SAVI—STING-associated vasculopathy with onset in infancy—helped show that different inflammatory pathways can lead to illnesses within the autoinflammatory family. As the name implies, the disease often becomes noticeable early in life. Features can include a rash, nodules, fever, lung abnormalities, and ulcers or gangrene in their fingertips. Blood testing shows elevation in markers of inflammation, as are normally seen in autoinflammatory diseases.
In the early reports, several treatments used for other inflammatory conditions were insufficient in the children described in early reports. As a result, doctors thought this constellation of symptoms may be due to a new disease. They were right–genetic testing in affected children showed a new mutation in a gene that makes a protein called STING. This mutation causes uncontrolled production of type I interferons. Interferons are molecules your body produces to fight viral infections; in a sense, they are your body’s antiviral medication. Usually, these molecules are tightly regulated–they are activated when you get the flu and go away when you recover.
In patients with STING mutations, however, interferon is always active. Your body makes antiviral molecules as if it were infected with a virus, but no virus can be found. These molecules, no longer tightly regulated, seem to cause the signs and symptoms of SAVI. Fortunately, doctors found that a new type of medication (JAK inhibitors) can block the effect of the antiviral molecules and may be useful in children with SAVI.
SAVI is especially associated with excess type I interferon signaling, rather than fitting a single IL-1-driven model. Instead, the vehicle for inflammation in patients with SAVI is interferon. Despite essential differences in fuel, the result–systemic inflammation, fever, rash–is characteristic of an autoinflammatory disease. Further proof that all roads lead to Rome, even those within our own bodies.
What has changed since the early reports?
SAVI is now an established interferonopathy. JAK inhibitors have been used in specialist care, with benefit reported in some patients, but response can be incomplete and treatment requires careful safety monitoring. Skin and lung disease need particular attention. These medicines are not a cure and are not interchangeable with treatments for every autoinflammatory disease.
Read the EULAR/ACR guidance on SAVI, CANDLE/PRAAS and AGS for the evidence and its limitations.
Updated September 30, 2026.