Renal Diseases and Glomerulonephritis Quiz

Nephritic syndrome is a clinical complex, typically acute, characterized by specific symptoms
Hematuria: Presence of red blood cells in urine (often appearing smoky brown)
Proteinuria: Excessive protein in urine (less than 1 gram per day)
Oliguria: Decreased urine output
Azotemia: Elevated blood urea nitrogen (BUN) and serum creatinine levels
Hypertension: Elevated blood pressure
Mild edema: Swelling, typically in the tissues

Primary (Infectious):
- Post-streptococcal
- Non-post-streptococcal (caused by other bacteria or viruses like pneumococci, HCV, HBV)
Secondary:
- Systemic diseases (SLE - systemic lupus erythematosus, schistosomiasis)

Glomerular inflammatory reaction: Initial inflammatory response in the glomeruli
Capillary hypercellularity: Increased number of cells within the glomerular capillaries
Mesangial and endothelial cell proliferation: Increase in mesangial and endothelial cells
Compressed narrow capillaries: Reduced space within the glomerular capillaries
Capillary wall injury: Damage to the walls of the glomerular capillaries
Renal ischemia: Reduced blood flow to the kidney
Hemodynamic changes: Alterations in blood flow and pressure within the kidney
Inflammation and WBCs: Immune cells are recruited to the area
RBCs & protein in the urine: Damage allows the leakage of red blood cells, protein and other components from the capillaries into the urine
Hematuria & Proteinuria: Red blood cells and proteins leak into the urine
Azotemia and Oliguria: Kidney functions affected, decreasing urine output and increasing waste products
RAAS (renin-angiotensin-aldosterone system) activation: Leads to hypertension (high blood pressure)
GFR (glomerular filtration rate) reduction: Kidney's ability to filter blood decreased, leading to other symptoms and effects

Acute diffuse proliferative glomerulonephritis (ADPGN): Characterized by an increase in glomerular cells, leukocytic infiltration, and compression of capillary lumina. Can progress to a crescent-shaped structure in severe cases
Rapid progressive glomerulonephritis (RPGN): Significant deterioration in kidney function, with formation of crescents in 50-80% of glomeruli, caused by parietal cell proliferation.

Cause: Often follows a streptococcal infection of the skin or upper respiratory tract. Nephritogenic strains of streptococci (type 12, 4, 1) are implicated.
Pathogenesis: Immune complexes deposit within the glomerulus, activating the complement system, initiating inflammation.

Sudden onset (1-4 weeks after infection): Often presenting with symptoms of nephritic syndrome (hematuria, oliguria, azotemia, hypertension, mild edema)
Urine appears smoky brown: due to presence of red blood cells in urine
High Anti-streptolysin O (ASO) titers: Indicator of streptococcal infection
Low complement (C3) levels: Result of complement system activation

Renal biopsy: A sample of kidney tissue is collected for examination, analyzed through different microscopic methods.
Light microscopy (LM): Visualizing macroscopic tissue changes (glomerular hypercellularity, thickening of GBM, etc.)
Fluorescence microscopy (FM): Identifying immune deposits in the tissue
Electron microscopy (EM): Examining detailed structures and locating immune complex deposits within the glomerulus

Glomerular hypercellularity (proliferative): Increase in the number of cells (mesangial and endothelial cells, inflammatory cells like neutrophils and monocytes)
Crescentic glomerulonephritis: Proliferation of parietal cells leading to crescent formation
Glomerular basement membrane (GBM) thickening: Splitting of the GBM due to immune deposits
Glomerular hyalinization or sclerosis: Abnormal hardening or deposition of material in the glomerulus
Deposition of material (fibrin, amyloid): Deposits of abnormal substances like fibrin or amyloid proteins

Fluorescein-labeled antibodies: Identify and localize immune components (IgG, IgA, IgM, and complements) in glomerular tissue
Granular pattern: Common, showing widespread deposition of immune complexes, and usually indicates immune complex-mediated glomerulonephritis
Linear pattern: Limited to the GBM (glomerular basement membrane) and usually suggests anti-GBM antibodies

Crucial for localizing immune complexes intracellularly
Various locations of immune deposition include subepithelial, subendothelial, intramembranous, and mesangial.

Children: Excellent prognosis; most recover fully (>90%)
Adults: Predominantly in 15-50 age group, chronic glomerulonephritis (chronic GN) may develop in 15-50% of cases, depending on how rapidly the condition is treated

Definition and characteristic features: Rapid and progressive loss of kidney function with severe oliguria (low urine output), acute renal failure. Histologically, crescents are formed in 50–80% of glomeruli, due to proliferation of cells lining a portion of the glomerulus
Pathogenesis-RPGN: RPGN is caused by various diseases, where the glomerular damage is triggered by immunological mechanisms, involving autoantibodies against endogenous antigens in glomerular basement membrane (GBM).
- Goodpasture syndrome: Specific antibody against GBM, producing hemoptysis (coughing up blood) as a pulmonary manifestation along with acute renal failure
Morphology-RPGN: Light microscopy (LM) shows crescents, while fluorescence microscopy (FM) shows linear deposits of immunoglobulins and C3 along the GBM. Electron microscopy (EM) typically reveals non-specific features

Normal glomeruli: The normal structure of a kidney glomerulus is presented for comparison
Illustrations of different types of glomerular changes including hypercellularity (proliferative and crescentic), GBM thickening, and hyalinization