New treatments are emerging for type-1 diabetes

“WHERE ARE the islets of Langerhans?” is a trick question that pops up from time to time in quizzes. The answer is to be found not in atlases of geography, but rather in those of anatomy, for the so-called islets are in fact clusters of cells scattered through the pancreas. There they synthesise and release a range of hormones, including insulin, which regulates glucose levels and thus metabolism.

The islets’ insulin producers are called beta cells. (Cell types alpha, gamma, delta and epsilon perform other tasks.) They are the only bodily sources of that hormone. So, if their number declines, trouble looms. And decline it does, in the condition known as type-1 diabetes. This happens when, in a phenomenon called autoimmunity, the body’s own immune system attacks its complement of beta cells, wiping out as many as 80%.