Cleveland Clinic Launches Multidisciplinary Initiative to Advance IgG4-Related Disease Diagnosis, Research, and Care
Key Insights
Cleveland Clinic specialists have formed a multidisciplinary group to improve early diagnosis and care pathways for IgG4-related disease (search) (IgG4-RD), a chronic fibroinflammatory condition that often mimics cancer or other immune-related pathologies.
A clinical trial of a BTK inhibitor (search) is underway, alongside development of an AI-based early warning system and a dedicated IgG4-RD patient registry at Cleveland Clinic.
Experts emphasize that while glucocorticoids (search) remain the mainstay of therapy, recently approved biologics and others nearing approval may help spare patients from long-term high-dose steroid exposure.
Cleveland Clinic has convened a multidisciplinary group of specialists dedicated to advancing research, education, and clinical practice around IgG4-related disease (search) (IgG4-RD), a chronic multiorgan fibroinflammatory condition that remains among the least diagnosed immune-mediated inflammatory diseases. The initiative aims to shorten diagnostic delays, create seamless care pathways, and accelerate therapeutic development for a disease that can cause irreversible organ fibrosis when left unrecognized.
"We want to develop methods for earlier disease identification, combine that with education of clinicians and patients, and put this disease on the radar screen moving ahead," said Leonard Calabrese, DO, Director of the R. J. Fasenmyer Center for Clinical Immunology at Cleveland Clinic.
A Disease That Masquerades Across Organ Systems
IgG4-RD was not formally identified until the early 2000s, and consensus guidelines on its pathology were only released in 2012 by an international committee of experts. The disease causes swelling and inflammation in one or more organs—including the pancreas, kidneys, lungs, retroperitoneum, bile ducts, lymph nodes, salivary and lacrimal glands, and blood vessels—and can affect organs successively or concurrently.
Because IgG4-RD can produce lesions and organ enlargement, it frequently mimics cancer, infection, or other immune-related pathologies. While elevated serum IgG4 concentrations, typically above 135 mg/dL, can serve as an indicator, serum levels alone are insufficient for diagnosis.
"It has probably been around forever but was masquerading as a litany of separate syndromes," Dr. Calabrese said. "People didn't appreciate what they were looking at."
Diagnosis requires the appropriate clinical picture combined with supportive laboratory results, compatible radiographic imaging, and characteristic pathology—and common mimics must be ruled out. Certain presentations, such as glandular swelling of the eyes, may more readily raise suspicion, but patients with nonspecific symptoms like weight loss or back pain often go years without appropriate evaluation.
The Diagnostic Delay Burden
The challenge of timely diagnosis extends well beyond Cleveland Clinic. During a recent Amgen-hosted panel discussion, patient advocate Katharine described her husband's experience: "In my husband's case, he was told he had stage four lung cancer." She added that the majority of people she speaks with have either been misdiagnosed with some sort of cancer, had organs removed because of suspected malignancy, or been told they have other autoimmune diseases.
Professor Emma Culver, MD PhD, head of department for Hepatology at John Radcliffe Hospital and Translational Gastroenterology and Liver Unit at the University of Oxford, noted that the publication of the International Consensus Guidance Statement on the Management and Treatment of IgG4-RD in 2015, followed by the 2019 ACR/EULAR Classification Criteria, has contributed to a more structured framework for recognizing and classifying the disease. Yet she cautioned that progress in knowledge does not always translate into day-to-day clinical practice.
"We need collaborative working between specialists to really enhance awareness and understanding of this disease," Dr. Culver said. "I've got a lot of hope for the future. I think we have to work collaboratively—all specialists, physicians, carers working together towards actually improving not just awareness, but also management of this disease."
Cleveland Clinic's Multifaceted Approach
The Cleveland Clinic group spans rheumatology, allergy and immunology, gastroenterology, neurology, nephrology, radiology, and pathology. Among its current projects are a clinical trial of a BTK inhibitor (search) for the treatment of IgG4-RD, evaluation of a large language model-based tool for disease assessment and management using clinical vignettes, and development of an IgG4-RD registry coupled with an "early warning" system powered by artificial intelligence.
Dr. Calabrese noted that while rheumatology, allergy, immunology, and gastroenterology specialists maintain high awareness of IgG4-RD, primary care and internal medicine clinicians are less likely to be familiar with the condition. Broader awareness, he said, can help clinicians facing patients with syndromes aligning with the disease.
The Evolving Therapeutic Landscape
"While glucocorticoids (search) remain the mainstay of the therapy for IgG4-RD, there has been great progress in therapeutic development," Dr. Calabrese said. "One recently approved biologic already is in use and others are likely to be approved in the near future. This will allow us to spare our patients long-term high-dose glucocorticoid exposure which we know carries a significant toll."
For patients diagnosed with severe forms of the disease—including autoimmune pancreatitis, inflammation of the aorta and large vessels, retroperitoneal invasion, and renal disease—targeted education is essential. "It is a serious disease, but one that can be very well controlled if treated early," Dr. Calabrese emphasized. "The big challenge is identifying patients early enough to benefit from it."
Patient advocate Silvia, who participated in the Amgen panel, underscored the importance of the patient voice in shaping care: "The reason why I'm involved in patient advocacy is so I can ensure other patients are heard when they're speaking to their healthcare professionals."
The Cleveland Clinic group's work, combined with growing international efforts to raise disease awareness through initiatives like IgG4-RD Awareness Month and organizations such as IgG4ward! and the European Federation for IgG4-RD, reflects a broader momentum toward improving outcomes for patients with this frequently overlooked condition.