Lupus Nephritis: A Comprehensive Overview

By Dr. Mohammed Fahad Khan, Nephrologist

What Is Lupus Nephritis?

Lupus nephritis is inflammation and injury to the kidneys caused by an autoimmune disease called systemic lupus erythematosus (SLE). In this condition, the immune system forms antibodies and immune complexes that deposit in the kidney — particularly in the glomeruli — leading to protein leakage (proteinuria), blood in the urine (haematuria), reduced kidney function, and sometimes nephrotic syndrome or even rapidly progressive kidney failure.

Lupus nephritis is one of the most significant organ manifestations of lupus because it has a strong influence on long-term outcomes. Clinically, it is confirmed and classified through a kidney biopsy, which is essential for guiding the intensity of treatment.

How Common Is Lupus Nephritis?

Across studies, around 40% of patients with SLE develop kidney involvement at some point in their illness, with estimates ranging from 25 to 60% depending on the population studied and how aggressively screening is carried out. In practical terms, roughly 1 in 2 lupus patients will show some degree of kidney involvement during their lifetime — which is why regular screening for proteinuria is so important.

The incidence and prevalence in any given clinical setting depends heavily on the type of practice. Rheumatology clinics may see fewer lupus nephritis cases, while tertiary nephrology centres tend to see a higher proportion, as patients with renal dysfunction, protein leakage, or blood in the urine are more likely to be referred to nephrologists.

Early Warning Signs of Kidney Involvement

Many patients have silent kidney disease in the early stages, with no noticeable symptoms at all. The most common early clues come from routine screening. Any new onset of protein in the urine — even if mild — is significant. Other early indicators include microscopic blood in the urine (detected via RBC casts or dysmorphic red blood cells), a rise in serum creatinine, or a fall in the glomerular filtration rate (GFR).

Later clinical signs include frothy urine, worsening swelling (oedema) in the feet or face, new-onset high blood pressure (hypertension), and features of nephrotic syndrome such as significantly low serum albumin and elevated blood lipids (hyperlipidaemia). In severe cases, reduced urine output (oliguria), fluid in the lungs (pulmonary oedema), or hypertensive emergencies with blood pressure exceeding 180/120 mmHg may also occur.

From a laboratory perspective, a flare of lupus nephritis is often accompanied by a rise in anti-double-stranded DNA (anti-dsDNA) antibodies and a drop in complement proteins C3 and C4. The American College of Rheumatology (ACR) recommends that all people with SLE and no known kidney disease be screened for proteinuria at least every 6 to 12 months, and also during any extra-renal flares.

Tests Used to Assess Kidney Involvement

A standard screening panel for lupus nephritis typically includes the following: urine routine examination with microscopy (looking for protein, blood, and casts); a urine protein-to-creatinine ratio to quantify protein leakage; a 24-hour urine protein and creatinine collection for further quantification; serum creatinine with calculation of the estimated GFR (eGFR); serum albumin; blood pressure documentation; and complement levels (C3 and C4). Anti-dsDNA antibody levels are also checked, as these would already be relevant to the overall lupus diagnosis.

When lupus nephritis is suspected, the next step is a kidney biopsy — unless the procedure is contraindicated. A biopsy is generally indicated when proteinuria exceeds 500 mg per day or when kidney function is impaired. The biopsy result guides the classification of lupus nephritis and determines how aggressively it needs to be treated.

How Is Lupus Nephritis Treated?

Treatment is divided into two broad components: kidney-protective (supportive) care and immunosuppression.

Background kidney-protective care includes hydroxychloroquine, RAAS blockade (for blood pressure control and reduction of protein leakage), dietary salt restriction, and statins if needed. Other important background measures include vaccination planning, infection prophylaxis for patients on immunosuppression, contraception counselling, and bone protection for patients on long-term steroids.

For proliferative lupus nephritis (Class 3, Class 4, with or without Class 5), treatment involves glucocorticoids combined with immunosuppression. Modern guidelines recommend triple therapy — steroids paired with two steroid-sparing agents. The steroid protocol involves pulse intravenous methylprednisolone at 250 to 1,000 mg daily for 1 to 3 days, followed by oral prednisolone at a maximum of 40 mg, tapered down to 5 mg by 6 months.

The steroid-sparing agent combinations used in triple therapy can be: mycophenolate mofetil combined with belimumab; mycophenolate mofetil combined with a calcineurin inhibitor such as tacrolimus or voclosporin (though voclosporin is not currently available in India); or the low-dose Euro-Lupus cyclophosphamide protocol combined with belimumab. Updated guidelines now recommend adding belimumab to the Euro-Lupus low-dose intravenous cyclophosphamide regimen, whereas previously cyclophosphamide was used alone.

This initial phase is called the induction phase. Once an adequate response is achieved, patients move to the maintenance phase, which continues for at least 3 to 5 years using a steroid-sparing agent — generally mycophenolate or azathioprine, depending on the clinical picture and whether pregnancy is being planned.

What to Expect After Starting Treatment

Patients improve at different speeds, but progress can generally be understood in three phases.

In the first 0 to 4 weeks, the goal is to halt inflammation and prevent irreversible scarring. Serum creatinine should stabilise during this period, though proteinuria typically lags behind creatinine recovery.

Between months 1 and 6, proteinuria should begin trending downward, and complement levels alongside anti-dsDNA antibodies often improve in parallel. Between months 6 and 12 and beyond, many patients who respond to treatment will reach low-level proteinuria with stable kidney function.

Some patients take longer to respond — particularly those with nephrotic-range proteinuria (greater than 3,000 mg per day) or those with significant chronic scarring (chronicity) seen on biopsy, as both factors are associated with poorer recovery.

Recent Advances in Treatment and Availability in India

The newer era of lupus nephritis treatment involves adding targeted biological agents on top of standard therapy. Belimumab, a monoclonal antibody that inhibits B-cell activating factor (BAFF, also known as BLyS), demonstrated significant benefit in the BLISS-LN trial. In the AURORA trial, voclosporin added to mycophenolate mofetil and steroids showed improved outcomes across Class 3, 4, and 5 lupus nephritis.

Most recently, the Phase 3 REGENCY trial, published in 2025, demonstrated that obinutuzumab — added to standard therapy — achieved significantly better complete renal responses in adults with active, biopsy-proven proliferative lupus nephritis. While these biologicals represent a meaningful expansion of treatment options, belimumab, voclosporin, and obinutuzumab are currently not available in India.

Progression to End-Stage Renal Disease and Transplantation

Even with treatment, some patients progress to end-stage renal disease (ESRD). A systematic review and meta-analysis found that approximately 10 to 15% of individuals with lupus nephritis progress to ESRD within 10 years of disease onset, with a 5-year risk of around 11% in developed countries. The risk is higher in patients with proliferative disease, delayed treatment, poor adherence, recurrent flares, high chronicity on biopsy, or uncontrolled blood pressure throughout the course of their illness.

For patients who develop significant chronic kidney disease, ongoing management focuses on blood pressure control, measures to reduce proteinuria, anaemia management, treatment of mineral bone disorder, and cardiovascular risk reduction — including appropriate vaccinations and infection-prevention medications. When a patient approaches end-stage renal disease (defined as a GFR below 15 mL/min/1.73 m²), kidney transplantation is preferred over dialysis, and pre-emptive transplantation is the preferred approach whenever feasible.

Transplantation can proceed without requiring complete serological remission, as long as there is no active renal disease at the time of surgery. And fortunately for patients, it is not necessary for ANA or anti-dsDNA antibodies to become negative before transplantation.

About Author:

Dr. Mohammed Fahad Khan is an award winning Nephrologist and Transplant Physician at Manipal Hospital, Bangalore. He brings a wealth of academic accomplishments and clinical expertise to the field. His area of interest lies in treating patients with Glomerular Disease, Dialysis, Acute and Chronic Kidney Disease, Stone Disease, AV Fistulas, and Renal Transplantation.