The immune system is built to protect the body. But an overactive immune system can do just the opposite. For patients with hemophagocytic lymphohistiocytosis (HLH), extreme immune activity can cause life-threatening inflammatory reactions.
If standard treatment fails, patients are left with few choices. Now, a promising new option has emerged from a study led by St. Jude Children’s Research Hospital.
In patients with HLH, a massive buildup of white blood cells can cause a “cytokine storm,” which triggers a dangerous inflammatory reaction. By recreating this scenario in the lab, researchers were able to search for drugs that reduced inflammation.
The scientists homed in on molecules called JAKs, which enable cytokines to carry out their normal functions. “We reasoned that inhibition of these JAKs might diminish inflammation and lessen disease,” said Kim Nichols, MD, of St. Jude Oncology.
They were right. Inhibiting JAK function with a drug called ruxolitinib reduced both inflammation and its negative biological effects. Since ruxolitinib has been well studied for many years in the treatment of other conditions, it is an attractive candidate for clinical trials for HLH.
“It is our hope that by incorporating JAK inhibitors, we can improve the cure rate for children and adults suffering from this devastating and often life-threatening disorder,” noted Nichols. The study was published in the journal Blood.