From the Guidelines
The initial treatment for IgG4 pancreatitis is oral glucocorticoids, typically prednisone at a dose of 40 mg daily or 0.6-0.8 mg/kg daily for the first 4 weeks. This recommendation is based on the most recent and highest quality study available, which suggests that starting doses of 40 mg daily or 0.6-0.8 mg/kg daily for the first 4 weeks have been widely recommended in Japanese, American and European Guidelines 1.
Key Considerations
- The treatment should be continued for 2-4 weeks before gradually tapering the dose over 3-6 months.
- Most patients show rapid clinical improvement within 2-3 weeks, with resolution of obstructive jaundice, reduction in pancreatic size, and improvement in pancreatic function.
- Glucocorticoids work by suppressing the underlying autoimmune inflammation characteristic of IgG4-related disease, reducing the infiltration of IgG4-positive plasma cells and lymphocytes in pancreatic tissue.
- Before starting treatment, it's essential to obtain baseline imaging (CT or MRI) and measure serum IgG4 levels to monitor response.
- Patients should be monitored for glucocorticoid side effects, including hyperglycemia, hypertension, and bone density loss.
Alternative Therapies
- For patients who relapse after steroid tapering or who cannot tolerate steroids, immunomodulatory agents such as rituximab, azathioprine, or mycophenolate mofetil may be considered as steroid-sparing alternatives or maintenance therapy 1.
- Emerging evidence from case series suggests that >95% of these patients with IgG4-RD will respond to biological therapy using anti-CD20 monoclonal antibodies such as rituximab.
- Rituximab is likely to be the preferred treatment for patients who fail to respond to first- or second-line treatment or whose disease flares on withdrawal of steroids, particularly in those with multisystem or complex disease.
From the Research
Initial Treatment for IgG4 Pancreatitis
- The initial treatment for IgG4 pancreatitis, also known as type 1 autoimmune pancreatitis (AIP), typically involves the use of systemic glucocorticoids 2, 3.
- The recommended initial dose of oral prednisolone is 0.6 mg/kg/day, administered for 2-4 weeks, and then gradually tapered to a maintenance dose of 2.5-5 mg/day over a period of 2-3 months 2, 3.
- Steroid therapy is the standard treatment, and symptoms are the major indications for treatment 2, 3.
- Before starting steroid therapy, obstructive jaundice and hyperglycemia should be controlled 3.
Response to Treatment and Relapse
- The short-term clinical, morphological, and functional outcomes of most IgG4-RD patients treated with steroid therapy are good 2.
- However, IgG4-RD can sometimes relapse after steroids, and maintenance therapy is usually performed to prevent relapse 2, 3.
- Readministration and dose-up of steroids are effective for relapses, and immunosuppressive drugs and rituximab have also been shown to be effective in some cases 2, 4, 3.
Alternative Treatment Options
- Rituximab, an anti-CD20 antibody, has been shown to be effective in treating IgG4-related pancreato-biliary disease, with a high remission rate and limited adverse events 4.
- Immunomodulatory drugs, such as azathioprine, may also be considered as an alternative treatment option for patients who are intolerant to steroids or have aggressive disease 2, 5.