What is the clinical presentation of Group A Streptococcus (GAS) glomerulonephritis (GN)?

From the Guidelines

Group A streptococcal glomerulonephritis typically presents with the sudden onset of hematuria, proteinuria, edema, and hypertension about 1-3 weeks after a streptococcal infection of the throat or skin, as noted in the 2013 commentary on the KDIGO clinical practice guideline for glomerulonephritis 1.

Clinical Presentation

The clinical presentation of group A streptococcal glomerulonephritis includes:

• Sudden onset of hematuria, proteinuria, edema, and hypertension
• Cola-colored or tea-colored urine due to the presence of blood
• Facial edema, particularly periorbital puffiness, which may progress to generalized edema with fluid retention
• Hypertension can be moderate to severe, sometimes leading to hypertensive encephalopathy with headaches, visual disturbances, or altered mental status

Laboratory Findings

Laboratory findings include:

• Elevated serum creatinine
• Decreased glomerular filtration rate
• Low C3 complement levels
• Positive streptococcal antibody titers (ASO or anti-DNase B)
• Urinalysis typically shows red blood cells, red cell casts, and moderate proteinuria

Management

The management of group A streptococcal glomerulonephritis involves treating the infectious disease and standard approaches to the management of the kidney manifestations, as suggested in the 2013 commentary on the KDIGO clinical practice guideline for glomerulonephritis 1.

• Appropriate treatment of the infectious disease
• Standard approaches to the management of the kidney manifestations, including salt restriction, diuretics for edema, and antihypertensive medications if needed
• Corticosteroids may be suggested for severe crescentic GN based on anecdotal evidence only, as noted in the 2013 commentary on the KDIGO clinical practice guideline for glomerulonephritis 1

From the Research

Clinical Presentation of Group A Strep Glomerulonephritis

• The clinical presentation of group A strep glomerulonephritis, also known as acute post-streptococcal glomerulonephritis (APSGN), typically includes microscopic or gross hematuria, arterial hypertension, edema, and acute kidney injury 2.
• Patients may also present with nephritic syndrome, characterized by hematuria, proteinuria, and reduced kidney function 3, 4.
• The disease often has a self-limiting course, but severe cases can lead to significant complications, such as overhydration, low glomerular filtration rate, hyperuricemia, and nephrotic proteinuria 2.

Key Features of Group A Strep Glomerulonephritis

• The disease is caused by an immunological complication of infection with group A β-hemolytic streptococcus (GAS) 2, 4.
• The diagnosis is supported by evidence of recent streptococcal infection, positive antistreptolysin O (ASO) titer or Anti-DNAase B titer, and associated hypocomplementemia 5.
• The disease is more common in children, who typically have an excellent prognosis, including in cases with severe renal impairment in the early stages of the disease 2, 5.
• Adults may have a higher incidence of hypertension and chronic renal failure as a result of post-streptococcal glomerulonephritis 5.

Management and Prevention

• The management of group A strep glomerulonephritis is symptomatic, and treatment is aimed at controlling hypertension, edema, and proteinuria 4, 6.
• The main way to prevent the disease is to treat group A streptococcal (GAS) infections with antibiotic therapy to prevent the development of complications 4.
• Disease-modifying immunosuppression may be necessary in some cases, and supportive therapy is often required to manage complications such as acute kidney injury and nephrotic syndrome 2, 6.