Summary

The "Old Friends Hypothesis" theorizes that the cause of autoimmune disorders is that humans evolved with intestinal parasites, which suppressed the immune system to survive in humans.

With that natural immune suppression now gone, the immune system is unleashed and dangerous. MS, also an autoimmune disease, is virtually nonexistent in Africa, where parasites still thrive in humans.

MS is twice as prevalent in women than men, perhaps because the female immune system evolved under double suppression of pregnancy to prevent immune attacks on the fetus.

With pregnancy controlled and parasites gone, women's immune systems may be doubly unleashed, which may account for the double incidence of MS in women over men.

SYN is testing pregnancy hormone estriol together with immunosuppresant MS blockbuster Copaxone for synergistic interaction. Phase 2 results due on April 29. If successful, it may piggyback off Copaxone sales.

Pathogenic infections are understandable. A foreign organism invades your body and you get sick. The immune system eventually takes care of it, sometimes with the help of other drugs. Autoimmune disorders, on the other hand, are much more frustrating. Why would your body suddenly start attacking itself? How would you even theoretically go about preventing such a thing?

In most cases autoimmune diseases are painful nuisances that can be managed. The autoimmune disease with the highest prevalence is Graves disease (page 11), which is when immune cells make the thyroid basically go berserk, speeding up the body's metabolism into turbo overdrive. The only way to manage it is to kill the thyroid gland and take supplemental thyroxin instead. The second most common is rheumatoid arthritis at around 1% of the global population (link above). Here the immune system attacks joints, destroying them and making it painful and difficult to move. The only long term treatment available is immune suppression.