Urinalysis Flashcards
Calcium Oxalate
Octahedral “envelope” crystal (dihydrate, most common); Spherical monohydrate esp. with Ethylene Glycol Poisoning; Normal Acidic/Neutral
Triple Phosphate
“Coffin-lid” crystal; Normal Alkaline
Ammonium biurate
“Thorny apple”; Normal Alkaline
Amorphous urates
irregular granules; normal acidic
Amorphous phosphates
irregular granules; normal alkaline
Uric acid
Pleomorphic. 4-sided, 6-sided, star shaped, rosettes, spears, plates; normal acidic
Calcium phosphate
needles, rosettes, “pointing finger”; Normal alkaline
Calcium carbonate
“Dumbbells” or aggregates; normal alkaline
Leucine
Oily spheres, concentric circles; abnormal acid/neutral (Severe liver disease)
Tyrosine
Needles in sheaves or rosettes; abnormal acid/neutral (Severe liver disease)
Cystine
Hexagonal (6-sides); abnormal acid (Cystinuria, metabolic disease)
Cholesterol
Flat plates, notched out corners “stair-steps”; abnormal acid (Nephrotic syndrome)
Bilirubin
Yellowish brown needles, plates, granules; abnormal acid (Liver disease)
Acute glomerulonephritis
Cause: Inflammation and damage to glomeruli
Macro: protein, blood
Micro: RBCs, WBCs, red cell casts
Notes: Frequently follows untreated group A strep
Nephrotic syndrome
Cause: Increased glomerular permeability
Macro: protein (4+)
Micro: Casts (all kinds), free fat, oval fat bodies
Pyelonephritis
Cause: Kidney infection (upper UTI)
Macro: Protein, LE, nitrite
Micro: WBCs, WBC casts, bacteria
Cystitis
Cause: bladder infection (lower UTI)
Macro: LE, nitrite
Micro: WBCs, bacteria, possible RBCs, no casts
Renal Calculi
AKA: Kidney Stones
Macro: Blood (4+)
Micro: RBCs, crystals (usually Ca Oxalate)
Major protein component of casts
Tamm-Horsfall protein
Fat in urine can be identified by
stain (Sudan III or IV); polarized light
Glucose reflex test. Condition?
Clinitest. Patient <2 yrs old.
Bilirubin reflex test. Condition?
Ictotest. Positive bilirubin.
Protein reflex test. Condition?
SSA. Trace protein result.
Renal threshold for Glucose
160-180 mg/dL
Yeast Infection
Macro: (+/-) protein, LE, Blood
Micro: WBC, RBC, Yeast
High Uro, +/- Bili
Liver disease
Normal Uro, + Bili
Biliary Obstruction
High Uro, - Bili
Hemolytic disorder
End-stage Renal Disease
Cause: any renal condition can lead to this
Macro: protein, +/- blood
Micro: Renal Epithelial cells, granular casts, broad waxy casts
If >2 hrs unpreserved before testing
Macro: pH up, protein slightly up, glucose down, ketones down, bili down, nitrite up
Micro: Casts down, RBCs down, Bacteria up, WBCs down
Creatinine clearance reference range
80-130 mL/min
Angiotensin
Produced when low plasma Na+, promotes Na+ reabsorption in PCT
Aldosterone
Produced when low plasma Na+, promotes Na+ reabsorption in DCT
ADH
opens door for passive transport of H2O in DCT (more ADH, more H2O reabsorbed)
GFR vs. Kidney disease
Stage 1: >= 90 mL/min
Stage 2: 60-89 mL/min
Stage 3: 45-59 mL/min
Stage 4: 15-29 mL/min
Stage 5: <15 mL/min
Nephritic
sterile, RBC casts
Nephrotic
fatty and waxy casts, protein +++
Broad casts
tubular dilation and stasis (chronic renal failure)
PKU (phenylketonuria)
Symptoms: Mousy-smelling urine, developmental delays
Pathology: Missing enzyme phenylalanine hydroxylase
Testing: Guthrie (B. subtilis on blood) or Ferric Chloride (urine)
MSUD (maple syrup urine disease)
Symptoms: very sweet smelling urine (keto acid buildup)
Pathology: buildup of leucine, isoleucine, and valine
Testing: 2,4-DNPH
Alkaptonuria
Symptoms: urine darkens as it turns alkaline at room temp
Pathology: buildup of homogentisic acid due to missing oxidase
Testing: Silver nitrate test
Melanuria
Symptoms: dark brown or black urine
Pathology: malignancy of melanocytes (melanoma)
Indicanuria
Symptoms: urine turns blue when exposed to air (“blue diaper syndrome”
Pathology: Deficient intestinal reabsorption of tryptophan (sometimes general aminoaciduria a.k.a. Fanconi syndrome)
Porphyria/Porphyrinuria
Symptoms: red/port wine colored urine
Pathology: Errors in heme synthesis (porphyrin metabolism)
Causes: inherited (rare), lead poisoning, iron deficiency, +++ alcohol
Testing: Watson-Schwartz test
Cystinuria
Symptoms: calculi of cystine crystals
Pathology: poor reabsorption of cystine and lysine (and sometimes arginine and ornithine) in renal tubules
Testing: Cyanide Nitroprusside (+), Silver Nitroprusside (-)
Homocystinuria
Symptoms: cataracts, FTT, intellectual disability, stroke, death
Pathology: buildup of homocystine (defects in methionine metabolism)
Testing: Cyanide Nitroprusside (+), Silver Nitroprusside (+)
Watson-Schwartz Test
Urine/Chloroform; Butanol/Urine
Y/R; R/Y = Urobilinogen
R/Y; Y/R = Porphobilinogen
R/Y; R/Y = Ehrlich-reactive
R/R; R/R = Urobilinogen/porphobilinogen
