AUTOIMMUNE TARGETS: This false-color transmission electron micrograph (TEM) displays a slice through a mammalian pancreatic islet cell, the target of an aberrant immune response in type 1 diabetes patients. The red spots in white spaces are membrane-bound secretory granules containing insulin and other hormones to be excreted into the blood. (Nucleus, upper right.)© SPL/SCIENCE SOURCE
History often repeats itself. More than 100 years ago, one of the world’s leading immunologists, Nobel Laureate Paul Ehrlich, doubted the very existence of autoimmunity, in which the immune system begins to attack healthy tissues. Envisioning a nightmare scenario where the body turns against itself, Ehrlich reasoned that it would be quite improbable. His skepticism regarding this phenomenon, which he termed “horror autotoxicus” (literally, “the horror of self-toxicity”), delayed the acceptance of this concept for another half century—even in the face of compelling clinical examples of immunity gone haywire.
A century of basic research later, scientists now accept that autoimmunity does in fact exist, with devastating consequences. More than 20 autoimmune diseases have been identified; these disorders affect every organ in the body and afflict ...
