What is the treatment for Post-Streptococcal Glomerulonephritis (PSGN)?

Treatment of Post-Streptococcal Glomerulonephritis (PSGN)

PSGN treatment is primarily supportive care focused on managing hypertension and fluid overload with diuretics and sodium restriction, combined with antibiotic therapy (penicillin or erythromycin) to reduce streptococcal antigenic load, even when active infection is no longer present. 1, 2

Antibiotic Therapy

Administer penicillin (or erythromycin if penicillin-allergic) regardless of whether active infection is still present to decrease the streptococcal antigenic load. 1, 2 This applies even 1-3 weeks after pharyngitis or 4-6 weeks after impetigo when PSGN typically manifests. 1

Alternative Antibiotic Options:

• First-generation cephalosporins (e.g., cephalexin) are appropriate for non-anaphylactic penicillin allergies or when beta-lactamase producing organisms are suspected. 1, 2
• Third-generation cephalosporins (e.g., ceftriaxone) should be used for severe infections or in areas with high prevalence of resistant organisms. 1, 2
• During outbreaks, systemic antimicrobials help eliminate nephritogenic strains of Streptococcus pyogenes from the community. 1, 2

Supportive Management of Nephritic Syndrome

The cornerstone of PSGN treatment is managing the clinical manifestations of acute glomerulonephritis. 2, 3

Hypertension and Fluid Management:

• Restrict dietary sodium to <2.0 g/day to control hypertension and fluid retention. 1, 2
• Use diuretics as first-line agents for managing fluid overload and hypertension. 1, 2
• Target blood pressure <130/80 mmHg (or <125/75 mmHg if proteinuria >1 g/day). 2
• Monitor closely for diuretic-related complications including hyponatremia, hypokalemia, GFR reduction, and volume depletion. 1, 2
• ACE inhibitors (captopril, enalapril) provide better blood pressure control and echocardiographic improvement compared to other antihypertensives. 4

Additional Supportive Measures:

• Provide dialysis if necessary for severe acute kidney injury with volume overload or uremia. 1, 2
• Treat metabolic acidosis if serum bicarbonate <22 mmol/L. 1, 2
• Consider treating dyslipidemia in patients with nephrotic syndrome, particularly those with other cardiovascular risk factors. 1

Immunosuppressive Therapy

Corticosteroids should be considered ONLY for severe crescentic PSGN with rapidly progressive glomerulonephritis. 1, 2 This recommendation is based on anecdotal evidence only, with weak evidence quality. 2

Critical Caveats:

• High-dose glucocorticoids and cyclophosphamide may be used for rapidly progressive crescentic disease, similar to treatment for ANCA-associated vasculitis. 5, 1
• Do NOT use immunosuppression for typical uncomplicated PSGN as the disease is self-limiting with excellent prognosis. 3, 4
• Evidence from randomized trials shows no advantage of combined immunosuppressants over supportive therapy alone for crescentic post-streptococcal glomerulonephritis. 4
• For patients with eGFR <30 ml/min per 1.73 m², supportive care alone is recommended unless there is active necrotizing or crescentic GN with preserved renal parenchyma. 5, 1

Monitoring and Follow-Up

Regular assessment is essential to identify the small subset of patients who develop complications. 1, 3

Key Monitoring Parameters:

• Assess C3 complement levels at diagnosis and follow serially—C3 should normalize within 8-12 weeks in uncomplicated cases. 1, 2
• If C3 remains low beyond 12 weeks, perform kidney biopsy to exclude complement C3 glomerulonephritis (C3GN). 1, 2
• Monitor kidney function, blood pressure, proteinuria, and hematuria regularly throughout the disease course. 1, 2
• Kidney biopsy is indicated when diagnosis is uncertain, atypical presentation occurs, or C3 remains persistently low beyond 12 weeks. 1

Common Pitfalls to Avoid

• Do not withhold antibiotics even when active infection is no longer clinically apparent—the goal is to reduce antigenic load. 1, 2
• Do not routinely use immunosuppression for typical PSGN as most patients have excellent prognosis with supportive care alone. 3, 4
• Do not assume chronic kidney disease based on initial severe presentation—even patients with very low GFR (11.2 ml/min/1.73 m²) can have complete recovery. 6
• Do not discontinue monitoring after initial recovery—persistent proteinuria, hypertension, or progression to chronic kidney disease may require long-term follow-up. 3, 7