PH 157 Hematology & Body Fluids - Urine Exam (Review) PDF

LECTURE PH 157: Hematology and Body Fluids 2/13/24 1.3 REVIEW OF THE EXAMINATION OF URINE AND FECES G. B. Dayrit Bo...

LECTURE PH 157: Hematology and Body Fluids 2/13/24 1.3 REVIEW OF THE EXAMINATION OF URINE AND FECES G. B. Dayrit Boric acid has also been used as a common [1.3] Review of the preservative Has lesser degradation and chemical Examination of Urine composition that can interfere with analysis B Correlating Results TRANS OUTLINE I. Examination of Urine III. Abnormal Structures in Table 1 A. Urinalysis Urine Correlating Urinalysis Results B. Correlating Results IV. Normal Crystals in Microscopic Elements Physical Chemical C. Abnormal Acidic Urine RBCs Turbidity +Blood Macroscopic V. Normal Crystals in Red color +Protein Characteristics Alkaline Urine WBCs Turbidity +Protein II. Normal Structures in VI. Abnormal Crystals +Nitrite Urine VII. Review Questions +LE VIII. References Epithelial cells Turbidity Casts +Protein Bacteria Turbidity pH +Nitrite I Examination of Urine +Leukocytes Crystals Turbidity pH A Urinalysis Color Bilirubin Note: LE = Leukocyte Esterase The most common reason for clinicians to request for a 1 Red Blood Cells (RBCs) urinalysis is for diagnosis of urinary tract infection (UTI) ○ Can help identify the causative agent of UTI, which can Color of urine is expected to be pinkish or reddish guide physician on the appropriate specific treatment ○ However, there are hemolysis (breakage of RBCs) that Can help prevent antimicrobial resistance (AMR) cannot be seen by the naked eye through macroscopic examination of the urine 1 Sample Collection There can also be RBCs even in light yellow-colored During sample collection, the urine specimen should be urine specimens midstream, clean catch Turbidity ○ To avoid contamination of the sample with ○ Can easily be observed when there is macroscopic microorganisms present in the genitalia due to normal hemolysis microflora, sexual contact, bacteria from the hands, etc. ○ Can be described as: ○ There is also a possibility that the first part of the urine is Clear: light can easily pass through; crystal clear concentrated Hazy: few particles floating Usually, the volume of the urine submitted is 10-15 mL Slightly turbid: has turbidity but not totally turbid ○ The urine container is commonly 20-50 mL Turbid: little to no light can pass through ○ It is important to document if the volume of the urine is Chemical strip reveals presence of: less than 10 or 12 mL ○ Blood Sample may be rejected because too little volume ○ Protein (due to hemoglobin) can give too little formed elements ○ Bilirubin (possible) 2 Processing of Urine Specimen Can be misinterpreted as yeast under the microscope ○ Yeast is budding Processing of the urine specimen involves the following Explore various fields in the slide to confirm identity steps: ○ Visual examination of the urine 2 White Blood Cells (WBCs) ○ Transfer the specimen to a tube Indicator of infection ○ Use the urine strip Generally observed based on turbidity, and not based on Have different parameters such as protein, the color of the urine bilirubin, leukocyte esterase, pH, specific gravity, ○ Can be slightly turbid or turbid etc. Chemical strip reveals presence of: Can fit into 12 mL of urine ○ Protein ○ Centrifuge ○ Leukocyte esterase ○ Decant the supernatant ○ Nitrite ○ Mix the precipitate Bacteria can convert nitrate to nitrite Can be done by gently tapping the tube to make sure it is well distributed NOTE ○ Put the precipitate in a glass slide ○ Observe under the microscope Epithelial cells, casts, bacteria, and crystals can all contribute to turbidity as well Analyzing and Preserving 3 Urine Samples C Abnormal Macroscopic Characteristics The best time to analyze a urine sample: ○ As soon as it has been received, ideally within 2 hours Table 2 Otherwise, pH may be affected and some Abnormal Characteristics Based on Color components (e.g., RBCs, WBCs & casts) would Color Cause disintegrate Dark yellow and amber/orange Hepatitis virus ○ Depends on the preservative used: Red/Pink Lysed blood Usually, urine specimens are preserved through Brown/Black Homogentisic acid/alkaptonuria refrigeration. However, there is still the possibility Blue/Green Pseudomonas infection of precipitation which leads to the formation of crystals. Consequently, results may be Purple Klebsiella/Providencia misinterpreted since they can obscure other Dark yellow and amber/orange elements present in the urine. ○ May be due to presence of bilirubin Explains hepatitis virus as a causative agent PH 157 | BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 1  Red/Pink Table 5 ○ May be caused by lysed blood or parasites Potential Change ○ It is possible to have RBCs depending on its turbidity Potential Change Change Occurring Over Time Clear urine Color Oxidation of substances May be due to hemoglobinuria or Clarity Increased turbidity due to myoglobinuria proliferation of bacteria or Differentiated by the color of plasma precipitation of chemical substances Cloudy urine Odor Increased strength due to proliferation Due to hematuria of bacteria pH Increases as bacteria convert urea to ammonia and the loss of CO₂ from the specimen Bilirubin Decreases due to photooxidation and hydrolysis Glucose Decreases due to metabolism by microorganisms Ketone Decreases due to Volatilization Nitrite Increases due to proliferation of bacteria, but also decreases as bacteria continue to convert nitrite to nitrogen Urobilinogen Decreases due to oxidation Crystals Appearing due to cooling of specimen Cells and Casts Decreasing due to cellular degradation Microorganisms Increasing due to proliferation Note: The bullet points written directly underneath this table are those that Figure 1. Red Urine were EMPHASIZED by Prof. Gigi during her F2F lecture. Brown/Black It is important for urine to be freshly collected. Otherwise, ○ Homogentisic acid or alkaptonuria some parameters of the urine might be affected Alkaptonuria is amino acid deficiency pH becomes more alkaline if urine is not examined right Blue/Green away ○ Pseudomonas infection ○ Due to increasing number of bacteria which can convert Purple urea to ammonia ○ Klebsiella or Providencia Bilirubin is light sensitive Table 3 Ketones decrease due to volatilization Causes for Urine Color and Clarity Nitrite results can be misleading due to the presence of Appearance Pathologic Cause bacteria which can either increased or decreased nitrite White Chyle Crystals increase only if there are already crystals initially Lipids present in the urine Pyuria (Many WBCs) Yellow to amber to orange Bilirubin Urobilin (excessive) II Normal Structures in Urine Yellow to green Bilirubin-biliverdin Pink to red Hemoglobin A RBCs Myoglobin Porphobilin Smooth, nonnucleated, biconcave disks Porphyrins Size: ~7 µm (maximum) Red blood cells Normal values: 0-3/HPF Red to purple Porphyrins ○ Make sure to scan the whole slide properly Red to brown Methemoglobin Myoglobin Brown to black Bilirubin Homogentisic acid Indican Melanin Methemoglobin Myoglobin Phenol 𝑝-Hydroxyphenylpyruvate Porphyrins Blue to green Biliverdin Indicans Pseudomonas infection Figure 2. Normal Structure of RBC in Urine A person with diabetes insipidus usually has clear urine WBCs ○ Due to dilution of urine since one of the symptoms of B diabetes insipidus is frequent urination Size: 12 µm Table 4 Neutrophil is predominant Abnormal Characteristics Based on Odor. Normal values: 0-5/HPF Odor Cause Fruity smell Diabetes Mellitus type 1 Mousy odor Phenylketonuria (PKU) Fishy UTI Ammoniacal odor UTI by Pseudomonas/Proteus Burnt sugar Maple syrup urine disease (MSUD) Phenylketonuria and maple syrup urine disease are also amino acid deficiencies Figure 6. Normal Structure of WBC in Urine PH 157| BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 2  1 Glitter Cells Normal structure Seen in hypotonic urine ○ Swells Non-pathologic Figure 5. Ghost Cells 4 Clinical Significance Damage to glomerular membrane or vascular injury to the genitourinary tract Macroscopic hematuria ○ If cloudy, red or pink urine: Advanced disease, trauma, acute infection, Figure 2. Glitter cells coagulation disorders Microscopic hematuria III Abnormal Structures in Urine ○ Check in high power field to see RBCs in urine ○ If clear urine, but RBCs are present in microscopic exam: A RBCs Early glomerular disease, malignancy, strenuous exercises, renal calculi confirmation 1 Identification Difficulties ○ Need to do correlation with other tests These are abnormal structures that may be misinterpreted B WBCs as RBCs, and they can be differentiated by: ○ Yeast: look for buds 1 Clinical Significance ○ Oil droplets: refractility More than 5 WBCs per HPF = pyuria ○ Air bubbles: refractility and possibly in a different plane ○ Pus in the urine ○ Starch: refractile, polarizes Infections: cystitis, pyelonephritis, prostatitis, urethritis You have to do reagent strip correlation Glomerulonephritis, lupus erythematous, interstitial ○ If there is no change in color for RBCs, there may be nephritis, tumors presence of other structures, such as those mentioned Report presence of bacteria NOTE Women are more prone to urinary tract infection than men. Possible reasons (phrased based on answers from the recitation): ○ The opening of the urethra is closer to the anus Figure 3. Common misidentified elements as RBC (Yeasts, Air droplets, and than in men, causing an increased risk of bacterial Oil droplets [Left to Right]) contamination 2 Crenated Red Cell ○ Women have a shorter urethra than men. Bacteria Irregular notching in the edge of erythrocytes have to travel a shorter distance and cause infection. Seen in hypersthenuric urine (high specific gravity and ○ Cleaning practices such as wiping from back to front osmolality) (should be front to back) after urinating/defecating ○ Very concentrated increases the risk of transferring the bacteria from the ○ Due to loss of water, causing cells to shrink (can be anus to the urethra. present in normal situations when there is no ○ Use of menstrual pads and pantyliners trap glomerular bleeding) moisture and decrease airflow, creating a moist Presence of protrusions in the cell environment conducive for bacterial growth ○ Indicates possible glomerular bleeding Women who use pantyliners are more prone to Also encountered as acanthocytes infection ○ Donut-shaped red cell with a central hole ○ Presence of blebbing C Clue Cells ○ Indicates upper tract bleeding Squamous cells with pathologic significance ○ Covered with bacteria Gardnerella vaginalis - vaginal infection Coccobacillus sp. - covers most of the cell and extends over the edges Seen in urine but more common in vaginal wet preparation Makes urine more alkaline ○ Compared to normal urine pH with predominant Lactobacillus acidophilus ○ Figure 4. Crenated Red Cells 3 Ghost Cells Seen in hyposthenuric urine (low specific gravity) In high presence of water PH 157| BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 3  Figure 3. Clue cells Figure 5. Hyaline Casts D Bacteria 2 RBC Cast Has RBCs surrounding it 1 Clinical Significance Confirmed by seeing free RBCs and positive reagent strip Urine is usually sterile; contamination occurs on the way out for blood ○ Contaminants multiply fast ○ Because hyaline casts do NOT have free RBCs surrounding it WBCs should accompany bacteria in UTI Look for cast matrix to avoid mistaking RBC clump for a ○ Bacteria are reported qualitatively as: cast Few, moderate, or many If there is bleeding within the nephron: casts are more ○ We DO NOT count them specific than free RBCs in urine Rods are more common in urine Glomerular damage: dysmorphic RBCs and elevated To check if bacterial concentration is high: protein ○ Nitrite helps to confirm rods, NOT cocci Also causes increased protein in the urine strip ○ If pH is more alkaline ○ If the urine is more turbid E Yeasts Single, refractile, budding structures Mycelial forms may be present Diabetic urine: ↑ glucose and acid ideal for yeast growth Nitrite negative, WBCs present Confused with RBCs 1 Clinical Significance Commonly seen in immunocompromised patients such as those with HIV or diabetes ○ prone to Candida albicans Figure 6. RBC Casts with surrounding RBCs (pointed arrows) If there is an overuse of antibiotics which can kill the normal 3 WBC Cast flora of our organs Vaginal moniliasis or candidiasis Same with RBC casts, WBC casts have WBCs surrounding the casts ○ Also look for cast matrix to avoid mistaking as WBC clump Seen in infection and inflammation of the tubules Pyelonephritis: WBC casts, bacteria Acute interstitial nephritis: WBC casts, but NO bacteria May accompany RBC casts Figure 4. Yeasts F Casts Formed in the distal collecting tubules and the collecting ducts Has parallel sides and rounded ends with inclusions inside Can be detected and reported under LPO ○ However, type of cast can only be identified using HPO Usually present at the edges of the slides after decanting Consistent excretion normally Figure 7. WBC Casts with surrounding WBCs ○ ↑ during stress and exercise 4 Epithelial Cast ↑ protein is from renal disease Can be seen with RBC casts and WBC casts especially if there 1 Hyaline Cast is huge kidney problem Most frequently seen in non-pathologic cases Should also look for cast matrix to avoid mistaking as ○ Stress, exercise, and dehydration epithelial cells Pathologic: Tubular damage, heavy metals, viral infections, drug ○ glomerulonephritis, pyelonephritis, chronic renal toxicity, graft rejection, and pyelonephritis disease, and congestive heart failure No RBCs surrounding it unlike RBC cast PH 157| BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 4  Urine sediment has pink color due to the pigment uroerythrin attached on surface of granules Often in clumps ○ May resemble casts but not contained in a matrix pH: usually greater than 5.5 Figure 7. Epithelial Casts G Urinary Crystals Most are NOT clinically significant but are reported True geometrically formed structures or as amorphous material Figure 7. Amorphous Urates Must be differentiated from the few abnormal crystals indicating liver disease, inborn errors of metabolism, and B Uric Acid Crystals damage to tubules If not pathogenic, not caused by an infection, or not clinically Rhombic, whetstones, wedges, with rosette formation significant, it can be iatrogenic Color: Yellow-brown ○ Iatrogenic: caused by medications or treatments May resemble cystine crystals but always polarize ○ Some components of the medicines have precipitated ○ Polarized: has different sides seen in light under which forms crystals microscope Can be reported as: rare, few, moderate, or many ↑ purines, nucleic acids ○ We do NOT count them unlike casts (counted in LPO), Chemotherapy for leukemia, gout WBCs, and RBCs (counted in HPO) Most have characteristic shapes and colors Most valuable ID is urine pH Classification: normal acid, normal alkaline ○ Crystals can be seen even in normal acid and normal alkaline urine All (most) abnormal crystals are found in acid urine Polarized microscopy characteristics are valuable in ID Table 6 Properties of Crystalline Compounds (Acid) Figure 8. Uric Acid crystals Crystalline Compound pH Acid Alkaline C Calcium Oxalate Crystals Amorphous urates + - Monohydrate shape: Dumbbell shape or oval Bilirubin + - Dihydrate shape: envelope or two-pyramid shape Calcium oxalates + ± ○ Most common Calcium sulfate + - pH: seen in acidic and neutral Cholesterol + - Major component of renal calculi Cystine + - Hippuric acid + ± Leucine + - Sodium urate + - Sulfonamides + - Tyrosine + - Uric acid + - X-ray dye + - Table 7 Properties of Crystalline Compounds (Acid) Crystalline Compound pH Figure 9. Calcium Oxalate Crystals Acid Alkaline Normal Crystals in Alkaline Ammonium biurates Amorphous phosphates ± - + + V Urine Calcium carbonate - + Calcium phosphates - + A Amorphous Phosphates Triple phosphates - + Note. ± crystals may be present at this pH, although they are more common May appear similar to amorphous urates at the other pH ○ Differentiate: Alkaline pH and heavy white precipitate Crystals appear or disappear depending on the pH after refrigeration Although urine is commonly acidic, there can still be Check urine pH: abnormalities that occur more if the pH is acidic ○ If acidic: Amorphous Urate ○ If alkaline: Amorphous Phosphate IV Normal Crystals in Acid Urine A Amorphous Urates Looks like dirt but present in acid urine Color: Yellow-brown granules PH 157| BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 5  Figure 11. Ammonium Biurate Crystals Figure 10. Amorphous Phosphate Crystals VI Abnormal Crystals in Urine B Triple Phosphate A Cystine Crystals Colorless, prism, or coffin-lid shaped Hexagonal, thin and thick plates Highly alkaline urine and UTIs SImilar to uric acid Polarize ○ Uric acid polarizes but only thick cystine crystals NO clinical significance polarize Seen in cystinuria: inability to reabsorb cystine Confirm: cyanide nitroprusside Figure 12. Cystine crystals B Cholesterol Crystals Refrigerated specimens Rectangular plates with characteristic notched corners Highly birefringent Nephrotic syndrome accompanying fatty casts and Occult Fecal Blood (OFBs) Figure 10. Triple Phosphate C Phosphate and Carbonate 1 Phosphate Flat rectangles and thin prisms in rosette formation NO clinical significance 2 Carbonate Small, dumbbell, and spherical shapes Figure 13. Cholesterol crystals Gas produced with addition of acetic acid NO clinical significance C Radiographic Dye Crystals Similar to cholesterol crystals, polarize Patient history Very high SG with refractometer D Liver Disease Crystals 1 Tyrosine crystals Fine yellow needles in clumps or rosettes Seen with Leucine crystals Figure 10. Phosphate and Carbonate Inherited amino acid disorders D Ammonium Biurate Crystals Yellow-brown, spicule-covered spheres “Thorny apples” These are the only urates found in alkaline urine Old specimens and with urea-splitting bacteria Figure 14. Tyrosine crystals PH 157| BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 6  2 Leucine crystals 2. What happens to the pH of the urine in the presence of Yellow-brown spheres with concentric circles and radial bacteria if it has not been examined immediately? striations a. It becomes more alkaline b. It becomes more acidic c. It stays the same 3. Which of the following statements is FALSE? a. Urinalysis can help identify the causative agent of urinary tract infection b. Epithelial cells can contribute to the turbidity of the urine specimen c. A clear urine is an indicator that it does not have any RBC 4. Red cells seen in very concentrated urine characterized by irregular notching on the edges and indicate possible glomerular bleeding a. Crenated red cells Figure 15. Leucine Crystals b. Ghost cells 3 Bilirubin crystals c. Glitter cells Clumped needles or granules d. Normal red cells Characteristic yellow color 5. It is characterized by cloudy, red urine that is indicative Viral hepatitis with tubular damage of advanced disease, trauma, acute infection, and Positive reagent strip for bilirubin coagulation disorders. a. Microscopic hematuria b. Macroscopic hematuria c. Pyuria 6. Which of the following is NOT TRUE about why women are more prone to urinary tract infections compared to men? a. The opening of the urethra is closer to the anus than in men, causing an increased risk of bacterial contamination b. Women have a shorter urethra c. Cleaning practices such as wiping from front to back Figure 15. Bilirubin crystals after using the bathroom increases the risk of infection E Sulfonamide Crystals d. The use of menstrual pads and pantyliners creates a moist environment that inhibits bacterial growth Possibility of tubular damage if crystals are forming in the e. Two of the choices nephron f. None of the choices Shapes most frequently encountered include needles, 7. I. Glitter cells are squamous epithelial cells covered rhombics, whetstones, sheaves of wheat, and rosettes with with bacteria. colors ranging from colorless to yellow-brown II. Clue cells are commonly more seen in vaginal wet preparation compared to urine. a. Only the first statement is correct. b. Only the second statement is correct. c. Both statements are correct. d. None of the statements are correct. 8. What crystal in acidic urine is a major component of renal calculi? a. Uric Acid Crystal b. Ammonium Biurate Crystal Figure 15. Sulfonamide crystals c. Calcium Oxalate Crystals F Ampicillin Crystals d. Amorphous Urate 9. What type of cast is implicated in tubular damage, Appears as colorless needles that tend to form bundles heavy metals, viral infections, drug toxicity, graft following refrigeration rejection, and pyelonephritis ○ Which is why it is better to analyze urine samples a. Hyaline Cast immediately, rather than after refrigeration b. RBC Cast c. WBC Cast d. Epithelial Cast 10. What crystal has the characteristic “thorny apple” appearance? a. Ammonium Biurate Crystal b. Amorphous Urate Crystal c. Amorphous Phosphate Crystal d. Uric Acid Crystal 11. Which of the following is true about casts? Figure 16. Ampicillin crystals a. Type of cast can be identified using LPO b. Formed in the distal collecting tubules and collecting duct c. Casts are decreased during stress and exercise 12. What type of cast is usually seen in pyelonephritis, acute interstitial nephritis, and in the infection and VII Review Questions inflammation of the tubules? a. Epithelial Cast 1. Which of the following can cause urine to have a dark b. WBC Cast yellow color? c. Hyaline Cast a. Alkaptonuria d. RBC Cast b. Hepatitis virus c. Pseudomonas infection PH 157| BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 7  Answer Key Page 1. B Hepatitis - dark yellow 1: Table 2 Alkaptonuria - brown/black Pseudomonas - blue/green 2. A Due to the conversion of urea to ammonia 2: Table 5 3. C Clear urine can have RBCs due to 2: Left hemoglobinuria or myoglobinuria 4. A 3: Left 5. B 3: Right 6. E Choice A and B are TRUE. 3: Right Choice C - wiping from back to front increases risk of UTI Choice D - inhibit → facilitate 7. B I. Clue cells are squamous epithelial cells 3: Right covered with bacteria. 8. C 5: Right 9. D 4: Right 10. A 6: Left 11. B Choice A - LPO → HPO 4: Left Choice C - decreased → increased 12. B 4: Right VIII References Dayrit, G. B. (2024). Review of Urinalysis and Fecalysis. PH 157| BSPH 2024 [1.3] REVIEW OF THE EXAMINATION OF URINE Group C | Nayve, Redobante, Tianela 8