Glomerulonephritis

Disease Description (Causes and Symptoms)

• Definition summary: Glomerulonephritis is a group of diseases in which inflammation develops in the renal glomeruli (clusters of capillaries that filter blood), causing symptoms such as hematuria, proteinuria, edema, and decreased kidney function. Causes and pathophysiology vary, and it may present as acute, chronic, nephrotic syndrome, or rapidly progressive forms.
• Major causes and pathophysiology
  • Primarily caused by immunological mechanisms (such as immune complex deposition and antibody-mediated injury).
  • Other causes include infections (e.g., poststreptococcal glomerulonephritis), autoimmune diseases (e.g., systemic lupus erythematosus), metabolic diseases (e.g., diabetes), genetic factors, and toxic or hemodynamic injury.
  • Pathophysiology: immune complex deposition or immune cell infiltration → damage to the glomerular filtration barrier → proteinuria, hematuria, decreased glomerular filtration rate, etc.
• Representative clinical features
  • Hematuria (gross or microscopic)
  • Proteinuria (≥3.0 g/day in nephrotic syndrome)
  • Generalized (facial and lower-extremity) edema
  • Hypertension
  • Acute form: oliguria and acute decline in kidney function, which may develop within days to weeks (e.g., postinfectious glomerulonephritis)
  • Rapidly progressive form: kidney failure progressing over weeks to months
  • Sometimes asymptomatic: only microscopic hematuria or mild proteinuria is found during a health examination (especially in IgA nephropathy)

Treatment Methods

• General principles
  • Identify the cause and administer standard treatment for that cause (such as immunosuppressive treatment for immune-mediated disease).
  • Treat complications (hypertension, edema, proteinuria, etc.) concurrently.
• Drug treatment
  • Immunosuppressants: steroids (initial treatment in many cases), with cyclophosphamide, cyclosporine and tacrolimus (calcineurin inhibitors), rituximab, etc. selected according to the lesion and symptoms when necessary.
  • Antihypertensive drugs: Renin-angiotensin system blockers (ACE inhibitors or ARBs) are recommended (to reduce proteinuria and preserve kidney function). ARBs may be used as the standard first-line recommendation.
  • Diuretics: Used as needed in combination with a low-salt diet to control edema (with monitoring for changes in kidney function).
  • Treatment of infections and other causes: for example, antiviral treatment may be considered for hepatitis B-related glomerulonephritis.
• Procedures/surgery
  • Most cases are managed with medical treatment. Dialysis or a kidney transplant is required if the disease progresses to chronic kidney failure with irreversible loss of kidney function.
• Lifestyle management and follow-up
  • Low-salt diet, monitoring of weight, blood pressure, and urine output, and smoking cessation.
  • During immunosuppressive treatment, prevent infections (vaccinations and prompt medical care if an infection develops) and monitor for side effects (osteoporosis, hyperglycemia, etc.).
• Precautions during treatment
  • Steroids and immunosuppressants carry risks of side effects (infection, osteoporosis, hyperglycemia, etc.) — regular testing and monitoring are necessary.
  • Diuretic use may worsen kidney function, so monitoring of kidney function and electrolytes is necessary.
  • Avoid taking traditional herbal medicines, folk remedies, or medications without medical advice (beware of nephrotoxic drugs).
• Emergency signs
  • A sudden decrease in urine output (oliguria), rapid weight gain or shortness of breath (suspected pulmonary edema), a rapid rise in creatinine, or severe hypertension requiring treatment requires immediate emergency medical care.

Checkpoints Before an Outpatient Visit (Including Sample Questions)

• Items to prepare and organize in advance
  • List of current medications (including prescription drugs, over-the-counter drugs, and herbal medicines)
  • Recent test results (blood pressure records, weight-change records, recent blood and urine test results, and a copy of any previous kidney biopsy results)
  • Symptom records: hematuria (onset and frequency), edema (location and onset), changes in urine output, fatigue, shortness of breath, etc.
  • Medical history: diabetes, hypertension, autoimmune disease, liver disease (e.g., hepatitis B), and recent infections (such as tonsillitis or skin infections)
  • Possibility of pregnancy or plans for pregnancy (for women)
• Information to tell the outpatient provider in advance
  • Any drug allergies and recent vaccinations (especially if immunosuppressive treatment is planned)
  • Recent weight and blood pressure measurements
• Sample questions (questions patients can prepare themselves)
  • “Could you tell me how the amount of proteinuria has changed in my recent tests?”
  • “Do the medications I am currently taking (e.g., antihypertensive drugs or anticoagulants) affect the treatment of glomerulonephritis?”

General Sample Questions to Ask the Doctor

• What are the main side effects of this medication (steroids or immunosuppressants), and how can they be prevented and monitored?
• What is the expected prognosis of my disease, and what are the treatment goals (proteinuria, blood pressure, and kidney function)?
• Among lifestyle factors (diet, exercise, smoking, etc.), what should I absolutely avoid and what is recommended?
• To prevent infections during immunosuppressive treatment, which vaccinations or tests (such as tuberculosis or hepatitis B tests) should I undergo?
• How should I manage my condition if I am planning a pregnancy?

Examples of Disease-Specific Questions

• Regarding kidney biopsy
  • “Is a kidney biopsy necessary in my condition? If so, what information is expected, and what are the risks (such as bleeding)?”
• Regarding management of proteinuria and hypertension
  • “Which medication do you recommend among ACE inhibitors and ARBs to reduce proteinuria? What is the target blood pressure (particularly a diastolic blood pressure target of 80 mmHg)?”
• What to do during acute worsening
  • “When should I go to the emergency room if my urine output suddenly decreases or my weight increases substantially over a short period?”

(Immediate medical care is recommended if acute worsening or an emergency occurs: a sharp decrease in urine output, severe shortness of breath, altered consciousness, or hypertension that does not respond to treatment, etc.)

---

Additional Recommended Tests (Primarily Used for Diagnosis and Follow-up)

• Urine tests (screening for microscopic hematuria and proteinuria), 24-hour urine protein or urine protein/creatinine ratio
• Blood tests: creatinine, eGFR, serum albumin, electrolytes, and cholesterol
• Immunological tests: C3/C4, ANA, anti-dsDNA, ANCA, anti-GBM, HBsAg/HCV antibodies, ASO, etc., selected according to the medical history
• Kidney ultrasound (to rule out structural abnormalities)
• Kidney biopsy: indications should be considered when proteinuria of 1 g or more per day persists in adults, or when the cause is unknown or kidney function is rapidly worsening

Note: This material provides general information; individualized treatment and medical decisions should be based on consultation with the treating specialist.