What is the treatment for post-infectious glomerulonephritis?

Treatment of Post-Infectious Glomerulonephritis

Treat post-infectious glomerulonephritis with antibiotics (penicillin or erythromycin) to reduce antigenic load even when active infection has resolved, combined with supportive management of nephritic syndrome using sodium restriction and diuretics, reserving corticosteroids only for severe crescentic disease with rapidly progressive renal failure. 1

Antibiotic Therapy

Administer antibiotics regardless of whether active infection is still present—the goal is to decrease streptococcal antigenic load, not to treat active infection. 1

• Penicillin is first-line therapy for classic post-streptococcal glomerulonephritis occurring 1-3 weeks after pharyngitis or impetigo 1
• Erythromycin is the alternative for penicillin-allergic patients 1, 2
• 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 2

Critical pitfall to avoid: Do not withhold antibiotics even when the infection appears resolved—antibiotics reduce antigenic burden and prevent spread, though they do NOT prevent acute glomerulonephritis itself 2

Supportive Management of Nephritic Syndrome

Managing clinical manifestations is the cornerstone of treatment, as most cases are self-limited with excellent prognosis. 1, 3

Fluid and Sodium 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 both fluid overload and hypertension 1, 2
• Monitor closely for diuretic-related complications including hyponatremia, hypokalemia, GFR reduction, and volume depletion 1, 2

Blood Pressure Control

• Target blood pressure <130/80 mmHg (or <125/75 mmHg if proteinuria >1 g/day) 1
• ACE inhibitors (captopril and enalapril) provide better control of blood pressure and echocardiographic changes than other antihypertensive drugs/diuretics 4
• Nifedipine is effective for controlling acute hypertension 4

Metabolic Management

• 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 2

Renal Replacement Therapy

• Provide dialysis if necessary for severe acute kidney injury with uremia, refractory fluid overload, or life-threatening hyperkalemia 2

Immunosuppressive Therapy

Corticosteroids should be considered ONLY for severe crescentic glomerulonephritis with rapidly progressive renal failure, based on anecdotal evidence with weak evidence quality. 1, 2

• Do NOT use corticosteroids for typical post-infectious glomerulonephritis—the disease is self-limited and most cases resolve spontaneously 2, 5
• Do NOT use corticosteroids for IgA-dominant post-infectious glomerulonephritis, which typically occurs with staphylococcal infections (including MRSA), particularly in elderly and diabetic patients 1, 6
• Combined immunosuppressants for crescentic poststreptococcal glomerulonephritis showed no advantages over supportive therapy alone in controlled trials 4

Critical pitfall to avoid: Do not routinely use immunosuppression—the evidence is anecdotal at best and can worsen infection in certain subtypes 2, 6

Monitoring and Follow-Up

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
• Regular assessment of serum creatinine, urinalysis with microscopy, and urine protein-to-creatinine ratio 2

Special Considerations for Non-Streptococcal Infections

For endocarditis-related glomerulonephritis (increasingly caused by staphylococcal species), antibiotic treatment must continue for 4-6 weeks, though hematuria, proteinuria, and azotemia may persist for months after infection eradication 1

• In adults, glomerulonephritis is more commonly secondary to bacteria such as staphylococci, viruses such as hepatitis C and HIV, and rarely parasitic infections 7
• Bacterial, viral, and parasitic infections may be associated with significant morbidity and long-term consequences, unlike the typically self-limiting course of post-streptococcal glomerulonephritis in children 7

Prognosis

The majority of children and patients with epidemic post-infectious glomerulonephritis have excellent prognosis with complete spontaneous resolution, which contrasts with the poor long-term outcome of sporadic cases in adults 5, 3, 8

• Most children make a full recovery with preserved renal function and no recurrence 3, 8
• Persistent proteinuria, hypertension, and progression to chronic kidney disease may require long-term monitoring 8