CLINICAL MICROSCOPY PDF

ranges 600-700mL/min CLINICAL MICROSCOPY 1. RENAL BLOOD FLOW URINARY FILTRATE FLOW ANATOMY AND PHYSIOLOGY OF THE KIDNEY AND FORMATION OF URINE...

ranges 600-700mL/min CLINICAL MICROSCOPY 1. RENAL BLOOD FLOW URINARY FILTRATE FLOW ANATOMY AND PHYSIOLOGY OF THE KIDNEY AND FORMATION OF URINE 1. renal artery 1. bowman capsule 2. afferent arteriole 2. proximal 3. glomerulus convoluted tubule I. INTRODUCTION OF RENAL FUNCTION 4. efferent arteriole 3. Descending loop of each kidney contains approximately 1-1.5 million functional 5. peritubular henle NEPHRONS capillaries 4. Ascending loop of 6. vasa recta henle CORTICAL NEPHRONS 7. renal vein 5. distal convoluted Make up approximately 85% of nephrons tubule ○ Responsible primarily for removal of waste 6. collecting duct products and reabsorption of nutrients 7. renal calyces JUXTAMEDULLARY 8. ureter Primary function is concentration of the urine. 9. bladder 10. Urethra 4 RENAL FUNCTIONS OF THE NEPHRONS 1. RENAL BLOOD FLOW The human kidneys receive approximately 25% of the blood pumped through the heart at all times. NICE TO KNOW Blood from the heart → afferent arteriole → efferent - Distal convoluted tube arteriole → peritubular capillaries and vasa recta → - Final reabsorption of sodium occurs at this renal vein point (maintaining water and electrolyte balance) - excess acid is removed from the body - varying sizes of these arterioles help to create the (acid-base balance) hydrostatic pressure differential important for - Collecting tubules/ducts glomerular filtration and to maintain consistency of - are the site for the FINAL glomerular capillary pressure and renal blood flow CONCENTRATION of URINE within the glomerulus. - ADH is produced in response to increased - peritubular capillaries surround the proximal and plasma osmolality and has the effect of distal convoluted tubules. preventing excess excretion of water - vasa recta are located adjacent to the ascending (antidiuresis) and descending loops of henle in juxtamedullary - Glomerulus nephrons. - urine formation begins with the glomerulus, the structure that delivers the URINE FORMATION: blood to the nephron Blood from circulation → Glomerulus → proximal - it is the “WORKING PORTION” of the convoluted tubule → descending loop of henle → kidney ascending loop of henle → distal convoluted tubule → - capable of filtering molecular weights less collecting tubule than about 70,000 daltons. - fluid that passes through this membrane is basically blood plasma without proteins Proximal convoluted and fats an ultrafiltrate of blood ○ immediate reabsorption of essential (glomerular filtrate) substances from the fluid - GLOMERULAR FILTRATE is Distal convoluted ISO-OSMOLAR with plasma, that iss, it ○ final adjustment of urinary composition has about the same osmolality as plasma, Ascending and Descending loops of Henle 232 to 300 mOsm/L, with a specific gravity (Ascending and Descending Limbs) of about 1.008 ○ major exchanges of water and salts take place between the blood and the medullary interstitium. ○ This exchange maintains the osmotic gradient (salt concentration) in the medulla, which is necessary for renal concentration. 2. GLOMERULAR FILTRATION Glomerulus of approximately N wight capillary lobes located Based on an average body size of 1.73 m2 of surface, the within Bowman’s capsule; serves as a nonselective FILTER TOTAL RENAL BLOOD FLOW is approximately of plasma substances with molecular weights less than 70,000 1200mL/min, and the TOTAL RENAL PLASMA FLOW daltons/ 70,000 KDA a. CELLULAR STRUCTURE OF THE GLOMERULUS FEL :> 1  - i. Fenestrated pores (increase capillary - requires electrochemical energy for trasnport permeability but do not allow the passage of of substances I lar ge molecules and blood cells) ii. Podocytes (restriction of large molecules PCT glucose, amino acids, occurs as the filtrate passes through the salts basement membrane) iii. Shield of negativity (repels molecules with a PCT & DCT sodium negative charge even though they are small enough to pass through the three layers of ALH chloride the barriers: RBCs b. GLOMERULAR PRESSURE i. By increasing or decreasing the size of the - Passive transport afferent arteriole, an autoregulatory - movement of molecules across a membrane mechanism within the juxtaglomerular as a result of differences (GRADIENT) in apparatus maintains the glomerular blood their concentration or electrical potential on pressure at a relatively constant rate opposite sides of the membrane. regardless of fluctuations in systemic blood pressure. Dilation of the afferent arterioles PCT & DCT & CT/CD water and constriction of the efferent arterioles when blood pressure drops prevent a marked decrease in blood flowing through PCT & ALH urea the kidney, thus preventing an increase in the blood level of toxic waste products. ALH sodium c. RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM - when the plasma concentration of a substance that is (RAAS) normally completely reabsorbed reaches an i. controls the regulation of the flow of blood to abnormally high level, the filtrate concentration and within the glomerulus. exceeds the maximal reabsorptive capacity (Tm) of ii. This system responds to CHANGES IN the tubules, and the substance begins appearing in BLOOD PRESSURE and PLASMA the urine CONTENT. - RENAL THRESHOLD (160-180): plasma concentration at which active transport stops. TUBULAR CONCENTRATION Actions and functions of the RAAS - Renal concentration begins descending and 1. Dilates the afferent arteriole and constricts the ascending loops of henle, where the filtrate is efferent arteriole exposed to the high osmotic gradient of the renal 2. stimulates sodium reabsorption in the proximal medulla. convoluted tubule - This selective reabsorption process is called the 3. triggers the adrenal cortex to release the countercurrent mechanism (DLH&ALH) and serves to sodium-retaining hormone aldosterone to cause maintain the osmotic gradient of the medulla sodium reabsorption and potassium excretion in - Maintenance of this osmotic gradient is essential for the distal convoluted tubule and collecting duct. the final concentration of the filtrate when it reaches 4. triggers antidiuretic hormone release by the the collecting duct. hypothalamus to stimulate water reabsorption in COLLECTING DUCT the collecting duct. - final concentration of the filtrate through the - Hypotension (low BP), Hypovolemia (low blood reabsorption of water begins in the late distal volume) and hyponatremia (low NA) → sensed by the convoluted tubule and continues in the collecting duct. MACULA DENSA → RENIN → Angiotensinogen → - The process is controlled by the presence of ADH, ANGIOTENSIN I → Angiotensin-converting which renders the walls of the distal convoluted tubule enzyme → ANGIOTENSIN II → ALDOSTERONE and collecting duct permeable or impermeable to and ADH release water. - ANGIOTENSIN II - Vasoconstriction Increase body hydration = decrease body hydration = - Sodium retention (PCT & DCT) - water reabsorption decrease ADH = increase increase ADH = decrease * Body hydration urine volume urine volume - Because this filtration is nonselective, the only AN difference between the compositions of the filtrate and ↓ body hydratea unive ↑ Body hydration ADH - ↑ Bolume the plasma is the absence of plasma protein, any urine volume protein bound substances, and cells 4. TUBULAR SECRETION - SPECIFIC GRAVITY of THE ULTRAFILTRATE - Maintains acid-base balance PLASMA: 1.010 TWO MAJOR FUNCTIONS 1. Elimination of waste products not filtered by the glomerulus 3. TUBULAR REABSORPTION 2. Regulation of the acid-base balance in the body cellular mechanisms involved in tubular reabsorption are through the secretion of hydrogen ions termed ACTIVE TRANSPORT and PASSIVETRANSPORT As a result of their small molecular size, hydrogen ions are - Active transport readily filtered and reabsorbed. Therefore, the actual excretion of excess hydrogen ions also depends on tubular secretion. FEL :> 2  FISHBERG TEST patients were deprived of fluids for 24 hours prior to measuring specific gravity. GLOMERULAR FILTRATION MOSENTHAL TEST Earliest glomerular filtration tests measured urea Compared the volume and specific gravity of day and INULIN: original reference method night urine samples to evaluate concentrating ability. Presently used test: CREATININE, CONCENTRATION TESTS BETA2-MICROGLOBULIN, CYSTATIN C, 1. Specific gravity - depends on the number of particles RADIOISOTOPES. present in a solution and the density of these particles note: Greatest source of error is the use of improperly timed 2. Osmolarity - affected only by the number of particles urine specimens. Specimen: 24 hr urine. present. SPECIFIC GRAVITY MEASUREMENTS CREATININE index of glomerular most useful as a screening procedure, and filtration/kidney function quantitative measurement of renal concentration ability is best assessed through OSMOMETRY. BETA2-MICROGLOBULIN tubular integrity FREEZING-POINT OSMOMETERS Measurement of freezing-point depression was the CYSTINE alternative marker for first principle incorporated into clinical osmometers, creatinine and many instruments employing this technique are CREATININE CLEARANCE: available now. Formula osmometers determine the freezing point of a solution ○ UV/P - urine plasma creatinine in mg/dL by supercooling a measured amount of sample to ○ UV/P x 1.73 - urine volume in mL/min approximately 27C normal creatinine clearance values approach 120 The heat of fusion produced by the crystallizing water mL/min. temporarily raises the temperature of the solution to its freezing point. GLOMERULAR FILTRATION TESTS - Standard test to measure the filtering capacity of the glomeruli is the TUBULAR SECRETION AND RENAL BLOOD FLOW CLEARANCE TEST. Tests to measure tubular secretion of non-filtered 1. Measures the rate at which the kidneys are able to substances and renal blood flow are closely related in remove (a filterable substance from the blood) that total renal blood flow through the nephron must 2. Substance analyzed must be one neither be measured by a substance that is secreted rather reabsorbed nor secreted by the tubules than filtered through the glomerulus. 3. stability of the substance in urine during a possible The test most commonly associated with tubular 24-hour collection period secretion and renal blood flow is the 4. consistency of the plasma level p-aminohippuric acid (PAH) test. 5. availability tests for analysis of the substance Historically, excretion of the dye phenolsulfonphthalein (PSP) was used to evaluate 1. Creatinine is COMPLETELY FILTERED BY THE these functions. GLOMERULUS, NOT REABSORBED and Titratable Acidity and Urinary Ammonia SECRETED BY THE TUBULES ○ a normal person excretes approximately 70 2. Chromogens present in human plasma react in the mEq/day f acid in the form of either titratable chemical analysis acid (H+) hydrogen phosphate ions 3. medications, including gentamicin, cephalosporins, (H2PO4-) or ammonium ions (NH4+) and cimetidine, inhibit tubular secretion of creatinine thus causing falsely low serum levels. Criteria involve in Criteria involve in 4. bacteria will breakdown urinary creatinine if COCKROFT AND GAULT MODIFIED DIET FOR specimens are kept at room temperature for extended FORMULA RENAL DISEASE (MDRD) periods 5. A DIET HEAVY IN MEAT consumed during collection 1. Body weight Race/Ethnicity of a 24-hour urine specimen will influence the results if the plasma specimen is drawn prior to the collection 2. Age Age period. 3. Gender/sex Serum Creatinine TUBULAR REABSORPTION 4. Serum creatinine Gender note: First function to be affected in renal disease urine and plasma osmolality as a ratio is used to BUN evaluate renal tubular concentration, which depends on the patient’s state of hydrations. Albumin Persons with normaal concentrating ability should have a specific gravity of 1.025 when deprived of Note: Specimens must be collected in CLEAN, DRY, fluids for 16 hours. LEAK-PROOF CONTAINERS. Containers for routine Following overnight water deprivation, a urine urinalysis should have a wide mouth to facilitate collections osmolarity of 800 mOsm or above indicates normal from female patients and a WIDE, FLAT BOTTOM to prevent concentrating ability. overturning. FEL :> 3  a DECREASE IN URINE OUTPUT WHICH IS: ○ 6.5) 0.001 must be added to the reading for every 3C that the CLINICAL SIGNIFICANCE OF URINE SPECIFIC GRAVITY specimen measures above the calibration temperature RESULTS For every 1 GRAM OF PROTEIN PRESENT, 0.003 must be subtracted from the SG reading 1.000 Physiologically impossible-same as PURE WATER; suspect adulteration of urine For every 1G GLUCOSE/DL PRESENT, 0.004 must be subtracted to the SG reading 1.001- DILUTE URINE associated with increased water 1.009 intake or water, DIURESIS (e.g. diuretics, Inadequate secretion/action of ADH) FEL :> 6  IMPORTANCE OF URINARY PH is primarily as an 1.010- Indicates average solute and water intake and AID IN DETERMINING THE EXISTENCE OF 1.025 excretion SYSTEMIC ACID-BASE DISORDERS of metabolic or respiratory origin and in the management of urinary conditions that require the urine to be maintained at a 1.025- CONCENTRATED URINE: associated with specific pH. 1.035 dehydration, fluid restriction, profuse sweating osmotic diuresis Physiologically impossible; indicates PRESENCE ACID URINE ALKALINE URINE >1.040 OF IATROGENIC SUBSTANCE (e.g. RADIOGRAPHIC CONTRAST MEDIA, Emphysema Hyperventilation mannitol) Diabetes mellitus Vomiting Starvation Renal tubular Dehydration acidosis Diarrhea Presence of Presence of acid- urease- producing HARMONIC OSCILLATION DENSITOMETRY producing bacteria bacteria based on the principle that the FREQUENCY OF A High-protein diet Diarrhea SOUND WAVE entering a solution changes in Cranberry juice Vegetarian diet proportion to the density of the solution Medications Old specimen methenamine mandelate SUMMARY OF URINE SPECIFIC GRAVITY [Mandelamine] MEASUREMENTS fosfomycin tromethamine METHOD PRINCIPLE URINOMETRY Density REFRACTOMETRY Refractive Index 8.0 Physiologically impossible; indicates: REAGENT STRIP pKa change of a Presence of an iatrogenic alkaline polyelectrolyte substance (intravenous medication) Improperly stored urine specimen Contamination with an alkaline chemical (preservative) 1. Maintaining urine at an alkaline pH discourages 5. pH formation of the calculi 2. Maintenance of an acidic urine can be of value in the treatment of urinary tract infections caused by NORMAL: 4.5 TO 8.0 (random); FIRST MORNING urea-splitting organisms. SPECIMEN: slightly acidic pH of 5.0 to 6.0 A PH OF 9 IS ASSOCIATED WITH AN IMPROPERLY PRESERVED SPECIMEN and REAGENT STRIP indicates that a fresh specimen should be obtained to ensure the validity of the analysis Persons on high-protein and high-meat diets tend Multistix: 5.0 to 8.5 METHYL Orange to to produce ACIDIC urine, whereas urine from increments RED AND yellow and vegetarians is more ALKALINE, owing to the BROMOTHY green to formation of bicarbonate following digestion of many Chemstrip: 5.0 to 9.0 MOL BLUE FINAL fruits and vegetables increments DEEP BLUE SUMMARY OF CLINICAL SIGNIFICANCE OF URINE PH 1. Respiratory or metabolic acidosis/ketosis METHYL RED turns BROMOTHYMOL BLUE 2. Respiratory or metabolic alkalosis from RED TO YELLOW turns from YELLOW TO 3. Defects in renal tubular secretion/reabsorption of in the pH range 4 to 6 BLUE in the pH range of 6 acids/bases —renal tubular acidosis to 9 4. Renal calculi formation 5. Treatment of urinary tract infections 6. Precipitation/identification of crystals 7. Determination of unsatisfactory specimens SOURCES of CORRELATION WITH FEL :> 7  ○ Use a spectrophotometric measurement of ERROR/INTERFERENCE OTHER TEST light reflection themed REFLECTANCE PHOTOMETRY No known interfering Nitrite Reflectance photometry substances ○ Principle: LIGHT REFLECTION from test pads DECREASES IN PROPORTION TO Runover from adjacent pads Leukocytes INTENSITY OF COLOR produced by the concentration of the test substances Old specimens Microscopic Highly acidic protein testing area may produce falsely acidic results in alkaline urine. 1. PROTEIN Protein determination is the MOST INDICATIVE OF 6. ODOR RENAL DISEASE, presence of proteinuria is associated with EARLY RENAL DISEASE; part of any physical examination. ALBUMIN Aromatic, faintly NORMAL URINE MAJOR SERUM PROTEIN FOUND IN URINE OTHER PROTEINS Ammoniacal Old urine, improperly sore3d Tamm Horsfall protein (Uromodulin) Tubular microglobulins PUNGENT, fetid URINARY TRACT INFECTION Proteins from prostatic, seminal and vaginal secretions Sweet, fruity ketone production due to: Diabetes mellitus NORMAL 8  TRACT INFECTIONS NEGATIV No increase in turbidity 400 chlorhexidine Loss of buffer from prolonged exposure of the COMPARISON OF REAGENT SRIP AND SSA PROTEIN reagent strip to the TEST RESULTS specimen REAGENT STRIP SSA POSSIBLE HIGH SPECIFIC GRAVITY EXPLANATION Correlations with other test; Blood, Nitrite, Leukocytes, POSITIVE NEGATIVE HIGHLY ALKALINE Microscopic OR BUFFERED URINE WITH NO ALBUMIN PRESENT (false REAGENT STRIP FOR PROTEIN REPORTING positivereagent strip test) Trace 9  other sugars in urine: Fructose, Galactose, Lactose CONTRAST MEDIA and Pentose PRESENT RENAL THRESHOLD: 160 to 180mg/dL Drugs and/or drug metabolites present MICROALBUMIN considered significant when: ○ 30 to 300 MG of ALBUMIN is excreted 24 SUMMARY OF CLINICAL SIGNIFICANCE OF URINE hours. GLUCOSE ○ ALBUMIN EXCRETION RATE (AER) is 20-200 UG/MIN HYPERGLYCEMIA-ASSOCI RENAL-ASSOCIATED Note: results reported in MG OF ALBUMIN/ 24 HOURS or as ATED the ALBUMIN EXCRETION (AER) IN UG/MIN. Note: MICROALBUMIN is an early risk predictor of DIABETIC NEPHROPATHY; 24 hour urine. Diabetes mellitus Fanconi syndrome Pancreatitis Advance renal disease Pancreatic cancer Osteomalacia Acromegaly Pregnancy ALBUMIN CREATININE RATIO Cushing syndrome provide simultaneous measurement of Hyperthyroidism albumin/protein and creatinine that permits an Pheochromocytoma ESTIMATION OF THE 24HR MICROALBUMIN CNS damage EXCRETION; by comparing the albumin excretion to Stress the creatinine excretion, the albumin reading can be Gestational Disease corrected for overhydration and dehydration in a random sample. GLUCOSE REAGENT STRIP Principle: DOUBLE SEQUENTIAL ENZYMATIC ALBUMIN CREATININE REACTION GLUCOSE OXIDASE AND PEROXIDASE 1st step: glucose oxidase catalyze a reaction between glucose albumin agent strips utilize based on the and room air to produce gluconic acid and peroxide the dye bis (3’,3’’, diodo-4’4’’ PSEUDOPEROXIDASE 2nd step: Peroxidase catalyzes the reaction between peroxide dihydroxy 5,’5-dinitro phenyl) ACTIVITY OF and chromogen to form an oxidized colored compound that -3,4,5,6-tetra-bromosulphon COPPER-CREATININE represents the presence of glucose. phthalein (DIDNTB), which COMPLEXES. The reaction has a higher sensitivity and follows the same principle as specificity for albumin the reaction for blood on the Multistix: 75-125 glucose oxidase GREEN to reagent strips. Reagent mg/dl peroxidase BROWN strips contain COPPER potassium iodide SULFATE (CuSO4, 3,3’,5,5’-tetramethylbenzidin Chemstrip: 40 glucose oxidase YELLOW TO e (TMB) and diisopropyl mg/dL peroxidase GREEN benzene dihydroperoxide tetramethylbenzidi (DBDH) ne FALSELY ELEVATED FALSELY ELEVATED RESULTS can be caused by RESULTS can be caused 1. visibly bloody urine by: FALSE POSITIVE FALSE NEGATIVE 2. abnormally colored 1. Visibly bloody urine urines 2. presence of gastric contamination by high levels of ascorbic acid RESULTS ARE REPORTED acid reducing drug OXIDIZING AGENTS and high levels of ketone AS 10 to 150 MG/L (1 to 15 cimetidine. DETERGENTS high specific gravity MG/DL) 3. abnormally colored low temperatures urine also may IMPROPERLY interfere with the PRESERVED SPECIMENS readings. Correlations with other tests ketones proteins ABNORMAL RESULTS FOR THE A:C RATIO 30 to 300 MG/G CLINITEST PROCEDURE/BENEDICT’S TEST 3.4 to 44.9 mg/mmol Relies on the ABILITY OF GLUCOSE AND OTHER 2. GLUCOSE SUBSTANCES to REDUCE COPPER SULFATE TO CURPOUS OXIDE in the presnce of ALKALI and most frequently performed chemical analyses of urine HEAT. FEL :> 10  A color change progressing from a NEGATIVE BLUE PURPLE. Chemstrip and Chem reagent strips include (CuSO4) through GREEN, YELLOW, and GLYCINE in the reaction pad, which enables the ORANGE/RED (Cu2O) occur when the reaction takes DETECTION OF ACETONE. place. The tables contain COPPER SULFATE, SODIUM CARBONATE, COIUM CITRATE, and SODIUM Multistix: 5-10 mg/dL Sodium nitroprusside HYDROXIDE. acetoacetic acid ○ place a glass test tube in a rack, add 5 drops of urine Chemstrip: 9mg/dL Sodium nitroprusside ○ add 10 drops of distilled water to the urine in acetoacetic acid Glycine the test tube 70mg/dL acetone ○ drop one line test table into the test tube and observe the reaction until completion (cessation of boiling). FALSE POSITIVE FALSE NEGATIVE Phthalein dyes Improperly preserved urine GLUCOSE OXIDASE AND CLINITEST REACTIONS Highly pigmented red urine Levodopa GLUCOSE CLINITEST INTERPRETATION Medications having OXIDASE sulfhydryl groups Negative positive NON GLUCOSE Correlations with other test: Glucose REDUCING SUBSTANCE PRESENT possible interfering substance for reagent SEMIQUANTITATIVE REPORTING OF KETONES IN strip REAGENT STRIPS 1+ POSITIVE NEGATIVE SMALL AMOUNT OF Trace 5mg/dL GLUCOSE PRESNT Small 15mg/dL 4+ POSITIVE NEGATIVE Possible OXIDIZING AGENT Moderate 40mg/dL INTERFERENCE on reagent strip Large 80 to 160mg/dL COMMONLY FOUND REDUCING SUGARS include GALACTOSE which is the most clinically significant, ACETEST/BUMIN TEST FOR KETONES represents an INBORN ERROR OF METABOLISM. Performed within 30 seconds Sodium nitroprusside, glycine, disodium phosphate and lactose enhances color result 3. KETONES 4. BLOOD Clinical reasons for INCREASE FAT METABOLISM >5RBCS/UL - amount of blood considered include the inability to metabolize carbohydrate, as in CLINICALLY SIGNIFICANT diabetes melitus; increased loss of carbohydrate from vomiting, and inadequate intake of carbohydrate HEMATURIA associated with STARVATION and CLOUDY RED URINE MALABSORPTION. MICROSCOPIC: INTACT RBCs BETA HYDROXYBUTYRIC ACID - 20% RENAL CALCULI, GLOMERULONEPHRITIS, ACETOACETIC ACID - 20% PYELONEPHRITIS, Tumors, trauma, exposure to ACETONE - 2% toxic chemicals, anticoagulants, strenuous exercise. CLINICAL SIGNIFICANCE OF URINE KETONES HEMOGLOBINURIA 1. Diabetic acidosis CLEAR RED URINE 2. insulin dosage monitoring TRANSFUSION REACTIONS, HEMOLYTIC 3. starvation ANEMIAS, Severe burns, Infections/alaria, 4. malabsorption/pancreatic disorder STRENUOUS EXERCISE/red blood cell trauma, 5. strenuous exercise Brown recluse spider bites. 6. vomiting MYOGLOBINURIA 7. inborn eror of amino acid metabolism CLEAR RED URINE KETONE REAGENT STRIP MUSCULAR TRAUMA/CRUSH SYNDROMES, based on SODIUM NITROPRUSSIDE Prolonged coma, Conclusions, MUSCLE-WASTING (NITROFERRICYANIDE) LEGAL’S REACTION to diseases, Alcoholism/overdose, Drug abuse, measure ketones EXTENSIVE EXERTION, Cholesterol-lowering stain ACETOACETIC ACID IN ALKALINE MEDIUM medications. REACTS WITH NITROFERRICYANIDE TO PRODUCE A COLOR CHANGE FROM BEIGE TO FEL :> 11  HEMOGLOBINURIA vs MYOGLOBINURIA Strong oxidizing agents High specific gravity/crenated Bacterial peroxidases cells HEMOGLOBIN MYOGLOBIN menstrual contamination Formalin Captopril CLEAR RED URINE CLEAR RED URINE High concentrations of nitrite Ascorbic acid 25 mg/dL RED or PINK plasma NORMAL plasma Unmixed specimens Decreased haptoglobin Increased CK, Aldolase correlations with other tests Protein Microscopic Intravascular hemolysis Rhabdomyolysis Note: the concentration of Myoglobin in the urine must be at LEAST 25 mg/dL before the red pigmentation can be BLONDHEIM’S TEST/AMMONIUM SULFATE TEST; visualized DIFFERENTIATE HEMOGLOBINURIA vs MYOGLOBINURIA 5. BILIRUBIN HEMOGLOBIN MYOGLOBIN early indication of liver disease; principal source of bilirubin (85%) is hemoglobin released daily from the CLEAR supernatant fluid RED supernatant fluid breakdown of senescent red blood cells in the reticuloendothelial system; PRODUCESA BEEER SUPERNATANT FLUID (-) SUPERNATANT FLUID (+) BROWN or DARK YELLOW FOAM IN URINE. Blood BLOOD CLINICAL SIGNIFICANCE OF URINE BILIRUBIN Hepatitis RED precipitate NO precipitate Cirrhosis liver disorders Note: 2.8g of AMMONIUM SULFATE are added to 5mL of biliary obstruction (gallstones, carcinoma) centrifuged urine BILIRUBIN REAGENT STRIP Note: the principle of this screening test is based on the fact Bilirubin combines with 2,4-dichloroaniline diazonium that the larger hemoglobin molecules are precipitated by salt or the ammonium sulfate, and myoglobin remains in the 2,6-dichlorobenzene-diazonium-tetrafluoroborate in supernatant. Therefore, when hemoglobin is present, the an ACID MEDIUM to produce an AZODYE, with supernatant retains the red color and gives a positive strip colors ranging from increasing degrees of tan or pink test for blood. to violet. Note: HEMOGLOBIN PRODUCES A RED PRECIPITATE DIAZO AND SUPERNATANT THAT TESTS NEGATIVE FOR Diazo as COMPONENT OF THE REAGENT BLOOD. ○ BILIRUBIN ○ LEUKOCYTES ○ UROBILINOGEN BLOOD REAGENT STRIP Diazo as PRODUCT OF THE REACTION PSEUDOPEROXIDASE ACTIVITY OF ○ NITRITE HEMOGLOBIN to catalyze a reaction between hydrogen peroxide an the chromogen TETRAMETHYLBENZIDINE to produce an oxidized multistix: 0.4-0.8 multistix: DEGREES OF chromogen, which has a GREEN-BLUE COLOR. mg/dL bilirubin 2,4-dichloroaniline TAN CHROMOGEN REACTS WITH A PERIXIDE IN THE diazonium salt PRESENCE OF HEMOGLOBIN OR MYOGLOBIN TO BECOME OXIDE AND PRODUCE A COOR chemstrip: 0.5 chemstrip: YELLOW TO CHANGE FROM YELLOW TO GREEN. mg/dL bilirubin 2,6-dichlorobenze GREEN ne-diazonium salt Multisix: 5-20 Diisopropylbenze YELLOW RBCs/mL, ne (NEGATIVE) to 0.015-0.062 dihydroperoxide GREEN TO FALSE POSITIVE FALSE NEGATIVE mg/dL tetramethylbenzi GREEN BLUE hemoglobin dine (POSITIVE) Highly pigmented urines, Specimen exposure to light SPECKLED: phenazopyridine Ascorbic acid 25 mg/dL Multisix: Dimethyl RBCS Indian (intestinal disorders) High concentrations of nitrite 5RBCs/mL Hydroperoxy iodine metabolites hemoglobin Hexane corresponding to tetramethylbenzi Correlations with other test: Urobilinogen 10 RBCs/mL dine FALSE POSITIVE FALSE NEGATIVE URINE BILIRUBIN AND UROBILINOGEN IN JAUNDICE FEL :> 12  Disease URINE URINE Procaine BILIRUBIN UROBILINOGEN Chlorpromazine Highly-pigmented urine Bile duct POSITIVE (+++) Normal obstruction FALSE POSITIVE FALSE NEGATIVE (chemstip) (chemstrip) Liver damage Positive or Positive (++) negative highly-pigmented urine old specimen, formalin Hemolytic Negative POSITIVE (+++) Correlations with other test: Bilirubin Disease WATSON SCHWARTZ TEST classic test for differentiation between urobilinogen, porphobilinogen, an Ehrlich-reactive compounds; Addition of SODIUM ACETATE enhances the color reaction CHLOROFORM EXTRACT URINE (Top layer) ○ UROBILINOGEN Colorless ○ PORPHOBILINOGEN Red ○ OTHER EHRLICH-REACTIVE SUBSTANCES Red ICOTEST: Confirmatory test for BILIRUBIN using ICTO disk CHLOROFORM (bottom) POSITIVE: presence of a BLUE-TO-PURPLE ○ UROBILINOGEN COLOR on the mat Red NEGATIVE: slight pink or red color and other colors ○ PORPHOBILINOGEN ○ add WATER directly to the mat; prevents Colorless interference ○ OTHER EHRLICH-REACTIVE SUBSTANCES 6. UROBILINOGEN Colorless BUTANOL EXTRACTION a small amount of urobilinogen - LESS THAN BUTANOL (Top layer) 1MG/DL or Ehrlich unit - NORMAL ○ UROBILINOGEN CLINICAL SIGNIFICANCE OF URINE UROBILINOGEN Red 1. Early detection of liver disease ○ PORPHOBILINOGEN 2. Liver disorders, hepatitis, cirrhosis Colorless 3. Hemolytic disorder ○ OTHER EHRLICH-REACTIVE 4. Hepatocellular carcinoma SUBSTANCES UROBILINOGEN REAGENT STRIP Red Azo Coupling reaction of urobilinogen with diazonium URINE (Top layer) salt in acid medium to forma azo dye color changes ○ UROBILINOGEN from light pink to dark pink are observed. Colorless ○ PORPHOBILINOGEN Multistix: 0.2 p-dimethylaminob Red mg/dL enzaldehyde ○ OTHER EHRLICH-REACTIVE urobilinogen SUBSTANCES LIGHT TO DARK Colorless Chemstrip: 4-methoxybenzen PINK 0.4mg/dL e-diazonium HOESCH TEST urobilinogen tetrafluoroborate used for RAPID SCREENING OR MONITORING OF URINARY PORPHOBILINOGEN test detects approximately 2mg/dL of porphobilinogen. 2mL of HOESCH REAGENT (EHRLICH DISSOLVED IN 6 M FALSE POSITIVE FALSE NEGATIVE HCL) (multistix) (multistix) Porphobilinogen Old specimens 7. BILIRUBIN Indican preservation in formalin provides a RAPID SCREENING TEST for the p-aminosalicylic acid PRESENCE OF URINARY TRACT INFECTION Sulfonamides (UTI); CULTURE is the PRIMARY TEST for Methyldopa diagnosing and monitoring BACTERIAL INFECTION FEL :> 13 NITRITE REAGENT STRIP compound then combines with a diazonium salt Based on GRIESS REACTION; sensitivity of the test present on the pad to produce a PURPLE AZO DYE. is standardized to correspond with a quantitative bacterial culture criterion of (105) 100,00 organisms per milliliter Multistic: 5-15 Derivatized NITRITE at an ACIDIC PH reacts with an aromatic WBC/HPF pyrrole amino amine(para-arsanilic acid or sulfanilamide) to form a acid ester DIAZONIUM COMPOUNT that then reacts with DIAZONIUM salt PURPLE TETRAHYDROBENZO QUINOLINE compounds to produce a PINK-COLORED AZO DYE (any shade of Chemstrip: 10-25 Indoxyl Carbonic pink) WBC/HPF acid ester DIAZONIUM salt Multistix: 0.06-0.1 p-arsanilic acid mg/dL Tetrahydrobenzo (h)-quinolin-3-ol FALSE POSITIVE FALSE NEGATIVE PINK Chemstrip: 0.05 sulfanilamide, Strong oxidizing agents High concentrations of mg/dL hydroxy Formalin protein, glucose, oxalic acid, tetrahydro Highly pigmented urine ascorbic acid, gentamicin, benzoquinoline Nitrofurantoin cephalosporins, tetracyclines Inaccurate timing FALSE POSITIVE FALSE NEGATIVE Correlations with other tests: Protein Nitrite Microscopic Improperly preserved Non Reductase-containing VITAMIN C/ ASCORBIC ACID/ ASCORBATE specimen bacteria has reducing proteins which inhibits reaction of blood, Highly pigmented urine INSUFFICIENT CONTACT bilirubin, glucose, leukocyte esterase and nitrite. TIME BETWEEN BACTERIA AND URINARY NITRATE (less than 4 hours) IV. MICROSCOPIC EXAMINATION Lack of urinary nitrate Presence of antibiotics THIRD PART of ROUTINE URINALYSIS; its purpose Large quantities of bacteria is to detect and identify insoluble materials present in Converting nitrite to nitrogen the urine. High concentrations of The LEAST STANDARDIZED and most ascorbic acid TIME-CONSUMING part of the routine urinalysis High specific gravity MICROSCOPIC EXAMINATION OF URINE is performed when Correlations with other tests: Protein Leukocytes ○ microscopic examination be performed when Microscopic requested by a physician ○ a laboratory specific patient population is being tested Note: TRUE POSITIVE NITRITE test should be ○ any abnormal physical or chemical result is ACCOMPANIED by POSITIVE LEUKOCYTE ESTERASE obtained. TEST COMMERCIAL URINE MICROSCOPIC ANALYSIS 8. LEUKOCYTE ESTERASE Cen-Slide R/S Workstations NORMAL VALUES for leukocytes vary from 0-2/HPF provides a specially consist of a glass flow cell to 0-5/HPF designed tube that permits into which urine sediment is LE detects the PRESENCE OF ESTERASE in the direct reading of the urine pumped, microscopically GRANULOCYTIC WHITE BLOOD CELLS sediment examined, and the flushed (NEUTROPHILS, EOSINOPHILS, AND from the system BASOPHILS) and MONOCYTES Esterases also are present in Trichomonas and histiocytes; LYMPHOCYTES, ERYTHROCYTES, Note: specimens should be examined while FRESH or BACTERIA, and RENAL TISSUE CELLS DO NOT ADEQUATELY PRESERVED CONTAIN ESTERASES INCREASED URINARY LEUKOCYTES are Note: FORMED ELEMENTS indicators of UTI primarily RBCs, WBCs and HYALINE CASTS - LEUKOCYTE ESTERASE REAGENT STRIP DISINTEGRATE rapidly, particularly in DILUTE uses the action of LE catalyze the hydrolysis of an ALKALINE URINE acid ester embedded on the reagent pad to produce Note: REFRIGERATION an aromatic compound and acid. The aromatic FEL :> 14  may cause precipitation of amorphous urates and phosphates and other nonpathologic crystals that can obscure other elements EXAMINATION OF THE SEDIMENT WARMING THE SPECIMEN TO 37 C PRIOR TO observe a MINIMUM OF 10 FIELDS under both CENTRIFUGATION may dissolve these crystals low (10x) and high (40x) power. OBSERVE @ LPO slide is first examined under low power to detect casts and to ascertain the general composition of VOLUME OF THE URINE the sediment Note: CAST have a TENDENCY TO LOCATE NEAR THE 10-15 mL 12mL EDGES of the cover slip; therefore, LOW-POWER scanning of the cover-slip perimeter is recommended. provides an adequate frequently used because OBSERVE @ HPO volume from which to obtain multiparameter reagent when elements such as CAST that REQUIRED a representative sample of strips are easily immersed in IDENTIFICATION are encountered, the setting is the elements present in the this volume, and capped changed to HIGH POWER specimen centrifuge tubes are often Note: when the sediment is examined UNSTAINED, ,many calibrated to this volume. sediments have a Refractive Index similar to urine, examined under REDUCED LIGHT when using bright-field Note; if obtaining a 12-mL specimen is not possible, as with microscopy. pediatric patients, the volume of the specimen used should SEDIMENT STAINS not be noted on the report. STAINING increases the OVERALL VISIBILITY OF SEDIMENT elements being examined using bright-field microscopy by changing their refractive index. CENTRIFUGATION 5 MINS @400 produces an optimum amount of RCF sediment with the least chance of damaging the elements. Note: Use of the braking mechanism to slow the centrifuge causes disruption of the sediment prior to decantation and should not be used. Note: To prevent hazardous aerosols, all specimens must be centrifuged in capped tubes. SEDIMENT PREPARATION to maintain a UNIFORM SEDIMENT STERHEIMER-M 0.5% TOLUIDINE 2% ACETIC CONCENTRATION FACTOR, URINE should be ALBIN BLUE ACID ASPIRATED off rather than poured off, unless otherwise specified by the commercial system in Most frequently A metachromatic Nuclear details use. used stain in stain, provides are also SEDIMENT must be thoroughly RESUSPENDED by urinalysis; ENHANCEMENT enhanced; cannot GENTLE agitation (methods) consists of OF NUCLEAR be used for initial 1. performed using a commercial-system pipette CRYSTAL DETAIL. sediment analysis 2. REPEATEDLY TAPPING THE TIP OF THE TUBE VIOLET and because RBCs WITH THE FINGER SAFRANIN O; are lysed by the VIGOROUS AGITATION commercially as acetic acid. should be AVOIDED, as it may disrupt some SEDI-STAIN or cellular elements KOVA STAIN CELLULAR ELEMENTS ARE DERIVED FROM TWO SOURCES; 1. Desquamated/spontaneously exfoliated epithelial Absorbed well by Useful in the lining cells of the kidney and lower urinary tract the WBCs, DIFFERENTIATI 2. Cells of hematogenous origin (leukocytes and Epithelial cells, ON BETWEEN erythrocytes) and casts, WBCs AND Note: recommended that EXAMINATION TAKE PLACE providing CLEAR RENAL WHEN THE SAMPLE IS FRESH, particularly if no DELINEATION of TUBULAR preservative has been added; Cells and casts begin to lyse structure and EPITHELIAL cells within 2 hours of collection. contrasting and is also used Note: Midstream collection is recommended for females to colors of the in the examination reduce contamination from vaginal elements. nucleus and of cells from other cytoplasm. body fluids. FEL :> 15  appear as smooth, non-nucleated, biconcave disks A measuring approximately 7mm in diameter; identified CRYSTAL-VIOLE using HIGH-POWER; MOST DIFFICULT FOR T SAFRANIN STUDENTS TO RECOGNIZE STAIN is commonly used to aid in delineation ROUTINELY REPORTED AS THE AVERAGE NUMBER of formed SEEN IN 10 HPFS elements in urine. 0-2 cells/hpf NORMAL ERYTHROCYTES LIPID STAINS >3 cells/hpf CONSIDERED ABNORMAL OIL RED O and SUDAN III and POLARIZING MICROSCOPY can be used to confirm the presence of these elements. TRIGLYCERIDES AND NEUTRAL FATS CRENATED orange-red concentrated (hypersthenuric) urine cells shrink CHOLESTEROL due to loss of water does not stain but is capable of polarization GHOST CELL DILUTE (hyposthenuria) urine, the cells absorb water, swell, and lyse rapidly, releasing their GRAM STAINS hemoglobin and leaving only the cell membrane. used primarily in the microbiology section for Note: if the specimen is not fresh when it is examined, differentiation between gram-positive (blue) and erythrocytes may appear as faint, colorless circles or gram-negative (red) bacteria “shadow cells” because the hemoglobin may dissolve out. limited to the identification of BACTERIAL CASTS, YEAST CELLS which can easily be confused with granular casts. usually exhibit BUBBLING OIL DROPLETS and AIR BUBBLES Highly refractile when the fine adjustment is focused up and down HANSEL STAIN Note: RBCs are frequently confused with YEAST CELLS, preferred stain for URINARY EOSINOPHILS; OIL DROPLETS, and AIR BUBBLES. consisting of methylene blue and eosin Y RBCs vs WBCs drug-induced allergic reaction producing Should the identification continue to be doubtful, inflammation of the renal interstitium, adding ACETIC ACID to a portion of the sediment EOSINOPHILS are present in the sediment will lyse the RBCs, LEAVING THE YEAST, OIL DROPLETS, AND WBCs INTACT. Supravital staining may also be helpful. PRUSSIAN BLUE STAIN stain for IRON is used and stains the hemosiderin granules a blue color, confirms that these granules DYSMORPHIC RBCs are hemosiderin RBCs that vary in size, have CELLULAR PROTRUSIONS, or are FRAGMENTED associated primarily with GLOMERULAR BLEEDING also have been demonstrated AFTER CYTODIAGNOSTIC URINE TESTING STRENUOUS EXERCISE, indicating a glomerular Preparation of permanent slides using origin of this phenomenon. cytocentrifugation followed by staining with DYSMORPHIC CELL Papanicolau stain provides an additional method most closely associated with glomerular bleeding for detecting and monitoring renal disease. appears to be the ACANTOCYTE WITH CYTODIAGNOSTIC URINE TESTING MULTIPLE PROTRUSIONS, which may be difficult frequently performed independently of routine to observe under bright-field microscopy; also urinalysis for detection of malignancies of the analyzed and better delineated with Wright’s stain. lower urinary tract; A voided FIRST MORNING The so-called “G1 CELL” which has a doughnut SPECIMEN is recommended for testing. shape with one or more membrane blebs, may be Cellular elements are also easily distorted by the MORE SPECIFIC than dysmorphic cells for widely varying concentrations, pH, and presence of DIAGNOSING GLOMERULAR HEMATURIA metabolites in urine, making identification more IMMUNOCYTOCHEMICAL STAINING OF URINARY difficult ERYTHROCYTES with Tamm-Horsfall protein in renal hematuria appears to be even more reliable than cellular morphology in terms of SEPARATING RENAL FROM NON-RENAL SOURCES OF ERYTHROCYTES 1. RED BLOOD CELLS FEL :> 16 Note: urinary eosinophil test: presence of RBCs in the urine is associated with PERCENTAGE OF DAMAGE TO THE GLOMERULAR MEMBRANE or EOSINOPHILS IN 100 TO VASCULAR INJURY within the genitourinary tract 500 CELLS IS MACROSCOPIC HEMATURIA is present, the DETERMINED; FINDING OF urine appears cloudy with a red to brown color MORE THAN 1% Microscopic analysis may be reported in terms of EOSINOPHILS IS greater than 100 per hpf CONSIDERED SIGNIFICANT PRESENCE OF NOT ONLY RBCs but also hyaline, granular, and RBC casts may be seen following strenuous exercise. MONONUCLEAR Specimens containing an the presence of hemoglobin that has been filtered CELLS increased amount of by the glomerulus produces a red urine with a mononuclear cells that cannot positive chemical test result for blood in the be identified as epithelial cells absence of microscopic hematuria. should be referred for cytodiagnostic urine testing. 2. WHITE BLOOD CELLS LYMPHOCYTES are the smallest WBCs, they may resemble RBCs; larger than RBCs, measuring an average of about RENAL TRANSPLANT 12mm in diameter rejection FEWER THAN FIVE LEUKOCYTES/HPF (normal PRIMARY CONCERN in the urine); Higher numbers found in females identification of WBCs is the Urinary neutrophil counts greater than 30 cells/hpf differentiation of mononuclear suggest acute infection cells and disintegrating neutrophils from renal tubular epithelial (RTE) cells NEUTROPHIL predominant WBC found in the urine sediment; identified using High power microscopy RTE CELLS larger than WBCs and more and are also REPORTED AS polyhedral in shape, with an THE AVERAGE NUMBER eccentrically located nucleus. SEEN IN 10 HPFS GLITTER CELLS -neutrophils exposed to HYPOTONIC Methods to differentiate RTE vs WBCs URINE absorb water and swell: BROWNIAN 1. SUPRAVITAL STAINING MOVEMENT of the granules 2. ADDITION OF ACETIC ACID within these larger cells 3. PEROXIDASE CYTOCHEMICAL REACTION produces a SPARKLING APPEARANCE; leukocyte PYURIA esterase reagent strip is INCREASE IN URINARY WBCS valuable in the confirmation Indicates the presence of an infection or inflammation of pyuria in hypotonic urine in the genitourinary system; Bacterial infections, specimens including pyelonephritis, cystitis, prostatitis, and Sternheimer-Malbin stain: urethritis, are frequent causes of pyuria stain light blue as opposed to the violet color usually seen with neutrophils, no pathologic significance. 3. EPITHELIAL CELL not unusual to find epithelial cells in the urine; EOSINOPHILS Presence of urinary derived from the linings of the genitourinary eosinophils is primarily system; represent NORMAL SLOUGHING OF OLD associated with CELLS DRUG-INDUCED 3 types of epithelial cells INTERSTITIAL NEPHRITIS, 1. SQUAMOUS small numbers of eosinophils 2. TRANSITIONAL (urothelial) may be seen with urinary tract 3. RENAL TUBULAR infection (UTI) and renal transplant rejection. 1.SQUAMOUS EPITHELIAL CELL Evaluation of a concentrated, largest cells found in the urine sediment, stained urine sediment is abundant, IRREGULAR CYTOPLASM and a required for performing a prominent nucleus about the size of an RBC FEL :> 17  often the first structures observed when the sediment is examined under low-power PROXIMAL CONVOLUTED TUBULE (PCT) magnification; can serve as a good reference for are larger than other RTE cell: cytoplasm is coarsely focusing of the microscope granular, and the RTE cell often resemble cast REPORTED in terms of RARE, FEW, MODERATE, OR MANY Cells from the DISTAL CONVOLUTED TUBULE represent NORMAL CELLULAR SLOUGHING and (DCI) are smaller than those from the PCT and are have NO PATHOLOGIC SIGNIFICANCE frequently round or oval, mistaken for WBCs and spherical seen in urine from FEMALE PATIENTS transitional epithelial cells Specimens collected using the MIDSTREAM OBSERVATION OF THE ECCENTRICALLY CLEAN-CATCH TECHNIQUE contain less squamous PLACED ROUND NUCLEUS AIDS IN cell contamination. DIFFERENTIATING THEM FROM SPHERICAL CLUE CELLS - variation of the squamous epithelial COLLECTING DUCT RTE CELLS are cuboidal and cell; PATHOLOGICALLY significant; indicative of are never round; presence of at least one straight vaginal infection by the bacterium GARDERELLA edge differentiates them from spherical and VAGINALIS. polyhedral transitional cell To be considered a clue cell, the bacteria should Cells from collecting duct appearing in groups of cover most of the cell surface and extend beyond three are called RENAL FRAGMENTS. RENAL the edges of the cell FRAGMENTS indicate SEVERE TUBULAR INJURY performed by examining VAGINAL WET WITH BASEMENT MEMBRANE DISRUPTION PREPARATION for the presence of the characteristic SINGLE CUBOIDAL CELLS are particularly cells; urinalysis may be the first test performed on noticeable in cases of SALICYLATE POISONING the patient RTE cells may contain the characteristic YELLOW-BROWN HEMOSIDERIN GRANULES. 2.TRANSITIONAL EPITHELIAL(UROTHELIAL) CELLS performed by staining the sediment with PRUSSIAN smaller than squamous cells and appear in several BLUE forms, including SPHERICAL, POLYHEDRAL, and PAPANICOLAOU STAIN is the most useful stain CAUDATE; differences are caused by the ability of distinguishing RTE cells from other mononuclear cells transitional epithelial cells to absorb large amounts of in urine water originate from the lining of the renal pelvis, calyces, ureters, and bladder, and from the upper portion of 4. OVAL FAT BODIES the male urethra All forms have distinct, CENTRALLY LOCATED LIPID.CONTAINING RTE CELLS, HIGHLY NUCLEI. Transitional cells are identified and REFRACTILE; uses FAT stains to confirm presence enumerated using HIGH-POWER MAGNIFICATION Another helpful clue to the proper identification of transitional cells is a characteristic ENDO-ECTO Tests to confirm OVAL FAT CYTOPLASMIC RIM BODY presence: SPHERICAL FORMS OF TRANSITIONAL CELLS are difficult to distinguish from RTE cells (presence of staining with SUDAN III OR OIL Fat stains stain CENTRALLY LOCATED rather than eccentrically RED O TRIGLYCERIDES and NUCLEUS BY SUPRAVITAL STAINING) NEUTRAL FATs, INCREASED NUMBERS OF TRANSITIONAL cells producing orange-red seen singly, in pairs, or in clumps (SYNCYTIA) are droplets present following invasive UROLOGIC PROCEDURES such as catheterization and are of NO CLINICAL SIGNIFICANCE Using POLARIZED MICROSCOPY polarized light: An increase in transitional cells exhibiting MALTESE CROSS ABNORMAL MORPHOLOGY such as vacuoles FORMATIONS and irregular nuclei may be INDICATIVE OF MALIGNANCY or VIRAL INFECTION STAINING should be performed on sediments 3. RENAL TUBULAR EPITHELIAL CELLS negative under polarized light THE MOST SIGNIFICANT CELLS IN THE URINE reported as the AVERAGE NUMBER PER HPF. Care vary in size and shape depending on the area of the should be taken not to confuse the droplets with renal tubules from which they originate. starch and crystal particles that also polarize. presence of increased amounts is INDICATIVE OF SPECIMEN CONTAMINATION BY VAGINAL NECROSIS of the RENAL TUBULES, with the PREPARATIONS and lubricants used in specimen possibility of affecting overall renal function.. collection must be considered when only free-floating presence of MORE THAN TWO RTE CELLS per high fat droplets are present. power field indicates TUBULAR INJURY can be found in LIPIDURIA and NEPHROTIC Conditions leading to tubular necrosis are exposure to SYNDROME; also seen with severe tubular necrosis, heavy metals, drug-induced toxicity, hemoglobin and diabetes melitus, and in trauma cases that cause myoglobin toxicity, viral infections, pyelonephritis, release of bone marrow fat from the long bones allergic reactions, malignant infiltrations, salicylate LARGE FAT-LADEN HISTIOCYTES in lipid-storage poisoning, and acute allogeneic transplant rejection. diseases can be mistaken as oval fat bodies; FEL :> 18  differentiated from oval fat bodies by their LARGE ENHANCE VISUALIZATION OF THE FLAGELLA SIZE OR UNDULATING MEMBRANE (observe for the BUBBLE CELLS - RTE cells containing LARGE, UNDULATING MEMBRANE if non-motile) NONLIPID-FILLED VACUOLES may be seen along Other parasites seen in urine: Schistosoma with normal renal tubular cells and oval fat CELLS. haematobium and Enterobius vermicularis bodies: REPRESENT INJURED CELLS in which the MOST COMMON FECAL CONTAMINANT is ova endoplasmic reticulum has dilated prior to cell death from the pinworm ENTEROBIUS VERMICULARIS 5. BACTERIA 8. SPERMATOZOA few bacteria are usually present as a result of vaginal, OVAL, SLIGHTLY TAPERED HEADS AND LONG urethral, external genitalia, or FLAGELLA-LIKE TAILS, found in the urine of both COLLECTION-CONTAINER CONTAMINATION; are men and women following sexual intercourse, of no clinical significance masturbation, or nocturnal emission produce a POSITIVE NITRITE TEST result and also Urine is toxic to spermatozoa; rarely of CLINICAL frequently result in a pH above 8, indicating an SIGNIFICANCE except in cases of MALE unacceptable specimen INFERTILITY or RETROGRADE EJACULATION Owing to their small size, they must be observed and POSITIVE REAGENT STRIP TEST FOR PROTEIN reported using HIGH-POWER MAGNIFICATION, Is seen: increased amounts of semen are present reported as FEW, MODERATE, OR MANY PER Laboratories NOT REPORTING its presence cite the HIGH-POWER FIELD lack of clinical significance and POSSIBLE LEGAL To be considered SIGNIFICANT FOR UTI, CONSEQUENCES BACTERIA SHOULD BE ACCOMPANIED BY Laboratories REPORTING SPERMATOZOA cite the WBCS. possible clinical significance and the MINIMAL PRESENCE OF MOTILE ORGANISMS IN A DROP POSSIBILITY OF LEGAL CONSEQUENCES OF FRESH URINE collected under sterile conditions correlates well with a positive urine culture: Observing bacteria for MOTILITY is useful in 9. MUCUS DIFFERENTIATING them from similarly appearing protein material produced by the g