番茄社区

Relatively little is known about the best care strategies for people with systemic polyarteritis nodosa (PAN).

That is the key conclusion of a literature review published in . According to its authors, the review will help inform fresh recommendations related to PAN diagnostics and management, which are set to appear in a forthcoming guideline on the subject developed by the American College of Rheumatology and the Vasculitis Foundation.

A total of 137 papers were ultimately included in the review, including 21 observational studies and seven randomized controlled trials, six of which were single-armed studies with only one having two arms.

Among the key findings, evidence emerged supporting a deep skin biopsy as a reliably accurate diagnostic tool. Additionally, cyclophosphamide in combination with high-dose glucocorticoids was determined to be an effective induction treatment for severe cases, while glucocorticoid monotherapy tended to suffice for patients with non-severe symptoms.

Yih Chang Lin, MD, a rheumatologist and researcher with the University of South Florida Health, served as the paper's first author. He recently discussed the review and its findings with 番茄社区. The exchange has been edited for length and clarity.

What was the main knowledge gap this review was designed to address?

Lin: People with untreated PAN have a poor prognosis, with mortality rates as high as 20% over a 5-year period. But we also know that prognosis markedly improves with treatment.

With this in mind, the first aim of this systematic review was to comprehensively search and compare the benefits and harms of different treatment options for patients with primary systemic PAN. The second aim was to determine the accuracy of commonly used diagnostic tests for PAN.

How would you summarize your key findings?

Lin: In general, we found that there were very, very limited good-quality data for PAN treatments and diagnostics.

Among our more interesting clinical findings, we found that even though glucocorticoid monotherapy is effective in treating non-severe PAN, this course of treatment also comes with a high rate of relapse.

Further, drug options such as the nonbiologic immunosuppressive class of therapies, which includes methotrexate, can be used in patients who did not improve or had side effects after using glucocorticoids.

Are there any clinical takeaways from this review for clinicians?

Lin: Since so much of our evidence was indirect and not based on randomized controlled trials, a lot of the recommendations in our forthcoming guideline are going to be conditional.

Still, we know we need high clinical suspicion, and we need to do more genetic testing, which makes sure the patient gets the right treatment as soon as possible.

Right now, diagnosis and treatment are really based on the patient's presentation, the patient's preferences, and the physician's experience.

It seems there are many potential avenues of research related to PAN diagnosis and treatment. How would you prioritize those areas?

Lin: We definitely need more randomized clinical trials to look at treatment regimens and identify the best induction treatment options for patients with severe and non-severe disease.

We also need to look for the best regimen for patients with PAN who have relapsed in spite of first-line treatment.

Overall, we need to know: What is the ideal maintenance therapy duration for PAN? There are very few papers that help guide physicians. So, I think there is a really good opportunity for us to do better.

You can read the study here.