CLINICAL BIOCHEMISTRY
Clinical laboratory diagnosis of kidney and urinary tract disorders
Nitrogen balance
Energy expediture and energy supply Oxygen metabolism in the body
Clinical laboratory diagnosis of liver and biliary tract disorders
Clinical laboratory diagnosis of kidney and urinary tract disorders
• diagnostically important urine investigation
• correct indication and interpretation of non-protein nitrogen substances in plasma and urine
(urea, creatinine, uric acid)
• functions tests - glomerular filtration rate (GFR)
- concentrations capability of kidney
• urinary proteins - proteinuria
Urinanalysis
Biochemical
>      urine analysis by test strips
Morfological
> microscopy of urine sediment
> flow cytometry
> direct digital microphotography
Urine samples
random specimen
first morning or 8h specimen
second morning urine
urine collected over a 24-h period
Test strips for chemical investigation
Blood (erythrocytes; hemoglobin)
Leukocytes
Nitrite
Protein
pH
Specific gravity
(Glucose, Ketones, Bilirubin, Urobilinogen)
/Hl K n AY
/111 K M AY
Microscopic examination of the urine (urinary sediment)
cells
erythrocytes leukocytes
epithelial cells (spheric, flat)
casts
hyalin casts granular casts
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Non-protein nitrogen substances
urea
creatinine uric acid
	Urea
(the end product of protein catabolism)	
Conditions assotiated with increas of urea concentration	
	in blood plasma
>	high-protein diet
>	high protein catabolism in the body
>	decreas glomerular filtration from extrarenal causes
	>     kidney diseases
Conditions associated with decreas of urea concentration in blood plasma	
>	hyperhydratation
>	protein malnutrition
>	liver failure
Creatinine
concentration in serum depends on:
• creatinine formation in muscels
• glomerular filtration in kidney
Uric acid
the end product of purine metabolism
(adenin, guanin)
Hyperuricaemia •acute attack of gout
•increased nutritional purin uptake (entrails in diet) •decreased uric acid excretion associated with renal insufficiency •massive cellular breakdown (myeloproliferative disease under chemotherapy)
Functions tests
glomerular filtration rate (GFR) concentrations capability of kidney
Glomerular filtration rate (GFR)
Creatinine clearance
UKr   x V[ml/s] ClKr = x (1,73 / body surface)
1,1 - 2,3 ml/s
Glomerular filtration rate (GFR)
M D R D
(Modification of Diet in Renal Disease)
> S-creatinine
> S-urea
> S-albumin
> age
> sex
Glomerular filtration rate (GFR)
CYSTATIN-C
All nucleated cells produce cystatin C (cysteine proteinase inhibitor; protein 13,3 kDa)
CysC filtrs freely through the glomerular basement membrane
The serum concentration is dependent only
on the GFR
Concentrations ability of renal tubuli is tested by using of Adiuretin test.
two drops of Adiuretin are applicated intranasaly urine is then collected in one-hour intervals (5h) in urine samples is measured osmolality
age urine osmolality (mmol/kg)
15-19 1090
20-29 1030 30-39 970 40-49 910 50-59 850 60-69 800
Common causes of acute renal failure
Prerenal
decresed intravascular volume
(dehydratation, acute hemorhages, acute heart failure,
spesis, shock)
Renal
acute tubular necrosis (drugs)
severe hemolysis, muscle trauma-crush syndrom
acute interstitial nephritis
Postrenal
ureteral or urethral obstruction
Diferencia! diagnosis of oligoanuria
prerenal renal
U-Na (mmol/l)	< 20	> 30 (70)
U-osmolality	> 400	< 350 (near S)
U-urea / S-urea	> 10	< 5
Differencial diagnosis of acute and chronic renal insufficiency
	acute	chronic
S-urea	ttt	tt
S-creatinine	t	ttt
B-hemoglobine	N	
S-anorg. P		t
S-calcium	N	
Laboratory indication to haemodialysis
S-potassium > 6.5 mmol/l
S-urea > 30 mmol/l
S-creatinine > 1000 ^mol/l
Anuria > 3-5 days
Serious metabolic acidosis Hyperhydratation with cardiac insufficiency
proteinuria
prerenal
renal
postrenal
	kind of proteinuria	typical proteines in urine
prerenal	over-flow	light chains   k, A
renal	selective-glomerular	albumin transferin
	nonselective-glomerular	albumin transferin.... Ig....
	tubular	a, and ß2 mikroglobulin
postrenal	urinary tract inflamation	a 2 makroglobulin
Nitrogen balance
Energy expediture and energy supply
Oxygen metabolism in the body
Nitrogen balance
Proteins [g] x 0.16 = Nitrogen [g]
Urea [mmol/24h] x 0.0336   = Nitrogen
100g protein   x 0.16                =  16 g N urea 450 mmol/24h   x   0.0336 =   15 g N extrarenal.....................................1-2 g N