MLAB 2401: Clinical Chemistry
Keri Brophy-Martinez
Pathophysiology of Renal Function
Glomerular Diseases
Associated with damage to the glomeruli
of the nephron
 Lead to tubular dysfunction
 Can be acute or chronic

Acute Glomerulonephritis (AGN)
Characterized by rapid onset of
symptoms that indicate damage to the
glomeruli.
 Population affected includes children and
young adults

Acute Glomerulonephritis (AGN)

Causes of:
◦ AGN often follows a group A streptococcal
infection
 Circulating immune complexes trigger an
inflammatory response in the glomerular basement
membrane
◦ Toxin/Drug-related exposures
◦ Acute kidney infections
◦ Systemic diseases
Acute Glomerulonephritis (AGN)
•
Symptoms
– Hematuria
– Proteinuria
– Oliguria
– Fever
– Malaise
– Rapid Onset
– Edema
– Hypertension
– Sodium & water
retention
•
Laboratory
Findings
– Decreased GFR
– Increased BUN &
creatinine
– Hyaline, granular, RBC
casts
– Increased protein in
urine
– Blood in urine
Chronic Glomerulonephritis (CGN)
Associated with the end stage of
persistent glomerular damage
 Irreversible loss of renal tissue
 Can result in renal failure
 Symptoms of CGN include:

◦ edema, fatigue, hypertension, metabolic
acidosis, proteinuria, decreased urine volume
Nephrotic Syndrome

Causes of:
◦ Complications of glomerulonephritis
◦ Circulatory disorders affecting kidneys

Hallmark
◦ Increased permeability of glomerular
basement membrane
 Allows for proteins & lipids to enter GFR
Nephrotic Syndrome

Symptoms:
◦
◦
◦
◦
◦
◦
Massive proteinuria (>3 g/day)
Albuminuria (>1.5 g/day)
Pitting edema
Hyperlipidemia
Hypoalbuminemia
Lipiduria: oval fat bodies
Urinary Tract Infection
•
Causes of:
– Pyelonephritis (kidneys)
• Acute: no permanent damage
• Chronic: permanent damage, possible renal failure
– Cystitis (bladder)
•
Lab Findings
– Positive nitrite on dipstick
– Hematuria
– Pyuria
– WBC casts
Obstructions

Causes of:
◦ Renal calculi
 Calcium oxalate most common
◦ Tumors
◦ Urethral strictures

Leads to chronic renal failure
Renal Failure

Acute
◦ Sudden decline in renal function
◦ GFR < 10 mL/minute
◦ Caused by nephrotoxic agents, necrosis,
hemorrhaging




Hemolytic transfusions reactions
Burns
Cardiac failure
Antifreeze ingestions
Renal Failure: Chronic (CKD)

Chronic
◦ Gradual decline in function
◦ Associated with hypertension and diabetes
◦ Risk factors
 Autoimmune diseases
 Urinary tract and systemic infections
 Some medications
o Complications from CKD
• Anemia
• Hyperparathyroidism
• Vitamin D deficiency/insufficiency
• Mineral and bone disorders
Dialysis

Method used to rid
the body of waste
products
References



14
Bishop, M., Fody, E., & Schoeff, l. (2010). Clinical Chemistry:
Techniques, principles, Correlations. Baltimore: Wolters Kluwer
Lippincott Williams & Wilkins.
Sunheimer, R., & Graves, L. (2010). Clinical Laboratory Chemistry.
Upper Saddle River: Pearson.
Vassalotti, MD, J. A., & Kaufman, MD, H. W. (2013, July). New
Guidelines to Evaluate and manage Chronic Kidney Disease.
MLO, 24-26.