Treatment of Nephritic Syndrome
For nephritic syndrome, treatment focuses on supportive care with blood pressure control using ACE inhibitors or ARBs, salt restriction, and diuretics for edema, while immunosuppressive therapy is reserved for specific underlying causes such as lupus nephritis, ANCA-associated vasculitis, or anti-GBM disease. 1
Understanding Nephritic Syndrome
Nephritic syndrome is characterized by hematuria, proteinuria (typically sub-nephrotic range), hypertension, and declining kidney function, distinguishing it from nephrotic syndrome which features heavy proteinuria (>3.0 g/24 hours) and hypoalbuminemia 1. The most common causes include post-infectious glomerulonephritis, IgA nephropathy, and lupus nephritis 1.
General Supportive Management
Blood Pressure and Proteinuria Control
- ACE inhibitors or ARBs are recommended for all patients with proteinuria >500 mg/g or arterial hypertension 2
- These agents provide both antihypertensive and antiproteinuric effects 2
- Target blood pressure control is essential to slow progression 1
Edema Management
- Salt restriction and loop diuretics for volume overload 1
- Monitor for complications of fluid retention 1
Additional Supportive Measures
- Statins for dyslipidemia management based on lipid levels and cardiovascular risk 2
- Consider anticoagulation in severe cases, particularly with serum albumin <20 g/L or presence of anti-phospholipid antibodies 3
Disease-Specific Immunosuppressive Treatment
Lupus Nephritis (Class III/IV)
For proliferative lupus nephritis, initial treatment consists of mycophenolate mofetil (2-3 g/day) or low-dose intravenous cyclophosphamide (500 mg every 2 weeks for 6 doses) combined with glucocorticoids 2:
- Glucocorticoid regimen: Intravenous methylprednisolone pulses (500-2500 mg total) followed by oral prednisone (0.3-0.5 mg/kg/day) for up to 4 weeks, tapered to ≤7.5 mg/day by 3-6 months 2
- Alternative: MMF (1-2 g/day) combined with tacrolimus, particularly for nephrotic-range proteinuria 2
- High-risk patients (reduced GFR, crescents, fibrinoid necrosis): Consider high-dose IV cyclophosphamide (0.5-0.75 g/m² monthly for 6 months) 2
Maintenance therapy: After achieving improvement, continue MMF/MPA (1-2 g/day) or azathioprine (2 mg/kg/day) with low-dose prednisone (2.5-5 mg/day) for at least 3-5 years 2, 3
Rapidly Progressive Glomerulonephritis (RPGN)
For RPGN with extensive crescents and rapid decline in kidney function 4:
- Standard treatment includes glucocorticoids plus cyclophosphamide or rituximab 4
- Plasma exchange is especially important for anti-GBM disease and select cases of ANCA-associated vasculitis 4
- Early diagnosis and prompt treatment are critical to prevent progression to ESRD 4
Post-Infectious Glomerulonephritis
- Typically self-limited and requires only supportive care 1
- Immunosuppression is generally not indicated 1
- Focus on blood pressure control, edema management, and treating underlying infection 1
IgA Nephropathy
- Optimize supportive care with RAS blockade first 2
- Consider immunosuppression only in specific high-risk scenarios based on proteinuria levels and kidney function decline 5
Treatment Goals and Monitoring
Target Outcomes
- Reduction in proteinuria of at least 25% by 3 months, 50% by 6 months 2
- Target proteinuria <500-700 mg/g by 12 months (complete clinical response) 2
- Preservation or improvement of kidney function 2
Monitoring Parameters
- Regular assessment of serum creatinine, eGFR, proteinuria, urinary sediment 3
- Blood pressure and serum albumin 3
- Disease-specific markers (complement levels, anti-dsDNA for lupus; ANCA titers for vasculitis) 3
- Visits every 2-4 weeks initially, then every 3-6 months long-term 3
Important Caveats
Common pitfall: Confusing nephritic syndrome with nephrotic syndrome leads to inappropriate treatment intensity. Nephritic syndrome generally carries a poorer prognosis and requires more aggressive monitoring 1.
Refractory disease: If treatment goals are not achieved, thoroughly evaluate adherence, consider therapeutic drug monitoring, and assess for alternative diagnoses 2. For active non-responding disease, switch to alternative initial therapies or consider rituximab (1000 mg on days 0 and 14) 2.
Avoid immunosuppression in patients with severely reduced kidney function (eGFR <25-30 ml/min per 1.73 m²) and small kidneys on ultrasound, or those with severe active infections 6.