HEMATURIA

Definition

1. It is the presence of more than 5 red blood cells/ high power field in sediment of

10ml centrifuged freshly voided urine.

2. Hematuria may be gross seen with naked eye (Figure 6.4) or microscopic.

Causes of hematuria in Children

1. Glomerular diseases

a. Acute post-streptococcal glomerulonephritis

b. Membranous glomerulonephritis

c. Membranous proliferative glomerulonephritis

d. Systemic lupus erytheromatosus

e. Nephritis of chronic infection

f. Rapidly progressive glomerulonephritis

g. Henoch – Schonlein purpura

h. Hemolytic – Uraemic syndrome

i. Interstitial nephritis

j. Post infections glomerulonephritis

2. Urinary tract infection

a. E. coli

b. Klebsiella

c. T.B

d. Bilharsiasis

3. Hematologic causes

a. Coagulopathies

b. Thrombocytopenia

c. Renal Vein thrombosis

d. Sickle cell disease

4. Traumatic

a. Blunt trauma

b. Stones

c. Hypercalciuria

5. Anatomic abnormalities

a. Congenital anomalies

b. Vascular abnormalities

c. Polycystic kidney

6. Miscellaneous

a. Tumors

b. Violent exercise

c. Drugs

i. Penicillin

ii. Aspirin

iii. Heparin

Differential diagnosis of hematuria

1. Hematuria must be differentiated from other causes of dark colored urine.

2. Causes of dark colored urine

a. Dark yellow

i. Concentrated urine

ii. Bilirubinuria

b. Red urine

i. Hemoglobinuria; As in acute hemolytic anemia.

ii. Myoglobinuria; As in muscular necrosis after severe trauma.

iii. Dyes; As colored candies, beet roots and black berries.

iv. Drugs

Rifampicin

Vitamin B complex

Desferoxamine

Phenolphthalein

v. Urates; Pink staining of the diaper, specially in neonates with decreased

fluid intake.

vi. Porphyria

c. Dark brown or black urine

i. Alcaptonuria

ii. Melanoma

iii. Methemoglobinuria.

Difference between renal & extra renal causes of hematuria

Extra renal causes Renal causes

Color

Three tube test

RBCS Casts

RBCS Clots

Blood clots

Edema

Hyper tension

Pink or red

RBCS in tube 1 more 3

Absent

Normal

May be present

Absent

absent

Brown or smoky

Similar in each tube

Present

Deformed

Absent

May be present

May be present

ACUTE POST STREPTOCOCCAL GLOMERULONEPHRITIS

Definition

1. It is an acute nephritic syndrome characterized by the sudden onset of hematuria,

edema, hypertension and acute renal insufficiency.

2. It is the most common glomerular cause of gross hematuria in children.

Etiology

1. It is an auto immune disease following group A beta hemolytic streptococcal

infection of the throat or the skin (nephrogenic strains).

Pathology

1. Gross picture. The kidneys appear symmetrically enlarged.

2. Light microscope examination (Figure 6.5). The glomeruli appear enlarged

and show diffuse proliferation of mesangial and endothelial cells with an increase

in mesangial matrix.

3. Electron microscope examination (Figure 6.6). Electron-dense deposits are

observed on the epithelial side of the glomerular basement membrane.

4. Immunofluorecence microscope examination (Figure 6.7). It shows a lumpy-

pumpy deposits of immunoglobulin and complement 3 (C3) on the glomerular

basement membrane.

Pathogenesis

1. Antibodies formed in response to streptococcal infection combine with their

antigens to from immune complexes that are trapped in the glomeruli.

2. These result in complement activation, release of mediators of inflammation and

glomerular injury and decreased the glomerular filtration rate.

Clinical manifestations

1. Age. It is most common in children 5-12 years and rare below 3 years.

2. Typical presentation include:

a. Hematuria

b. Oliguria

c. Edema

d. Hypertension

3. However, there is a wide range of presentations from just a symptomatic

microscopic hematuria discovered during routine urine examination to acute renal

failure. In some cases, the patient presents mainly with one or more of the

complications.

4. Hematuria is usually gross with smoky, brown or cola-colored urine but urine

usually becomes clear by the end of the first week.

5. Oliguria is present in the majority of cases, very few cases may have anuria and

in some cases the urine volume is normal.

6. Edema is usually mild (puffy eyes and slight edema of the extremities) (Figure

6.8, Figure 6.9). Severe edema is seen in cases with severe oliguria, heart

failure or renal failure.

7. Hypertension is present in 70% of patients. It may appear at any time during the

acute phase and may be as high as 200/120 mm/Hg. It may progress rapidly

within few hours, so blood pressure must be measured every 4 hours. Usually

blood pressure returns to normal slowly by the end of the first week.

8. Renal insufficiency is usually mild and transient in most cases, but severe renal

failure may occur.

9. Non-specific symptoms such as malaise, lethargy, abdominal pain and fever are

common.

10.The acute phase generally resolves within 2 months after onset, but urinary

abnormalities may persist for more than 1 year.

Laboratory findings

1. Urinanalysis

a. Hematuria

b. RBCs casts

c. Few Leucocytes

d. Moderate proteinuria (500-2000 mg/24 hr urine)

2. Blood picture. Mild normochromic anemia due to hemodilution and low grade

hemolysis.

3. Serum C3 level is reduced in the acute phase and return to normal in 6-8 weeks.

4. Kidney function. Increased urea and creatinine.

Diagnosis

1. Diagnosis of acute post streptococcal glomerulonephritis is mot likely in a child

aged between 5-12 years presenting with acute nephritic syndrome with history

of recent streptococcal infection and a low C3 level.

2. Confirmation of the diagnosis requires clear evidence of invasive streptococcal

infection.

a. Positive throat swab

b. Increased Anti-streptolysin O (ASO) titer using the streptozyme test

document pharyngeal streptococcal infection.

c. Increased deoxyribonuclease B antigen document cutaneous streptococcal

infection.

3. Renal biopsy should be considered in the presence of he following:

a. Acute renal failure

b. Associated nephrotic syndrome (heavy proteinuria)

c. Absence of evidence of streptococcal infection.

d. Normal C3 level.

e. Persistence of condition more than 2 months.

4. Differential diagnosis. See other causes of hematuria.

Complications

1. Acute Heart Failure

a. Decreased glomerular filtration rate results in salt and water retention and

secondary circulatory overload.

b. When severe and combined with hypertension, it may lead to heart failure and

pulmonary edema manifested by dyspnea, orthopnea, tachycardia, pulmonary

crepitations, and enlarged tender liver.

c. Chest x-ray will show enlarged heart and pulmonary congestion (Figure 6.10 )

2. Acute renal failure

a. Severe reduction of renal filtration rate results in:

i. Reduced urine production

ii. Electrolyte disturbances (hyperkalemia, hyperphosphatemia,

hypocalcemia)

iii. Acid-base disturbances (acidosis)

iv. Impaired excretion of waste products

b. Clinically it is manifested by marked oliguria or anuria, acidotic breathing,

vomiting, anemia, convulsions and disturbed consciousness (drowsiness,

stupor or coma).

3. Hypertensive encephalopathy

a. Hypertensive encephalopathy is an emergency. It occurs with rapidly rising

blood pressure and consequent loss of auto-regulation of cerebral circulation

resulting in dilation of vessels and brain edema.

b. Clinically it is manifested by irritability, headache, vomiting, blurring of vision,

drowsiness, coma and convulsions.

c. It may be wrongly diagnosed as CNS infection, so blood pressure should be

measured in any child presenting with altered consciousness or convulsions.

Prevention

1. Early systematic antibiotic therapy for streptococcal throat and skin infections

does not eliminate the risk of acute post streptococcal glomerulonephritis.

2. Family members of patients with acute post streptococcal glomerulonephritis

should be cultured for group A hemolytic streptococci and treated if culture is

positive.

Treatment

1. Diet and fluid intake

a. Salt and water are restricted in hypertension, oliguria or anuria, and heart

failure.

b. Fluid intake should be restricted to insensible water loss (400 ml/m2 /24hr)

plus urinary output.

c. Protein and potassium intake restriction is indicated only in renal failure, and

should be continued until renal function has normalized.

2. Treatment of hypertension

a. Diuretics. Furosemide (1 mg/kg/dose IV, every 4-6 hours for rapid decrease

in blood pressure; or 1-2 mg/kg oral every 6-12 hr)

b. Beta blocker. Propranolol (0.05-1 mg/kg/day, in 3-4 doses, oral/IV)

c. Vasodilators. Hydralazine (0.1-0.4 mg/kg/dose, every 2-4 hr, IV)

d. Angiotensin converting enzyme (ACE) inhibitors. Captopril (0.1-0.5

mg/kg/dose, every 8-12 hr, maximum 6 mg/kg/day, oral)

3. Benzathine penicillin or oral penicillin for 10 days is recommended to limit

spread of the nephrogenic organisms (see treatment of group A streptococci ).

Prognosis

1. Complete recovery occurs in 95% of cases

2. Recurrence is extremely rare.