Interpretation of Urinalysis,  MUHAMMAD Y EBRAHIM, MD.  Consultant Nephrologists SRMC & MBH.  Director of inpatient dialysis at SRMC, SRCH & MBH.  Co-medical director at out patient dialysis unit at Dialysis & Clinics Inc DCI.  Chief Department of Nephrology at SRMC.

Interpretation of Urinalysis, Muhmmad Y Ebrahim, MD

What is Urinalysis?  It provides information about:  The state of the kidney and urinary tract.  Metabolic or systemic (non-kidney) disorders.  Urinalysis can reveal diseases that have gone unnoticed because they do not produce striking signs or symptoms.  Examples include diabetes mellitus, various forms of kidney failure, and chronic urinary tract infections.

Urinary System:  Recall the urinary system consists of two kidneys, two ureters and the bladder.

5 Specimens Types : Varies in method used and in time frame in which to collect specimen Types of specimens:  Random  First morning  Clean catch midstream  Timed  24 hour

Clean Catch:

7 Catheterization:  Urinary catheter  Urinary catheter – plastic tube inserted to provide urinary drainage  Catheterization  Catheterization – procedure during which the catheter is inserted

Specimen Collection: Supra-pubic Needle Aspiration

− Macroscopic Examination. − Chemical Analysis (Urine Dipstick). − Microscopic Examination. − Culture (not covered in this lecture). − Cytological Examination. Types of Analysis:

Macroscopic Exam:  Examination of the physical properties including….  Color  Clarity (or transparency)

Macroscopic Examination Odor: − Ammonia-like:(Urea-splitting bacteria) − Foul, offensive:Old specimen, pus or inflammation − Sweet: Glucose − Fruity: Ketones − Maple syrup-like: Maple Syrup Urine Disease Color: − Colorless Diluted urine − Deep YellowConcentrated Urine, Riboflavin − Yellow-GreenBilirubin / Biliverdin − RedBlood / Hemoglobin − Brownish-redAcidified Blood (Actute GN) − Brownish-blackHomogentisic acid (Melanin)

Drugs - Desferol, rifamfin or phenazopyridine (red) - Furazolidone (brown) - L-dopa (red- brown) - Metocarbamole (green – brown) - Metronidazole or methyldopa (dark)

Macroscopic Exam: Left to right: Straw, clear; yellow, clear; yellow, hazy; yellow, clear; red-orange, clear; brown, hazy.

Macroscopic Exam  Clarity (or transparency) - normal  Clear  Clarity - abnormal (due to insoluble elements such as cells, crystals, etc.)  hazy  cloudy  turbid

Chemical Exam:  The presence of normal and abnormal chemical elements in the urine are detected using dry reagent strips.  These plastic strips contain absorbent pads with various chemical reagents for determining a specific substance.

Reagent Strips:

Using Reagent Strips:  BRIEFLY dip the strip in urine.  Colors are matched to those on the bottle label at the appropriate times.  Timing is critical for accurate results.

Chemical Exam:  When the test strip is dipped in urine the reagents are activated and a chemical reaction occurs.  The chemical reaction results in a specific color change.

Chemical Exam:  After a specific amount of time has elapse, this color change is compared against a reference color chart provided by the manufacturer of the strips.

Automation  Dip sticks rarely, if ever, read by hand.  Automated readers automatically reads a urine dipstick and prints out results.  Increases accuracy of results.

Typical Substances Tested & Significance:  pH - partial assessment of acid base status; alkaline pH indicates old sample or urinary tract infection.  Specific Gravity - state of kidney and hydration status of patient.  Protein - primarily detects protein called albumin; important indicator in the detection of renal disease.  Glucose - primarily detects glucose (sugar); important indicator of diabetes mellitus

Typical Substances Tested & Significance  Blood - red blood cells, hemoglobin, or myoglobin (muscle hemoglobin); sensitive early indicator of renal disease.  Ketone - normal product of fat metabolism; increased amounts seen in diabetes or starvation (extreme dieting).  Bilirubin - detects bilirubin (a product of red cell breakdown); indicator of liver function.  Urobilinogen - another by-product of red cell breakdown; increased amounts seen in fever, dehydration, hemolytic anemia and liver disease

Typical Substances Tested & Significance:  Nitrite - certain bacteria convert normal urine nitrate to nitrite; indicator of urinary tract infection  Leukocyte Esterase - detects esterase enzyme present in certain white blood cells (e.g, neutrophils, monocytes); indicator of urinary tract infection

Glucose:  Presence of glucose (glycosuria) indicates that the blood glucose level has exceeded the renal threshold.  Useful to screen for diabetes.

Bilirubin:  Bilirubin is a byproduct of the breakdown of hemoglobin.  Normally contains no bilirubin.  Presence may be an indication of liver disease, bile duct obstruction or hepatitis.  Since the bilirubin in samples is sensitive to light, exposure of the urine samples to light for a long period of time may result in a false negative test result.

Ketones:  Ketones are excreted when the body metabolizes fats incompletely (ketonuria )

Specific Gravity:  Specific gravity reflects kidney's ability to concentrate.  Want concentrated urine for accurate testing, best is first morning sample.  Low – specimen not concentrated, kidney disease.  High – first morning, certain drugs

Blood:  Presence of blood may indicate infection, trauma to the urinary tract or bleeding in the kidneys.  False positive readings most often due to contamination with menstrual blood.

Ph:  pH measures degree of acidity or alkalinity of urine

Protein:  Presence of protein (proteinuria) is an important indicator of renal disease.  False negatives can occur in alkaline or dilute urine or when primary protein is not albumin.

Urobilinogen:  Urobilinogen is a degradation product of bilirubin formed by intestinal bacteria.  It may be increased in hepatic disease or hemolytic disease

Nitrite:  Nitrite formed by gram negative bacteria converting urinary nitrate to nitrite

Leukocytes:  Leukocytes (white blood cells) usually indicate infection.  Leucocyte esterase activity is due to presence of WBCs in urine while nitrites strongly suggest bacteriuria.

Normal Values:  Negative results for glucose, ketones, bilirubin, nitrites, leukocyte esterase and blood.  Protein negative or trace.  pH  Urobilinogen Ehrlich units

Microscopic Exam:  The urine specimen is centrifuged and the liquid portion is poured off the concentrated cellular sediment …. is then placed on a microscope slide, covered with a cover slip and viewed under a microscope.

Microscopic Examination of Urine:  A variety of normal and abnormal cellular elements may be seen in urine sediment such as:  Microscopic sediment  Red Blood Cells  White Blood Cells  Epithelial Cells  Casts  Crystals  Miscellaneous structures

Preservation - Cells and casts begin to disintegrate in hrs. at room temp. - Refrigeration for up to 48 hours (little loss of cells). Specimen concentration - Ten to twenty-fold concentration by centrifugation. Types of microscopy - Phase contrast microscopy (most offices use this) - Polarized microscopy (used in bigger institutions) - Bright field microscopy with special staining (e.g., Sternheimer-Malbin stain) Microscopic Examination: General Aspects

Microscopic Examination: Per High Power Field (HPF) (400x) –> 3 erythrocytes –> 5 leukocytes –> 2 renal tubular cells –> 10 bacteria Per Low Power Field (LPF) (200x) –> 3 hyaline casts or > 1 granular cast –> 10 squamous cells (indicative of contaminated specimen) –Any other cast (RBCs, WBCs) Presence of: –Fungal hyphae or yeast, parasite, viral inclusions –Pathological crystals (cystine, leucine, tyrosine) –Large number of uric acid or calcium oxalate crystals Abnormal Findings

Erythrocytes - “Dysmorphic” vs. “normal”(> 10 per HPF) Leukocytes - Neutrophils (glitter cells)More than 1 per 3 HPF - EosinophilsHansel test (special stain) Epithelial Cells - Squamous cellsIndicate level of contamination - Renal tubular epithelial cells Few are normal - Transitional epithelial cells Few are normal - Oval fat bodies Abnormal, indicate Nephrosis Microscopic Examination: Cells

Microscopic Exam:  Red blood cells  presence of a few is normal  higher numbers are indicator of renal disease  result of bleeding at any point in urinary system 40x objective

Microscopic Exam:  White blood cells  a few are normal  high numbers indicate inflammation or infection somewhere along the urinary or genital tract 40x objective

Microscopic Exam:  Mucus  look like long, ribbon- like threads  common finding in urine sediment  secreted by glands in the lower urinary tract 40x objective

Microscopic Exam:  Epithelial cells  cells are large and flat  normal cells that line the urinary and genital tract or renal tubules 40x objective

Microscopic Exam:  A variety of normal and abnormal crystals may be present in the urine sediment.

Microscopic Exam:  Crystals of calcium oxalate  colorless octahedron  found in acid urine  Crystals of triple phosphate  colorless, “coffin-lid” prism  common finding; not clinically significant

Casts:  Urinary casts are cylindrical aggregations of particles that form in the distal nephron, dislodge, and pass into the urine. In urinalysis they indicate kidney disease. They form via precipitation of Tamm-Horsfall mucoprotein which is secreted by renal tubule cells.nephronurineurinalysiskidneyTamm-Horsfallmucoproteinrenal tubule

Types of casts  Acellular casts Hyaline casts Granular casts Waxy casts Fatty casts Pigment casts Crystal casts  Cellular casts Red cell casts White cell casts Epithelial cell cast

Erythrocyte Casts: Glomerular diseases Leukocyte Casts: Pyuria, glomerular disease Degenerating Casts: - Granular castsNonspecific (Tamm-Horsfall protein) - Hyaline castsNonspecific (Tamm-Horsfall protein) - Waxy castsNonspecific - Fatty castsNephrotic syndrome (oval fat body casts) Microscopic Examination: Casts

Microscopic Exam:  Hyaline Casts  colorless and fatter than mucus  a few are normal  may be increased after strenuous exercise  form when protein solidifies in the nephron Hyaline cast & epithelial cell, 40x objective

Microscopic Examination RBCs Cast

Microscopic Examination WBCs Cast

Microscopic Examination Tubular Epith. Cast

Microscopic Examination: Granular Cast

Microscopic Examination: Waxy Cast

Microscopic Examination: Hyaline Cast

 Oval Fat Bodies/Maltese Cross indicate Nephrotic-range proteinuria (>3.5g proteinuria/day). Urinalysis: Simerville et. al., Am Fam Physician, 71, 2005

 Broad Casts/Waxy Casts indicate CKD Urinalysis: UpToDate

 Hematuria  With RBC cast, think glomerulonephritis  If RBC cast not present, think RCCa or bladder Ca. bladder Ca. Urinalysis Simerville et. al., Am Fam Physician, 71, 2005

 Muddy Brown/Granular Casts suggests ATN. Urinalysis Simerville et. al., Am Fam Physician, 71, 2005

Microscopic Examination RBCs

Dysmorphic RBC ’ s

Microscopic Examination WBCs

Squamous Cells

Microscopic Examination Tubular Epithelial Cells

Microscopic Examination Transitional Cells

Microscopic Examination Transitional Cells

Microscopic Examination Oval Fat Body

Bacteria -BacteriuriaMore than 10 per HPF Yeasts - CandidiasisMost likely a contaminant but should correlate with clinical picture. Viruses -CMV inclusionsProbable viral cystitis. Microscopic Examination Bacteria & Yeasts

Microscopic Examination Bacteria

Yeasts

Cytomegalovirus

Cytological Examination Staining:  Papanicolau  Wright’s  Immunoperoxidase  Immunofluorescence

Cytology: Normal

Cytology: Reactive

Cytology: Polyoma (Decoy Cell)

Cytology: Squamous Cell Ca.

Cytology: Renal Cell Ca.

 Fractional Excretion of Sodium (FENa):  <1% indicates pre-renal, acute post-renal state, or acute GN.  >1% indicates intrinsic renal disease  Fractional Excretion of Urea/Uric Acid:  Should be used if FENa not an accurate reflection of tubular function (i.e. presence of diuretics).  Urine Net Charge ([Na + K] – Cl) :  In acidemic state:  Negative charge – normal renal function vs. proximal RTA  Positive charge – presence of distal RTA  Urine Chloride  Volume assessment:  <40 indicates pre-renal or acute post-renal  >40 indicates intrinsic renal disease  Metabolic alkalosis:  <40 indicates volume contraction as cause of metabolic alkalosis.  >40 indicates non-volume contracted etiology of metabolic alkalosis. Urine Chemistries

79 Pregnancy Tests:  Used to detect human chorionic gonadotropin (hCG)  Secreted by placenta  EIA- Enzyme immunoassay test