04/19/23AQEEL ALGHAMDI1

PROTEINURIA

DR AQEEL ALGHAMDIMBBS,DCH,JBCP,ABP,FBNconsultant pediatric nephrology

04/19/232

Contents:

Introduction

Pathophysiology

Causes

History

Examination

Investigations

Management

IntroductionIntroduction

proteinuria on a routine screening urinalysis is proteinuria on a routine screening urinalysis is commoncommon

ProteinProtein can be found in the urine of healthy can be found in the urine of healthy children , LESS THAN children , LESS THAN 150mg/24hr (4150mg/24hr (4

mg/m2/hrmg/m2/hr) )

up to up to 10% 10% of children aged 8-15 yr test of children aged 8-15 yr test positivepositive for proteinuria by for proteinuria by urinary dipstick urinary dipstick at at

some timesome time

In a 24-hour urine collection: In a 24-hour urine collection:

Normal values : <4 mg of Normal values : <4 mg of protein/m2/hr protein/m2/hr

Significant values 4–40 mg/m2/hr Significant values 4–40 mg/m2/hr

Nephrotic range >40 mg/m2/hr Nephrotic range >40 mg/m2/hr ""

The challenge is to differentiate The challenge is to differentiate the child with the child with proteinuria related to renal disease from the proteinuria related to renal disease from the

otherwise healthy child with transient orotherwise healthy child with transient or

other benign forms of proteinuria other benign forms of proteinuria

Causes of proteinuriaCauses of proteinuria

Isolated Orthostatic Persistant

Glomerular tubulointerstitial

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11..Transient ProteinuriaTransient Proteinuria

The majority of children found to have The majority of children found to have positive urinary dipstick values for protein positive urinary dipstick values for protein

have have normal dipstick values on repeated normal dipstick values on repeated measurementsmeasurements

The proteinuria usually does not exceed 1-2+ on The proteinuria usually does not exceed 1-2+ on the dipstickthe dipstick

No evaluation or therapy No evaluation or therapy is neededis needed

22..Orthostatic (Postural) ProteinuriaOrthostatic (Postural) Proteinuria

Orthostatic proteinuria is the Orthostatic proteinuria is the most common most common cause of persistent proteinuria in school-cause of persistent proteinuria in school-

aged children and adolescentsaged children and adolescents

Occurring in up to Occurring in up to 60% 60% of children with of children with persistent proteinuriapersistent proteinuria

Patients Patients with orthostatic proteinuria excrete with orthostatic proteinuria excrete normal or minimally increased amounts of normal or minimally increased amounts of

protein in the supine positionprotein in the supine position..

Children with this condition are usually Children with this condition are usually asymptomatic, and the condition is discovered asymptomatic, and the condition is discovered

on routine urinalysison routine urinalysis..

In the In the upright position, urinary protein upright position, urinary protein excretion may be increased 10-foldexcretion may be increased 10-fold, up , up

to 1,000 mg/24 hr (1 g/24 hr)to 1,000 mg/24 hr (1 g/24 hr)..

33..Persistant ProteinuriaPersistant Proteinuria

proteinuria proteinuria indicates renal diseaseindicates renal disease and may be caused by either :and may be caused by either : glomerular or tubular disordersglomerular or tubular disorders

Significant proteinuria on a first morning Significant proteinuria on a first morning urine sample on 3 consecutive days urine sample on 3 consecutive days (>1+ (>1+ on dipstick ,urine specific gravity >1.015 on dipstick ,urine specific gravity >1.015

or protein : creatinine ratio >0.2) or protein : creatinine ratio >0.2)

Initial evaluation of a child with persistantInitial evaluation of a child with persistant proteinuria should include :proteinuria should include :

- Measurement of serum creatinine- Measurement of serum creatinine and electrolyte and electrolyte

- First morning urine - First morning urine protein :creatinineprotein :creatinine

ratio ratio - Serum albumin level - Serum albumin level - Complement - Complement levels.levels.

I. Glomerular ProteinuriaI. Glomerular Proteinuria

Glomerular proteinuria can range from <1 g toGlomerular proteinuria can range from <1 g to >30 g/24 hr.>30 g/24 hr.

Glomerular proteinuria results from alterations in the Glomerular proteinuria results from alterations in the permeability permeability of any of the layers of the glomerular of any of the layers of the glomerular

capillary wall to normally filtered proteins and capillary wall to normally filtered proteins and occurs in a variety of renal diseases. occurs in a variety of renal diseases. ""

Glomerular proteinuria should be suspectedGlomerular proteinuria should be suspected in any patient with:in any patient with:

- First morning urine protein : creatinine- First morning urine protein : creatinine ratio >1.0, or ratio >1.0, or

- Proteinuria accompanied by:- Proteinuria accompanied by: . Hypertension. Hypertension

. Hematuria. Hematuria . Edema . Edema

. Renal dysfunction. Renal dysfunction

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ii. Tubular Proteinuriaii. Tubular Proteinuria

A variety of renal disorders that primarily A variety of renal disorders that primarily involve the tubulointerstitial compartment of the involve the tubulointerstitial compartment of the

kidney can cause kidney can cause low-grade fixed proteinuria low-grade fixed proteinuria (protein : creatinine ratio <1.0(protein : creatinine ratio <1.0

Injury to the proximal tubules Injury to the proximal tubules can result in:can result in:• Diminished reabsorptive capacity Diminished reabsorptive capacity

• Loss of these low molecular weight proteinsLoss of these low molecular weight proteins in the urinein the urine

Tubular Tubular proteinuria may be seen in acquiredproteinuria may be seen in acquiredand inherited disorders and may be associated with and inherited disorders and may be associated with other defects of proximal tubular functionother defects of proximal tubular function, such as, such as

the Fanconi syndrome. the Fanconi syndrome. (glycosuria, phosphaturia, bicarbonate (glycosuria, phosphaturia, bicarbonate

wasting, and aminoaciduria).wasting, and aminoaciduria).

Asymptomatic Asymptomatic patients having persistent persistent proteinuria proteinuria generally have glomerular rather than glomerular rather than

tubular proteinuriatubular proteinuria

Tubular proteinuria is a consistent finding among patients with the X-linked tubular syndromeX-linked tubular syndrome, Dent Dent diseasedisease, caused by mutations of the renal chloride

channel

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In occult cases , glomerular and tubular In occult cases , glomerular and tubular proteinuria can be distinguished by proteinuria can be distinguished by electrophoresis electrophoresis of the urine.of the urine.

In In tubular proteinuria, little or no albumin is tubular proteinuria, little or no albumin is detected, whereas in glomerular proteinuria detected, whereas in glomerular proteinuria

the major protein is albuminthe major protein is albumin.

Clinical Approach

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Asymptomatic proteinuria 11

Hematuria or other signs of

kidney disease

Nonrenal diseases Recheck when resolves

Isolated proteinuriaCollected 12 –hrRecumbent urine

<50 mg/m2/12hr

Isolated intermittent Proteinuria

or orthostatic proteinuria

Reassure

90%

No

No

Yes

Asymptomatic proteinuria

22

Hematuria or other signs of

kidney disease

Nonrenal diseases

Isolated proteinuriaCollected 12 –hrRecumbent urine

50 - 200mg/m2/12hr

Limited evaluationBUN ,Creatinine ,S.electrolyte

sSpot UPr: UCr ratio , S .Total

proteinC3 ,C4 ,ASOT, Lupus

serology (selected cases)Renal imaging ,index of

tubular proteinuria

Follow -up

5%

No

No

Normal

Asymptomatic proteinuria

33

Hematuria or other signs of

kidney disease

Nonrenal diseases

Isolated proteinuriaCollected 12 –hrRecumbent urine

>200mg/m2/12hr

50 - 200mg/m2/12hr

Limited evaluationBUN ,Creatinine ,S.electrolytes

Spot UPr: UCr ratio , S .Total proteinC3 ,C4 ,ASOT, Lupus serology

(selected cases)Renal imaging ,index of tubular

proteinuria

•Evaluation•Consider referral•S .Total protein•HIV status•Fractionated 24-hr urine collection•S. Albumin•S. Cholesterol•ASOT•C3,C4•ANA , anti-DNA•GFR•Renal imaging•Renal biopsy

Abnormal

Yes

5%

No

No