Dr. Prosper's presentation covered the approach to proteinuria. It began with background on proteinuria and the basic physiology of the glomerular filtration barrier (GFB). Proteinuria was defined as excessive proteins in urine over 150mg/24hrs. Measurement methods including dipstick tests and 24hr urine collections were discussed. The etiology of proteinuria was classified as benign, glomerular, tubular, overflow or post renal. A thorough history, physical exam, labs, urine studies and renal ultrasound were recommended in the evaluation. A renal biopsy may be indicated in persistent cases. Treatment focuses on controlling underlying causes like diabetes or hypertension and reducing cardiovascular risk factors.

1. APPROACH TO
PROTEINURIA
Presenter: Dr INGABIRE Prosper
Supervisor: Dr BABANE Jean Felix
August 1st ,2022

2. Outline
• Background
• Basic Physiology of GFB
• Definitions
• Etiology
• Evaluation &Management

3. Background
• Proteinuria is a common incidental finding in
daily clinical practice
• Mostly transient& benign
• Persistent proteinuria:
marker of early kidney diseases
 independent factor for atherosclerotic
vasculopathy
• 5% of general pop develop Asx proteinuria in
their lifetime
• From those , 15% develop CKD

4. GFB

5. Physiology
• The permeability to GFB depends on size
&charge of proteins
• Small proteins ＜69 kDA of albumin filtered,
mostly reabsorbed in PT
• Large negatively charged molecules are retained.
• Physiological normal proteinuria: orthostatic,
febrile, exercise
• Proteinuria﹥3.5 g/day: Nephrotic range

6. Definitions
• Healthy individuals can excrete:
 less than 150 mg/day of Total proteins
less than 30 mg/day of albumin
• Proteinuria: Excessive amount of proteins in
urine > 150mg/24hrs
• Albuminuria: Urinary albumin excretion.
> 30mg/24hrs

7. Def.-Cont’d

8. Normal proteinuria
• 150 mg of of urinary protein/composition:
Albumin (20%)
Tamm-Horsfall proteins(40%)
Immunoglobulins
Hormones, enzymes
Mucopolysaccharides

9. Measurement

10. Qualitative -Dipstick
 Based on PH change in presence of anionic
proteins
 Mainly detects Albumin &transferrin
 Low sensitivity to LMW proteins
 High screening for albuminuria
 Detection level:
• 150 mg/l for albumin, 200mg/l transferrin
• 500mg/l Ig G& ﹥1000 mg/l Ig Light chains

11. Significance /qualitative values
• Urine dipstick/Albumin based
Negative
Trace — between 15 and 30 mg/dl
1+ — between 30 and 100mg/dl
2+ — between 100 and 300 mg/dl
3+ — between 300 and 1000 mg/dl
4+ — >1000 mg/dl

12. Measurement
• Sulfosalicylic acid test:
 Detects all proteins in the urine
 Detect those missed by the dipstick
• Quantitative: 24hr urine collection
 Good diagnostic tool
 Needs monitoring in old people with confusion
• ACR/PCR: strong correlation with
quantitative way

13. Clinical Significance/Proteinuria
• Early marker of kidney damage
• Tool to differentiate diagnoses
• Helps to assess prognosis &monitoring the
treatment response
• Surrogate marker for progressive
atherosclerosis& increased Renal&CV risks
• Persistent moderately increased albuminuria:
marker of early diabetic nephropathy

14. Etiological Classification
• Benign Proteinuria: Fever, Strenuous exercise,
Acute illness, Emotional stress, Orthostatic
proteinuria
• Pathological :
Glomerular
Tubular
Overflow
Post renal

15. Pathogenesis

16. Classification

17. Etiology/JCC, May 2011

18. Approach -History
• Symptoms with duration
history of recent fever with sore throat
 Periorbital puffiness progressing to anasarca
Frothy urine , high colored urine, oliguria, nausea
Vomiting ,abdominal pain, joint pain etc.
• PMH-DM, hypertension, renal
• Drug hx-NSAIDS, Cyclosporine, exposure to
heavy metals
• Family history of renal disease

19. Approach
• Proteinuria: Full hx done , P/E, Labs& Urine
studies&Renal US
• Renal biopsy indicated:
 proteinuria persists and is greater than 1 g/day
with no transient cause
 Non-isolated findings (hematuria, active urine
sediment, hypertension, low GFR
 Nephrotic range proteinuria.
• An active urine sediment: presence of >5 RBCs and
>5WBCs per hpf and/or the presence of cellular casts.

20. Microscopic Urinalysis
• Pathological findings:
Dysmorphic RBCs
WBCs (like eosinophils)
Casts (RBC, WBC, waxy and broad).
• Dysmorphic RBCs and RBC casts: glomerular
injury.
• WBC casts: Interstitial and/or tubular damage.
• Lipid droplets or fatty cast: Common w/ NS
Proteinuria: A Guide to Diagnosis and Assessment, Internal Medicine Open Journal, USA, June 2020

21. Work up, Proteinuria in Adults: A Diagnostic Approach - American Family
Physician

22. Management
• Treat the underlying cause
• Blood pressure control, Glycemic control
• Edema- diuretics, sodium restriction
• ACE inhibitors, ARB‘s
• Lipid control
• Specific immunosuppressive therapies for
primary glomerular diseases

23. Management, WJCC

24. Take Home Message
• Proteinuria is not a disease, it’s a marker of
Kidney damage
• Albuminuria is associated with bad
outcomes(CVD, Mortality, ESRD)
• Screen risk patients regularly
• Focus on CV risk factor reduction as patients
with early stage CKD die from CV diseases

25. References
1. Michael F.(2000).Proteinuria in Adults: A
Diagnostic Approach, Madison accessed on
April 18,2021
2. Sasha et.al (2020), ‘Proteinuria: A Guide to
Diagnosis and Assessment’ INTERNAL
MEDICINE Open Journal. Doi:
I0.17140/IMOJ-4-112
3. Uptodate
4. KDIGO Clinical practice 2021 for
management of diabetes