Microscopic Exam – Part 2 PDF

6/25/2024 Microscopic Exam – Part 2 Chapter 7 1 Preamble PowerPoints are a general overview and are provided to help students take notes over the video lecture ONLY. PowerPoints DO NOT cover the details...

6/25/2024 Microscopic Exam – Part 2 Chapter 7 1 Preamble PowerPoints are a general overview and are provided to help students take notes over the video lecture ONLY. PowerPoints DO NOT cover the details needed for the Unit exam Each student is responsible for READING the TEXTBOOK for details to answer the UNIT OBJECTIVES Unit Objectives are your study guide (not this PowerPoint) Test questions cover the details of UNIT OBJECTIVES found only in your Textbook! 1  6/25/2024 Oval Fat Bodies RTE cells that have absorbed lipid in the filtrate Also free-floating refractile droplets Maltese cross formation with polarized light If negative check with Sudan III or oil red O stain Oval Fat Bodies (continued_1) Stain polarizing negative structures Cholesterol polarizes Triglycerides and neutral fats stain Lipiduria: nephrotic syndrome, severe tubular necrosis, diabetes, trauma cases 2  6/25/2024 Bacteria Urine is usually sterile, contaminated on the way out; contaminants multiply fast Cocci=spherical, bacilli=rods Report few, moderate, many per hpf WBCs should accompany bacteria in UTI Enterobacteriaccae=most common with UTI 5 Yeast Single, refractile, oval structures Mycelial forms may be present Report: few, moderate, many Immunocompromised, vaginal moniliasis Diabe c urine: ↑ glucose and acid ideal for yeast growth WBCs present 3  6/25/2024 Parasites Most common: Trichomonas vaginalis Pear-shaped flagellate Swims across field rapidly Report few, moderate, many per hpf If not moving, may resemble WBC, transitional, or RTE cell Schistosoma haematobium-seldom seen Enterobius vermicularis-most common contaminant 7 Parasites (continued_2) 8 4  6/25/2024 Spermatozoa Oval, tapered heads and long tail Urine is toxic to sperm, so they are immobile Rarely significant, infertility: sperm expelled into bladder instead of urethra May cause positive protein Reporting varies with laboratories Lack of clinical significance, legal consequences 9 Mucus Protein from RTE, glands, epithelial cells Threadlike, low refractive index Confuse with casts Reported rare, few, moderate, many per lpf More frequent in female specimens, no clinical significance 5  6/25/2024 Casts Elements unique to the kidney Formed in DCT and collecting duct Parallel sides, rounded ends Detect under low power, ID high power Scan edges of glass cover slip Low light is essential Report number per lpf 11 Cast Composition and Formation Consistent excretion Formation of protein Uromodulin is major normally fibrils into matrix constituent ↑ stress and exercise Urine stasis, acidity, Na, and Ca Uromodulin protein ↑ protein is from not detected by renal disease reagent strips 6  6/25/2024 Composition and Formation Formation Aggregated uromodulin fibrils attached to RTEs Interweaving to loose network, traps elements More interweaving to form solid matrix Attachment of elements to matrix Detachment of fibrils from RTEs Excretion of cast Cylindroids Tapered ends, one or both Same significance as cast Cylindruia=presence of urinary casts 13 Hyaline Casts Low refractive index Colorless when unstained Uromodulin protein Use low light or phase Normal parallel sides and rounded sides, wrinkled, cylindroid, occasional adhering cell or granule 14 7  6/25/2024 Hyaline Casts (continued_1) Most frequently seen 0 to 2 is normal Nonpathologic: stress, exercise, heat exposure, dehydration Pathologic: acute glomerulonephritis, pyelonephritis, chronic renal disease, congestive heart failure Hyaline Casts (continued_2) 8  6/25/2024 RBC Casts Orange-red color Embedded and adhering cells May be fragmented Confirm seeing freestanding RBCs and positive reagent strip for blood Look for cast matrix to avoid mistaking a RBC clump for a cast 17 RBC Casts (continued_2) Bleeding within the nephron, casts are more specific than free RBCs in urine Glomerular damage or nephron capillary damage Glomerular damage: dysmorphic RBCs and elevated protein May be seen following strenuous exercise 9  6/25/2024 RBC Casts (continued_3) Cells begin to disintegrate with more stasis of urine flow Hemoglobin and myoglobin damage tubules Hemoglobin degraded to methemoglobin = dirty brown casts Look for RTE cells to confirm tubular necrosis WBC Casts WBC casts are seen with infection and inflammation of the nephron Pyelonephritis: WBC casts, bacteria Acute interstitial nephtitis: WBC casts, no bacteria May accompany RBC casts in glomerulonephritis 20 10  6/25/2024 WBC Casts (continued_2) Mostly neutrophils and lobed nucleus and granules are seen Staining helps differentiate from RTE cells May be tightly packed; look for clump matrix to distinguish from WBC clump Bacterial Casts Seen in pyelonephritis May be pure bacteria or mixed with WBCs Identification is difficult, resemble granular casts Look for free WBCs and bacteria Confirm with Gram stain Seen in pyelonephritis 11  6/25/2024 Epithelial Cell Casts Tubular damage, heavy metals, viral infections, drug toxicity, graft rejection, pyelonephritis Cells may appear bilirubin stained Look for matrix to distinguish fragments Epithelial Cell Casts (continued_2) Formed in DCT = smaller, round cells, oval cells Fibrils forming cast pull cells from damaged tubules Majority of cells are on the cast matrix Differentiate from WBCs: stain to show single nucleus 12  6/25/2024 Fatty Casts Nephrotic syndrome, diabetes, crush injuries, tubular necrosis Seen with oval fat bodies (OFBs) and fat droplets Highly refractile, OFBs may attach to matrix Polarized microscopy and lipid stain Triglycerides and neutral fats stain orange RBC and WBC casts in glomerulonephritis WBC and RTE cell casts, or WBC and Mixed bacterial casts in pyelonephritis Cellular Casts Identification difficult Staining or phase microscopy aids in the identification Follow lab protocol when reporting 26 13  6/25/2024 Granular Casts Coarse and finely granular Granule origin RTE lysosomes, excreted in normal metabolism, more after exercise and activity Disintegration of cellular casts and free cells 27 Granular Casts (continued_2) Detect with low power, ID with high power Final identification, use high power Granules disintegrate to form waxy casts Differentiate granular casts from clumps of debris and crystals; look for matrix 14  6/25/2024 Waxy Casts Brittle, highly refractile Often fragmented with jagged ends and notches Stains a homogenous dark pink Degenerated hyaline and granular casts Extreme urine stasis Renal failure 29 Broad Casts Renal failure casts Destruction and widening of the DCTs Formation in the upper collecting duct All types of casts may be broad Most common are granular and waxy Bile stained from viral hepatitis 30 15  6/25/2024 Broad Casts (continued_1) Break time 16  6/25/2024 Urinary Crystals Most are not clinically significant but are reported True geometrically formed structures or as amorphous material Must differentiate from the few abnormal crystals indicating liver disease, inborn errors of metabolism, and damage to tubules Iatrogenic: caused by medications Report: rare, few, moderate, many Crystal Formation Precipitation of urine solutes: salts, organic compounds, and medications Formation based on temperature, solute concentration, and pH Many crystals in refrigerated specimens High specific gravity needed in fresh specimens Organic and iatrogenic compounds crystallize more easily with acidic pH 17  6/25/2024 Crystal Formation (continued) Temperature and pH contribute to formation and solubility Amorphous urates form in refrigerated acid urine; will dissolve if warmed Amorphous phosphates form in refrigerated alkaline urine; will dissolve in acetic acid; so will RBCs General Identification Techniques Polarized Most have All abnormal Classification: microscopy characteristic Most valuable ID crystals are normal acid, characteristics shapes and is urine pH found in acid normal alkaline are valuable in colors urine ID 18  6/25/2024 Normal Crystals Seen in Acidic Urine Most commonly seen Amorphous urates Uric acid Acid urates Sodium urates Most appear yellow to reddish brown Normal Crystals Seen in Acidic Urine (continued_1) Amorphous urates Yellow-brown granules microscopically Urine sediment has pink color due to the pigment uroerythrin attaching on surface of granules pH usually greater than 5.5 19  6/25/2024 Normal Crystals Seen in Acidic Urine (continued_3) Uric acid crystals Rhombic, whetstones, wedges, rosettes Yellow-brown color May resemble cystine crystals but always polarize ↑ purines, nucleic acids Chemotherapy for leukemia, Lesch-Nyhan syndrome, gout Normal Crystals Seen in Acidic Urine (continued_5) Calcium oxalate crystals Acid and neutral pH Dihydrate is envelope or two pyramid–shaped Most common Monohydrate is oval or dumbbell shaped Antifreeze poisoning Calcium oxalate is a major component of renal calculi Sodium urates are needle shaped, that are seen in synovial fluid during episodes of gout, and they may appear in urine 20  6/25/2024 Normal Crystals Seen in Acidic Urine (continued_9) Calcium oxalate crystals Normal Crystals Seen in Alkaline Urine Amorphous phosphates Granular in appearance May appear similar to amorphous urates Differentiate Alkaline pH and heavy white precipitate after refrigeration 21  6/25/2024 Normal Crystals Seen in Alkaline Urine (continued_2) Triple phosphate Colorless, prism, or coffin-lid shaped Highly alkaline urine and urinary tract infections (UTIs) Birefringent under polarized light No clinical significance Urea-splitting bacteria Normal Crystals Seen in Alkaline Urine (continued_4) Calcium phosphate Colorless, flat rectangles and thin prisms in rosettes No clinical significance Calcium carbonate Small, colorless, dumbbell, and spherical shapes Gas produced with addition of acetic acid Birefringent No clinical significance 22  6/25/2024 Normal Crystals Seen in Alkaline Urine (continued_5) Ammonium biurate Yellow-brown, spicule-covered spheres; “thorny apples” Only urates in alkaline urine Old specimens and with urea-splitting bacteria Abnormal Urine Crystals Abnormal crystals Identity confirmed Found in acidic have characteristic by patient disorders urine shapes and medications 23  6/25/2024 Abnormal Urine Crystals (continued_1) Cystine crystals Hexagonal, thin and thick plates Can be difficult to differentiate UA polarizes but only thick cystine crystals polarize Seen in cystinuria: inability to reabsorb cystine Confirm: cyanide nitroprusside Cholesterol Crystals Refrigerated specimens Rectangular plates with characteristic notched corners Highly birefringent Nephrotic syndrome accompanying fatty casts and OFBs 24  6/25/2024 Radiographic Dye Crystals Radiographic dye Similar to cholesterol crystals, polarize Patient history and comparison of results of other UAs Very high SG with refractometer 49 Crystals Associated With Liver Disease Tyrosine crystals Fine colorless yellow needles in clumps or rosettes Seen with leucine crystals Inherited amino acid disorders Leucine crystals Yellow-brown spheres with concentric circles and radial striations Accompanied by tyrosine crystals 50 25  6/25/2024 Crystals Associated With Liver Disease Bilirubin crystals Hepatic disorders Clumped needles or granules Characteristic yellow color Viral hepatitis with tubular damage 51 Sulfonamide Crystals Dehydration Possibility of tubular damage if crystals are forming in the nephron Shapes most frequently encountered include needles, rhombics, whetstones, sheaves of wheat, and rosettes with colors ranging from colorless to yellow- brown 26  6/25/2024 Ampicillin Crystals Ampicillin crystals appear as colorless needles that tend to form bundles following refrigeration Urinary Sediment Artifacts Starch, oil droplets, air bubbles, pollen grains, vegetable fibers, and fecal decontamination diaper fiber Reporting is not necessary 54 27  6/25/2024 Urinary Sediment Artifacts (continued_1) 55 Urinary Sediment Artifacts (continued_2) 56 28  6/25/2024 Urinary Sediment Artifacts (continued_3) Hair and fibers from clothing and diapers may be mistaken for casts They are much longer and more refractile Examination under polarized light frequently can differentiate between fibers and casts Fibers often polarize; casts do not polarize Urinary Sediment Artifacts (continued_4) 58 29  6/25/2024 Urinary Sediment Artifacts (continued_5) 59 Postamble READ the TEXTBOOK for the details to answer the UNIT OBJECTIVES. USE THE UNIT OBJECTIVES AS A STUDY GUIDE All test questions come from detailed material found in the TEXTBOOK (Not this PowerPoint) and relate back to the Unit Objectives 30