Renal Pathology Quiz

Pathology

Manifestations of Renal Disease:

Azotemia:

• Elevated blood urea nitrogen and creatinine levels
• Reflects a decreased glomerular filtration rate (GFR)
• Prerenal azotemia: due to hypoperfusion of the kidneys resulting in decreased GFR in the absence of parenchymal damage
• Postrenal azotemia: due to obstruction below the level of the kidney. Relief of the obstruction results in correction of the azotemia.

Uremia:

• Azotemia + Clinical Manifestation/Systemic Abnormalities
• Failure of renal excretory function + metabolic and endocrine alterations incident to renal damage
• Secondary involvements: gastrointestinal - uremic gastroenteritis, neuromuscular - peripheral neuropathy, cardiovascular - uremic fibrinous pericarditis

Clinical Presentations of Renal Disease:

Acute Nephritic Syndrome:

• Due to glomerular injury
• Dominant: acute onset of usually grossly visible hematuria (red blood cells and red cell casts in urine), proteinuria of mild to moderate degree, azotemia, edema, hypertension
• Classic presentation of acute poststreptococcal glomerulonephritis

Nephrotic Syndrome:

• Glomerular syndrome
• Characterized by: heavy proteinuria, hypoalbuminemia, severe edema, hyperlipidemia, lipiduria

Asymptomatic Hematuria or Non-Nephrotic Proteinuria or Combination:

• Manifestation of subtle or mild glomerular abnormalities

Acute Renal Injury:

• Has prolonged symptoms and signs of uremia
• Due to progressive scarring in the kidney from any cause and may culminate in end-stage kidney disease
• Stages:

Chronic Kidney Disease:

• Dominant: oliguria or anuria and recent onset of azotemia
• Due to glomerular injury

Renal Tubular Defects:

• Dominant: polyuria, nocturia, and electrolyte disorders

Others:

• UTI: kidney - pyelonephritis; bladder - cystitis
• Nephrolithiasis/Renal stones: renal colic-severe spasms of pain, hematuria
• Urinary tract obstruction

Glomerular Alterations:

Hypercellularity:

• Proliferation of mesangial and endothelial cells
• Leukocytic infiltration
• Formation of crescents: accumulation of cells that are composed of proliferating parietal epithelial cells and infiltrating leukocytes; occurs following an inflammatory/immune injury

Thickening of Basement Membrane:

• Manifestation: thickening of the capillary wall which could be secondary to deposition of amorphous electron dense material such as immune complexes, fibrin, amyloid, cryoglobulins, and abnormal fibrillary proteins; primary thickening of the glomerular basement proper (diabetic glomerulosclerosis)

Hyalinization/Hyalinosis and Sclerosis:

• Accumulation of homogenous and eosinophilic material resulting in obstruction of lumen and endothelial/capillary wall injury
• EM: amorphous substance made up of plasma proteins

Glomerular Alterations:

• Immune mechanisms cause most forms of primary glomerulonephritis and many forms of secondary glomerular disorders

• Antibody injury: Abs reacting in situ with the glThe text describes various pathological conditions affecting the kidney. These include:

• Glomerulonephritis: inflammation of the glomeruli, the tiny filters within the kidney that remove waste from the blood. Different types of glomerulonephritis are characterized by specific features seen under the microscope, such as deposits of immune complexes (consisting of antibodies and other proteins) and complement proteins (part of the immune system that helps destroy pathogens).

• Hereditary syndromes of isolated hematuria: conditions that run in families and cause blood in the urine (hematuria) but generally do not lead to kidney failure. These syndromes include Alport syndrome, which affects the collagen that makes up the glomerular basement membrane (GBM), and thin basement membrane disease, which causes BM thinning but usually does not affect kidney function.

• Dialysis changes: alterations seen in the kidney tissue of patients undergoing long-term dialysis, a treatment for kidney failure that involves filtering the blood outside the body.

The text also mentions various diagnostic techniques used to study kidney diseases, such as electron microscopy (EM) and immunofluorescence (IF).