Q.Autoimmunity is a misdirected immune response. Justify.

Step 1. A core, defining feature of a normally functioning immune system is its ability to distinguish self from non-self, reacting destructively only against molecules foreign to the host.

Step 2. In autoimmunity, this distinguishing ability breaks down: the immune system fails to properly tell self from non-self and instead attacks the body's own molecules and tissues.

Step 3. This produces autoantibodies and cytotoxic T cells that are reactive against the host's own antigens (autoantigens), even though these are not foreign invaders.

Step 4. Because the immune response is still fully active and mechanistically normal — it is only its target that is wrong — it is accurately described as 'misdirected' rather than absent or weak (which would instead be immunodeficiency). …

Contrast the immune system's intended target (foreign antigens) with autoimmunity's actual target (self …

• Describing autoimmunity as the immune system being 'weak' or 'absent' (that would be immunodeficiency) rather than misdirected …