Potatoes contain toxic compounds known as glycoalkaloids, of which the most prevalent are solanine and chaconine.

Solanine is a glycoalkaloid poison.

One study suggests that the toxic mechanism of solanine is caused by the chemical's interaction with mitochondrial membranes. Experiments show that solanine exposure opens the potassium channels of mitochondria, increasing their membrane potential. This in turn leads to Ca2+ being transported down its concentration gradient into the mitochondria, and it is this increased concentration of Ca2+ in the cell that triggers cell damage and apoptosis.

Apoptosis is the process of programmed cell death (PCD) that may occur in multicellular organisms.

Apoptosis occurs when a cell is damaged beyond repair, becomes infected, or suffers a stressful situation.

The "decision" for apoptosis can come from the cell itself, from the surrounding tissue, or from a cell that is part of the immune system. In these cases apoptosis functions to remove the damaged cell, preventing it from sapping further nutrients from the organism, or halting further spread of an infection.

Autoimmune diseases, in my opinion, are linked to Chronic solanine poisoning.