Because the disease can affect many different organs at the same time, it may look very different from person to person. Symptoms depend on which organs are affected. You may notice:
IgG4-Related Disease
(IgG4-RD)
How to pronounce it:
Eye-Gee-Gee-Four Related Disease
¿Qué es la enfermedad relacionada con IgG4 (IgG4-RD)?
Enfermedad relacionada con IgG4 (IgG4-RD) Es una enfermedad inmunomediada que puede afectar a casi todos los órganos del cuerpo. Puede causar hinchazón (inflamación), daño y, en ocasiones, cicatrices (fibrosis) en uno o más órganos.
Actualmente no se clasifica como una artritis autoinmune o autoinflamatoria, pero sí involucra al sistema inmunitario. Los investigadores aún estudian cómo funciona y qué lugar ocupa entre las enfermedades inmunitarias.
¿Por qué es?
Ai¿Concienciación sobre la artritis?
Aunque la IgG4-RD no forma parte oficialmente de la
AiEn el marco general de la artritis, muchas personas pueden ser diagnosticadas erróneamente con una enfermedad autoinmune o incluso permanecer sin diagnóstico. La enfermedad relacionada con IgG4 (IgG4-RD) se considera actualmente de origen inmunológico, pero podría clasificarse como autoinmune o autoinflamatoria en el futuro. Si la artritis también se considera un síntoma importante, podría incluirse en este grupo, pero por ahora esto está por determinar.
Symptoms Often Associated with IgG4-Related Disease (IgG4-RD)
IgG4-RD Symptoms Tracker & Summary Log
This toolkit was developed to help expedite detection, diagnosis, or rediagnosis of IgG4-RD and was built using the same model as our Juvenile Idiopathic Arthritis (JIA) Health Journey Communication Aids toolkit . The guides in this toolkit grew out of the AUTO + Inflammatory Arthritis = X (or YZ) project and Mystery Patient Guide , which both aim to help expedite diagnosis for AiArthritis diseases and related conditions, such as IgG4-RD.
Communication Aids Included in this Toolkit:
- Symptoms Summary Communication Aid: Designed to help you share a summary of the symptoms you've experienced over a period of time with your healthcare provider.
- Symptoms Log: A tool that will help you track your symptoms and complete the Symptoms Summary Communication Aid.
- Additional Symptoms Communication Aid: Since IgG4-RD can involve multiple organ systems, this aid can help you summarize additional symptoms that are not covered in the Symptoms Summary Communication Aid. Additionally, this aid can be used with your primary care physician to determine of you need to be connected with a specialist.
IgG4-RD can be hard to diagnose. There isn’t one single test that confirms it. Doctors usually look at a combination of the following:
1. Blood Tests
- Nivel de IgG4: puede ser elevado en muchas personas con IgG4-RD, pero no siempre. Un nivel normal no lo descarta.
- Niveles de IgG1, IgE y complemento (C3 y C4): también pueden mostrar cambios relacionados con la inflamación.
- Pruebas específicas de órganos: los médicos pueden comprobar cómo funcionan el hígado, los riñones, el páncreas u otros órganos.
2. Imaging Scans
- Tomografía computarizada (TC): muestra el agrandamiento de órganos o masas.
- Resonancia magnética (RM): útil para observar la afectación de tejidos blandos o del cerebro.
- Ecografía: se usa frecuentemente para detectar inflamación en órganos como las glándulas salivales o los riñones.
- Tomografía por emisión de positrones (PET): ayuda a mostrar la inflamación activa.
3. Biopsy
A biopsy is when a small sample of tissue is taken from a swollen or affected area. Doctors look at the tissue under a microscope for signs of IgG4-RD, such as:
- High numbers of IgG4-positive plasma cells
- Storiform (whorled) fibrosis
- Obliterative phlebitis (veins blocked by inflammation)
Not all biopsies show all of these features, but together they help confirm the diagnosis.
Misdiagnosis is Common
Because symptoms can look like other diseases, IgG4-RD is often misdiagnosed as:
- Cancer (most common)
- Sjögren’s disease
- Sarcoidosis
- Infections
- Other autoimmune conditions
The goal of treatment is to control the disease, reduce inflammation, and prevent long-term organ damage.
Common Treatments:
- Steroids (such as prednisone) – Often the first treatment to reduce inflammation quickly
- Immunosuppressive medications(such as azathioprine or mycophenolate mofetil) – May be used to keep the disease under control
- Biologics(like uplizna and rituximab) – Used for patients who don’t respond well to steroids or need longer-term treatment
- Envía TU consejo
IgG4-RD usually requires a team of doctors, depending on which parts of the body are affected. This may include:
- Rheumatologist – Expert in immune and inflammatory diseases
- Gastroenterologist – For pancreas, liver, or bile duct involvement
- Nephrologist – For kidney involvement
- Pulmonologist – If the lungs are affected
- Ophthalmologist – For eye-related problems
- Radiologist & Pathologist – Help interpret scans and biopsies
- Primary care doctor – Helps coordinate care
These doctors work together to create a treatment plan that fits your needs.
Visit aiarthritis.org/Equation to download our Mystery Patient Guide and listen to Talk Show episodes
Find more resources at:
- Igg4ward.org – Organización de defensa del paciente – Educación, recursos y búsqueda de un médico
- igg4rdoutloud.com – Herramientas y planificación de la atención
- uplizna.com – Información sobre el tratamiento aprobado por la FDA
Post-Conference Webinar
In this webinar, Leila summarizes all of the IgG4-RD research updates presented at the 2025 EULAR and ACR conferences. We invited patients, organizations, and other individuals interested in or conducting research in the IgG4-RD space to discuss research from the conferences and highlight awareness & education materials from AiArthritis.
Estudios de investigación
Learn more about the latest clinical trials and their results which cover a variety of topics including treatments, disease activity, diagnosis journeys, and more. Click the button below to access the latest trials.
More IgG4-RD Content By AiArthritis
Go With Us! to ACR 2025: Understanding IgG4-RD -- New Research at ACR is Bringing Hope to Patients
Join Leila P.L. Valete, Health Education Manager at AiArthritis, as she delivers a special Go With Us! report dedicated entirely to IgG4-related disease (IgG4-RD) — a condition gaining new attention in the rheumatology community.
Go With Us! to ACR 2025: IgG4 and CAR T Therapy: Science Bringing New Hope for Patients
In this ACR 2025 "Go With Us" debrief video, Health Education Manager Leila P.L. Valete discusses IgG4-related disease (IgG4-RD) and CAR T-cell therapy, two of the most talked-about topics in rheumatology this year. IgG4-related disease (IgG4-RD) is often misdiagnosed as cancer or Sjögren’s because it can affect multiple organs. Accurate diagnosis requires a biopsy of the affected organ since elevated IgG4 blood levels alone aren’t definitive.
Ep 109: The Mystery Patient Experience and the Overlap with IgG4-RD
Managing AiArthritis diseases is tough without a clear diagnosis. In this episode, AiArthritis Health Education Manager Leila discusses the “mystery patient” experience of those with persistent symptoms. She revisits earlier topics and introduces resources like the updated Mystery Patient Guide and the AUTO + Inflammatory Arthritis = X or YZ Project, exploring conditions such as IgG4-related disease. Leila also shares a touching story of a patient who struggled for years without a diagnosis.
Learn about IgG4-Related Disease, a rare immune-mediated condition that can cause complex, overlapping symptoms across the body, and why greater awareness matters for patients seeking answers and care.
¡Acompáñanos a EULAR 2025!: ¿Qué es la enfermedad relacionada con IgG4 y por qué tantos pacientes reciben un diagnóstico erróneo?
En este vídeo resumen de EULAR 2025 «Go With Us», la directora de Educación para la Salud, Leila PL Valete, habla sobre la enfermedad relacionada con IgG4 (IgG4-RD), una afección inmunitaria poco frecuente que a menudo se confunde con otras enfermedades autoinmunes. Los temas tratados incluyen: desafíos diagnósticos, la importancia del «SACQ» y las discrepancias entre los resultados de laboratorio y los síntomas, el papel de la histología y sus posibles dificultades, los tratamientos y la importancia de la atención personalizada.
Episodio 109 360it: AiLa lucha de la artritis por los "pacientes misteriosos" sin diagnosticar.
A muchas personas se les dice que su dolor es "solo psicológico". AiArthritis está cambiando esta percepción para pacientes con afecciones sin diagnosticar en todo el mundo. Este video explica cómo se fundó AiArthritis para apoyar a pacientes sin diagnóstico y destaca los esfuerzos continuos para educar a los profesionales de la salud y al público en general, con el fin de acelerar el diagnóstico y el tratamiento.
Ep 109 360it: The First Six Months Are Critical
Did you know you have the best chance at remission if you get treated within six months of symptoms starting? This video explains why getting proper treatment early — especially within six months of symptom onset — is vital to improving remission rates and preventing additional health complications.
Ep 109 360it: Culturally Competent Care for Earlier Diagnosis
What if more culturally competent care could help communities of color get diagnosed sooner? This video highlights how AiArthritis is gathering insights from Black, Latino, and Asian communities to create culturally informed resources that help healthcare providers diagnose and treat patients earlier and more equitably.
Ep 109 360it: Descubriendo la enfermedad relacionada con IgG4: una causa oculta de diagnóstico erróneo
¿Podría una enfermedad rara como la IgG4-RD ser la verdadera causa de un diagnóstico erróneo de cáncer o síndrome de Sjögren? Este video explica cómo AiArthritis está creando conciencia sobre la enfermedad relacionada con IgG4, que a menudo se confunde con afecciones como el síndrome de Sjögren, la sarcoidosis, la vasculitis o incluso el cáncer, y por qué su detección temprana es vital para proteger múltiples órganos.
Ep 109 360it: FDA Approves B-Cell Therapy for Better Patient Outcomes
A groundbreaking FDA approval means new treatment options — and new hope — for patients living with this disease. This video shares the exciting news about the FDA approval of B-cell depletion therapy, offering patients a new, targeted treatment option to improve quality of life.
Go With Us to EULAR 2023 - Ig-G4, UCTD, RMDs and the Brain
Tiffany, Deb, and Eileen do a deep-dive into the newest research and information presented throughout EULAR 2023 which includes an update on IgG4 from the European Congress of Rheumatology.
Get Involved!
Sometimes the best medicine is diving in to learn more, meeting those who have similar lived experiences, and doing activities that can help to improve your health and the
AiArthritis community!
Where to Start:
- Follow
AiArthritis on Social Media:
- Become a Volunteer
- Join AiArthritis Voices
- Submit a Rant
- Join our Research Database
- Join our Online Community
Agradecemos al equipo de Enfermedades Raras de Amgen su continuo apoyo a esta iniciativa.
