Gluc_serum> 180mg/dL=> +Gluc_urine

- dipstick--> gluc oxidase & peroxidase--> sensitive  

gluc--> gluconate + hydrogen peroxide

- Copper sulfate method

- Copper sulfate method --> low senstivity

1.Unique solubility property of light chain proteins

Precipitate-40⁰C & Re-dissolve - 100^oC

when cooled--> Precipitate-60⁰C & Re-dissolve-40^oC

2.Urine protein electrophoresis

- Myoglobinuria--> Hx: severe muscle tenderness, elevated [CK/aldolase]_serum, [haptoglobin]_nml

- Hemoglobinuria <-- hematuria / Hemolysis_{intravascular}

!!!Mgb = soluble in NH₄SO₄

Bilirubin_urine +

Urobilinogen_urine +++

DDx

Conjugated Hyperbilirubinemia

Hepatitis

UTI --> most organisms = nitrite + (E.coli)

!!! - = enterococci, N. gonorrhea, M tb

UTI--> screen -->reflection of urinary neutrophils #

!!!false + <-- trichomonads & eosinophils

Fixed Urine_specgrav = 1.010= Glomerular filtrate_specgrav

Term & cause

Isosthenuria

tubular damage-- renal medullary dysfunction

Sickle Cell disease

Ascorbate --> inhibits

Dipstick tests: Gluc, Hgb, Bilirubin, nitrite, leukocyte esterase

Calcium oxalate stones

Causes of Oxaluria

Crohn's, s/p small bowel resection/bypass, ingestion of excessive amounts of oxalate(rhubarbs, spinach, nuts)

1⁰ hyperoxaluria --> stones in childhood

--> little effect on Calcium oxalate crystallization

--> elevated pH--> Calcium Phosphate stones, struvite

--> acidotic pH--> urate stones

Mutation in the voltage gated chloride channel5 gene=>

hypercalciuria--> stone

Struvite

--> urea-splitting organisms=> alkalotic pH

Common stones in Pts s/p colectomy

Rx

Urate stones-Hyperuricosuria-Rx: 1.allopurinol=xanthine oxidase inhibitor--> reduces endogenous urate

2.Urine alkalization

2,8-Dihydroxyadenine stones-Cause?

Rx?

deficiency - Adenine phosphoribosyl transferase

-->purine metabolism

Rx: Allopurinol

Urine Crystals

Envelopes

~ dumpells

Calcium oxalate Dihydrate(envelopes)/monohydrate (dumpells,spindle/oval)

"recieved the -envelope late-> dump it"

Pleomorphic crystals most often--> diamond/square/rod

polarize in a variety of colors

yellow-brown rhombic/hexagonal plates, needles/rosettes

Uric acid

DDx:Sulfonamide crystals-->soluble in acetone

"URing w shapes/diamonds/colors"

Urine crystals?

"Coffin lids"

Struvite-Triple Phosphate (Mg, ammonium phosphate)

--> alkaline pH, staghorn calculi

"Coffin of Proteus-->staghorn-->struvite "

Cysteine --> cystinuria

"Cola --> hexagonal glass bottle"

Urine crystals?

yellow brown needles

Bilirubin

"Bins and needles"

Sulfadiazine

<-- trimethoprim-sulfadiazine administration

Cholesterol

"cholesterol results-->broke the glass"

Tyrosine

<--severe liver disease

Ammonium biurate

"thorn=ankathi"

Urine crystals?

"Maltese cross" under polarized light

Leucine

"Leukos cross"

Leucine and Tyrosine urine crystals

Causes?

often--> severe liver disease

rare: Tyrosinosis, "Maple syrup disease"

Hyaline casts = nonspecific

<--Dehydration, vigorous exercise, renal disease

white cell cast and budding yeast

<--Tubulointerstitial nephritis

Granular cast (acellular)~>nonspecific

<--renal disease

Fatty cast<-- Nephrotic syndrome

lipid droplets-->polarized light--> maltese cross

Red  cell cast

<-- glomerulonephritis

waxy cast

<-- renal diseaserenal disease

Acute renal failure

Urine Micro: Erythrophagocytosis

Dx?

RPGN

"Phagocytosis"

Acute renal failure

Urine Micro: numerous granulocytes( neutros & eos)

Dx?

AIN

"Nephritis-numerous neutros"

CSF

pink / yellow-tinged fluid following centrifucation

Term and etiology

Xanthochromia

Pink<-- free Hgb--> subarachnoid hemorrhage

Yellow<--Bilirubin (12hrs,peak72hrs, t_1/2=2wks)

Artifactual: hyperbili,CSF_protein>150mg/dL, carotinoids, melanin,rifambin, >1hr processing delay

Post traumatic rhinorrhea/otorrhea

tests to r/o CSF leak

[Gluc ] = [Gluc]_CSF-->nonspecific

Protein electrophoresis--> twin transferrin peak ,pre-albumin band

[asialated transferrin]

elevated IgG_CSF:IgG_serum

Control: Albumin_CSF:Albumin_serum

Dx?

MS

IgG index =IgG_CSF:IgG_serum/ control

--> exclude the effect of increase permeability

CSF-Agarose gel electrophoresis/Isoelectric focusing:

Oligoclonal bands (g-region)

MS

2 or >2 band = +

IEF (+IgG Ab) -->4 or > 4

Increased [IgA]_CSF

Dx?

[Gluc]_CSF < 30% (normal 60%, 60mg/dL)

Dx?

elevated [Glutamine]_CSF

Dx?

Neurosyphilis

- Screening test?

- Confirmatory test?

CSF- FTA-ABS

CSF-VDRL

--> counter to serum

CSF: Protein>100, Gluc <40

Leuko's count 1000 -10,000 diff predom Polys

Dx?

Bacterial meningitis

~ predom lymphos --> if partially treated

CSF: Protein= 20-100, Gluc< 40

Leukos count=50-500, diff: polys

Dx?

early viral meningitis--> HSV (Gluc=decreased)

lymphs--> late viral meningitis vs. fungal/mycobacterial( also Gluc-->decreased) 

Pleural effusions

Transudate

Causes

Most common -->CHF (larger on the right)

Cirrhosis, nephrotic syndrome--> decreased Osmotic pressure

Pleural fluid chemistries:

pH<7.2, LDH>700, Gluc<30

Dx?

most common = RA

collagen vascular diseases

Pleural effusion

elevated Amylase

Causes?

Malignancy

Esophageal perforation--> pH<6.0

Pancreatitis--> left-sided

Pleural fluid micro:

Lymphocytic effusion

sparse mesothelial cells

Dx?

Pleural fluid micro:

Eosinophils

a/w?

Pleural fluid micro:

conspicuously decreased mesothelial cells

DDX?

Pleural effusion - milky

Micro: lymphos

Triglycerides > 110mg/dL

Chylomicrons: electrophoresis +

Chylous-chylothorax

<--thoracic duct obstruction

Pleural effusion - milky

Micro: mixed leukos, cholesterol crystals

Triglycerides < 50mg/dL

Chylomicrons: electrophoresis -

Pseudochylous effusion

<-- gradual accumulation of lipids<--cellular break down <--Tb, RA, myxedema

Peritoneal fluid

Albumin_Serum - Albumin_ascites > 1.1g/dL

Dx?

Portal hypertension

<1.1 <-- other causes

+ Diagnostic Peritoneal Lavage --> Indication for exploratory labarotomy

Criteria

gross blood >15mL / RBCs > 100,000/mL

WBCs>500/mL, Gram stain: bacteria

Chest tube/ Foley catheter : peritoneal fluid 

Synovial fluid

1. elevated lactate (>250mg/dL) --> dx?

2. low complement --> ddx?

1. septic artritis

2. RA / Lupus

Calcium pyrophosphate

<--pseudogout

Alizarin red S stain + crystals

non-birefringent