From the Guidelines
IgG4-related disease should be treated with glucocorticoids as the first-line treatment, starting with prednisone 0.6-1 mg/kg/day (usually 30-40 mg daily) for 2-4 weeks, followed by a gradual taper over 3-6 months to a maintenance dose of 5-10 mg daily for up to 3 years to prevent relapse, as recommended by the most recent guidelines 1. The treatment of IgG4-related disease aims to reduce inflammation, prevent organ damage, and improve quality of life.
Key Considerations
- The initial dose of prednisone can be adjusted based on the patient's response and tolerance, with some studies suggesting that lower doses (10-20 mg daily) may be effective in controlling the disease, particularly in elderly patients with relative contraindications for corticosteroid treatment 1.
- For patients who cannot tolerate steroids or have refractory disease, rituximab is an effective alternative, administered as 1000 mg IV infusions two weeks apart, with maintenance therapy every 6-12 months based on clinical response 1.
- Other steroid-sparing agents like azathioprine (2 mg/kg/day), mycophenolate mofetil (1000-2000 mg/day), or methotrexate (15-25 mg weekly) may be used for maintenance therapy, as recommended by the British Society of Gastroenterology and UK-PSC guidelines 1.
Monitoring and Maintenance
- Regular monitoring of organ function, serum IgG4 levels, and inflammatory markers is essential to assess treatment response and detect relapses early 1.
- Patients with complex IgG4-related disease or those with suspected malignancy should be referred to a specialist multidisciplinary team for review and management 1.
Additional Therapies
- UDCA (ursodeoxycholic acid) may be used in patients with fibrosing cholangiopathies, including IgG4-related disease, due to its anticholestatic and anti-inflammatory effects, although its corticosteroid-sparing effects are still being studied 1.
- Endoscopic intervention with balloon dilatation and stenting may be necessary for patients with distal or hilar bile duct strictures who are unresponsive to medical treatment 1.
From the Research
Overview of IgG4-Related Disease
- IgG4-related disease (IgG4-RD) is a systemic inflammatory disease that can affect nearly all organs, leading to fibrosis 2, 3, 4, 5, 6
- The disease is characterized by a dense, polyclonal, lymphoplasmacytic infiltrate rich in IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis 3, 4
Diagnosis of IgG4-Related Disease
- Diagnosis is based on a combination of typical radiological findings, elevation of serum IgG4 levels, histopathological findings, and response to steroids 4
- Histopathological approach is particularly recommended for diagnosis 4
Treatment of IgG4-Related Disease
- Systemic glucocorticoids are the first-line treatment for IgG4-RD, with an initial recommended dose of 0.6 mg/kg/day of oral prednisolone 4
- Rituximab, a B cell depletion therapy, has been shown to be effective in treating IgG4-RD, particularly in patients who are refractory to glucocorticoids and disease-modifying antirheumatic drugs (DMARDs) 2, 3, 5, 6
- DMARDs, such as azathioprine, methotrexate, and mycophenolate mofetil, may be effective in some cases, but their efficacy is limited 2, 5
- Surgical intervention and radiotherapy may be effective in inducing clinical remission and reducing recurrence rates in local disease 2
Treatment Outcomes and Response
- Glucocorticoids and rituximab have been shown to induce substantial responses in IgG4-RD patients, with high rates of treatment response and clinical remission 2, 5, 6
- However, recurrences and flares are common, and treatment algorithms are still ill-defined 2, 5
- The IgG4 responder index (IgG4-RI) is a promising outcome measure in IgG4-RD, but still in development 5