Humans naturally produce anti-idiotypic antibodies and autoantibodies directed against their own immunoglobulins as part of the immune system's normal regulatory network.
The retrieved papers document the existence and physiological role of anti-idiotypic antibodies and natural autoantibodies that recognize and bind to other immunoglobulins (such as anti-IgE autoantibodies). This confirms that the human immune system mounts responses against its own antibodies.