Treatment specialists

Pulmonologists and nephrologists help find silent IgG4-RD in lungs and kidneys to protect organ function.

Pulmonologists and nephrologists: How lung and kidney specialists protect your organs

When IgG4-related disease (IgG4-RD) involves the lungs or kidneys, clinicians take it seriously because these organs can develop potentially damaging inflammation before symptoms are obvious. Lung involvement may progress before you notice changes in exercise tolerance or breathing, and kidney involvement may first appear as abnormalities on blood or urine testing rather than pain or other clear warning signs.

This is why pulmonologists and nephrologists are valuable partners in IgG4-RD care: they bring organ-specific expertise, help clarify what the disease is doing in that organ system, and guide monitoring so changes are detected early and managed in a timely, organ-protective way.

In this lesson, we’ll talk about what they do, why they matter in IgG4-RD, what to expect at visits, and how to ask the right questions.

Why lungs and kidneys deserve special attention in IgG4-RD

Because IgG4-related disease (IgG4-RD) is a systemic fibro-inflammatory disease, it can cause inflammation and scarring (fibrosis) in many different organs. The lungs and kidneys are two organs that physicians watch especially closely, because changes there can sometimes build quietly in those organs long before they become clinically apparent. ¹

That means inflammation may show up on imaging (like a CT scan) or on lab tests (blood and urine tests) before you feel much different day to day. Because of that, your team may recommend periodic testing even when you feel okay, so they can catch early changes while there’s still a good chance to protect organ function. ⁴

The lungs also bring an extra challenge: when IgG4-RD affects them, the patterns on imaging can mimic other diseases, including infections, sarcoidosis, ANCA-associated vasculitis, lung cancer, or interstitial lung disease. That’s why organ-specific evaluation—often with a pulmonologist’s close review—matters so much. It helps your team make sure they’re treating the right problem in the right way, and not overlook anything. ⁵

What is a pulmonologist?

A pulmonologist is a physician specialized in treating conditions and diseases of the respiratory system, including the airways and the tiny air sacs in the lungs (alveoli). ⁶

Why you might see a pulmonologist in IgG4-RD

You might be referred to a pulmonologist if:

• you have known or suspected lung involvement on imaging

• you have breathing symptoms (like cough or shortness of breath)

• your care team wants baseline lung testing so future changes are easier to spot

What a pulmonologist may do for IgG4-RD lung care

Pulmonologists often help with both the “detective work” and the “monitoring work”, meaning they help figure out whether IgG4-RD is truly affecting the lungs (and what else it could be), and then in keeping a steady eye on things over time. They do this by carefully reviewing chest imaging, checking breathing tests, and pairing those results with your symptoms and exam.

Pulmonologists may:

• review chest imaging closely (CT scans are common for this purpose)

• order breathing tests (often called pulmonary function tests)

• help decide whether a bronchoscopy or biopsy is needed (only when it’s truly necessary)

• track your lung function and imaging over time so your team can tell the difference between active inflammation (often more reversible) and fibrosis (scar-like change that can be harder to reverse).¹

• manage the symptoms of reactive airway disease (asthma) that many patients with IgG4-RD have.

A helpful thing to remember: lung findings in IgG4-RD can mimic other diagnoses, so pulmonology input can prevent both under treatment (missing active disease) and treating the wrong thing.⁵

What is a nephrologist

A nephrologist is a medical doctor who specializes in diagnosing and treating kidney conditions. ⁷

Why you might see a nephrologist in IgG4-RD

Kidney involvement in IgG4-RD is well recognized, and one common pattern is tubulointerstitial nephritis, an inflammation problem in the kidney’s “filter support tissue.”

You might see a nephrologist if:

• your blood tests show changes in kidney function,

• urine tests show protein or blood,

• imaging suggests kidney involvement,

• IgG4-RD has caused related problems that threaten the urinary  system (for example, inflammation and scarring in the retroperitoneum can obstruct urine flow and endanger kidney function). ⁸

What a nephrologist may do for IgG4-RD kidney care

Nephrologists protect kidneys in practical, step-by-step ways. Many visits involve:

• blood tests (to see how well kidneys are filtering the blood),

• urine tests (to check for signs of kidney inflammation or damage),

• blood pressure review (because blood pressure and kidneys affect each other closely),

• coordination with your IgG4-RD team on whether kidney findings are likely active inflammation, scarring, or something else entirely. ⁷

They also play a key role in making sure “kidney-safe” choices are made, such as adjusting medication doses when needed and watching for side effects.

How these specialists fit into your IgG4‑RD team

IgG4-RD often requires a team approach because different organs can be involved at different times.¹ 

A common setup looks like this:

• A rheumatologist (or another lead physician experienced in IgG4-RD) helps manage the whole-body plan.

• A pulmonologist focuses on lung testing, imaging interpretation, and symptom monitoring.

• A nephrologist focuses on kidney labs, urine testing, blood pressure, and kidney-specific decisions.

When the team works well together, it reduces delays in diagnosis and helps prevent long-term organ injury. It’s important to remember, that time matters when inflammation is active. ⁹

Key Takeaways:

• IgG4-RD can be quiet in some organs. Doctors may use imaging and labs to check for silent involvement in organs like the lungs and kidneys. 

• Deciding whether to treat is shared. Treatment choices often involve weighing current symptoms, organ risk, and your preferences. 

• Early recognition protects organs. Delays can allow inflammation to persist and increase the chance of fibrosis (scar-like change). 

Questions you can bring to visits

Here are a few questions that often help people feel more in control:

For your pulmonologist

• “What did you notice on my CT scan, and what else could it look like?” 

• “Should I have breathing tests now so we have a baseline?”

• “What symptoms should prompt me to call you quickly?”

For your nephrologist

• “Are my kidney changes more consistent with inflammation, scarring, or something else?”

• “How often should we repeat blood and urine tests?”

• “Do any of my medicines need dose adjustments for kidney safety?”

Summary

Pulmonologists and nephrologists are organ-focused partners in your IgG4-RD care. A pulmonologist protects your breathing system and helps interpret lung findings that can mimic other diseases.

A nephrologist protects kidney function using blood and urine testing and helps guide kidney-safe treatment decisions. Because IgG4-RD can affect multiple organs—and sometimes silently—this kind of specialist looks for ways to prevent long-term damage and support a steady, confident plan forward. 

References

1. Stone JH, Zen Y, Deshpande V. IgG4-Related Disease. N Engl J Med. 2012;366:539–551. https://www.nejm.org/doi/10.1056/NEJMra1104650

2. Lang D, Zwerina J, Pieringer H. IgG4-related disease: current challenges and future prospects. Ther Clin Risk Manag. 2016;12:189–199. https://pmc.ncbi.nlm.nih.gov/articles/PMC4760655/

3. Peyronel F, Della-Torre E, Maritati F, et al. IgG4-related disease and other fibro-inflammatory conditions. Nat Rev Rheumatol. 2025;21:275–290. https://doi.org/10.1038/s41584-025-01240-x

4. IgG4ward! Foundation. Reader’s Guide to the Fireside Chat: IgG4-RD and Treatment. 2025. PDF https://igg4ward.org/wp-content/uploads/2025/06/Readers-Guide_FiresideChat_Treatment.pdf

5. Arias-Intriago M, Gomolin T, Jaramillo F, et al. IgG4-Related Disease: Current and Future Insights into Pathological Diagnosis. Int J Mol Sci. 2025;26:5325. https://pubmed.ncbi.nlm.nih.gov/40508133/

6. Cleveland Clinic. What’s a Pulmonologist & When Should I See One? 2024. https://my.clevelandclinic.org/health/articles/22210-pulmonologist

7. Cleveland Clinic. What Is a Nephrologist? 2025. https://my.clevelandclinic.org/health/articles/24214-nephrologist

8. IgG4ward! Foundation. Fireside Chat: Retroperitoneal Fibrosis & IgG4-RD, 2025. https://igg4ward.org/igg4ward-educational-resources/watch-the-fireside-chat-igg4-rd-and-retroperitoneal-fibrosis

9. Stone JH; Katharine Provencher, “Understanding IgG4-related disease (IgG4-RD) & Education,” video discussion, https://www.youtube.com/watch?v=CvY3VN0OpW0