Type 1 autoimmune pancreatitis (AIP-1) is a chronic inflammation of the pancreas that predominantly affects men over the age of 60. It is the main manifestation of the IgG4-related disease, a rare condition (in Italy, about 5–10 new cases per 100,000 inhabitants are recorded) characterized by tumor-like masses rich in plasma cells (the immune cells that produce antibodies) in various organs of the body.

In AIP-1, phases of relapse—where disease symptoms and/or organ lesions detected by imaging reappear—alternate with phases of remission, during which both symptoms and radiological signs disappear.

Relapses are treated with repeated courses of glucocorticoids, drugs with anti-inflammatory and immunosuppressive properties. However, over time, both the disease itself and continuous exposure to glucocorticoids can further damage different organs, increasing the risk of developing diabetes mellitus and osteoporosis.

For this reason, patients with factors that predispose them to a more aggressive form of the disease—such as high blood levels of IgG4 or frequent relapses—may receive maintenance therapy using lower doses of glucocorticoids or other types of immunosuppressive drugs.

Nevertheless, in about 25% of patients, IgG4 levels remain elevated even when symptoms disappear, and overall, evidence supporting maintenance therapy in selected cases of AIP-1 remains limited.

Dr. Marco Lanzillotta, internist and immunologist at the Unit of Immunology, Rheumatology, Allergy, and Rare Diseases of IRCCS San Raffaele Hospital in Milan, Dr. Emanuel Della Torre, rheumatologist, allergist, and immunologist in the same Unit, and Professor Lorenzo Dagna, Head Physician of the Unit and Associate Professor of Internal Medicine at Vita-Salute San Raffaele University, are among the authors of a study whose results, if confirmed, open new perspectives for tailoring maintenance therapy for patients with type 1 autoimmune pancreatitis.

Study Results

In the study, which involved 42 European research centers, the researchers retrospectively examined 577 patients with AIP-1 who had achieved complete or partial remission of symptoms after initial immunosuppressive treatment.

Of these 577 patients, 255 received maintenance therapy with low doses of glucocorticoids or other immunosuppressive or anti-inflammatory drugs, while the remaining patients did not undergo such therapy.

The authors first evaluated the effectiveness of maintenance therapy in preventing relapse after three and five years from remission. They observed that relapses were less frequent among patients on maintenance therapy compared to those without it.

Specifically, after three years, about 22% of patients on maintenance therapy experienced relapse, compared to about 35% of patients without maintenance. After five years, relapse occurred in about 29% of patients receiving maintenance therapy versus 46% of patients without it.

Thus, consistent with limited previous evidence, maintenance therapy effectively reduced the frequency of disease relapses at both three and five years.

The researchers then asked whether the benefits of maintenance therapy were the same for all AIP-1 patients, regardless of whether they were at low or high risk of relapse.

To answer this, they used a statistical model based on prognostic factors derived from the scientific literature.

Specifically, they combined protective factors against relapse (such as maintenance therapy, prior pancreatic surgery, presence of localized tumor-like masses, and female sex) with risk factors for relapse (involvement of bile ducts, involvement of other organs besides the pancreas, and presence of acute pancreatitis or jaundice at onset). Based on this model, they developed a scoring system to classify patients according to their risk of relapse.

The authors found that maintenance therapy effectively prevented relapses in patients classified as high risk (score above 155), compared to high-risk patients who did not receive maintenance.

In patients classified as low risk (score below 155), however, maintenance therapy made no difference compared to patients with the same risk who did not receive it.

“This system lays the groundwork for a standardized evaluation of relapse risk in AIP-1 patients, and thus for personalized treatment strategies. In fact, if confirmed by further studies, in the future, this system could help physicians measure the predicted relapse risk in individual patients with type 1 autoimmune pancreatitis,” comments Dr. Lanzillotta, first author of the study.

“Physicians will therefore be able to rely on an objective criterion to guide the decision of whether or not to prescribe maintenance therapy for patients at high risk of relapse,” adds Dr. Emanuel Della Torre.

“Once again, our Unit is at the forefront of research on immune-mediated diseases such as IgG4-related disease, a rare condition about which we still know little. With the interdisciplinary group I lead, we are committed every day to understanding the mechanisms underlying these diseases to develop clinical practices aimed at personalizing diagnosis and therapy for each individual patient,” concludes Professor Lorenzo Dagna.

 

Written by: Laura Celotto

Published on: 14/10/2025