‘Systemic sclerosis patients should take care of ANCA-associated vasculitis’

Systemic sclerosis (SSc) patients suffering from skin stiffening and organ disfunction should guard against the occurrence of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis in case they had found ANCAs through previous checks, researchers said Tuesday.

Professor Lee Sang-won and Doctor Ha Jang-woo of the Department of Rheumatology at Yonsei University Severance Hospital made these and other points in their recent study, “The significance of antineutrophil cytoplasmic antibody positivity in patients with systemic sclerosis: a single-center pilot study in Korea.”

Professors Lee Sang-won (left) and Ha Jang-woo of the Department of Rheumatology at Yonsei University College of Medicine, Severance Hospital, warn against the occurrence of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis in case they had found ANCAs in previous checks.

The research was published in Clinical and Experimental Rheumatology (CER).

SSc and ANCA-associated vasculitis (AAV) are both rare autoimmune diseases. SSc is caused by excessive formation and accumulation of collagen. As a result, part of the skin stiffens asymmetrically, and organs like the lungs, heart, and kidney show functional disorders. Typical complication developments include pulmonary hypertension, interstitial pneumonia, and delay in intestinal excretion that hinders the flow of digestion.

AAV includes microscopic polyangiitis, granulomatosis with polyangiitis (formerly called Wegener’s granulomatosis), and Churg-Strauss syndrome. It is a systemic disease that causes inflammation in small vessels like a capillary vessel that stretches out all over the body, causing inflammation and damage in vital organs. Infected organs show minor symptoms like high fever, arthralgia, muscle pain, skin rash, and severe symptoms, such as renal failure, hemoptysis, cerebral stroke, and cardiac infarction.

The disease’s diagnosis is very difficult and complicated, leading to delays in treatment. Around 10-20 percent of delayed treatment can lead to death. However, if the treatment begins at an appropriate time with effective drug treatment, 70-80 percent of patients with very low disease activity can reach the stage of remission.

Recently, an Australian research team has announced that ANCA is found in 8.9 percent of SSc patients. This has a close relationship with severe complications developed like interstitial pneumonia or pulmonary embolism and mortality, indicating that ANCA positivity has an important role in predicting the prognosis of the disease.

Between June 2004 and November 2020, the Korean research team conducted the study at Yonsei University College of Medicine, Severance Hospital, on 177 SSc patients. These 177 corresponded to diagnostic criteria of U.S. and Europe’s Associations for Rheumatology. Those SSc patients with the possibility of false-positive of ANCA and taking medications were excluded.

The average age of patients was 52. Of the 177, 23 were men, and 36, or 20.3 percent, were ANCA-positive, higher than the Australian research’s 8.9 percent, showing that chances of ANCA positivity are higher in Korean SSc patients than Caucasians. Also, unlike the finding from the Australian study, Korean SSc patients having ANCA positivity had no meaningful relationship with mortality and not developed severe complications.

On the other hand, three of the 36 SSc patients with ANCA positivity suffered from AAV in serial assessment by biopsy organs like lungs, kidneys, and nerves.

The rate of 2.6 percent was also 0.23-1.6 percent higher than those of Australian and U.K. studies, indicating the chances of SSc accompanied by AAV are higher among Koreans than Caucasians.

“The research on the importance of ANCA positivity in SSc patients is meaningful because it was the first conducted on Koreans, not Caucasians like Australians or British,” Doctor Ha said. “Having higher rates of ANCA positivity in SSc patients and AAAV than Caucasians is assumed to be related to ethnic differences.”

Professor Lee Sang-won, who led the research, also said, “We cannot neglect the 2.6 percent of ANCA-positive Korean SSc patients who progressed with having AVV.

When similar symptoms of AVV are observed from vital organs like lungs, kidneys, and nerves, it is important to confirm the possibilities of accompanied AVV through active examination, including biopsy, he added.

Unlike in Australian research, Korean SSc patients with ANCA positivity showed no meaningful relationship with mortality and did not develop severe complications.