Urine Sediment Analysis
	Urine is one of the most complex body fluid specimens - > 60 meaningful elements
	Contents dramatically affected by both physiology and collection/storage techniques
	Need for differentiation of "artifacts" from significant particulates

Urine sediment provides DIFFERENT information than urine chemistry
	Chemistry = measure of overall homeostatic state, mirrors serum chemistry
	Sediment elements = measure of urinary tract physiology, incremental to serum chemistry
Anatomy of Renal-Urinary Tract
"Normal" Sediment Elements
Element		Source
Red blood cells		Vascular system of UT
White blood cells		Vascular system of UT
Squamous epithelial		Vaginal or urethral walls or cells renal tubules
Mucus		Renal tubules or vaginal epithelium
Crystals		Solutes in urine
Hyaline casts		Renal tubules
Microorganisms		Bacteria and yeast from sampling contamination
Spermatozoa		Vagina or urethra
("normal" elements can be abnormal when elevated)
"Abnormal" Sediment Elements
Element		Source
Non-hyaline casts		Renal tubules
Renal cells		Renal tubules
Transitional		Lining of renal and urinary epithelial cells tract
Tumor cells		Kidney, bladder, urethra
Crystals		Solutes or drugs in urine
Microorganisms		Bacteria, yeast, fungi, or parasites from UTI or contaminated specimen
Erythrocytes in Urine Sediment
Origin:		vascular system of urinary tract
Size:		5 to 10 uM diameter
Appearance:		non-nucleated biconcave disks with light yellow-orange color; crenated in hypertonic and ghosts in hypotonic urine
Variable Morphologies:		"dysmorphic" cells having distorted shapes associated with glomerular bleeding; sickle cells can be observed
Normal Range:		0 to 3 per HP field (0 to 16/uL)
Macroscopic Correlations:		+ hemoglobin (potential interference from ascorbate; pink/red/brown color;  turbidity
Detection Interferences:		may be confused with yeast, CaOx crystals, small WBC, bubbles, oil droplets
Confirmatory Tests:		phase microscopy for dysmorphic cells

Causes of Hematuria
Strenuous exercise Pyelonephritis Urethritis Nonbacterial nephritis Tissue injury (monocytes) Mycoplasmosis/mycosis Trichomonas Contamination with vaginal or hemorrhoidal blood	Glomerulonephritis Cystitis Prostatitis Transplant rejection (lymphocytes) Chlamydia infection Tuberculosis Other inflammation (histiocytes)

Squamous Epithelials in Urine Sediment
Origin:			urethral lining (fem.) or distal urethra (male)
Size:			40 to 60 uM diameter
Appearance:			thin, "fried egg" with small nucleus and large slightly grainy cytoplasm - often curled edges
Variable Morphologies:			"clue cells" (from vaginal contamination) - cells covered with coccobacilli (Gardnerella vaginalis) causing "shaggy" edges
Normal Range:			0 to 4 per HP field (0 to 22/uL)
Macroscopic Correlations:			turbidity with very high cell concentrations
Detection Interferences:			none
Confirmatory Tests:			vaginal swab for clue cells
(large numbers of these cells are almost always collection artifacts)
Transitional Epithelials in Urine Sediment
Origin:			epithelial lining of bladder, ureters, kidneys
Size:			20 to 40 um diameter
Appearance:			round or oblong shape with dense round nucleus and large cytoplasm, often in clumps or sheets - deeper layer cells are thicker and rounder
Variable Morphologies:			based on layer of origin in transition epithelium Superficial layer - largest, flat cells (30-40uM) Intermediate layer - smaller, round (20-30uM) Basal layer - smallest, elongated or columnar
Normal Range:			0 to 2 per HP field (0 to 11/uL)
Macroscopic Correlations:			none
Detection Interferences:			may be confused with WBC or renal cells
Confirmatory Tests:			none
Renal Epithelials in Urine Sediment
Origin:			renal tubule epithelium
Size:			10 to 60 um diameter
Appearance:			round, oval, or elongated with granular or smooth cytoplasm
Variable Morphologies:			Convoluted cells - proximal and distal (difficult to distinguish) - small nucleus; Collecting duct cells - smaller and not round with large dense nucleus, sometimes in fragments "Oval fat bodies" - tubular cells filled with fat
Normal Range:			0 to 1 per HP field (0 to 5/UL)
Macroscopic Correlations:			none
Detection Interferences:			convoluted cells may be confused with casts or with transitional cells
Confirmatory Tests:			supravital staining; cytocentrifugation and differential stain; fat stains and polarizer
Causes of Transitional and Renal Epithelials in Urine Sediment
Transitional Cells
Urinary catheterization Transitional cell carcinoma Diseases of bladder or renal pelvis
Renal Tubular Cells (Any condition which increases renal tubule cell exfoliation rate!)
Ischemic or toxic renal tubule disease Acute tubular necrosis Heavy metal or drug toxicity   Glomerulonephritis   Nephritis   Acute infections   Kidney transplant rejection   Renal trauma
Casts (Cylindroids) in Urine Sediment
Origin:			secretion/precipitation of Tamm-Horsfall protein with entrapment of local objects in matrix (enhanced by acid pH and plasma proteins)
Size:			50 to 150 um long, 5 to 50 um wide
Appearance:			cylindrical "molded" in shape of tubule, but extremely variable - many possible inclusions
Variable Morphologies:			Hyaline - no inclusions, protein matrix only - can be colored by Hb, Bil, drugs Waxy - "solid", highly refractile appearance with sharp edges and ends - degraded form RBC - embedded cells, very fragile WBC - embedded cells, often including bacteria Epithelial - embedded cells Granular - fine or coarse T/H protein granules Fatty - embedded fat globules, poss. granules Crystal - hemosiderin, CaOx, sulfa Broad - large width from dilated tubules
Normal Range:			Hyaline, 0 to 3 per LP field (0 to 1/UL); rare granular casts (<1 per LPF) also "normal"
Macroscopic Correlations:			inclusion casts associated with presence of free embedded elements; urine protein increased but NOT albumin
Detection Interferences:			possible damage due to shaking or mixing of specimen; disintegration in hypertonic or alkaline conditions; confusion with refractile fibers or mucus
Confirmatory Tests:			phase microscopy; staining for cellular and other inclusion casts (but no effective stain for T/H protein!); oil stains for fatty casts

Causes for Casts in Urine Sediment
Hyaline:	Exercise (high elevation, normal after 24-48 hrs) Dehydration or fever Acute glomerulonephritis Acute pyelonephritis Malignant hypertension Chronic renal disease
Waxy:	Severe chronic renal disease ("renal failure casts") Renal allograft rejection Acute glomerulonephritis Nephrotic syndrome Renal amyloidosis Malignant hypertension Diabetes-origin kidney disease
RBC:	Strenuous exercise ("athletic pseudonephritis") Acute glomerulonephritis Lupus nephritis Collagen diseases Renal infarction Malignant hypertension
WBC:	Acute glomerulonephritis Acute pyelonephritis Chronic renal disease Non-bacterial renal infection
Granular:	Strenuous exercise (rare) Heavy proteinuria (nephrotic syndrome) Orthostatic proteinuria Acute or chronic renal disease Congestive heart failure with proteinuria
Epithelial:	Glomerulonephritis (severe tubule damage) Vascular disease Viral inflammations Renotoxicity
Fatty:	Nephrotic syndrome (with high proteinuria) Crush trauma injury Diabetes Toxic episodes
Broad:	Acute tubular necrosis (poor prognosis) Severe chronic renal disease
Crystals in Urine Sediment
Origin:	precipitation of solutes in urine - usually not present physiologically but form after collection
Size:	extremely variable
Appearance:	extremely variable color and shape
Variable Morphologies:	formation based on pH and solute concentration across a very wide range of size and shape
Normal Range:	any concentration of "normal" crystals can be non-pathologic
Macroscopic Correlations:	turbidity with high concentrations
Detection Interferences:	amorphous urates forming in cold acid urine may obscure any other analytes; small crystals can be confused with red cells
Confirmatory Tests:	acid/base or heat solubility; polarizing microscope; chemical tests for amino acids or drugs (e.g. diazo for sulfonamide)

Crystals in Urine Sediment - Crystals in Normal, Acid Urine
Type	Description	Pathol. Significance
Amorphous Urate	colorless or yellow-brown granules (visible pink color)	none
Uric Acid	colorless, yellow-, or red-brown with square, diamond, or wedge shapes, often in rosettes	usually none - large numbers may indicate gout or drug toxicity
Calcium Oxalate	Octahedral with "star" or "dumbbell" shape, birefringent	usually none - ingestion of high-oxalate foods, renal disease, stones, or ethylene glycol tox.
Amorphous Phosphate	colorless ("sand grain") granules	none
Triple Phosphate	colorless prisms, 3 to 6 sides ("coffin lid") or "fern leaf"	usually none - stone formation or chronic UTI
Ammonium Biurate	yellow-brown "thorny apple" spheres, rare in fresh urine	usually none
Calcium Phosphate	colorless prisms, often in rosettes, can be very large	usually none - may assoc. with chronic UTI
Calcium Carbonate	small, colorless granules, similar to bacteria	usually none - may assoc. with stones
Crystals in Urine Sediment - Crystals in Abnormal, Acid Urine
Type	Description	Pathol. Significance
Tyrosine	colorless or yellow fine metabolic disorders or	needles, clumps or single liver disease
Leucine	yellow to brown spheres with radial surface striations	metabolic disorders or liver disease
Bilirubin	yellow-red-brown fine needles, granules, or plates	bilirubinuria - assoc. with high BIL chemistry
Cholesterol	colorless rectangular plates with notched corners (always observed with fat)	chyluria, UTI, or nephrotic syndrome
Cystine	clear hexagonal plates, often layered together	cystinuria or congenital cytinosis
Sulfonamide	yellow-brown needles in bundles ("sheaves of wheat") (Bactrim as brown spheres)	ingestion of sulfa drugs
Ampicillin	long colorless prisms or needles	large ampicillin doses
Aspirin	colorless prisms or "stars"	ingestion of salicylates
Radiographic Contrast Material	colorless elongated needles or flat rectangular plates -  associated with elevated urine specific gravity >1.040	recent X-ray procedures (clears from urine in 4 hrs.)
Bacteria in Urine Sediment
Origin:	usually lower UT - possible bowel fistula
Size:	very small (<1 um) to large (10 - 30 um rods)
Appearance:	rods (bacilli) or spheres (cocci), individual or chained
Variable Morphologies:	extreme range of size and shape
Normal Range:	normal urine is sterile - bacteria due to UTI, specimen contamination during collection, or improper post-collection handling
Macroscopic Correlations:	presence of leukocytes or pos. LE in UTI; pos. nitrite chemistry for gram-negativeonly; turbidity with high concentrations
Detection Interferences:	can be difficult to resolve from amorphous urate or other crystals
Confirmatory Tests:	gram stain on wet mount; cytocentrifugation; urine culture
Guidelines for Bacteria/UT Infection
UTI versus contaminated specimen: >100,000/mL = UTI 10,000 to 100,000/ml = indeterminate <10,000/ml = contamination Upper versus lower UTI No casts and low protein = lower UTI Casts with high proteinuria = upper UTI
Yeast in Urine Sediment
Origin:	often from vaginal contamination of specimen, from urethral infection, or from renal Candida infection during immunosuppression
Size:	3 to 50 um (hyphae can be very large)
Appearance:	round or oval refractile cells showing budding or hyphae
Variable Morphologies:	Candida albicans - most common, with hyphae Candida glabrata - no hyphae
Normal Range:	none
Macroscopic Correlations:	presence of leukocytes in primary UTI
Detection Interferences:	difficult to discriminate from RBC
Confirmatory Tests:	gram stain in wet mount (yeast gram pos.); KOH prep for vaginal secretion; cytocentrifugation
Vaginal Contaminants in Urine Sediment
Trichimonas vaginalis
Size:	5 to 30 um, average 15 um
Appearance:	turnip-shaped cells with anterior and posterior flagella
Macroscopic Correlations:	none
Detection Interferences:	may be confused with WBC
Confirmatory Tests:	observation of flagellar motion and undulation
Spermatozoa (found in both female and male urines)
Size:	heads 3 to 5 um, tails 30 to 60 um long
Macroscopic Correlations:	none
Confirmatory Tests:	motility in wet prep using phase microscopy
Mucous in Urine Sediment
Origin:	renal tubules (Tamm-Horsfall protein) or vaginal epithelium
Size:	extremely variable
Appearance:	short or long wavy strands with low contrast
Variable Morphologies:	none
Normal Range:	common in normal urines in any concentration
Macroscopic Correlations:	none
Detection Interferences:	possible confusion with some casts or fibers
Confirmatory Tests:	none
Fat in Urine Sediment
Origin:	renal tissue with lipiduria in nephrotic syndrome, diabetes, hyperlipidemia, or after crush injuries
Size:	variable - 2 to 50 um diameter
Appearance:	spherical globules, light yellow or brown, highly refractile
Variable Morphologies:	none
Normal Range:	none
Macroscopic Correlations:	presence of oval fat bodies, fatty casts, or cholesterol crystals
Detection Interferences:	oil or cream lotion contaminants or microscopic immersion oil can be mistaken for fat
Confirmatory Tests:	Sudan or Oil Red O staining for triglycerides; polarizing microscopy
Tumor Cells in Urine Sediment
Origin:	possible origin from tumors of renal pelvis, renal parenchyma, ureters, or bladder (RARE in urine!)
Size:	large, >50 um
Appearance:	spherical dense cells often in clumps or fragments
Variable Morphologies:	extreme range of characteristics: Urothelial cells/fragments - in catheterized urines but also papillomas and low grade bladder tumors Glandular epithelial fragments - bladder cystitis but also adenocarcinoma
Normal Range:	none
Macroscopic Correlations:	usually RBC in urine (increased vascularization)
Detection Interferences:	none
Confirmatory Tests:	cytocentrifugation/staining; biopsy
Artifacts and Other Objects in Urine Sediment
Hemosiderin Granules:	iron from ferritin degradation found 2-3 days after severe hemolytic episode (confirm with Prussian blue staining - Rous test)
Starch Granules:	from gloves or body powders; may be confused with cholesterol crystals (confirm via "scalloped edge" shape with polarizer)
Fibers:	hair, cotton, or other threads; may be confused with casts, but thicker at ends (confirm with polarizing microscopy)
Parasites:	pinworm (Enterobius vermicularis)or Entamoeba histolytica from fecal contamination of specimen (confirm with activated charcoal test for UT-bowel fistula)
Glass Fragments:	from glassware used in sample prep; may strongly resemble crystals
Pollen Grains:	large with thick wall; confused with parasite ova

Sediment Profiles in Diseases
Renal Diseases
			R
			E					E
			N					P
			A		H			I	G
			L		Y			T	R
					A			H	A
			E		L			E	N	F
			P		I			L	U	A	W
			I	B	N	W	R	I	L	T	A
			T	A	E	B	B	A	A	T	X
			H	C		C	C	L	R	Y	Y
			E	T	C
			L	E	A	C	C	C	C	C	C
	W	R	I	R	S	A	A	A	A	A	A
	B	B	A	I	T	S	S	S	S	S	S
	C	C	L	A	S	T	T	T	T	T	T
Acute Glomerulonephriti	2+	4+	1+	0	2+	1-2+	4+	1+	1-2+	0-1+	1+
Acute Pyelonephritis	4+	2+	1-2+	+	2+	4+	2+	0-1+	2+	0-1+	0-1+
Toxic or Viral Nephrosis	1+	1+	4+	0	2+	1+	1+	4+	2+	0-1+	0-1+
Lipoid Nephrosis	0	0	1+	0	1+	0-1+	0-1+	0	1+	2+	0
Nephrosclerosis Hypertension	1+	2+	1+	0	2+	0-1+	2-3+	0-1+	1-2+	0-1+	1+
Chronic End-Stage Kidney Disease (Tubular Necrosis)	1-2+	1-2+	1-2+	0	2+	1-2+	1-2+	1-2+	1-2+	0-1+	2-3+
Other Disorders
Strenuous Exercise	0-1+	0-1+	0	0	3-4+	0	0	0	1+	0	0
Trauma	0-1+	1-3+	0	0	0-1+	0	0	0	0	0	0
Acute Cystitis	4+	2+	0	1+	1+	0	0	0	0	0	0
Systemic Lupus	1-2+	2-4+	0-1+	0	1-3+	1-3+	2-4+	1-2+	1-2+	0-1+	0-1+
Thrombocytopenic Purpura	0-1+	1-2+	0-1+	0	0	0	0	0	0	0	0
Drug-induced Renal Toxicity	0-1+	1-2+	0	0	0-1+	0	1-2+	0	0	0	0

Sediment Profiles in Disease

Discriminate artifacts of sample collection/preparation/analysis from physiologic elements Standardized, controlled procedures essential for meaningful reference ranges