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)4( ‫عدد االوراق‬
‫باطنية‬
‫ ضياء الحمداني‬.‫د‬
2012-11-12
Proteinuria
Introduction
 180 liters /24hr.
 11 -15 gm of protein.
 600 -1200 ml fluid as urine,(8O mg) less than 150 mg of
protein.
 40% albumin,light chain IG 9%,tam-horsfull protein.
 Normally not more than 150 mg/24hr.
 increase on standing ambulation fever with use of presser
drug norepinephrine,and angiotensin.
 proteinuria more than 200mg/24 hr is regarded as abnormal
the amount of proteinuria .
The clinical importance of proteinuria
 Early diagnosis prevent progression of disease.
 Proteinuria is a marker of renal disease.
 The importance of urine examination.
Patients at risk:
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who required urine examination as screening test for proteinuria.:
Hypertension.
DM.
Systemic dis.
Pregnancy.
Nephrotoxic drug.
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Source of proteinuria
 plasma protein normal or abnormal filtered at glomerulqr
capillaries escape reabsorptionby pct.(glomerular proteinuria.
 Protein secreted by renal tubules .
 lower urinary tract.
Amount of proteinuria:
 Normally proteinuria less than 150 mg/24hr
 the physiological range of albuminnuria is 6 - 20 mg/24hr
and greater than 30 mg/24hr are abnormal.
 microalbuminuria refer to albuminuria in arrange of 30 –
300 mg/24hr.this equates to urinary albumin to creatinine
ratio 17- 250 mg/g for men and 25 – 355mg/g for women .
 its escape the detection by conventional method dipstick it
need albumin specific strip test .
 300 – 500 mg/24hr termed overt proteinuria detected by
dipstick.
 More than 3.5 gm/24h nephrotic range and give frothy
appearance of the urine.
Pathophysiology of proteinuria
 Glomerular (selective and nonselective.
 Albumin.
Glomerular lesion
 Primary GD include :Minimalchanges glomerulopathy,IgA
nephropathy,focal
and
segmental
glomerulosclerosis,
membranous,
membranoproliferative,
andcrescentic
glomerulonephritis.
 Secondary causes:multisystemic disease, SLE, SSC,
metabolic (DM,) neoplasm mylomamlymphoma solid tumors.
infection, drug (pencillin, gold, lithium, NSAID,).
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Tubular proteinuria:
 B2 microglobulins more than albumin .
Causes :
 Heavy metal poisoning .
 tubulintrestitial disease.
 acute hypersensitivity interstitial nephritis.
 obstructive uropahy .
 acute bacterial pyelonephritis.
 light chain nephropathy.
 it compromised alpha and B globins which can be detected
by urine electrophoresis appearing in the alopha and Beta
fraction.it is in a range of 200 to 2000 mg/24hr.
 Overflow proteinuria.
Overflow proteinuria
 occurs when the capacity of renal tubules.
 In hemolytic anemia free Hb will appear in the urine
 rhabdomyolysis there will be myoglobinuria.these proteins
discolor the urine and are detected by specific reagent .
 Monoclonal gamopathies can result in monoclonal light
chains or immuonglobulins in the urine.their identity is
confirmed
by
monoclonal
band
in
urine
immuonoelectrophoresis.
 hemoglobinuria,myoglobinuria,myloma,light chain disease.and
amyloidosis.
 quantity rang from minor to nephrotic range.
Tissue proteinuria
 Tissue proteinuria occur secondary to:
 UTD ,inflammation,tumors.
 Its relatively low concentration up to 0.5 gm/gm
mg/24hr .
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500
 associated with non glomeruler hematuria,and can be
detected by urine electrophoresis.
Evaluation (Detection and quantification of proteinuria.
 dipstick (Strip test) a paper impregnated with indicator
dye (tetrabromophenole)
 which change its color change color green to blue with
albumin In concentration range of (20 – 300 mg/dl).
 it is insensitive to other protein(glibuline,BJ protein).
 a
false
positive
result
with
strong
alkaline
urine,tobutamide,cephalosporine use and radiocontrast
agent. and false negative result with diluted urine.
 the dipstick
test is available for detection of
microalbuminuria as a screening test in DM,raised BP,SLE.
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false positive result :
strong alkaline urine.
tobutamide,cephalosporine use.
radiocontrast agent.
Fever.
Vigorous exercise.
Postural proteinuria.
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 false negative result with
 diluted urine.
 Microalbuminuria.
Turbidmetry test
 utilizing acetic acid or sulfosalicylic acid used to detect
lower level proteinuria (5mg/dl) and react equally to albumin
and globulins.
 borderline or negative test with dipstick test positive
result with Turbidmetry indicate presence of globulin like
light chain .
orthostatic proteinuria
confirmation by comparison with recumbent sample . timed 24 hr
collection.
 Its important to differentiate between u protinuria/ u
creatinine and urinary albumin/ creatinine .
 to measure the selectivity urinary protein content one can
do electrophoresis of the urinary protein. Selective
proteinuria mean mainly excretion of albumin.
Urinary Protein to creatinine ratio.
 The inaccuracies in urine collection .
 inconvenience of transporting a large volume of urine.
 Have made the estimation of protein content in a sample of
urine more attractive .
 urinary protein in mg/d / urinary creatinine mg / day. The
unit of measuring urinary protein to creatinine ratio is
mg/mg or gm/gm.
 Abnormal ratio will be greater than 0.2mg/dl protein on
1mg creatinine or 0.2 mg/mg or gm/gm.
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The most consistent results are obtained from 1st voided
sample in the morning but the test can be applied to random
sample obtain in the clinic.
If the level exceed 200 mg/24hr, then the evaluation
should consider the identification of the cause.
The initial step is urine microscopic examination for freshly
voided sample.
To assess the presence of erythrocytes leucocytes and
erythrocytes cast.
presence of proteinuria and glomerular hematuria suggest
glomerular pathology.
History is important for symptoms of renal disorder or
extra renal disease in autoimmune disease,family history of
renal disease,drug history or exposure to toxic substance.
CBP,serum albumin,globulins,
cholesterol,calcium,phosphate,uric acid.
liver function test.
serological test for HBV,HCV,HIV.
US of kidney.
immunological studies including ANA,ANCA,complement
levels rheumatoid factor,cryoglobulins .
serum protein electrophoresis.
Proteinuria less than 2000 mg/24 not accompanied by
hematuria,no symptoms of renal disease,the kidney size
normal and symmetrical immunological studies are normal
observation for several months .
orthostatic proteinuria without other features of renal
disease should in frequently and does not required further
evaluation.
Renal biopsy indicated in
 Nephrotic range proteinuria.
 Proteinuria in SLE.
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 Glomerular protiuria, investigation protein – creatinine ratio
or 24hr protein excretion.
 Serumalbumin.
 Cholesterol.
 plasma and urine protein electrophorsis.
 GUE.for RBC cast.
Tubular proteinuria.
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plasma and urine electrophoresis.
U protein electrophoresis: alpha, beta microglobulins.
heavy metal screen.
Bence Jones protein
LDH.
haptoglobins.
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