One Potential HIV Cure Could Lead Immune System to Attack Organs

The New York Times has reported that the kind of immunotherapy being used to cure cancer (and could possibly cure HIV) may lead to life threatening conditions like diabetes, pancreatitis, and hepatitis when the immune system attacks the body's organs.

A healthy immune system attacks disease and leaves everything else alone. Cancer tricks the immune system into thinking it isn’t a threat, and researchers haven’t figured out how to paint a target on cancer tumors to make it so the immune system see them. Instead, new immunotherapies make it so the immune system doesn’t turn itself off.

Treating patients with a combination of two of the major immunotherapy drugs, nivolumab and ipilimumab, has been very successful, fighting — and even curing — the cancer of more than 40 percent of patients with advanced melanoma.

Unfortunately, without an added off switch, the immune system can see other things — like the liver, lungs, kidney, pancreas, adrenal and pituitary glands and even, in rare cases, the heart — as invaders that need to be attacked.

“We are playing with fire,” Dr. John Timmerman, an oncologist and immunotherapy researcher at the University of California, Los Angeles, told the Times. After immunotherapy drugs reportedly “melted away” a patient’s cancer, the woman died from an inflammatory response, which Timmerman called “a mass riot, an uprising” of her immune system.

A 2015 study published in The New England Journal of Medicine revealed that side effects that were severe, required hospitalization, or were life-threatening occurred a whopping 54 percent of the time when the combination immunotherapy was used. 

More recently, researchers found 30 percent of patients receiving the threapy experience “interesting, rare, or unexpected side effects.” Most of those side effects can reportedly be managed by suppressing the immune system that had been previously unleashed. But, 25 percent of reactions are severe, life-threatening, or require hospitalization. Some patients have died, including, Times reports, five in recent clinical trials of a new immunotherapy drug being tested by Juno Therapeutics Inc.

Yale endocrinologist, Dr. Kevan Herold, told the Times he believes these drugs are sparking a new form of Type 1 diabetes. Type 1 (often called juvenile diabetes) ususally attacks children and involves the immune system slowly destroying cells in the pancreas, which makes insulin the body needs to metabolize sugar and transform food into energy.

Herold has noted an increase in the number of patients 50 or older, who suddenly lose their ability to produce insulin as a side effect of immunotherapy. An unrestrained immune system can destroy a pancreas in a surprisingly short period of time: days or even hours.

“Her pancreas isn’t coming back,” Yale oncologist, Dr. Harriet Kluger told the Times in reference to a patient experiencing the diabetic effects of immunotherapy. Then again, Kluger added, “she has her life.” The woman was successfully cured of cancer.

Some cancer-fighting drugs like vorinostat have shown promise in “kick and kill” HIV curative strategies, but a new study hints that reactivating and fighting HIV reservoirs in organs could also lead to immune response-related imflamation—including enchephilitis (swelling of the brain).

What is a cancer cure worth? The occasional death and many patients being left with a lifelong chronic condition? Now that HIV is no longer the killer it once was, will the risk of potentially irreversible side effects be worth a possible cure?