Hematuria and Proteinuria in the Pediatric Patient

Laurie Fouser, MD Pediatric Nephrology

Swedish Pediatric Specialty Care

Hematuria in the Child

• Definition • ³ 1+ on dipstick on three urines over three weeks • 5 RBCs/hpf on three fresh urines over three weeks

• Prevalence • 4-6% for microscopic hematuria on a single

specimen in school age children • 0.3-0.5% on repeated specimens

Sources of Hematuria

• Glomerular or “Upper Tract” – Dysmorphic RBCs and RBC casts – Tea or cola colored urine – Proteinuria, WBC casts, renal tubular cells

• Non-Glomerular or “Lower Tract” – RBCs have normal morphology – Clots/ Bright red or pink urine

The Glomerular Capillary Wall

The Glomerular Capillary Wall

Glomerular Causes of Hematuria

• Benign or self-limiting – Benign Familial Hematuria – Exercise-Induced Hematuria – Fever-Induced Hematuria

Glomerular Causes of Hematuria

• Acute Glomerular Disease – Poststreptococcal/ Postinfectious – Henoch-Schönlein Purpura – Sickle Cell Disease – Hemolytic Uremic Syndrome

Glomerular Causes of Hematuria

• Chronic Glomerular Disease – IgA Nephropathy – Henoch-Schönlein Purpura or other Vasculitis – Alport Syndrome – SLE or other Collagen Vascular Disease – Proliferative Glomerulonephritis

Non-Glomerular Hematuria

• Extra-Renal • UTI • Benign urethralgia +/- meatal stenosis • Calculus • Vesicoureteral Reflux, Hydronephrosis • Foreign body • Rhabdomyosarcoma • AVM • Coagulation disorder

Non-Glomerular Hematuria

• Intra-Renal • Hypercalciuria • Polycystic Kidney Disease • Reflux Nephropathy with Renal Dysplasia • Sickle Cell Crisis • Renal Vein Thrombosis • Renal Hemangioma • Tumor or Leukemia • Nutcracker syndrome/Loin Pain Hematuria

Evaluation – Phase I

• Complete History – Duration, color, discrete clots vs diffuse? – In males, change during stream? – Pain or painless (dysuria, abdominal, flank) – Recent or current infection? – Rashes, joint, or GI symptoms?

Evaluation – Phase I

• Complete Physical – Blood pressure – Volume status (“dry or wet”, rales, gallop) – Edema (periorbital, pretibial, ascites) – Rash

Urinalysis with Microscopy

Evaluation - Phase I

• Complete H&P • Urinalysis with microscopy • Urine culture • Urine calcium: urine creatinine ratio • CBC with platelets (+/-Sickle prep), BUN,

Creatinine, albumin, C3 • Ultrasound of kidneys and bladder • Urine dipsticks on parents and siblings

Evaluation - Phase II

• C3, C4, ANA, Hepatitis B & C • Streptozyme • BUN, creatinine, electrolytes, albumin,

calcium, phosphorus • Hearing evaluation • VCUG or CT

Evaluation - Phase III

• Other laboratory

• Renal biopsy

• Cystoscopy

When to Refer • Family history of kidney disease • Gross hematuria or clots • RBC casts • Proteinuria ³ 1+ • Elevated creatinine or BUN • Hypertension • Imaging abnormalities • Parental anxiety

Proteinuria in the Child

Proteinuria

• Definition – 1+ or more on dipstick – Urine protein:creatinine

• >0.2 mg/mg if over 2 yrs • >0.6 mg/mg ages 6 months-

2yrs • Nephrotic range is >2 mg/mg

– Timed urine protein excretion

• >96 mg/m2/24 hrs • >150 mg/1.73m2/24hrs • Nephrotic range is >3

gm/1.73m2/24 hrs

Causes of Proteinuria

• Physiologic or Intermittent • Postural or Orthostatic • Pathologic

– Glomerular – Tubular

Glomerular Permeability Barrier

Physiologic or Intermittent Proteinuria

• Mechanism is change in glomerular capillary wall permeability – Increased luminal

hydrostatic pressure – Increased blood

flow

• Causes – Acute elevations in BP

or intraglomerular volume

– Catecholamines/stress – Metabolism

Physiologic or Intermittent Proteinuria

• Clinical Settings – Fever – Physical stress (march

proteinuria) – Pregnancy – Immediately post op

unilateral nephrectomy – Acute hypertension or

CHF

• Duration – Transient (hours-

days) – Self-remitting – No need for referral

Postural or Orthostatic Proteinuria

• Two patterns – Fixed, reproducible (15-20%) – Transient (75-80%)

• Accounts for 60% of children and 75% of adolescents with proteinuria

• Incidence – 2-5% of adolescents • MUST DISTINGUISH FROM PATHOLOGIC

PROTEINURIA WITH A POSTURAL COMPONENT

Postural or Orthostatic Proteinuria

• Evaluation:

– Blood pressure, edema should not be present, UA/UC

– First am void for urine protein:creatinine (patient must be sure to go to bed with empty bladder)

• If <0.2 mg/mg, likely orthostatic – Normal renal function panel and renal

ultrasound

Postural or Orthostatic Proteinuria

• Protein in 24 hr fractional urine collection – Supine: <50-75 mg for 8-12 hrs – Upright: 200-1000 mg

• Etiology – Variant of normal permeability or renal vein

kink/entrapment • Long term follow-up

– 10-20 years: resolution or benign outcome

Pathologic Proteinuria

Pathologic Proteinuria

• Fixed proteinuria >150-300 mg/24hrs or

• First am void has urine protein:creatinine >0.2 or

• Edema

– PE (edema, rash, volume), Ht, Wt, BP

– UA (?hematuria), 24 hr urine protein &creatinine

– BUN, creatinine, albumin, lytes, calcium, phosphorus, lipids, C3, C4

– CBC

Causes of Pathologic Proteinuria

• Nephrotic syndrome – Minimal change, FSGS, membranous

• Glomerulonephritis – Henoch-Schonlein purpura, IgA nephropathy,

Alport nephritis • Tubular Proteinuria

– Dent’s disease, Fanconi syndrome

When to Refer

• Parental anxiety or confirmation of orthostatic proteinuria

• Any pathologic proteinuria • ASAP for edema/anasarca,

hypoalbuminemia, hypertension, associated hematuria, elevated creatinine