L81 - Biochemical Investigation of Urogenital Diseases II Flashcards
(70 cards)
Major urinary proteins?
IAABRC
- IgG
- Albumin
- a1-Microglobulin
-Retinol Binding
Protein (RBP)
- Cystatin C
- B2-Microglobulin
Filtration of protein in down to which metrics?
molecular size (20 - 40A)
protein molecular mass ( 30 - 70kDa)
Charge
How does charge influence protein filtration?
Negatively charged molecules have lower permeability
Proportion of Albumin relationship with severity of proteinuria?
proportion of Albumin increases with increasing severity of proteinuria
Normal daily excretion of protein? What protein makes up 40-50% excretion?
< 150 mg;
about 40 - 50% is Albumin
3 types of proteinuria?
Glomerular
Tubular
Overflow
What causes glomerular proteinuria?
Increased glomerular permeability
What causes overflow proteinuria?
Increased plasma concentration of
relatively freely filtered proteins
What is the consequence of glomerular proteinuria?
Progressively increasing excretion
of higher molecular weight proteins
because permeability increases
Give 5 CAUSES of tubular proteinuria?
1) PCT damage
2) DCT damage
3) Decreased nephron number
4) Orthostatic proteinuria
5) Transient proteinuria
What is the consequence of PCT damage in Tubular proteinuria?
decreased tubular reabsorptive capacity and/or release of intracellular components
What is the consequence of damaged nephron number in Tubular proteinuria?
Decreased nephron number:
increased filtered load per nephron
Give examples of proteins excreted due to overflow proteinuria?
- Bence Jones protein (BJP)
- Lysozyme
- Myoglobin (not haematuria but due to breakdown)
What is orthostatic proteinuria?
Protein excretion varies with posture,
increasing on standing/
prolonged upright posture
What is transient proteinuria?
Mild to moderate proteinuria
due to systemic illnesses apparently not related to the kidneys
Give examples of causes of transient proteinuria?
- high fever,
- congestive heart failure,
- seizures
- strenuous exercise
- urinary tract infection
What is the normal urinary albumin: creatinine ratio in male and female?
≤2.5 (males)
≤3.5 (females)
Normal Urine Reagent
Strip (‘dipstick’) reading?
Negative
Normal Urine Protein:
Creatinine ratio mg/mmol?
<15 mg/mmol
Normal Urine Total
Protein Excretion g/24h?
<0.15 g/24h
Urinary protein measurements should be taken in What new discovered changes in blood metrics?
raised serum creatinine / reduced GFR
haematuria (esp. microscopic haematuria)
What is urinary protein measurement for?
Assessment of severity of known kidney disease
e.g.Structural renal tract disease, recurrent renal calculi
Urinary protein measurement should be included when initially assessing which patients?
patients with hypertension
patients with newly diagnosed type 2 diabetes
Family history/ hereditary stage 5 CKD
Suspected multisystem disease, e.g., SLE
2 methods to collect urine protein specimen? (think timing)
Timed: 24-hour, 12-hour overnight, 4-hour
Random: assess Urine Protein / Creatinine ratio
