Organ affected: kidneys

When IgG4-RD affects the kidneys: silent changes, blocked drainage, and early warning signs

IgG4-related disease (IgG4-RD) can affect many parts of the body. In this chapter, we’ll focus on the kidneys—two bean-shaped organs that quietly filter the blood, balance fluid and electrolytes, help control blood pressure, and support several important body systems twenty-four hours a day.

When IgG4-RD involves the kidneys, it can cause inflammation within the kidney tissue itself. It can also cause scar-like tissue around the kidneys and nearby tubes leading to a blockage of the normal flow of urine through the ureters to the bladder. That second problem is often related to retroperitoneal fibrosis, a medical term for inflammation and fibrosis in the deep back part of the abdomen, where the kidneys and ureters sit.

Kidney symptoms can be confusing because kidney disease may be silent at first. Some people feel well, even when blood or urine tests are beginning to change. Others may notice swelling in the legs, high blood pressure, fatigue, flank pain, or trouble urinating. Others have no symptoms but have worrisome findings detected incidentally at imaging performed for some other purpose.

This chapter will walk you through what might be happening, why kidney involvement can be hard to recognize early, and how clinicians use blood tests, urine tests, imaging, and sometimes biopsy to understand what is going on.

IgG4-RD and kidney involvement
In this short video clip from EuroJAM in London, Dr. James Tomlinson explains what the kidneys are, what the kidneys do, how the kidneys go wrong in IgG4-related disease, and why blood pressure is important.