31. Differential diagnosis of proteinuria in childhood.

Question 1

specific type of protein excreted in the urine, such as albumin or low-molecular-weight (LMW) proteins, depends on the type of kidney disease how ?

Answer 1

Albuminuria is more strongly associated with CKD as a marker of glomerular disease and is a long-term complication of diabetes and hypertension

urinary loss of LMW proteins is more reflective of tubulointerstitial disease

Question 2

definition of poreinurea?

Answer 2

abnormal Protein excretion
100 mg/m2 per day or more than 0.2 mg protein/mg creatinine

neonates and infants, a higher amount of protein excretion, up to 300 mg/m2

Nephrotic-range proteinuria
greater than 1 mg/m2 per day or
greater than 50 mg/kg per day,

Question 3

what are the classifications of porteinurea ?

Answer 3

Proteinuria can be classified as transient, orthostatic, and persistent.

Transient proteinuria, which can be defined as proteinuria noted on 1 or 2 occasions
but not present on subsequent testing,
seen - fever, exercise, stress, seizures, and hypovolemic/dehydration status

Orthostatic proteinuria is characterized by increased protein excretion in the upright position

persistent proteinuria
subclassified as glomerular, tubular, or overflow.

Question 4

Orthostatic proteinuria is one of the most common causes of proteinuria in ?

Answer 4

adolescents

Question 5

how is orthostatic porteinurea diagnosed ?

Answer 5

urine dipstick

normal protein to creatinine ratio

<0.2mg protein /mg creatinin
>2 years

<2years
<0.5 mg/mg

on the first morning void with negative urine dipstick test result,

positive urine dipstick test result, or a UPr/Cr ratio of more than 0.2) at least four to six hours after the patient has been upright

these patients excrete less than 1 g of protein in 24 hours in the upright position, and this normalizes to less than 50 mg in 8 hours of supine position

Question 6

describe the subclassifications of persistent proteinurea ?

Answer 6

glomerular
- increased filtration of macromolecules
- result from glomerular disease most often minimal - selective albuminurea idiopathic nephrotic syndrome (ABSCENCE OF HYPERTENSION AND GROSS HEAMTUREA, BUT THERE IS HYPERLIPIDEMIA)
GLOMERULONEPHRITIS - nephrotic syndrome

tubular 
excretion of low molecular weight protein such as beta-2 micro globulin 
alpha 1 microglobulin
retinol binding protein 
causes - tubulointersttal disease 
acute interstitial nephritis 
acute tubular necrosis 
Fanconi syndrome (glycosuria, phosphaturia, etc.); 
Wilsons disease; Galactosemia; 
Polycystic kidney disease

outflow proteinurea
increased excretion of increased excretion of LMW proteins due to marked overproduction which exceeds tubular reabsorptive capacity

Question 7

how can we measure the urinary protein ?

Answer 7

urine dipstick which measures the albumin

24-hour urine protein excretion. In children, the normal amount of protein is less than 100 mg per m2 per day

sulfosalicylic acid
detects all protein even the low molecular that are not detected by the dipstick
followed by assessment of the degree of turbidity