4.2A Hematuria

Question 1

Permits passage of small molecules while restricting macromolecules

Answer 1

Glomerular Capillary Wall

Question 2

Three Components of Glomerular Capillary Wall

Answer 2

Endothelial Cell (Fenestrae & Glycosalyx)
Basement Membrane (Proteins & Collagen)
Epithelial Cell (Epithelial podocyte, filtration slit, & slit diaphragm)

Question 3

Mechanism of how the kidneys handle protein via Glomerular Permeability

Answer 3

Steric Hindrance - spatial alignment of the passing molecules (membrane pores)
Viscous Drag - impedance to movement (fluid lining)
Electric Hindrance - due to electrostatic repulsion (molecular size)

Question 4

Function of glomerulus

Answer 4

filtration

Question 5

Function of tubules

Answer 5

reabsorption and secretion of certain molecules, ions, and other macromolecules

Question 6

It is the abnormal losses of intermediate MW proteins (Albumin)

Answer 6

Glomerular Injury

Question 7

Increased losses of low MW proteins

Answer 7

Tubular damage

Question 8

Normal protein excretion

Answer 8

Child: <100mg/m2/day or 150 mg/day
Neonates: up to 300 mg/m2

Question 9

Protein Excretion Contents

Answer 9

50% Uromodulin (Tamm-Horsfall protein)

50% Plasma proteins (Albumin & LMW proteins)

Question 10

Abnormal protein excretions

Answer 10

Proteinuria: >100mg/m2/day or 4mg/m2/hour (U p/c: >0.2)

Heavy (Nephrotic Range) Proteinuria: >1000mg/m2/day or 40mg/m2/hour (>2)

Question 11

Prevalence of Proteinuria

Answer 11

Single test urine: 5 - 15%
1 of 4 specimens - 10.7% of children
4 of 4 specimens - 0.1% of children

Question 12

Glomerular Proteinuria

Answer 12

Increased macromolecules filtration

Causes: MCD, non-pathologic conditions (fever, extensive exercise, orthostatic & postural proteinuria)

Question 13

Tubular Proteinuria

Answer 13

Increased excretion of LMW proteins (B2-microglobulin, A1-microgloulin, retinol-binding protein)
Causes: Tubulointerstitial diseases

Question 14

Overflow Proteinuria

Answer 14

Increased excretion of LMW proteins due to marked overproduction of a particular protein (exceeds tubular reabsorptive capacity)
Examples:
-Light chains - Multiple Myeloma
-Myoglobin - Rhabdomyolysis

Question 15

Asymptomatic Proteinuria

Answer 15

Most common presentation

proteins excretion is above the upper limits for normal age but no clinical manifestations