2. Renal Function Tests
Important in –
Detecting presence of disease
Assessing progress of disease
Not so important in-
Determining the cause of disease
3. Major Renal Function Tests
1. Urine analysis
Physical characteristics-
Volume-
Color- Pale yellow
Odor- Aromatic
Appearance (clear/turbid)
Specific gravity
pH
Chemical characteristics
Presence of protein
Reducing sugar
Ketone bodies
Blood
Bile salts
Bile pigments
Microscopy-
Presence of WBCs
RBCs
Casts
4. Major Renal Function Tests
2. Serum markers of renal function
a. Serum creatinine
b. Serum urea (or BUN)
3. Estimation of glomerular filtration rate (GFR)
a. Creatinine clearance
b. Urea clearance
c. Inulin clearance
4. Tests of renal tubular function
a. Water deprivation test
b. Urine acidification test
5. Proteinuria
Proteinuria can be defined as presence of protein in urine in
excess of 150 mg/day.
Albumin- 30 mg/day
Normal barrier to protein filtration
Selective permeability of glomerular capillary
Negatively charged basement membrane
When negative charges are lost in some disease- protein
filtered & appeared in urine.
7. Pathophysysiological Proteinuria
Types Daily
secretion of
Protein
Pathophysiologic
feature
Cause
Glomerular >2gm/d ↑ glomerular
permeability to
protein
primary & secondary
glomerulopathy
Tubular <2gm/d ↓ tubular
reabsorption
tubular/ interstitial
disease
Overflow <2gm/d ↑ production of
LMW protein
Hemoglobinuria
Myoglobinuria
Multiple myeloma
Amyloidosis
8. Detection & quantifying urinary protein
Qualitative test
Dipstick analysis
Heat coagulation test
Salicylic acid turbidity test
(SSA)
Quantitative test
24 hrs urinary protein
estimation
Urine protein to creatinine
ratio
9. Microalbuminuria
Microalbuminuria is defined as the presence of 30-
300 mg of albumin in a 24-h urine collection
Early & independent predictor of renal damage in
diabetes mellitus
10. Microalbuminuria
Not detected by routine dipstick test
ACR/ albumin creatinine ratio
Normal: <3.5 mg A/mmol of creatinine
Borderline: 3.5- 10 mg A/mmol of creatinine
Definite: >10 mg A/mmol of creatinine
AER/ albumin excretion rate
Normal: 20-200 μgm/min
11. Abnormal constituents of urine
Constituent Clinical significance Disease conditions
Protein Glomerular proteinuria Nephrotic syndrome
Glomerulonephritis
Diabetic nephropathy
Tubular proteinuria Fanconi’s syndrome
Nephrotoxicity due to heavy metal
Overflow proteinuria Multiple myeloma
Hemoglobinuria
Amyloidosis
Postrenal proteinuria UTI (Protein derived from UT)
Glucose Hyperglycemic glycosuria Uncontrolled diabetes mellitus
Renal glycosuria Fanconi’s syndrome
12. Constituent Clinical significance Disease conditions
Ketone bodies Increased ketogenesis Diabetic ketoacidosis
Starvation
Blood Hematuria Renal stone
UTI
Hemoglobinuria Incompatible blood
transfusion
Malaria
Bile salt & bile
pigments
Obstruction of biliary
tree
Gall stone
Ca head of the pancrease
Abnormal constituents of urine