Understanding which organs IgG4-RD affects

The internal organs … and this really particularly things that are inside the abdominal cavity — so the pancreas, the bile ducts, the aorta, the kidneys, and then the soft tissues that are behind the aorta called the retroperitoneal or retroperitoneal soft tissues — this collection is most likely most susceptible to damage. In particular, the pancreas is one I would really highlight. And secondly, the bile ducts.

There’s probably multiple aspects to why they’re more prone to damage. I think a major thing relates to … you can’t see these, and you often can’t really examine them when you’re seeing patients with this disease as a doctor either. So they’re a little bit more hidden. I mean, they’re physically hidden with inside the abdomen. We’re often relying on cross-sectional imaging, like a CAT scan or an MRI to detect and measure damage in these organs.

And they don’t always cause symptoms when they’re inflamed. So I think there’s a gradient of inflammation could be very low level, maybe at the microscopic level if we did a biopsy. And we don’t always see that, you know, manifesting in bloodwork or necessarily by symptoms. And then, on the far end of the range, you could have really overt inflammation throughout an organ that’s causing enlargement of the organ, that’s seen on imaging, more likely to have symptoms and see bloodwork abnormalities as well. So, across this whole continuum of inflammation where damage may be occurring.

So, the organs like the salivary and lacrimal glands, when they’re affected by the disease, you’re more likely to see that because you can visually inspect parts of your your head and neck in the mirror and see when they’re enlarged.

And additionally, you know, we don’t really understand why this aspect is, but the pancreas definitely does seem more prone to having functional impairment, which takes the form of reduced digestion or the development of diabetes. When the pancreas is not fully functioning.

We don’t see as much functional impairment of the lacrimal or salivary glands, which would more likely take the form of dry eyes or dry mouth. There’s some of this, this symptom burden for patients, but it’s a lot less salient than what we see from the digestion or diabetes perspective.

So why there’s this different susceptibility to these organs for damage? We don’t quite know that. And it may, like I’m saying, relate to the timeline of when patients are seeking medical attention. You know, they may be coming in sooner if they see large, you know, tumor-like masses in their neck versus their pancreas is inflamed and they have no idea about it.