Severance Hospital said its researchers have discovered a biomarker that can predict organ damage in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis patients, for the first time in the world.

A Severance Hospital research team, led by Professors Lee Sang-won (left) and Pyo Jung-yoon, has found a new biomarker that can predict organ damage in ANCA-associated vasculitis patients. (Severance)

ANCA-associated vasculitis is an autoimmune disease that causes inflammation by attacking the walls of blood vessels due to abnormal immune regulation.

Since blood vessels are spread to every corner of the body, symptoms appear throughout the body. Depending on the invading organs, symptoms range from mild ones such as high fever, joint pain, muscle pain and skin rash to severe ones, including kidney failure, hemoptysis, stroke, and myocardial infarction.

Diagnosing the disease is very difficult and can delay treatment, while 10 to 20 percent of patients die due to late diagnosis.

If effective drug treatment begins at the right time, however, 70 to 80 percent of patients can reach a state of remission with very low disease activity, the hospital said. To this end, the degree of organ damage in patients with ANCA-associated vasculitis can only be accurately evaluated by performing several tests, including radiographic tests, it added.

“Therefore, there have been concerns about difficulty and inaccuracies in detecting the disease in the actual medical field,” it said. “The team’s biomarker that can predict the degree of damage through blood tests is clinically useful and meaningful.”

To discover the biomarker, the team, led by Professors Lee Sang-won and Pyo Jung-yoon, looked at the Interleukin 16 (IL-16) protein as a possible candidate.

IL-16 secreted by various cells, including immune cells, such as white blood cells, induces inflammation depending on the disease or, conversely, lowers inflammation. In the field of vasculitis, however, the role of IL-16 had not been identified.

To determine the role of IL-16 in vasculitis, the team conducted a study on 78 out of 220 patients enrolled in the ANCA-associated vasculitis patient cohort operated at Severance Hospital.

The researchers first measured the concentration of IL-16 in serum isolated from blood in patients diagnosed with ANCA-associated vasculitis before receiving immunosuppressants. Afterward, they investigated how IL-16 correlates with ANCA-related vasculitis evaluation index, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP).

As a result, IL-16 showed a significant correlation with the vasculitis damage index (VDI) among the ANCA-related vasculitis index. There was no significant correlation with other ANCA-related vasculitis evaluation indicators, ESR, and CRP.

The team also found that the concentration of IL-16 was significantly higher in patients with ear, nose, and throat symptoms among various organs.

“Among the various ANCA-related vasculitis evaluation indexes, VDI is an evaluation index that requires many tests, so it was difficult for both patients and medical staff to measure the index every time the patient visited the hospital,” Professor Lee said. “There was also great concern about the possibility of inaccurate measurement.”

However, this study confirmed the possibility of serum IL-16 concentration as a biomarker that can predict organ damage in patients with ANCA-associated vasculitis, he added.

Professor Pyo also said, “The discovery of new biomarkers gives clues to the disease state of vasculitis patients and becomes a piece of important information for planning treatment.”

Pyo added that the research team plans to conduct further researches to apply the finding in the actual clinical field.

Arthritis Research & Therapy has published the results of the study.

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