### 날짜 : 2024-03-21 16:13 ### 주제 : Nephrotic Syndrome #medicine #공부 ---- Nephrotic syndrome is a kidney disorder characterized by a group of symptoms, including: - **Massive proteinuria**: Excretion of 3.5 grams or more of protein in the urine per day. - **Hypoalbuminemia**: Low levels of albumin in the blood. - **Edema**: Swelling, particularly in the legs, feet, and around the eyes. - **Hyperlipidemia**: Elevated levels of lipids in the blood. ### Pathophysiology: The primary pathology in nephrotic syndrome involves damage to the glomeruli, the filtering units of the kidneys. This damage results in an increased permeability of the glomerular basement membrane to proteins, particularly albumin. The loss of albumin and other proteins in the urine (proteinuria) leads to a decrease in plasma oncotic pressure, causing fluid to leak out of the blood vessels and into the surrounding tissues, resulting in edema. Several mechanisms contribute to the hyperlipidemia seen in nephrotic syndrome: - **Increased Hepatic Lipoprotein Synthesis**: The liver compensates for the loss of albumin by increasing its synthesis, which also leads to increased production of lipoproteins. - **Decreased Clearance of Lipoproteins**: There is also a decreased clearance of lipoproteins from the circulation. ### Causes: Nephrotic syndrome can result from a variety of conditions that cause damage to the glomeruli, including: - **Primary glomerular diseases**: Such as [[Minimal change disease]], focal segmental glomerulosclerosis (FSGS), and membranous nephropathy. - **Secondary causes**: Include systemic diseases like diabetes mellitus, lupus erythematosus (SLE), amyloidosis, and infections such as HIV and hepatitis. - **Drugs**: Certain drugs can induce nephrotic syndrome by causing direct damage to the glomeruli or by precipitating a secondary cause. ### Clinical Features: - **Edema**: Often the most noticeable symptom, starting in the eyelids, face, and lower extremities before becoming generalized. - **Foamy urine**: Due to the high protein content. - **Fatigue**: From low albumin and chronic illness. - **Weight gain**: Due to fluid retention. ### Diagnosis: Diagnosis involves a combination of clinical presentation, laboratory tests, and sometimes kidney biopsy. Laboratory tests typically show: - **Proteinuria**: Specifically, the presence of albumin in the urine. - **Hypoalbuminemia**: Low serum albumin levels. - **Hyperlipidemia**: Elevated cholesterol and triglyceride levels. - **Renal function tests**: May be normal in early or uncomplicated cases. A kidney biopsy may be necessary to determine the underlying cause of the nephrotic syndrome, particularly in adults or when the syndrome is resistant to standard treatments. ### Treatment: The treatment of nephrotic syndrome focuses on the underlying cause, reducing symptoms, and preventing complications, such as: - **Corticosteroids and immunosuppressants**: For diseases like minimal change disease. - **Control of hypertension and edema**: Using ACE inhibitors, angiotensin receptor blockers (ARBs), and diuretics. - **Statins**: For managing hyperlipidemia. - **Anticoagulation**: In patients at risk of thrombosis due to the hypercoagulable state associated with nephrotic syndrome. - **Dietary modifications**: Such as reduced sodium intake to manage edema. Managing the underlying cause is crucial for resolving nephrotic syndrome, and the prognosis varies widely depending on the cause and the response to treatment. # Case Example ### Patient Information: - **Name**: 주신장 (Note: This is a fictional name for illustrative purposes) - **Age**: 32 years - **Sex**: Male - **Presenting Complaint**: Swelling around the eyes and ankles, frothy urine, and fatigue for the past 3 weeks. ### History and Examination: - **Medical History**: No significant previous medical history. Non-smoker, occasional alcohol. - **Family History**: Father has type 2 diabetes mellitus. - **Physical Examination**: Blood pressure is 130/85 mmHg. Notable periorbital and pedal edema. No other abnormalities on systemic examination. ### Investigations: 1. **Urine Analysis**: 4+ proteinuria on dipstick. 2. **24-Hour Urine Protein**: 4.5 grams of protein in 24 hours. 3. **Blood Tests**: - Serum albumin: 2.8 g/dL (normal: 3.5-5.0 g/dL). - Serum cholesterol: 250 mg/dL (normal: <200 mg/dL). - Serum creatinine: 1.0 mg/dL (normal: 0.6-1.2 mg/dL). - Blood urea nitrogen (BUN): 14 mg/dL (normal: 7-20 mg/dL). - HbA1c: 5.6% (normal: <5.7%). 4. **Kidney Ultrasound**: Normal size and echotexture of both kidneys without any signs of obstruction. Given the significant proteinuria, hypoalbuminemia, hyperlipidemia, and edema, Mr. Smith is diagnosed with nephrotic syndrome. ### Differential Diagnosis: - Minimal change disease (MCD) - Focal segmental glomerulosclerosis (FSGS) - Membranous nephropathy - Diabetic nephropathy (less likely given HbA1c and lack of diabetes diagnosis) ### Management Plan: 1. **Initial Management**: - Salt restriction and diuretics (e.g., Furosemide) to manage edema. - [[ACE inhibitor (e.g., Lisinopril) to reduce proteinuria and protect renal function.]] - Statins (e.g., Atorvastatin) for hyperlipidemia. - Patient education about the condition, importance of medication adherence, and lifestyle modifications including dietary changes and regular exercise. 2. **Further Investigation**: - Kidney biopsy to determine the specific pathological cause of the nephrotic syndrome, which is crucial for guiding further treatment. 3. **Specific Treatment**: - The treatment would be tailored based on the biopsy results. For example, if MCD is diagnosed, corticosteroids would be initiated. 4. **Follow-Up**: - Regular follow-up appointments for monitoring blood pressure, renal function, proteinuria, lipid profile, and response to treatment. - Adjustment of medications based on clinical response and side effects. 5. **Prevention of Complications**: - Thromboprophylaxis consideration depending on risk assessment. - Vaccinations as appropriate, including pneumococcal and influenza, due to the increased risk of infections. ### Outcome: - The prognosis depends on the underlying cause of nephrotic syndrome, response to treatment, and development of any complications. Early diagnosis and appropriate management can significantly improve outcomes. This case example highlights the approach to diagnosing and managing a patient with nephrotic syndrome, underscoring the importance of a comprehensive evaluation and individualized treatment plan.