# Lupus Nephritis: Histology, Activity, and Chronicity

Persistent abnormalities can reflect active inflammation, scarring, a different lesion, or treatment-delivery problems. Do not escalate automatically without revisiting the explanation.

![Infographic: Lupus Nephritis: Histology, Activity, and Chronicity](https://urinenephrology.org/visual-reference/images/mastery-lupus.png?v=20261003c)

## A spectrum of kidney lesions

Lupus can affect glomeruli, vessels, and interstitium. Clinical urine findings do not fully describe the class, activity, or chronicity of injury.

## Recognize subtle disease

Hematuria or proteinuria may precede striking systemic activity. Quiet serologies do not reliably exclude important kidney pathology.

## Consider biopsy for meaningful renal findings

KDIGO’s evaluation pathway considers kidney biopsy when quantified proteinuria is ≥500 mg/day, with sediment and kidney-function findings also informing the decision. An unexplained decline or active sediment can be important even when symptoms or serologies are quiet. Confirm collection and investigate alternative causes.

## Treat active lesion, not serology alone

Class III/IV proliferative lesions require a different regimen from isolated class V disease or predominantly chronic damage. Use pathology, proteinuria, eGFR, pregnancy plans, infection risk, and prior response to choose among guideline-supported combinations. Persistent proteinuria may reflect scarring rather than continuing immune activity.

## Monitor beyond response definitions

Infection, cytopenias, metabolic effects, fertility, adherence barriers, and cumulative toxicity matter alongside proteinuria and filtration.

## Reassess apparent resistance

Persistent abnormalities can reflect active inflammation, scarring, a different lesion, or treatment-delivery problems. Do not escalate automatically without revisiting the explanation.

## Supporting evidence

- [Supporting guideline or source](https://kdigo.org/wp-content/uploads/2024/01/KDIGO-2024-Lupus-Nephritis-Guideline.pdf)

## Source lessons

- [lupus nephritis treatment evidence](https://urinenephrology.org/mastery/glomerular/lupus-nephritis-treatment-evidence.html)
- [lupus nephritis](https://urinenephrology.org/mastery/glomerular/lupus-nephritis.html)

Read alongside the full lessons; the findings and decisions shown here require the stated clinical context.