1 / 19

Proteinuria

Proteinuria. Anh Nguyen, MD, MPH. Objectives. Define normal range of proteinuria Define abnormal range of proteinuria Learn to work-up for proteinuria. Normal urinary protein excretion. In normal adult, normal urinary protein excretion should be < 150 mg/day

connor
Download Presentation

Proteinuria

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Proteinuria Anh Nguyen, MD, MPH

  2. Objectives • Define normal range of proteinuria • Define abnormal range of proteinuria • Learn to work-up for proteinuria

  3. Normal urinary protein excretion • In normal adult, normal urinary protein excretion should be < 150 mg/day • Normal rate of albumin excretion is < 20 mg/day (15 mcg/min), increases with age and higher body weight

  4. Abnormal proteinuria • Previously, abnormal proteinuria was defined as excretion of protein > 150 mg/day • However, early renal disease is reflected by lesser degrees of proteinuria • Persistent albumin excretion between 30 and 300 mg/day (20 to 200 mcg/min): high albuminemia (formerly called microalbuminuria) • Albumin excretion > 300 mg/day (200 mcg/min): overt proteinuria or very high albuminuria (formerly called macroalbuminuria)

  5. Nephrotic Syndrome • Massive proteinuria—at least 3.5 g/day • Hypoalbuminemia (albumin < 3.5 mg/dL) • Generalized edema • Hyperlipidemia, hyperlipiduria • Dysmorphic and red cell casts in urine

  6. Isolated proteinuria (benign) • Defined as proteinuria without hematuria or reduction in glomerular filtration rate (GRF) • In most cases, patient is asymptomatic • Urine sediment is unremarkable: few than 3 erythrocytes/hpf and no casts) • Protein excretion is less than 3 g/day (non-nephrotic) • Serologic markers of systemic disease are absent

  7. Types of proteinuria • Glomerular proteinuria: increased filtration of macromolecules (such as albumin) across the glomerular capillary wall. • Tubular proteinuria: excretion of low-molecular-weight proteins, such as beta2-microglobulin, immunoglobin light chains, retinol-binding protein and polypeptides derived from breakdown of albumin • Overflow proteinuria: increased excretion of low-molecular-weight proteins; almost always due to immunoglobin light chains in multiple myeloma, lysozymes in AML, or myoglobin in rhabdomyolysis • Post-renal proteinuria: inflammation in the urinary tract (UTI), excreted proteins are generally non-albumin (IgA or IgG)

  8. Approach to the patient with proteinuria • Careful medical history and physical exam • Examine urine sediments • A patient with isolated proteinuria (normal urine sediment, normal kidney function), should rule out transient and orthostatic proteinuria

  9. Case 1 • 20 year-old man with no significant PMH who came to clinic for a physical for college football. No physical complaints. Vital signs, BP WNL. Physical exams WNL. • UA: no casts, +2 protein

  10. Work-ups for proteinuria • UA and microscopic examination for at least 3 separate occasions • Spot Alb/Cr or Pro/Cr ratio • UA on early morning sample before patient is involved in physical activities or • Split urine collection: daytime (7 AM to 11 PM) and nighttime (11 PM to 7 AM)

  11. Case 1 (cont.) • Repeat UA in the morning before physical activites: negative

  12. Case 2 • 43 year-old woman with h/o HTN and anemia since age 12 presents progressive shortness of breath, hematuria, abdominal pain, and recurrent epistaxis. • Constitutional symptoms: subjective fever with night sweat, 30 lb weight loss, extreme fatigue and weakness, dry mouth and dry eyes • Pleuritic chest pain, shortness of breath with walking 5 steps • Arthritis with morning stiffness • Abdominal pain with loose stool, more recently becoming black • Large lymph nodes in the neck • Epitaxis for one week • Fingers and toes are cold with tingling and had non-blanching petechiae • Excessive hair loss every morning on pillows over the past 6 months • Violaceous rash on from thighs to ankles, neck and chest

  13. Case 2 • 43 year-old woman with h/o HTN and anemia since age 12 presents progressive shortness of breath, hematuria, abdominal pain, and recurrent epistaxis. • Constitutional symptoms: subjective fever with night sweat, 30 lb weight loss, extreme fatigue and weakness, dry mouth and dry eyes • Pleuritic chest pain, shortness of breath with walking 5 steps • Arthritis with morning stiffness • Abdominal pain with loose stool, more recently becoming black • Large lymph nodes in the neck • Epitaxis for one week • Fingers and toes are cold with tingling and had non-blanching petechiae • Excessive hair loss every morning on pillows over the past 6 months • Violaceous rash on from thighs to ankles, neck and chest

  14. Case 2 • Lab Studies: • BMP: electrolytes WNL, BUN 10 Cr 0.8, Glu 97, Ca 7.8 • CBC: WBC 3.3 Hgb 8.6 Hct 25.6 PLT 42 MCV 84.9 • AST: 56 ALT: 13 • Iron Panel: Iron plasma 32, TIBC 217, FeSat 50%, Ferritin 213 • UA: 200 protein spot, RBC 182 • 24 hour urine protein: 5.7 g • CRP 2.6 ESR 109

  15. Work-ups for proteinuria • 24-hour urine Pro/Cr • Rule out secondary causes: HA1C, ANA, ANCA, anti-dsDNA, C3, C4, SPEP/UPEP, HBV, HCV, HIV, RPR, phospholipase A2 receptor Ab • Renal biopsy

  16. Case 2 (cont.) • Work-ups for nephrotic-range proteinuria showed: • ANA Positive 1:320 • Anti-dsDNA1:640 • Decreased C3 of 13.8 • Decreased C4 of 2.0 • Renal biopsy: Lupus Nephritis Class IV (capillary proliferation, wire loop thickening and sub-endothelial deposits)

  17. Take Home Messages • In normal adult, normal urinary protein excretion should be < 150 mg/day • Persistent albumin excretion between 30 and 300 mg/day (20 to 200 mcg/min): high albuminemia (formerly called microalbuminuria) • Albumin excretion > 300 mg/day (200 mcg/min): overt proteinuria or very high albuminuria (formerly called macroalbuminuria) • Nephrotic syndrome: massive proteinuria—at least 3.5 g/day, hypoalbuminemia (albumin < 3.5 mg/dL), generalized edema, hyperlipidemia, hyperlipiduria

  18. Take Home Messages (cont.) • Work-ups for isolated proteinuria: repeat UA in the morning or split urine collection • Work-ups for proteinuria with systemic disease symptoms: 24-hour urine Pro/Cr, rule out secondary causes, renal biopsy

  19. References • Rennke HG, Denker BM. Renal Pathophysiology: The Essentials 2nd edition. Lippincott Williams & Wilkins, 2007. • Sabatine MS. Pocket Medicine, 4th edition. Wolters Kluwer Health/Lippincott Williams & Wilkins, 2011. • Rovin BH. The assessment of urinary protein excretion and evaluation of isolated non-nephrotic proteinuria in adults. UpToDate

More Related