Clinical Microscopy: Chemical and Microscopic Analysis of Urine PDF

CLINICAL MICROSCOPY: Chemical and Microscopic Analysis of Urine brainrotgaIore || March 2023 READING SENSITIVITY REACTION and SPECIFICITY...

CLINICAL MICROSCOPY: Chemical and Microscopic Analysis of Urine brainrotgaIore || March 2023 READING SENSITIVITY REACTION and SPECIFICITY TEST PRINCIPLE REAGENTS TIME Multistix Chemstrip CLINICAL SIGNIFICANCE False (+) False (-) ✓ Pigmented M: Dichloroaniline diazonium Only conjugated bilirubin appear in the ✓ Exposure to light specimen salt urine ✓ Ascorbic acid 30 s (M) 0.4-0.8 ✓ Indican (intestinal BILIRUBIN Diazo reaction 0.5 mg/dL >25 mg/dL 60s (C) mg/dL disorder) C: Dichlorobenzene diazonium Bilirubinuria: ✓ ↑ Urine ✓ Metabolites of salt Hepatitis, Cirrhosis, Gallstones, concentration Lodine Carcinoma Correlation: Urobilinogen M: Glucose oxidase, Peroxidase, Potassium iodide (green → brown) C: Glucose oxidase, ✓ ↑ Ascorbic acid, Double sequential Peroxidase, SG, Ketone enzymatic Tetramethylbenzidine 75-125 40 ✓ Oxidizing agents ✓ ↓ Temperature 30 s GLUCOSE reaction (Glucose (yellow → green) mg/dL mg/dL ✓ Detergents ✓ Improperly oxidase and Renal threshold: 150-180 mg/dL preserved Peroxidase) CHROMOGENS specimen Clinistix: O-toluidine Correlation: Ketone, Protein (pink → purple) Aminopropyl-carbazol (yellow → orange-brown) ✓ Levodopa ✓ Sulfhydril 9 mg/dL M: Sodium nitroprusside medication Sodium (acetoacetic (detects acetoacetic acid) 5-10 mg/dL (mercaptoethane ✓ Improperly nitroprusside acid) 40 s KETONES (acetoacetic sulfonate sodium preserved (Nitroferricyanide) C: Sodium mitroprusside + Early indicator of insufficient dosage in acid) and captopril) specimen reaction 70 mg/dL glycine (detects acetoacetic Type 1 diabetes ✓ Phthalein dyes (acetone) acid and acetone) ✓ Pigmented Correlation: Glucose specimen M: Poly (methylvinylether / maleic anhydride) bromthymol Specimens with a pH of 6.5 or higher pKa change of blue ✓ Highly alkaline SPECIFIC have decreased readings caused by ✓ ↑ Protein 45 s polyelectrolyte in 1.000 – 1.030 urine > pH 6.5 GRAVITY interference with bromthymol blue concentration alkaline medium C: Ethyleneglycol diaminoethylether tetraacetic acid, bromthymol blue Page 1 of 12  Normal random samples: 4.5-.8.0 Double indicator 5.0-8.5 5.0-9.0 Methyl red Improperly preserved specimens: > 8.5 system of methyl 60 s pH in 0.5 in 1.0 and No known interfering substance red and bromthymol increments increments Bromthymol blue Correlation: Nitrite, Leukocytes, blue Microscopic ✓ Highly buffered alkaline urine ✓ Loss of buffer from prolonged exposure if reagent strip to the specimen M: Tetrabromophenol blue (technical) ✓ Highly pigmented Protein C: Tetraclorophenol specimen ✓ Proteins other 60 s PROTEIN (Sorensen’s) error 15-30 mg/dL 6 mg/dL Trace 1+ 2+ 3+ 4+ tetrabromosulfonphthalein ✓ Pigment than Albumin of indicator 200 25 mg/dL M: Color change (orange → green → dark blue) ✓ Oxidizing agents ✓ ↑ SG (crenated 5-20 5 RBCs/mL Diisopropylbenzenediydriperoxi Pseudoperoxidase Speckled blue: intact RBCs (hematuria) ✓ Menstrual RBCs), Nitrite RBCs/mL to HGB ~ 10 de and tetramethylbenzidine 60 s BLOOD activity of Uniform blue: hemoglobin and contamination (>10 mg/dL) 0.015-0.062 RBCs/mL hemoglobin myoglobin ✓ Bacterial mg/dL HGB (0.3 mg/dL) C: Dimethyldihydroperoxide Hematuria: cloudy red urine peroxidase ✓ Formalin and tetramethylbenzidine Hemoglobinuria: clear red urine ✓ Captopril ✓ Unmixed Correlation: Protein, Microscopic specimens Multistix ✓ Porphobiliogen Multistix ✓ Indican ✓ Old specimen ✓ P-aminosalicylic M: p- ✓ Preservation in acid dimethylaminobenzaldehyde formalin ✓ Sulfonamide (Ehrlich reagent) ✓ Methyldopa Chemstrip 60 s UROBILINOGEN Ehrlich’s reaction 0.2 mg/dL 0.4 mg/L ✓ Procaine ✓ Old specimen ✓ Chlorpromazine C: methoxyenzene-diazonium- ✓ Preservation in ✓ Highly pigmented tetrafluoroborate (azocoupling; formalin urine more specific) ✓ ↑ Nitrite (azocoupling Correlation: Bilirubin Chemstrip interference) ✓ Highly pigmented urine Page 2 of 12  ✓ Non-reducatase- containing bacteria M: p-arsanilic acid ✓ Improperly ✓ ↑ Ascorbic acid, tetrahydrobenzoquinolin 0.06-0.1 preserved SG 0.05 mg/dL 60 s NITRITE Greiss reaction mg/dL This test does not measure the degree of specimens ✓ Lack of urinary nitrite ion C: sulfonamide, nitrite ion ✓ Highly pigmented nitrate hydroxytetrahydro bacteruria and results are reported only as either negative or positive urine ✓ Large quantities benzoquinoline of bacteria ✓ Presence of Correlation: Protein, Leukocytes, Microscopic antibiotics ✓ Strong oxidizing ✓ ↑ SG (lysed M: derivatized pyrrole amino Leukocyte agents leukocytes), acid ester, diazonium salt esterase 5-15 10-25 ✓ Formalin Protein, 120 s LEUKOCYTE WBC/hpf WBC/hpf ✓ Highly pigmented Glucose, Oxalic C: indoxylcarbonic acid ester, urine acid, Ascorbic diazonium salt Correlation: Protein, Nitrite, Microscopic (Nitrofurantoin) acid, Antibiotics Ascorbic acid reduces a dye impregnated in 17 mg/dL in ASCORBIC ✓ Free-sulfhydryl 60 s the reagent pad, 67% of 2,6-dichlorophenolindopheno ACID drugs causing a color urines tested change from blue to orange Page 3 of 12  URINALYSIS SEDIMENTS APPEARANCE SOURCES OF ERROR REPORTING CLINICAL SIGNIFICANCE CORRELATIONS ✓ Non-nucleated biconcave disks ✓ Yeast cells ✓ Color ✓ Crenated in hypertonic urine Average number Microscopic RBCs ✓ Oil droplets ✓ Reagent strip blood ✓ Ghost cells in hypotonic urine per 10 hpfs ✓ Air bubbles reaction ✓ Dysmorphic with glomerular membrane damage ✓ Larger than RBCs ✓ Leukocyte esterase ✓ Granulated, multilobed neutrophils Average number ✓ Nitrite Microscopic WBCs Renal tubular epithelial cells ✓ Glitter cells in hypotonic urine per 10 hpfs ✓ Specific gravity ✓ Mononuclear cells with abundant cytoplasm ✓ pH Rare, few, Increased numbers may indicate Squamous Largest cells in the sediment with abundant, irregular Rarely encountered, folded cells moderate, or Clarity contamination of the urine specimen Cells cytoplasm and prominent nuclei may resemble cast many per lpf due to poor collection technique Increased numbers may be seen with: Rare, few, ✓ Clarity Transitional Spherical, polyhedral, or caudate with centrally located Spherical forms resemble RTE ✓ UTI moderate, or ✓ Blood, if malignancy- Cells nucleus cells ✓ renal carcinoma many per hpf associated ✓ after catheterization Increased in tubular necrosis, possibly arising from: Epithelial cells ✓ Leukocyte esterase and ✓ exposure to heavy metals nitrite (pyelonephritis) ✓ drug-induced toxicity Rectangular, columnar, round, oval or, cuboidal with ✓ Color ✓ hemoglobin and myoglobin toxicity ✓ Spherical transitional cells Average number RTE Cells an eccentric nucleus possibly bilirubinstained or ✓ Clarity ✓ viral infections ✓ Granular casts per 10 hpfs hemosiderin-laden ✓ Protein ✓ pyelonephritis ✓ Bilirubin (hepatitis) ✓ allergic reactions ✓ Blood ✓ malignant infiltrations ✓ salicylate poisoning ✓ acute allogenic transplant rejection ✓ Clarity Increased in glomerular damage by: ✓ Blood ✓ nephrotic syndrome Oval Fat Confirm with fat stains and Average number Highly refractile RTE cells ✓ Protein ✓ tubular necrosis Bodies polarized microscopy per hpf ✓ Free fat droplets or fatty ✓ diabetes mellitus casts ✓ long bone trauma Few, moderate, ✓ pH or many per hpf; Amorphous phosphates and ✓ Nitrite Bacteria Small spherical and rod-shaped structures the presence of urates ✓ Leukocyte esterase (LE) WBCs may be ✓ WBCs required Rare, few, Miscellaneous Structures moderate, or ✓ Glucose Small, oval, refractile structures with buds and/or many per hpf; Yeast RBCs ✓ Leukocyte esterase (LE) mycelia the presence of ✓ WBCs WBCs may be required Rare, few, ✓ Leukocyte esterase (LE) Trichomonas Pear-shaped, motile, flagellated WBCs, RTE cells moderate, or ✓ WBCs many per hpf Present, based Spermatozoa Tapered oval head with long, thin tail None on laboratory Protein protocol Mucus Rare, few, Single or clumped threads with a low refractive index Hyaline casts moderate, or None many per lpf Page 4 of 12  ✓ Glomerulonephritis ✓ Mucus ✓ Protein ✓ Pyelonephritis ✓ Fibers Hyaline Colorless, homogenous matrix ✓ Blood (exercise) ✓ Chronic renal disease ✓ Hair ✓ Color (exercise) ✓ Congestive heart failure ✓ Increased lighting ✓ Stress and exercise ✓ RBCs ✓ Glomerulonephritis RBC Orange-red color, cast matrix containing RBCs RBC clumps ✓ Blood ✓ Strenuous exercise ✓ Protein ✓ WBCs ✓ Pyelonephritis WBC Cast matrix containing WBCs WBC clumps ✓ Protein ✓ AIN ✓ Leukocyte Esterase (LE) ✓ WBC casts (pyelonephritis) ✓ WBCs Bacteria Bacilli bound to protein matrix Granular casts Pyelonephritis ✓ Leukocyte Esterase (LE) ✓ Nitrite ✓ Protein ✓ Protein Casts Epithelial Cell RTE cells attached to protein matrix WBC cast Average number Renal tubular damage ✓ RTE cells per lpf ✓ Protein ✓ Glomerulonephritis ✓ Clumps of small crystals ✓ Cellular casts Granular Coarse and fine granules in a cast matrix ✓ Pyelonephritis ✓ Columnar RTE cells ✓ RBCs ✓ Stress and exercise ✓ WBCs ✓ Protein ✓ Cellular casts ✓ Stasis of urine flow Waxy Highly refractile cast with jagged ends and notches Fibers and fecal material ✓ Granular casts ✓ Chronic renal failure ✓ WBCs ✓ RBCs ✓ Nephrotic syndrome ✓ Protein Fat droplets and oval fat bodies attached to protein ✓ Toxic tubular necrosis Fatty Fecal debris ✓ Free fat droplets matrix ✓ Diabetes mellitus ✓ Oval fat bodies ✓ Crush injuries ✓ Protein ✓ WBCs ✓ Fecal material ✓ Extreme urine stasis Broad Wider-than-normal cast matrix ✓ RBCs ✓ Fibers ✓ Renal failure ✓ Granular casts ✓ Waxy casts Page 5 of 12  MAJOR CHARACTERISTICS OF NORMAL URINARY CRYSTALS CRYSTAL pH COLOR and FORM NOTES SIGNIFICANCE SOLUBILITY ILLUSTRATION Yellow-brown Pleomorphic ✓ Diamond or Rhombic Chemotherapy ✓ Rosettes Uric acid Color varies with thickness Alkali ✓ Wedges Gout ✓ Hexagonal Strong birefringence ✓ Four-sided flat plate (whetstone) ✓ Barrel Form pink precipitate due to uroerythrin Brick dust or Yellow-brown Strong birefringence Alkali and Heat Amorphous urate ACID ✓ Irregular (~60°C) ✓ Granular appearance Converts to uric acid with acidification with acetic acid or concentrated HCl None Uncommon Colorless to Light-yellow Alkaline and Monosodium urate Often in small clusters of 2–3 Heat (~60°C) ✓ Pencil-like prisms with blunt ends crystals Dihydrate Dihydrate: weak to moderate Colorless birefringence Dihydrate Monohydrate: Strong ✓ Octahderal birefringence ACID or ✓ Envelopes Monohydrate: Ethylene Calcium oxalate Neutral ✓ Pyramidal Monohydrate form may be Dilute HCl glycol ingestion (Alkaline) mistaken for RBCs. Monohydrate Monohydrate ✓ Oval Most common constituent of ✓ Dumbbell renal calculi. ✓ Hourglass From oxalate-rich foods Page 6 of 12  White to Beige precipitate Form white precipitate Amorphous phosphates ✓ Irregular Insoluble at ~60°C ✓ Granular appearance Thin prisms ALKALINE or Colorless None Neutral Apatite Dibasic (Common): ✓ Flat plates Rosette form may resemble ✓ Stellar form sulfonamide crystals Dilute Acetic acid Calcium phosphate ✓ Thin prisms often in rosette form ✓ Prims have one tapered end Dibasic: Weak birefringence Flat plate Monobasic (Rare): Only needle form seen in ✓ Irregular alkaline urine ✓ Granular-appearing sheets Colorless Struvite ✓ Coffin Lids ✓ Prism-shaped Feathery appearance when Triple phosphate ✓ Fern leaf-shaped (induced by they disintegrate ammonia) ✓ Sheets ✓ Flakes Moderate birefringence ✓ Staghorn ALKALINE Urea-splitting bacteria Seen in old specimens Yellow-brown Strong birefringence Acetic acid with heat Ammonium biurate ✓ Thorny Apples: spiculed or (~60°C) Convert to uric acid with striated spheres concentrated HCl or acetic acid Page 7 of 12  Colorless With acetic acid Calcium carbonate ✓ Tiny granular spheres Strong birefringence None produces CO2 gas ✓ Often in pairs (Dumbbells) (effervescence) ✓ Aggregates Page 8 of 12  MAJOR CHARACTERISTICS OF ABNORMAL URINARY CRYSTALS CRYSTAL pH COLOR and FORM NOTES SIGNIFICANCE SOLUBILITY ILLUSTRATION Often mistaken as uric acid crystals Colorless Inherited Cysitunuria Ammonia Cystine Does not polarize light ✓ Hexogonal plates Cystinosis Dilute HCl Confirm by cyanide- nitroprusside test Colorless Chloroform Mistaken as Cholesterol ✓ Parallelogram-shaped plates with Liver disease Radiographic dye crystal notched corners “staircase Ether pattern” ACID Bright yellow Acetic acid, HCl, Bilirubin Liver disease NaOH, Ether, ✓ Clumped needles or granules Chloroform, Alkali Colorless Meglumine Diazotrizoate Radiographic Dye ✓ Intravenous: Flat parallelogram- Radiographic picture Strong birefringence and shaped plates Polychromatic ✓ Retrograde: Long, slit-like prisms Yellow-brown Aminoaciduria ACID or Leucine Pseudo Maltese cross pattern Hot Alkali or Alcohol Neutral ✓ Spheres with concentric circles Severe Liver disease and striations Page 9 of 12  Fine Needle Clump Colorless to Yellow Tyrosine Often seen with Leucine Alkali or Heat ✓ Needles in clusters or sheaves Rosette Form Colorless to Yellow-brown May be mistaken with Calcium phosphate crystals Sulfonamide ✓ Needles Antibiotic therapy Acetone (Calcium phosphate is soluble ✓ Sheaves of wheat to dilute Acetic acid) ✓ Rosette Colorless; Gray to Brown when aggregated Indinavir Sulfate Antiretroviral therapy ✓ Slender, feather-like “wing-like bundles” Page 10 of 12  Non-refrigerated Colorless Ampicillin Refrigeration forms bundles High-dose Antibiotic therapy ✓ Long, thin needles Refrigerated Page 11 of 12  URINE SEDIMENT ARTIFACTS Occur when corn-starch is the powder used in powdered gloves Highly refractile spheres usually with dimpled center Starch Resemble fat droplets when polarized, producing Maltese cross formation May occasionally be confused with RBCs Highly refractile resembling RBCs Oil Droplets May result from oil contamination by immersion oil or lotions and creams Can be seen in fecal contamination Air Bubbles Occur when the specimen is placed under a cover slip Seasonal contaminants that appear as spheres with a cell wall and occasional concentric circles Pollen Grains Their large size may cause them to be out of focus with true sediment constituents Initially mistaken for casts but are much longer and more refractile Hair and Fibers Examination under polarized light aid in the differentiation Fiber: polarizes | Cast: do not polarize Due to improperly collected specimens or rarely the presence of a fistula between the intestinal and urinary tracts Fecal Contamination Brown amorphous material in variety of sizes and shapes Page 12 of 12