Explore This Treatment Program


Addressing IgG4-RSD as a Systemic Disease

IgG4-related systemic disease (IgG4-RSD) links a number of inflammatory disorders that previously were considered unrelated. Various clinical manifestations of the condition can cause fibrosis (the formation of excessive connective tissue) in a growing list of organs and tissues.

Mass General is one of the only U.S. hospitals to recognize and treat IgG4-RSD as a systemic (i.e. whole-body) disease that affects multiple organs and tissues. Our research on this emerging disease has led to several important milestones, including:

  • Pioneering a new treatment (rituximab)
  • Establishing IgG4-RSD's link with thoracic aortitis and with Riedel's thyroiditis
  • Organizing the first international symposium on IgG4-RSD

What to Expect

Many patients are referred to us by a pathologist who suspects IgG4-RSD. At your first visit, you will meet with John Stone, MD, MPH, who has treated this disease since its emergence in recent years.

Your doctor will review your medical history, perform a physical examination and, because information about IgG4-RSD is so hard to find, educate you about the disease. If necessary, we may recommend blood tests or review your biopsy specimen with a Mass General pathologist to confirm a diagnosis.

For many patients, receiving the diagnosis of IgG4-RSD comes as a relief. The condition often causes organ swelling, which previously may have been mistaken for a malignant tumor. Some patients have even undergone unnecessary surgery for this reason.

If IgG4-RSD is diagnosed early, we can usually control the inflammation within organs and prevent further damage. In addition, our multispecialty expertise is essential in managing problems within organs that can result from damage associated with IgG4-RSD.

Our collaborators from other medical specialties include:

Exploring a Promising New Treatment Option

Treatment for IgG4-RSD traditionally has involved prednisone, a steroid medication. Prednisone has proven very effective in treating this condition but also leads to side effects such as weight gain, osteoporosis, high blood pressure and diabetes.

Mass General is hosting a clinical trial of rituximab, which to date has shown to be as effective as prednisone in IgG4-RSD but without the side effects. As a patient in our program, you will begin treatment for IgG4-RSD with two months of prednisone therapy. However, if symptoms subsequently return, you may be eligible to participate in the study of rituximab.

We typically see patients in our program monthly for the first three months of treatment and then every three months thereafter.

About this Program

IgG4-related systemic disease (IgG4-RSD) typically affects multiple organs and tissues—most commonly the:

  • Aorta tissue
  • Kidneys
  • Lacrimal glands (which produce tears)
  • Lungs
  • Pancreas
  • Retroperitoneal tissue (in the abdominal area)
  • Salivary glands

The condition causes fibrosis, in which the formation of excessive connective tissue prevents normal organ/tissue function. It may also lead to swelling that can be mistaken for tumors.

Particularly if diagnosed early, IgG4-RSD is highly treatable. Our program offers both traditional steroid therapy (prednisone) and, should that prove ineffective, a medication called rituximab that has shown great promise in treating the condition.

Unlocking the Mysteries of IgG4-RSD

The IgG4-RSD Program is led by Rheumatology Unit clinical director John Stone, MD, MPH. His research group has published several papers on IgG4-RSD, and he is organizing the first international symposium on this emerging disease. In addition, he has co-led a groundbreaking clinical trial that has established rituximab as the standard of care for the treatment of a severe form of vasculitis.

A current Mass General clinical trial is studying the use of rituximab in patients with IgG4-RSD. Preliminary results have shown that rituximab therapy leads to the rapid decline of serum IgG4 levels and prompt clinical improvement. This trial is accepting new patients; please contact the Rheumatology Unit for details on participating.

In the area of basic research, physicians from the Rheumatology Unit were the first to report IgG4-RSD's link with thoracic aortitis and with Riedel's thyroiditis. Today, we are conducting several studies aimed at improving our understanding of the causes of IgG4-RSD. We plan to apply this knowledge in developing more-effective treatments for this condition.