MLAB 2401: Clinical Chemistry Keri Brophy-Martinez Pathophysiology of Renal Function.

MLAB 2401: Clinical MLAB 2401: Clinical ChemistryChemistryKeri Brophy-MartinezKeri Brophy-Martinez

Pathophysiology of Renal Function

Glomerular DiseasesGlomerular DiseasesAssociated with damage to the

glomeruli of the nephronLead to tubular dysfunctionCan be acute or chronic

Acute Glomerulonephritis Acute Glomerulonephritis (AGN)(AGN)Characterized by rapid onset of

symptoms that indicate damage to the glomeruli.

Population affected includes children and young adults

Acute Glomerulonephritis Acute Glomerulonephritis (AGN)(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 Acute Glomerulonephritis (AGN)(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 Chronic Glomerulonephritis (CGN)(CGN)Associated with the end stage of

persistent glomerular damageIrreversible loss of renal tissue Can result in renal failureSymptoms of CGN include:

◦ edema, fatigue, hypertension, metabolic acidosis, proteinuria, decreased urine volume

Nephrotic SyndromeNephrotic SyndromeCauses of:

◦Complications of glomerulonephritis ◦Circulatory disorders affecting

kidneys

Hallmark◦Increased permeability of glomerular

basement membrane Allows for proteins & lipids to enter GFR

Nephrotic SyndromeNephrotic SyndromeSymptoms:

◦Massive proteinuria (>3 g/day)◦Albuminuria (>1.5 g/day)◦Pitting edema◦Hyperlipidemia◦Hypoalbuminemia◦Lipiduria: oval fat bodies

Urinary Tract InfectionUrinary 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

ObstructionsObstructionsCauses of:

◦Renal calculi Calcium oxalate most common

◦Tumors◦Urethral strictures

Leads to chronic renal failure

Renal FailureRenal FailureAcute

◦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 Renal Failure: Chronic (CKD)(CKD)

Chronic◦ Gradual decline in function◦ Associated with hypertension and diabetes◦ Risk factors

Autoimmune diseases Urinary tract and systemic infections Some medicationsoComplications from CKD• Anemia• Hyperparathyroidism• Vitamin D deficiency/insufficiency• Mineral and bone disorders

DialysisDialysis

Method used to rid the body of waste products

ReferencesReferences 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.

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