The Damage Can Be Progressing Even When the Kidneys Still Seem to Work Normally
A routine urine test shows protein or blood.
The patient feels well.
There is little reason to suspect that an uncommon kidney disorder may already be affecting the filtration system.
C3 glomerulopathy (C3G) is a rare kidney disease characterized by abnormal activation of the complement system, leading to the buildup of complement protein C3 within the glomeruli—the tiny filtering units of the kidneys. Over time, this can interfere with normal kidney function and may progress if not appropriately evaluated and managed.
Diagnosing C3G is rarely straightforward. Initial laboratory findings often prompt further investigation, but confirmation typically requires a kidney biopsy, where tissue is examined using specialized pathological techniques. Blood tests and complement studies may also help clinicians understand the underlying disease process.
What makes C3G particularly challenging is that its symptoms and routine laboratory findings can resemble those of other kidney disorders. Reaching a diagnosis often requires close collaboration between nephrologists, pathologists, and clinical laboratories.
For patients, the first sign may be a routine test result that seems unexpected.
For clinicians, it's the beginning of a detailed diagnostic journey aimed at identifying a rare disease that cannot be confirmed through symptoms alone.