OVERVIEW

What is rapidly progressive glomerulonephritis?

Rapidly progressive glomerulonephritis (RPGN), also known as crescentic glomerulonephritis, is a clinical syndrome characterized by rapidly worsening kidney dysfunction, often accompanied by oliguria or anuria.

Pathological findings on renal biopsy typically reveal extensive crescent formation (more than 50% of glomeruli affected), hence its alternative name.

This condition has the poorest prognosis among all types of nephritis, progressing rapidly. Without prompt diagnosis and treatment,

most patients will develop end-stage renal failure or die within weeks or months.

Prognosis depends on timely treatment, immunopathological type, crescent quantity and type, as well as the patient's age and general condition. Isolation is unnecessary, but quality of life is severely impacted.

Is rapidly progressive glomerulonephritis common?

No, it is uncommon.

What are the types of rapidly progressive glomerulonephritis?

By etiology:

• Primary rapidly progressive glomerulonephritis;
• Secondary to systemic diseases (e.g., systemic lupus erythematosus);
• Crescentic glomerulonephritis developing from primary glomerular diseases.

By immunopathological classification:

• Type I: Anti-glomerular basement membrane type;
• Type II: Immune complex type;
• Type III: Pauci-immune type.

Some scholars further classify it into 5 types based on ANCA serology:

• Type IV: ANCA-positive original type I;
• Type V: ANCA-negative original type III.

SYMPTOMS

What are the common manifestations of rapidly progressive glomerulonephritis?

• Most patients have prodromal symptoms of upper respiratory tract infection, with an acute onset and rapid disease progression.

• The main clinical manifestations are rapidly progressive nephritic syndrome, such as hematuria, proteinuria, edema, and hypertension. As the disease progresses, oliguria or anuria may occur, and renal function deteriorates rapidly within a short period, leading to uremia.

• A few patients have a very insidious onset, with prodromal symptoms such as unexplained fever, arthralgia, myalgia, and hemoptysis. By the time they seek medical attention, renal damage has already reached the uremic stage.

• Blood pressure may be normal or slightly elevated in the early stages but worsens as the disease progresses. Severe cases may develop hypertensive encephalopathy.

• Gastrointestinal symptoms such as nausea, vomiting, and hiccups are common, and a few patients may experience upper gastrointestinal bleeding.

• Infection is also a common complication and a significant cause of death.

How does rapidly progressive glomerulonephritis develop?

Rapidly progressive glomerulonephritis has the worst prognosis among all types of nephritis. The clinical progression is rapid, and without timely diagnosis and treatment, most patients will progress to end-stage renal failure or death within weeks or months.

What are the complications of rapidly progressive glomerulonephritis?

Hypertensive encephalopathy, uremia, internal environment disturbances, infections, death, etc.

CAUSES

What are the common causes of rapidly progressive glomerulonephritis?

Based on etiology, it can be classified into:

• Primary rapidly progressive glomerulonephritis;

• Rapidly progressive glomerulonephritis secondary to systemic diseases, such as systemic lupus erythematosus;

• Crescentic glomerulonephritis developing on the basis of primary glomerular diseases.

Currently, smoking, drug abuse, and exposure to hydrocarbons are considered predisposing factors for this disease. Additionally, genetic predisposition plays a certain role in its onset.

Is rapidly progressive glomerulonephritis contagious?

No.

Is rapidly progressive glomerulonephritis hereditary?

Genetic predisposition plays a certain role in the onset of this disease.

DIAGNOSIS

How is rapidly progressive glomerulonephritis diagnosed?

When diagnosing rapidly progressive glomerulonephritis, doctors primarily rely on serological tests for specific antibodies and kidney biopsy.

What tests are required for suspected cases of rapidly progressive glomerulonephritis?

• Urinalysis: May show proteinuria, red and white blood cells, and possibly red blood cell casts.

• Complete blood count (CBC) and erythrocyte sedimentation rate (ESR): Assess for anemia, infection, etc.

• Renal function tests: Progressive increase in serum creatinine and blood urea nitrogen (BUN), with a progressive decline in endogenous creatinine clearance rate.

• Renal imaging: B-mode ultrasound and other imaging may reveal bilateral kidney enlargement.

• Circulating antibody tests: Aid in classification.

• Kidney biopsy: Essential for diagnosis, differential diagnosis, and guiding treatment.

What precautions should patients with rapidly progressive glomerulonephritis take during a kidney biopsy?

Before and during the biopsy:

• Since bed rest for 24 hours is required post-biopsy, prepare a bedpan for urination and defecation and practice using it. Practice the prone position with a small pillow under the abdomen and holding breath (both after inhaling and exhaling).
• During the biopsy, briefly hold breath for about 30 seconds and practice urinating while lying down to facilitate cooperation during the procedure.
• Shower the night before and wear loose clothing on the day of the procedure. Avoid one-piece garments or skirts.
• A family member must accompany the patient on the day of the test. Empty the bladder and bowels before the procedure. Female patients cannot undergo biopsy during menstruation.
• On the day of the procedure, eat semi-liquid foods such as congee, noodle soup, dumplings, minced meat, mashed vegetables, or small steamed buns. Avoid overeating or fasting.
• Stay as relaxed as possible during the procedure to minimize tension.

After the biopsy:

• Stay in bed for 24 hours, lying flat for the first 6 hours (only moving the head, hands, and feet). After 6 hours, slow turning is allowed. Use a bedpan for urination and defecation.
• Drink plenty of water post-procedure to help flush out minor bleeding through urine. Collect urine samples three times for routine testing.
• The biopsy dressing can be removed after 1–2 days, and bathing should be avoided for 3 days.
• Normal diet can resume on the first post-operative day. After 24 hours, if no complications are found during the doctor's rounds, the patient may get out of bed but should avoid collisions and sudden movements.
• Rest more and engage in light activities for a week. Avoid heavy labor, intense exercise, and sexual activity for one month.
• If symptoms such as significant hematuria, paleness, rapid heart rate, weakness, or cold limbs occur, contact a doctor immediately.

Is a kidney biopsy absolutely necessary for patients with rapidly progressive glomerulonephritis?

Yes, a kidney biopsy is crucial for diagnosis, differential diagnosis, and guiding treatment.

Which diseases can be confused with rapidly progressive glomerulonephritis, and how are they distinguished?

Rapidly progressive glomerulonephritis may be confused with rapidly worsening primary glomerular diseases, thrombotic microangiopathy, acute tubular necrosis, acute allergic interstitial nephritis, or obstructive nephropathy. Doctors differentiate these conditions based on medical history, clinical manifestations, and auxiliary tests such as kidney biopsy.

TREATMENT

Which department should I visit for rapidly progressive glomerulonephritis?

Nephrology, Emergency Department, or ICU. You may also consult the General Internal Medicine department.

Can rapidly progressive glomerulonephritis heal on its own?

No.

How is rapidly progressive glomerulonephritis treated?

Early diagnosis and intensive treatment are key to improving therapeutic success, including aggressive immunosuppressive therapy targeting immune-mediated inflammatory damage in the glomeruli and other symptomatic treatments.

• Adrenal corticosteroids combined with cytotoxic drugs: Primarily involving prednisolone and cyclophosphamide.

• Plasma exchange.

• Symptomatic treatment: Including blood pressure control, infection management, and correction of water-electrolyte and acid-base imbalances.

• Renal replacement therapy: For patients who progress to end-stage renal failure despite treatment, long-term dialysis is required.

Under what circumstances should plasma exchange therapy be given to patients with rapidly progressive glomerulonephritis?

Plasma exchange is mainly used for: Goodpasture syndrome with pulmonary hemorrhage or early-stage type I RPGN.

When can plasma exchange therapy be discontinued in patients with rapidly progressive glomerulonephritis?

Plasma exchange therapy is usually performed daily or every other day and typically lasts for 10–14 days or until serum antibodies (e.g., anti-GBM antibodies, ANCA) or immune complexes become negative.

Does rapidly progressive glomerulonephritis require hospitalization?

Yes.

Can rapidly progressive glomerulonephritis be cured?

Patient prognosis depends on factors such as timely treatment, immunopathological type, the number and type of crescents, as well as the patient's age and general condition.

DIET & LIFESTYLE

What should patients with rapidly progressive glomerulonephritis pay attention to in their daily life and diet?

Patients should rest in bed and avoid fatigue. Limit salt and protein intake, focusing on high-quality animal protein. Control fluid intake based on output.

Does rapidly progressive glomerulonephritis require follow-up examinations? How?

Yes, regular follow-up tests including blood tests, urine tests, and renal function tests are necessary.

PREVENTION

Can rapidly progressive glomerulonephritis be prevented? How to prevent it?

Prompt and standardized treatment of diseases such as systemic lupus erythematosus and Henoch-Schönlein purpura that may cause secondary kidney damage; quit smoking; seek medical attention at a regular hospital promptly if discomfort occurs.

How can patients with rapidly progressive glomerulonephritis prevent complications?

Early detection, early diagnosis, and early treatment, closely monitoring changes in the patient's condition, and providing good patient care.