APPROACH TO A PATIENT

WITH ACTIVE URINARY

SEDIMENTS

Dr. Sayan Chakraborty

First Year PGT-MD Tropical Medicine

School of Tropical Medicine, Kolkata

Urine Microscopy

The ‘Liquid Renal Biopsy’!

INDICATIONS:

• Suspected urinary tract infection

• Suspected acute glomerulonephritis.

• Suspected acute interstitial nephritis

(requires staining for eosinophils).

• Unexplained acute or chronic renal failure.

• Haematuria (with or without proteinuria) on

urine dipstick test.

• Suspected urinary tract malignancy.

Classification of Urinary

Sediments

• Cells

• Renal casts

• Crystals

• Microorganisms

• Mucus

• Miscellaneous

Cells- Erythrocytes

Description

• Size: 7-8 µm in diameter

• Pale or yellowish, smooth

biconcave disk

• No nucleus or cytoplasmic

granules

• Normal: Less than 2

RBC/HPF

• Can originate from any part

of the urinary tract

Associated Conditions

Glomerulonephritis

Calculi

BHP/ Prostatitis

Carcinoma of

bladder/kidney

Trauma

IgA nephropathy

Urinary Schistosomiasis

etc.

Hematuria

Leucocytes

Description

• Typically neutrophils

(PMN)

• Larger than RBC, 10-12 µm

in diameter

• Contain nucleus and

cytoplasmic granules

• Brownian

movement (“glitter cells”)

• Normal: no more than 2

WBC/HPF

Associated Conditions

Can originate from any part

of the urinary tract

(glomerulus to urethra)

Increased In inflammatory

processes of the urinary

tract (pyuria)

PYURIA BACTERIURIA

EPITHELIA

• Squamous epithelia

• Large flat cell with central oval nucleus

• Transitional (bladder) epithelia

• Spindle shaped with large oval nucleus

• Maybe in sheet

• Renal tubular epithelia

• Small cell with large oval nucleus

• Most clinically significant

Squamous

Epithelial Cells

Large, flat,

irregular-shaped

cells

Principally from

the urethra and

vagina

Transistional

Epithelial Cells

2-4 times larger

than leukocytes

Round, pear-

shaped, tail-like

projections

Large round

nucleus

Renal Tubular Epithelial Cells

Description

• Slightly larger than WBC

• Flat, cuboidal or columnar

• One large round nucleus

Associated conditions

Tubular damage

Pyelonephritis

ATN

Salicylate intoxication

Transplant rejection

Renal Tubular Cells

Urinary Casts

• First described by Henry Bence

Jones (1813-1873)

• Cylindrical structures

• Formed in the distal convoluted

tubule and collecting ducts of nephrons

• Form via precipitation of Tamm-

Horsfall mucoprotein which is secreted

by renal tubule cells, and sometimes also

by albumin in conditions of proteinuria

Classification of Casts

Acellular casts

• Hyaline casts

• Granular casts

• Waxy casts

• Fatty casts

• Pigment casts

• Crystal casts

Cellular casts

• Red blood cell casts

• White blood cell casts

• Bacterial casts

• Epithelial cell casts

Hyaline Cast

Most common type of cast

Solidified Tamm-Horsfall

mucoprotein secreted from the tubular

epithelial cells.

CAUSES: Low urine flow, concentrated

urine, acidic environment, dehydration or

vigorous exercise.

Phase contrast microscopy leads to easier

identification.

HYALINE CASTS

Granular Casts

Second-most common type of cast

Result from the breakdown of cellular casts

or the inclusion of aggregates of plasma

proteins (e.g. albumin) or Ig light chains

Classified as fine or coarse depending on

the size of inclusions

Most often indicative of chronic renal

disease

The "muddy brown cast" seen in acute

tubular necrosis is a type of granular cast.

Fine Granular Cast Coarse Granular Cast

Waxy Casts

• End product of cast evolution

• Waxy casts fall under the umbrella of

“broad” casts

• Suggest very low urine flow associated with

severe, longstanding kidney disease such as

chronic renal failure.

• Formed in diseased, dilated ducts

Broad Cast

Waxy Cast

Fatty Cast • Hyaline casts with fat

globule inclusions

• Formed by the breakdown

of lipid-rich epithelial cells

• If cholesterol or cholesterol

esters are present -

“Maltese cross” sign under

polarized light

• Pathognomonic for high

urinary protein nephrotic

syndrome

Pigment Cast

• So named due to discolouration

• Formed by the adhesion of metabolic

breakdown products or drug pigments

• Caused by:

Hemoglobin in hemolytic anemia

Myoglobin in rhabdomyolysis

Bilirubin in liver disease.

Drug pigments, such as phenazopyridine

RBC Cast

• Always pathological, and is strongly

indicative of glomerular damage

• Causes:

Glomerulonephritis from various causes

Wegener's granulomatosus

Systemic lupus erythematosus

Goodpasture’s syndrome

Renal infarction

Subacute bacterial endocarditis

RBC Cast

WBC Cast

• Indicative of inflammation or infection

• Causes:

Pyelonephritis (strong suggestion)

Acute allergic interstitial nephritis

Nephrotic syndrome

Post-streptococcal acute

glomerulonephritis

WBC Cast

Bacterial Cast

• Found in pyelonephritis

• Seen in association with loose bacteria,

white blood cells, and white blood cell casts

• Discovery is rare, due to the infection-

fighting efficiency of neutrophils, and the

possibility of misidentification as a fine

granular cast.

Epithelial

Cell Cast

Stasis and

desquamation of

renal tubular

epithelial cells

following

tubular damage

and necrosis.

Crystals

In Acidic Urine

• Uric Acid

• Calcium Oxalate

• Cystine

• Leucine

• Cholesterol

• Tyrosine

• Sulfonamide

In Alkaline Urine

• Triple phosphate

• Ammonium biurate

• Calcium phosphate

CRYSTALS IN ACIDIC URINE

Uric Acid Crystal

Description

• Many different

shapes, diamond,

rhombic prism or

rosette

• Yellow or brown in

colour

Associated conditions

• Very common

• Can be normal

occurence

• Associated with

increased purine

metabolism

Uric Acid Crystals

Calcium oxalate crystal

Description

• Colorless, octahedral or

envelope

Associated Conditions

• Ingestion of oxalate-rich

foods: spinach, rhubarb,

tomatoes, garlic,

oranges, asparagus

• High intake of ascorbic

acid

• Ethylene glycol

poisoning

Calcium Oxalate

Crystal

Cystine Crystal

• Colorless, refractile, hexagonal plates

• Found in Congenital cystinosis or cystinuria

Leucine Crystal

Description

• Oily, highly

refractile, yellow or

brown spheroids and

concentric striations

Associated Conditions

• Clinically significant

• Maple syrup urine

disease, Oasthouse

urine disease, severe

liver disease

• Seen with tyrosine in

liver disease

Cholesterol Crystal

Description

• Large, flat,

transparent

• Notched corners

Associated Conditions

• Excessive tissue

breakdown

• Obstructed lymphatic

flow

• Nephritis and

nephrotic conditions

Tyrosine Crystal

Description

• Very fine, highly

refractile needles

• Black, yellow

• In sheaves or clusters

Associated Conditions

• Severe liver disease

• Tyrosinosis

CRYSTALS IN ALKALINE

URINE

Triple Phosphate Crystal

Description

• Colorless prisms

• 3-6 sides, oblique

ends

• Coffin lids

Associated Condition

• Can be found in

normal urines

• Chronic urinary

inflammation

Triple Phosphate Crystals

Ammonium Biurate Crystal

• Yellow brown

• spherical bodies with

long irregular spicules

Calcium Phosphate Crystal

• Long thin, colorless

needles

• One pointed end

• Arranged as

rosettes or star

• Can be found

normally

Active Urinary Sediments

• Indicates inflammation

in the glomerular

capillary wall

• The sediments are:

• Red blood cells/casts

• White cells/casts

Approach to a patient with RBCs

or RBC casts in urineHEMATURIA

Microscopic hematuria D/D

Glomerular

• Primary nephritis (post streptococcal glomerulonephritis, Ig A nephropathy, Anti-GBM disease)

• 2nd nephritis (SLE, Goodpasture’s syndrome, ANCA related vasculitis)

• Alport’s syndrome (hereditary nephritis)

• Thin basement membrane nephropathy (benign familial hematuria)

Microscopic hematuria D/D

contd..Extra-glomerular:

Renal

• Malignancy

• Vascular disease (malignant hypertension, AVM, nutcracker syndrome, renal vein thrombosis, sickle cell trait/disease, papillary necrosis)

• Infection (pyelonephritis, TB, CMV, EBV)

• Hypercalciuria

• Hereditary disease (polycystic kidney disease, medullary sponge kidney)

Microscopic hematuria D/D

contd..

Extra-renal

• malignancy (prostate, ureter, bladder)

• BPH

• Nephrolithiasis

• Coagulopathy

• Trauma

Extraglomerular vs Glomerular Hematuria in Urine Analysis

Extraglomerular Glomerular

Color (if

macroscopic)Red or pink

Red, smoky brown,

or "Coca-Cola"

Clots May be present Absent

Proteinuria <500 mg/dayMay be >500

mg/day

RBC morphology Normal Dysmorphic

RBC casts Absent May be present

Major causes of hematuria by age

and duration

Glomerular Hematuria with

active sedimentsHISTORY:

• Early morning periorbital puffiness,

oliguria, dark colored urine, edema or

hypertension

• Recent throat or skin infection may suggest

postinfectious glomerulonephritis

• Joint pains, skin rashes, and prolonged fever

in adolescents suggest a collagen vascular

disorder

• Skin rashes and arthritis can occur in

Henoch-Schönlein purpura and systemic

lupus erythematosus

• A family history that is suggestive of Alport

syndrome, collagen vascular diseases,

urolithiasis, or polycystic kidney disease is

important

• Passage of clots in urine suggests an extra-

glomerular cause

Physical Examination

• Measurement of the blood pressure (with an

appropriately sized cuff)

• Evaluation for the presence of periorbital

puffiness or peripheral edema

• Detailed skin examination to look for

purpura.

• Abdominal examination to look for palpable

kidneys

Initial Work up

• CBC, PT, INR, electrolytes, kidney function

• UA and microscopy to determine the number and morphology of RBC, crystal and casts

• Consider urine C/S

• Repeat UA in a few days

Further Work up

• Throat swab C/S, ASO titre, complement

levels for PSGN

• ANA, dsDNA for SLE

• Skin biopsy showing IgA deposition s/o

HSP

• ANCA for systemic vasculitis

• Imaging: USG, CT, Radionuclide studies

Renal Biopsy

Indications:

• Significant proteinuria

• Abnormal renal function

• Recurrent persistent hematuria

• Serologic abnormalities (abnormal complement,

ANA, or dsDNA levels)

• Recurrent gross hematuria

• A family history of end stage renal disease

Approach to a patient with pyuria

or WBC cast

Differential Diagnosis:

Asymptomatic Bacteriuria

Cystitis

Pyelonephritis

Prostatitis

Complicated UTI

CASE 1

A 40 year old female patient presented with

Dysuria

Frequency

Urgency

What is the approach for management?

Diagnostic ApproachPatient profile Management

1. Otherwise healthy woman, not

pregnant, clear history

Uncomplicated cystitis:

• No Urine c/s needed

• OPD management

2. Woman with unclear history or risk

factors for STD

Uncomplicated cystitis or STD:

• Dipstick, Urinalysis

• STD evaluation, pelvic examination

3. Male with pelvic, perineal or

prostatic pain

Acute prostatitis:

• Urinalysis and C/S

• Urologic evaluation

4. Indwelling urinary catheter CAUTI:

• Change or remove catheter

• Urinalysis, C/S

• Blood C/S if fever

5. All other patients Complicated UTI;

• Urinalysis, C/S

• Modify functional or anatomic

abnormality

Case 2

A patient presented with acute onset of:

Back pain

Nausea/vomiting

Fever

Possible cystitis symptoms

Approach?

Diagnostic Approach

Patient profile Management

Otherwise healthy woman, not pregnant Uncomplicated pyelonephritis:

• Urine Culture

• OPD management

All other patients Pyelonephritis:

• Urine Culture

• Blood Culture

Patients with non-localizing systemic symptoms like fever,

altered mental status along with leucocytosis:

Consider Complicated UTI or Pyelonephritis :-

Look for other potential etiologies

Urine Culture

Blood Culture

Case 3

30 year old second gravida lady in her third

trimester presented with a positive urine

culture in the absence of any symptom.

What should be her ideal management?

Diagnostic Approach

Patient profile Management

Pregnant or renal transplant

recipient or planned to undergo an

invasive urologic procedure

Asymptomatic Bacteriuria (ABU)

Screening and treatment

warranted

All other patients Consider ABU

No additional treatment and

workup needed

Patient with urinary catheter Consider CA-ABU

No additional treatment and

workup needed

Remove unnecessary catheters

Case 4

68 year old gentleman presented with

recurrent acute urinary symptoms.

Approach to management?

Diagnostic Approach

Patient Profile Management

Male Consider chronic bacterial prostatitis:

• Meares-Stamey 4-glass test

• Urology consultation

Otherwise healthy female not pregnant Consider reucurrent cystitis:

• Urine Culture

• Consider prophylaxis or patient

initiated management

QUIZ BUGS

Carrot no. 1

• A 10 year old male child presented with

hearing loss, dimness in vision and

persistent hematuria. Gene study showed

COL4A4 mutation.

What is your diagnosis?

Carrot no. 2

• 21 Year old female visited ophthalmology

clinic with complaints of pain in eyes and

difficulty in adjusting to dark. She was

found to have iliac horns and gave history

of passage of reddish urine.

What is your diagnosis?

Carrot no. 3

• 30 year old lady

presented with pain in

left lower quadrant

along with hematuria.

The figure beside

shows the etiology.

What is your diagnosis?