skin, and joints, triggering an inflammatory response that results in tissue damage.

When immune complexes accumulate in tissues, they activate the complement system and attract inflammatory cells, such as neutrophils and macrophages, to the site. This accumulation of immune cells contributes to local inflammation and can lead to conditions such as vasculitis, glomerulonephritis, and arthritis, all characteristic of systemic lupus erythematosus. Thus, the direct action of these immune complexes on tissues is pivotal in the pathogenesis and resultant tissue injury seen in this and other similar disorders.

While the other options may play a role in the broader context of immune function or disease, they do not specifically explain the direct mechanism of tissue injury as effectively as the deposition of immune complexes does.