IgG4-related disease (IgG4-RD)

IgG4-RD can impact many parts of the body, including:

• Salivary glands (causing swelling near the jaw or under the chin)
• Lacrimal (tear) glands (causing eye swelling or dryness)
• Pancreas (autoimmune pancreatitis)
• Bile ducts and liver
• Kidneys
• Lungs
• Lymph nodes
• Aorta and blood vessels
• Retroperitoneum (area behind the abdomen)

Symptoms vary depending on the organ involved. The signs of IgG4-RD may develop slowly, and they can be different for each person. Common symptoms include:

• Swelling or enlargement of glands and organs
• Fatigue
• Mild pain or discomfort
• Unexplained weight loss (in some cases)
• Dry eyes or dry mouth
• Abdominal pain or jaundice (if pancreas or bile ducts are involved)
• Unexplained diarrhea or new onset worsening diabetes
• Shortness of breath (if lungs are involved)

Some people may have few or no symptoms; in that case, the condition is typically found through imaging or blood tests.

Diagnosing IgG4-RD can be challenging because it can look like other conditions, such as infections, cancers or other autoimmune diseases. Because of this, doctors use a careful process to diagnose IgG4-RD.

Ruling out other conditions

Before confirming IgG4-RD, your doctor will first make sure that other possible causes are not responsible for your symptoms. This may involve:

• Blood tests
• Imaging (such as CT or MRI scans)
• A biopsy

This step is important because many conditions can mimic IgG4-RD, but the treatments are very different.

Looking for features of IgG4-RD

Once other conditions have been ruled out, your doctor will examine the following to determine IgG4-RD:

• Clinical features (which organs are affected and how)
• Blood tests, including IgG4 levels
• Imaging findings, for patterns of swelling or inflammation
• Biopsy results (if done), for specific changes in the tissue

Because IgG4-RD can closely resemble other diseases, this step-by-step approach helps ensure:

• The correct diagnosis is made.
• Unnecessary treatments are avoided.
• The most effective therapy is started early.

Treatment of IgG4-RD aims to reduce inflammation, preserve organ function and prevent long-term damage, such as fibrosis or obstruction. We tailor the care plan based on which organs are involved and how severe the disease is.

Medications to control inflammation

Corticosteroids (first-line treatment)

Medications such as prednisone are usually the first step. They work quickly to reduce inflammation and organ swelling. Most patients respond well initially. 

Because long-term steroid use can have side effects, additional medications are often used to reduce steroid exposure.

Immunosuppressive medications (steroid-sparing therapy)

These medications help maintain disease control and prevent relapse without relying on long-term, high-dose steroids.

Conventional synthetic DMARDs

• Examples: azathioprine, mycophenolate, methotrexate
• Help stabilize the immune system over time
• Often used when the disease returns after steroids

Targeted biologic therapy (advanced treatment): B-cell depletion therapy

• Targets specific immune cells involved in IgG4-RD
• Has shown strong effectiveness in many patients
• Often used when steroids or other medications are not sufficient
• Long-term treatment is needed

Surgical and procedural interventions

While medications treat the underlying inflammation, procedures may be needed when there is structural damage or blockage.

Surgery is usually not the primary treatment, but may be important in specific situations.

Relief of obstruction

• For example, bile duct or ureteral obstruction
• May involve stenting or drainage procedures

Surgical resection or biopsy

A surgical resection or biopsy is sometimes needed when diagnosis is uncertain, a mass needs to be distinguished from cancer, or there is localized organ damage.

Living with a chronic condition can be challenging, but many people still lead full and active lives.

Here are some tips for navigating your life with IgG4-RD:

• Keep regular follow-up appointments
• Report new symptoms early
• Take medications as prescribed
• Maintain a healthy lifestyle (diet, exercise, sleep)

IgG4-RD is often managed by a team that may include:

• Rheumatologist
• Gastroenterologist
• Hepatologist 
• ENT specialist
• Ophthalmologist
• Nephrologist
• Pulmonologist
• Radiologist and pathologist
• Neurologist

Contact your doctor if you notice:

• New swelling in glands or organs
• Worsening fatigue
• New pain or unexplained symptoms
• Side effects from medications

• American College of Rheumatology
• IgG4ward Foundation
• The National Pancreas Foundation
• Vasculitis Foundation