Pigmenturia Flashcards
Endogenous pigmenturia likely
myoglobinuria, porphyria, haemoglobinuria, bilirubinuria, haematuria, melanuria
Exogenous pigmenturia
admin of numerous drugs/chemicals will result in discoloured urine
Normal urine coloured by
- urochrome
- urobilin
- uroerythrin
- uroporphyrins
- trace amts of riboflavin
Urine colour should be analysed in relation to
USG
If there is abnormal colour to urine, consider these differentials
- diet
- medications
- environment inborn error of metabolism
- haemolysis
- haematuria
- rhabdomyolysis
- metabolic effect
Physical appearance of Haematuria
- contains clots or is red, red-brown, brown & cloudy
- dvlp a deposit w/ time & clear w/ centrifugation
- depends on oxidation of Hgb, more rusty over colour
Microscopic appearance of Haematuria
- erythrocytes or ghosts in sediment
- crenation if SG >1.020
- spherocytes if SG <1.010
- high protein
Occult haematuria
often incidental finding w/ other Sx of UT dz
Spurious haematuria cause
Genital tract incl prostate
Which is present on the right?
Haemaglobinuria
Haematuria in FUS
- mainly blood in urine along w/ struvite crystals
Renal Haematuria
- accounts for 15-30% of all haematurias
- of glomerular origin, RBCs distorted
- persistent or intermittent haematuria (hrs to days)
What are some causes of renal haematuria
renal trauma, renal calculi or crystals (oxalate monohydrate), ARF, haemorrhagic diathesis, acute pyelonephritis, acute glomerulonephritis, renal neoplasia, arteriovenous malformation, parasitism, renal cysts, renal infarcts/embolism, radiation, idiopathic, passive congestion
glomerular haemorrhage RBCs in renal haematuria have what appearance?
doughnut-like shape, membranous protrusions or blebs + target configuration
MB & Hb are partially reabsorbed by
renal tubular cells & haem iron reincorporated into ferritin & haemosiderin
spun urine for myoglobinuria is what colour?
orange-red to brown “mahogany brown”
spun urine for haemaglobinuria is
red to red-brown “port wine red”
Myoglobin has a greater susceptibility to oxidize leading to
a chocolate brown colour
Myoglobinuria has what colour serum when spun?
clear
Haemoglobin spun serum is what colour
pink
Mild myoglobinemia occurs w/
renal failure & active cardiac injury
Gross pigmenturia can occur w/
rhabdomyolysis
Myoglobinaemia peaks in & is cleared from…
about 12 hrs injury & is cleared from plasma in 1-2d
Myoglobinuria (port wine) means
- severe muscle damage & need to flush out kidneys to avoid renal damage –> can cause myoglobinuria renal necrosis
Rhabdomyolysis in horse causes urine to become
- reddish tinge if very fresh if haemoglobinuria
- if there is a lot & has oxidized, it is black
What are haemaglobin globules
globules of hgb found w/ extensive Haemglobinuria w/ colour dependent on stain
IHA & intravascular haemolysis & haemoglobinuria can create
Haemoglobin globules bilirubin crystals
Leaves that can cause haemolytic anaemia in horses
red maple (acer rubrum), esp wilted
Sugar maple, silver maple, Pistacia
What Allium species cause haemolytic anaemia & in what species?
Onions - horse, cattle, dogs
Garlic, chives, leek
What other things can cause haemolytic anaemia?
minerals/drugs
infectious
genetic
Dipsticks are super sensitive to what molecule?
Haem
What test is most sensitive for myoglobinuria?
RIA
How do you differentiate Myoglobinuria, haemoglobinuria, and haematuria with the urine dipstick?
Greenish dot = haem
Free Hb/Mb = uniform colour (haem dissoleveD)
Mburia = appropriate clin situation, + dipstick, no red coloured serum, no RBCs in urine sediment
Differentiating between myoglobinuria, haemoglobinuria, haematuria, otheruria
- Dipstick test neg - likely porphyria or exogenous pigments
- Microscopic analysis for rbcs & ghosts pos - likely haematuria
- dipstick test & protein test pos & pink spun serum - hburia
- Dipstick, protein, ammonium precipitation pos - mburia
Porphyrin
tetra pyroles conjugated by double bonds giving light absorption & colour
Porphyrin binds what metals?
Fe, Mg, Cu, Zn
Haemoproteins contain..
oxidized Fe2+ at centre
Roles of porphyrin
- Hb/Mb carry oxygen
- cytochromes transfer electrons for hepatic detox or mitochondrial respiration
- antioxidants
- gas sensors (CO, NO)
- pigments
Porphyria
purple pigment in urine
what causes porphyria?
excessive production & excretion of porphyrins or their precursors due to haem biosynthetic pathway defect
Porphyria is associated w/
cutaneous photosensitivity & neurologic abnormalities
Bovine Congenital Erythropoietic Porphyria
Causes: red-brown discolouration & fluorescence of bones & teeth (erythrodontia), urine that is pink to deep burgundy, photosensitization, normochromic haemolytic anaemia, fluorescytes
Bovine Congenital Erythropoietic porphyria is a genetic deficiency of
Uroporphyrinogen III cosynthetase
What are the steps of porphyrin/ haem synthesis?
- gamma-aminolevulinate synthase
- gamma-aminolevulinate dehydrase = porphobilinogen synthase
- Uroporphyrinogen I synthase = porphobilinogen deaminase
4. Uroporphyrinogen III cosynthase (CEP) - Uroporphyrinogen decarboxylase
- Coproporphyringen III oxidase
- Protoporphyrinogen oxidase
- Ferrochelatase, Haem synthase (BEP)
Uroporphyrin I accumulates in
urine in CEP & imparts red colour
Bovine erythropoietic protoporphyria occurs in what species
Limousin cattle & humans
When can melanuria a rare complication of dz?
metastatic malignant melanoma in grey horses
