Alternative Names: Nephritis – lupus; Lupus glomerular disease
Lupus nephritis is an inflammation of the kidney caused by systemic lupus erythematosus (SLE), a disease of the immune system. Apart from the kidneys, SLE can also damage the skin, joints, nervous system and virtually any organ or system in the body.
General symptoms of lupus include malar rash, discoid rash, photosensitivity, oral ulcers, nonerosive arthritis, pleuropericarditis, renal disease, neurological manifestations, and haematological disorders.
Clinically, SLE usually presents with fever, weight loss (100%), arthralgias, synovitis, arthritis (95%), pleuritis, pericarditis (80%), malar facial rash, photodermatosis, alopecia (75%), anaemia, leukopaenia, thrombocytopaenia, and thromboses (50%).
About half of cases of SLE demonstrate signs of lupus nephritis at one time or another. Renal-specific signs include proteinuria (100%), nephrotic syndrome (55%), granular casts (30%), red cell casts (10%), microhematuria (80%), macrohematuria (2%), reduced renal function (60%), RPGN (30%), ARF (2%), hypertension (35%), hyperkalemia (15%) and tubular abnormalities (70%).
The World Health Organization (WHO) developed a system to classify the six different stages of lupus nephritis:
Stage 1: no evidence of lupus nephritis:
In histology, Stage I (minimal mesangial) disease has a normal appearance under light microscopy, but mesangial deposits are visible under electron microscopy. At this stage urinalysis is typically normal.
Stage 2: mildest form, easily treated with corticosteroids:
Stage 2 disease (mesangial proliferative) is noted by mesangial hypercellularity and matrix expansion. Microscopic haematuria with or without proteinuria may be seen. Hypertension, nephrotic syndrome, and acute renal insufficiency are rare at this stage.
Stage 3: earliest stage of advanced lupus. Treatment requires high amounts of corticosteroids. The outlook remains favorable.
Stage 3 disease (focal lupus nephritis) is indicated by sclerotic lesions involving less than 50% of the glomeruli, which can be segmental or global, and active or chronic, with endocapillary or extracapillary proliferative lesions. Under electron microscopy, subendothelial deposits are noted, and some mesangial changes may be present. Immunofluorescence reveals the so-called “Full House” stain, staining positively for IgG, IgA, IgM, C3, and C1q. Clinically, haematuria and proteinuria is present, with or without nephrotic syndrome, hypertension, and elevated serum creatinine.
Diffuse proliferative lupus nephritis; photo shows the classic “flea-bitten” appearance of the cortical surface in the diffuse proliferative glomerulonephritides
Stage 4: advanced stage of lupus.
Stage 4 lupus nephritis (diffuse proliferative) is both the most severe, and the most common subtype. More than 50% of glomeruli are involved. Lesions can be segmental or global, and active or chronic, with endocapillary or extracapillary proliferative lesions. Under electron microscopy, subendothelial deposits are noted, and some mesangial changes may be present. Immunofluorescence reveals the so-called “Full House” stain, staining positively for IgG, IgA, IgM, C3, and C1q. Clinically, haematuria and proteinuria are present, frequently with nephrotic syndrome, hypertension, hypocomplementemia, elevated anti-dsDNA titres and elevated serum creatinine. There is the risk of kidney failure. Patients require high amounts of corticosteroids and immune suppression medications.
A wire-loop lesion may be present in stage III and IV. This is a glomerular capillary loop with subendothelial immune complex deposition that is circumferential around the loop. Stage V is denoted by a uniformly thickened, eosinophilic basement membrane. Stage III and IV are differentiated only by the number of glomeruli involved (which is subject to inherent sample bias), but clinically the presentation and prognosis are both expected to be more severe in stage 4 versus stage 3.
Stage 5 (membranous lupus nephritis) is characterized by diffuse thickening of the glomerular capillary wall (segmentally or globally), with diffuse membrane thickening, and subepithelial deposits seen under electron microscopy. Clinically, stage V presents with signs of nephrotic syndrome. Microscopic haematuria and hypertension may also been seen. Plasma creatinine is usually normal or slightly elevated, and stage V may not present with any other clinical/serological manifestations of SLE (complement levels may be normal; anti-DNA Ab may not be detectable). Stage 5 also predisposes the affected individual to thrombotic complications such as renal vein thromboses or pulmonary emboli.Excessive protein loss and swelling. Doctors will treat with high amounts of corticosteroids. Doctors may or may not give immune-suppressing drugs.
A final stage is usually included by most practitioners, stage VI, or advanced sclerosing lupus nephritis. It is represented by Global sclerosis involving more than 90% of glomeruli, and represents healing of prior inflammatory injury. Active glomerulonephritis is usually not present. This stage is characterised by slowly progressive renal dysfunction, with relatively bland urine sediment. Response to immunotherapy is usually poor.
A tubuloreticular inclusion is also characteristic of lupus nephritis, and can be seen under electron microscopy in all stages. It is not diagnostic however, as it exists in other conditions. It is thought to be due to chronic interferon exposure.
Systemic lupus erythematosus (SLE, or lupus) is an autoimmune disease. This means there is a problem with the body’s immune system.
Normally, the immune system helps protect the body from infection or harmful substances. But in patients with an autoimmune disease, the immune system cannot tell the difference between harmful substances and healthy ones. As a result, the immune system attacks otherwise healthy cells and tissue.
SLE may damage different parts of the kidney, leading to interstitial nephritis, nephrotic syndrome, and membranous GN. It may rapidly worsen to kidney failure.
Lupus nephritis affects approximately 3 out of every 10,000 people. In children with SLE, about half will have some form or degree of kidney involvement.
More than half of patients have not had other symptoms of SLE when they are diagnosed with lupus nephritis.
SLE is most common in women ages 20 – 40.
The diagnosis of lupus nephritis depends on blood tests, urinalysis, X-rays, ultrasound scans of the kidneys, and a kidney biopsy. On urinalysis, a nephritic picture is found and RBC casts, RBCs and proteinuria is found.
The World Health Organization has divided lupus nephritis into five stages based on the biopsy. This classification was defined in 1982 and revised in 1995.
* Class I is minimal mesangial glomerulonephritis which is histologically normal on light microscopy but with mesangial deposits on electron microscopy. It constitutes about 5% of cases of lupus nephritis. Renal failure is very rare in this form.
*Class II is based on a finding of mesangial proliferative lupus nephritis. This form typically responds completely to treatment with corticosteroids. It constitutes about 20% of cases. Renal failure is rare in this form.
* Class III is focal proliferative nephritis and often successfully responds to treatment with high doses of corticosteroids. It constitutes about 25% of cases. Renal failure is uncommon in this form.
*Class IV is diffuse proliferative nephritis. This form is mainly treated with corticosteroids and immunosuppressant drugs. It constitutes about 40% of cases. Renal failure is common in this form.
* Class V is membranous nephritis and is characterized by extreme edema and protein loss. It constitutes about 10% of cases. Renal failure is uncommon in this form.
Medicines are prescribed that decrease swelling, lower blood pressure, and decrease inflammation by suppressing the immune system: Patients may need to monitor intake of protein, sodium, and potassium. Patients with severe disease should restrict their sodium intake to 2 grams per day and limit fluid as well. Depending on the histology, renal function and degree of proteinuria, patients may require steroid therapy or chemotherapy regimens such as cyclophosphamide, azathioprine, mycophenolate mofetil, or cyclosporine.
*Acute renal failure
*Chronic renal failure
*End-stage renal disease
There is no cure for lupus nephritis. The goal of treatment is to keep the problem from getting worse. Stopping kidney damage early can prevent the need for a kidney transplant.
Treatment can also provide relief from lupus symptoms.
Common treatments include:
*minimizing intake of protein and salt
*taking blood pressure medication
*using steroids to reduce swelling and inflammation
*taking immune-suppression medicines like prednisone to reduce immune system damage to the kidneys
Extensive kidney damage may require additional treatment.
Drug regimens prescribed for lupus nephritis include mycophenolate mofetil (MMF), intravenous cyclophosphamide with corticosteroids, and the immune suppressant azathioprine with corticosteroids. MMF and cyclophosphamide with corticosteroids are equally effective in achieving remission of the disease. MMF is safer than cyclophosphamide with corticosteroids, with less chance of causing ovarian failure, immune problems or hair loss. It also works better than azathioprine with corticosteroids for maintenance therapy.
Prognosis: How well you do depends on the specific form of lupus nephritis. You may have flare-ups, and then times when you do not have any symptoms.
Some people with this condition develop chronic kidney failure.
Although lupus nephritis may return in a transplanted kidney, it rarely leads to end-stage kidney disease.
Prevention: There is no known prevention for lupus nephritis.
Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.