Discuss how circulating immune complexes are formed in systemic lupus

Question

erythematosus (SLE), where they deposit, how tissue is destroyed, and how this relates
to the cluster of symptoms associated with SLE.

What will be an ideal response

Answer 1

SLE is associated with a variety of autoantibodies directed against nuclear components (antinuclear antibodies or
ANAs). Since the body's cells die and are replaced constantly, there is a ready supply of nuclear material circulating
as debris. When there are high titers of ANAs, immune complexes form with the nuclear debris, and these
complexes are often too large to be phagocytized efficiently. Thus, the immune complexes circulate systemically
and deposit randomly in the tissues, although certain tissues are anatomically more vulnerable to immune complex
deposition. The glomerulus of the kidney and the joints are two particularly vulnerable areas. Arthritis is the most
common symptom of SLE, but one of the most common causes of morbidity is kidney failure due to immune
complex deposition in the kidney. When immune complexes deposit and activate complement, the nearby tissue is
efficiently destroyed, and the glomeruli of the kidney are particularly susceptible. Since the immune complexes can
deposit anywhere, however, symptoms of SLE include skin rashes, skin photosensitivity, fatigue, cardiac
symptoms, central nervous system problems, and so on. The generalized inflammation induced is also associated
with low grade fever in SLE patients.