What Are the Classes, Signs, and Symptoms of Lupus Nephritis?

In the early stages of lupus nephritis, there are very few signs that anything is wrong. In fact, some patients have no specific symptoms. Kidney problems often start around the same time that lupus symptoms appear.


The first symptoms of lupus nephritis are often:
Swelling, usually in legs, feet or ankles Weight gain
Fatigue Foamy, bubbly or frothy urine

Clinical signs of lupus nephritis include:

  • Leakage of a high level of protein into the urine (a condition known as proteinuria). Extra protein in the urine shows up in a clinical laboratory urine test.
  • Leakage of blood into the urine (a condition known as hematuria)
  • High blood pressure
  • Inflammation or scarring of the kidneys as confirmed through a kidney biopsy

Lupus Nephritis Classes and Related Signs and Symptoms

Lupus nephritis is divided into 6 different stages or classes based on the results of a kidney biopsy. The following table provides an overview of these different classes as well as certain signs and symptoms that may occur during various stages.

Early symptoms of lupus nephritis often include weight gain; swelling in the legs, feet, or ankles; and urine that is foamy, bubbly, or frothy. Additional signs and symptoms associated with the different classes of lupus nephritis are noted below.

Class Description Signs and Symptoms
Class 1
Minimal mesangial glomerulonephritis
Minimal damage to kidneys No obvious symptoms
Class 2
Mesangial proliferative glomerulonephritis
Some evidence of lupus nephritis in a small defined area of the kidney Microscopic amounts of blood in urine (a condition known as hematuria) and/or excess protein in urine (a condition known as proteinuria).
Class 3
Focal glomerulonephritis
Damage to less than 50% of important blood vessels in the kidney

Blood and/or excess protein in urine

Possible high blood pressure

Class 4
Diffuse proliferative nephritis
Damage to more than 50% of important blood vessels in the kidney

High blood pressure

Worsening kidney function or kidney failure (dialysis or kidney transplant may be needed)

Class 5
Membranous glomerulonephritis
Advanced hardening of important blood vessels in the kidney

Class 5 may occur in combination with Class 3 or 4

High blood pressure

Worsening kidney function or kidney failure (dialysis or kidney transplant may be needed)

Class 6
Advanced sclerotic
Damage to more than 90% of important blood vessels in the kidney Progressively worse kidney function (dialysis or kidney transplant may be needed)

Based on 2003 classification by the International Society of Nephrology (ISN) and the Renal Pathology Society (RPS).

Higher than normal levels of PROTEIN IN THE URINE (a condition known as proteinuria) Key Feature of Lupus Nephritis:

Guide to Talking with Your Doctor

Make the most of your healthcare appointments. Download this helpful discussion guide and bring it with you to your next doctor's visit.

Download Guide

Stay Connected. Stay Informed.

Sign up to receive:

  • Ongoing news and updates about lupus nephritis
  • A USB drive that contains helpful printable resources

Register Now