What are the main differentiating factors between Nephrotic Syndrome (NS) and Nephritic Syndrome (NeS)?

From the Guidelines

Nephrotic and nephritic syndromes are distinct kidney disorders with different clinical presentations and underlying pathophysiology, primarily differentiated by the presence of heavy proteinuria, hypoalbuminemia, and edema in nephrotic syndrome, versus hematuria, moderate proteinuria, hypertension, and oliguria in nephritic syndrome. The main differentiating factors between these two syndromes include the level of proteinuria, with nephrotic syndrome characterized by heavy proteinuria (>3.5g/day) and nephritic syndrome by moderate proteinuria (<3.5g/day) 1. Other key differences include:

• The presence of hypoalbuminemia, hyperlipidemia, and edema in nephrotic syndrome, which are not typically seen in nephritic syndrome
• The presence of hematuria, especially red blood cell casts, and hypertension in nephritic syndrome, which are not characteristic of nephrotic syndrome
• The underlying pathophysiology, with nephrotic syndrome resulting from damage to the glomerular filtration barrier and nephritic syndrome resulting from inflammation within the glomeruli
• The causes of the two syndromes, with nephrotic syndrome commonly resulting from minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and diabetic nephropathy, and nephritic syndrome typically stemming from post-streptococcal glomerulonephritis, IgA nephropathy, lupus nephritis, and rapidly progressive glomerulonephritis 1. Treatment approaches also vary accordingly, with nephrotic syndrome often requiring immunosuppressants like steroids, calcineurin inhibitors, or rituximab, while nephritic syndrome may require aggressive immunosuppression, especially for rapidly progressive forms 1. Understanding these differences is crucial for proper diagnosis and management of these kidney disorders, as highlighted in the KDIGO 2021 clinical practice guideline for the management of glomerular diseases 1.

From the Research

Differentiating Factors between Nephrotic and Nephritic Syndromes

The main differentiating factors between nephrotic and nephritic syndromes can be identified based on their clinical presentation, underlying causes, and pathophysiology.

• Nephrotic syndrome is characterized by:
  • Hypoalbuminemia
  • Severe proteinuria
  • Peripheral edema
  • Hyperlipidemia
  • Frequently associated with primary or secondary causes such as focal segmental glomerulosclerosis, membranous nephropathy, or diabetes mellitus 2, 3, 4
• Nephritic syndrome, on the other hand, is characterized by:
  • Hematuria
  • Proteinuria
  • Hypertension
  • Acute kidney injury and fluid retention in some cases
  • Often associated with infection-related glomerulonephritis, IgA nephropathy, lupus nephritis, or antineutrophil cytoplasmic antibody-associated vasculitis 5

Clinical Presentation and Diagnosis

The clinical presentation of nephrotic syndrome typically includes edema, proteinuria, hypoalbuminemia, and hyperlipidemia, whereas nephritic syndrome presents with hematuria, proteinuria, hypertension, and possible acute kidney injury 3, 5.

• Diagnosis of nephrotic syndrome involves measuring proteinuria and serum albumin and lipid levels, as well as assessing for secondary causes 4
• Diagnosis of nephritic syndrome involves identifying the underlying cause, such as infection-related glomerulonephritis or IgA nephropathy, and assessing for acute kidney injury and fluid retention 5

Treatment and Management

Treatment and management of nephrotic syndrome typically involve reduction of proteinuria with glucocorticoids, dietary sodium restriction, edema management, and blood pressure control 4

• Treatment and management of nephritic syndrome involve addressing the underlying cause, such as treating infection-related glomerulonephritis or IgA nephropathy, and managing acute kidney injury and fluid retention 5