What is Lupus Nephritis?
Systemic lupus erythematosus (SLE) is a condition where the body mistakenly attacks its own organs, resulting in chronic inflammation and damage. This is commonly recognized through medical tests and the presence of certain antibodies. The term “lupus” comes from the Latin word for “wolf,” due to a common facial rash associated with the disease resembling a wolf’s bite. The first recorded case of lupus goes all the way back to 400 BC, even though it was only correctly understood between the 1700s and 1800s.
A serious issue in people with SLE is the potential damage to the kidneys, a condition known as lupus nephritis (LN). It’s crucial to regularly monitor the kidney function in people with SLE, as early detection and treatment can significantly improve kidney health outcomes. Typically, lupus nephritis develops within three to five years after the initial onset of SLE. Even patients who don’t show clear signs of kidney disease often have evidence of lupus nephritis under a microscope. Doctors keep track of lupus nephritis through repeated tests measuring creatinine levels and protein in the urine. Because lupus nephritis can seriously affect a person’s health, effective treatment is key in preventing it from developing into a more severe kidney disease.
Treatment aims firstly to restore normal kidney function, or at least stop any further decline. Different treatment options are considered, based on the specific damage caused by the disease.
What Causes Lupus Nephritis?
Lupus nephritis is a kidney inflammation caused by a type-3 hypersensitivity reaction in patients with Systemic Lupus Erythematosus (SLE). Genetic factors, such as specific variations in genes like PTPN22, CRP, and FCGR3A, play a role in the development of SLE and lupus nephritis. Environmental factors also contribute to the disease. Deficiencies in genes like C1Q, C1R, C1S, C2, C4, and FcγRIIa are associated with SLE and lupus nephritis. In SLE, autoantibodies react against nucleosome from dying cells, leading to an autoimmune response. Disordered B lymphocyte response and epitope spreading contribute to the production of autoantibodies in SLE patients.
Risk Factors and Frequency for Lupus Nephritis
Research has shown that lupus nephritis, a kidney-related complication of lupus, is more likely to affect men, those of younger age, and those of African, Asian, and Hispanic ethnicity. 30.5% of lupus patients, in a Spanish study, were found to have lupus nephritis, which often got diagnosed when these patients were around 28.4 years old. Younger people, men, and Hispanics are at a higher risk of developing this condition. However, it has been noted that those taking antimalarial drugs had a lower risk of developing lupus nephritis.
- Lupus nephritis is more common in men, young people, and individuals of African, Asian, and Hispanic descent.
- In a Spanish study, 30.5% of lupus patients were found to have lupus nephritis.
- The average age of diagnosis for this disease is 28.4 years old.
- Younger individuals, men, and Hispanics are at a higher risk of developing this condition.
- Using antimalarial drugs may lower the risk of developing lupus nephritis.
Lupus nephritis generally occurs earlier in the course of disease in those who have lupus, often appearing in patients aged between 20 to 40 years old. Interestingly, children with lupus seem to be at a higher risk of kidney involvement than adults.
- Lupus nephritis usually occurs early in the disease course.
- It often affects patients aged 20 to 40.
- Children with lupus are at higher risk of kidney involvement than adults.
While lupus is more common in women, with a female-to-male ratio of 9:1, men with lupus are more likely to experience clinically evident kidney disease with a worse prognosis.
- Lupus is more common in women, with a female-to-male ratio of 9:1.
- However, the clinically evident kidney disease is more common and severe in men with lupus.
Lupus is more prevalent in African Americans and Asians compared to Whites, and the highest prevalence is seen in Caribbean people. Even though lupus nephritis is more common in Asians than Whites, Asians with the condition have better outcomes and survival rates in a 10 year period.
- Lupus is more prevalent in African Americans, Asians, and people from the Caribbean than Whites.
- Asians have a higher risk of lupus nephritis compared to Whites, but they also have a better 10-year outcome and survival rate.
Signs and Symptoms of Lupus Nephritis
Symptoms of lupus nephritis can vary but may include facial or skin rashes, fatigue, fever, sensitivity to sunlight, heart or lung inflammation, mouth sores, joint swelling without erosion, seizures, mental illness, or blood disorders. Some people may also experience increased urine output, night-time urination, frothy urine, high blood pressure, and swelling. Regular check-ups can reveal signs of active lupus nephritis, such as abnormal creatinine levels, low protein levels in the blood, or excess protein or abnormal sediment in the urine. Physical exams may show evidence of generalized SLE, as well as signs of active kidney inflammation. In cases of membranous lupus nephritis, symptoms of nephrotic syndrome, such as swelling and fluid accumulation, may be observed.
Testing for Lupus Nephritis
If you have active Lupus, routine lab tests may show low levels of specific proteins and the presence of an autoantibody. Your kidney function may also be affected, and you might have protein in your urine. Extremely high levels of protein in the urine indicate kidney damage. Regular screening for proteinuria and blood in the urine is recommended for people with active Lupus. A kidney ultrasound can help rule out any blockage or swelling of the kidneys. If your proteinuria is severe or if you’ve had repeated kidney inflammation, a kidney biopsy can provide useful information about the form and stage of the disease. The decision to get a kidney biopsy should depend on whether the results could potentially change your treatment. Different classes of lupus nephritis exist, each with its unique features that help doctors diagnose and treat the condition effectively.
Treatment Options for Lupus Nephritis
The treatment for lupus nephritis, a kidney disease caused by lupus, depends on the severity of the disease. Patients with mild cases may only need monitoring, while those with more severe cases require immunosuppressive and steroid therapies. In advanced cases, kidney replacement therapy may be necessary. Medications to lower cholesterol and control blood pressure are also prescribed. The treatment consists of two phases: induction and maintenance. Induction therapy involves anti-inflammatory drugs and immune system suppressants, while maintenance therapy involves long-term treatment to prevent relapse. Different drugs are used depending on the class of lupus nephritis. Pregnant patients are treated differently, and all patients are typically prescribed hydroxychloroquine.
What else can Lupus Nephritis be?
While diagnosing kidney-related conditions, doctors must consider multiple possible causes. These can include:
- Other types of nephrotic syndrome, which involves damage to the kidney’s filtering units
- Kidney stones
- Hydronephrosis, a condition where the kidneys swell due to a build-up of urine they can’t drain into the bladder
- Acute kidney injury, which can be caused by certain medications
- Acute interstitial nephritis, an inflammation condition that can cause the kidneys to function poorly
- Golmerulonephritis, which is inflammation of the kidneys’ filters
- Glomerulosclerosis, a scarring of the kidney’s tiny filtering units
- Chronic glomerulonephritis, an often slowly progressing form of kidney disease
- Diffuse proliferative glomerulonephritis, a type of kidney damage caused by an overactive immune system
- Granulomatosis with polyangiitis, a rare disorder that causes exaggerated inflammation in small blood vessels
- Membranous glomerulonephritis, a kidney disorder that can lead to poor kidney function
- Polyarteritis nodosa, a rare disease that causes inflammation of the arteries
- Rapidly progressive glomerulonephritis, a severe form of kidney inflammation that quickly leads to kidney failure
Doctors need to carefully consider all these possibilities and conduct the necessary tests to accurately diagnose the condition.
What to expect with Lupus Nephritis
Lupus nephritis can be a serious condition with potential complications and even fatal outcomes. The prognosis of the disease depends on its specific category according to the World Health Organization’s classification system. Categories 1 and 2 have a better long-term outlook, while categories 3 and 4 have a worse prognosis. Early treatment can improve outcomes.
Fortunately, the treatment approach for lupus nephritis has greatly improved over the years, leading to better health and increased life expectancy for patients. In the past, survival rates were low, but now, with drugs like Intravenous (IV) cyclophosphamide, the majority of patients survive at least 5 years after diagnosis.
Death rates associated with lupus nephritis, especially when it progresses to end-stage kidney disease, have significantly decreased in recent decades. The death rate per 100 patients per year has gone down, and deaths due to heart problems and infections have also decreased.
Patients with lupus nephritis, especially those who develop it early in life, are at a higher risk of heart disease due to reduced blood flow to the heart. This is because the condition can cause the nephrotic syndrome, which leads to swelling, fluid build-up, and high cholesterol levels.
Possible Complications When Diagnosed with Lupus Nephritis
It’s crucial for health care providers to be aware of the key complications associated with certain conditions. These may include:
- High blood pressure that doesn’t respond well to treatment
- Excessive swelling
- Long-term kidney disease
- Final stage of kidney disease, also known as End-Stage Renal Disease (ESRD)
Preventing Lupus Nephritis
Patients need to be informed about the signs and symptoms of a condition called lupus nephritis, as well as when to reach out to a healthcare professional for help. In cases where kidney replacement therapy is needed, patients and their families should be supported and informed about the processes of hemodialysis and kidney transplant. For those who are dealing with systemic lupus erythematosus, it’s crucial to understand that catching complications like lupus nephritis early can improve treatment success and long-term health.
Pharmacists have a key role in helping patients understand the medications commonly used in treatment and any side effects. Nurses also play a crucial part by providing comprehensive education to patients and families about the condition.
