Scientists have made an important discovery that may help explain why some people develop both leukemia and autoimmune diseases.
The research was carried out by scientists at the Garvan Institute of Medical Research in Australia. Their findings could eventually lead to better ways to diagnose, treat, and even prevent these serious illnesses.
Leukemia is a type of cancer that begins in the blood and bone marrow, the soft tissue inside bones where blood cells are made. People with leukemia produce abnormal blood cells that grow out of control and interfere with the body’s normal functions.
Autoimmune diseases are different, but they are also caused by problems in the immune system. In autoimmune diseases, the body’s defense system mistakenly attacks healthy tissues instead of protecting them from germs and infections.
Examples of autoimmune diseases include rheumatoid arthritis, which affects the joints, and aplastic anemia, a condition in which the bone marrow cannot make enough blood cells.
Doctors have known for many years that people with leukemia are more likely than the general population to also have autoimmune diseases. However, scientists did not fully understand why these two very different conditions seemed to appear together in some people. The new study offers a possible answer.
The researchers focused on special immune cells called killer T cells. These cells are normally an important part of the body’s defense system.
Their job is to search for viruses, infected cells, and cancer cells and destroy them before they can cause harm. Most of the time, killer T cells work exactly as they should. But sometimes, they can become abnormal and start behaving in dangerous ways.
The scientists concentrated on a protein called STAT3. This protein acts like a control center inside immune cells. It helps regulate how T cells and another type of immune cell called B cells grow, survive, and communicate.
To understand what happens when STAT3 changes, the researchers used a powerful gene-editing tool called CRISPR-Cas9 to create specific mutations in mice. They also studied blood samples from children who had rare inherited autoimmune diseases.
The results were striking. The researchers found that certain changes in the STAT3 gene caused killer T cells to grow and multiply much more than normal. These cells became larger, more active, and more aggressive.
Although they represented only a tiny part of the immune system, making up just 1 to 2 percent of immune cells, they were still able to cause major problems.
Normally, the immune system has many checks and balances that stop immune cells from attacking the body. These protective mechanisms are important because they prevent unnecessary inflammation and tissue damage.
However, the mutated killer T cells were able to escape these controls. They kept growing and continued attacking healthy tissues, creating conditions that could lead to autoimmune disease.
The scientists also discovered that two important signaling systems inside cells may contribute to the problem. These systems help cells respond to stress and send messages to each other. When these signaling pathways are affected by the same genetic mutations, they may help push killer T cells into their rogue state and make them even more harmful.
The findings give researchers a much clearer picture of how autoimmune diseases may begin and why they sometimes occur together with blood cancers such as leukemia. The study also offers hope for more personalized treatments.
Some medicines known as JAK inhibitors already target similar signaling pathways in the immune system. These drugs are approved for use in Australia and many other countries. The new research suggests that they may be especially helpful for people who carry these specific genetic changes.
In the future, doctors may be able to use detailed blood tests to identify rogue immune cells before they cause serious damage. Earlier detection could allow doctors to begin treatment sooner and tailor therapies to each person’s unique genetic profile.
This discovery also highlights how closely cancer and autoimmune diseases can be connected. A small change in one immune protein may be enough to trigger two very different but potentially life-threatening conditions. Understanding these links could open new opportunities for precision medicine and improve the lives of people affected by these diseases.
The study was led by Dr. Etienne Masle-Farquhar and was published in the journal Immunity. Although more research is needed, the findings represent an important step toward understanding how the immune system can go wrong and how future treatments might prevent or control both leukemia and autoimmune diseases.
If you care about medicine, please read studies that vitamin D could help lower the risk of autoimmune diseases, and drug for inflammation may stop spread of cancer.
For more health information, please see recent studies about which drug can harm your liver most, and results showing this drug can give your immune system a double boost against cancer.
Copyright © 2026 Knowridge Science Report. All rights reserved.
