PEDIATRIC NEPHROLOGY 1.1 (AB) Flashcards
Where is the glomerulus located?
Retroperitoneal
What structures are found in the outer layer (cortex) of the kidney?
Glomerulus
What structures are found in the inner layer (medulla) of the kidney?
Loops of Henle
How many nephrons are present at birth?
Approximately 1 million nephrons
When is nephron formation complete?
34-36 weeks gestation
Can new nephrons form after birth?
No
What are risk factors for reduced nephron number?
Low birth weight
What conditions can reduced nephron number lead to?
Primary hypertension
What is the role of mesangial cells and matrix?
They provide structural support for the glomerular capillary
What structure surrounds the glomerulus?
Bowman’s capsule
What is the best parameter to describe kidney function?
Glomerular filtration rate (GFR)
What types of molecules filter freely in the glomerulus?
Electrolytes
What types of molecules are retained in circulation by the glomerulus?
Albumin and globulins
What is the significance of albumin in urine?
It is almost always pathologic and indicates potential glomerular damage
What laboratory parameter is affected by hydration and nitrogen balance?
Blood Urea Nitrogen (BUN)
What is BUN a product of?
Protein breakdown
What is creatinine derived from?
Muscle metabolism
How is creatinine production described?
Steady and relatively constant
What happens to creatinine in renal insufficiency?
Serum creatinine rises because it is not excreted properly
What formula is used to estimate GFR in pediatric patients?
Schwartz formula
What is the Schwartz formula?
eGFR = 0.413 x height (cm) / serum creatinine (mg/dL)
What is the creatinine clearance for a 10-year-old male who is 144 cm tall with a creatinine of 0.56 mg/dL?
eGFR = 0.413 x 144 / 0.56 = 106.2 mL/min/1.73 m²
What does glomerular disease affect?
The glomerulus
What are potential causes of glomerular disease?
Genetic
What causes glomerulonephritis?
Immunologic injury to the glomerulus
What is the definition of hematuria?
Presence of more than 5 RBC/HPF
What are benign causes of transient hematuria?
Fever
How many RBC/uL suggest underlying pathology?
10-50 RBC/uL
What level of RBC/HPF is considered significant hematuria?
More than 50 RBC/HPF
What substances can cause false positive hematuria?
Ascorbic acid >2000 mg/day
What are common causes of upper urinary tract disease?
IgA nephropathy
What are multisystem diseases that can cause hematuria?
SLE nephritis
What are examples of tubulointerstitial diseases?
Pyelonephritis
What vascular disorders can cause hematuria?
Arterial/venous thrombosis
What anatomic disorders can cause hematuria?
Hydronephrosis
What lower urinary tract diseases can cause hematuria?
Cystitis
What condition was formerly known as Munchausen syndrome by proxy?
Factitious syndrome by proxy
Which glomerulonephritides present with hypocomplementemia?
Postinfectious GN
What percentage of children with acute or chronic hematuria is associated with systemic illness?
0.1
What is the most common chronic glomerular disease in children?
Immunoglobulin A Nephropathy (Berger Nephropathy)
Where are IgA deposits found in Berger nephropathy?
Mesangial glomerular deposits
How is Berger nephropathy diagnosed?
Renal biopsy with immunologic staining
What is the triad presentation of nephropathy/nephritis?
Hematuria
What condition presents with the same abnormalities as Henoch-Schönlein purpura nephritis?
Immunoglobulin A Nephropathy (Berger Nephropathy)
What is the typical preceding event 1-2 weeks before the onset of IgA nephropathy?
Upper Respiratory Tract Infection (URTI)
What is the serum C3 level in IgA nephropathy?
Normal
What is the main treatment goal for all nephritis?
Appropriate blood pressure control
When is dialysis indicated for nephritis in children?
Only if absolutely required
What gene mutation is responsible for 85% of Alport Syndrome cases?
COL4A5 gene
What type of collagen is affected in Alport Syndrome?
Type IV collagen
What is the hallmark microscopic hematuria finding in Alport Syndrome?
Persistent asymptomatic microscopic hematuria
In Alport Syndrome
when does proteinuria typically worsen in boys?
What type of hearing loss occurs in Alport Syndrome?
Bilateral sensorineural hearing loss (non-congenital)
What is the pathognomonic ocular abnormality in Alport Syndrome?
Anterior lenticonus
What are key diagnostic steps for Alport Syndrome?
Family history
What are the microscopy findings in Alport Syndrome?
Mesangial proliferation
What is seen on electron microscopy in Alport Syndrome?
Diffuse thickening
What medications can slow the progression of Alport Syndrome?
ACE inhibitors and ARBs
At what age does ESRD typically occur in Alport Syndrome?
Before 30 years old
What condition is characterized by persistent microscopic hematuria and isolated GBM thinning?
Thin Basement Membrane Disease
What triggers hematuria in Thin Basement Membrane Disease?
Respiratory tract infections
What are the key monitoring parameters in Thin Basement Membrane Disease?
Hypertension
What type of infection often precedes Acute Post-Streptococcal Glomerulonephritis (APSGN)?
Throat (1-2 weeks) or skin (3-4 weeks) infection
What pathogen causes Acute Post-Streptococcal Glomerulonephritis?
Group A beta-hemolytic streptococci
What is the age range most commonly affected by APSGN?
5-12 years old
What type of immune reaction causes APSGN?
Immune complex mediated
What happens to serum C3 in APSGN?
Low
What is the triad presentation of APSGN?
Hematuria
What causes oliguria and edema in APSGN?
Inflammation leading to fluid retention
What is the first-line medication for hypertension in APSGN?
Furosemide (loop diuretics)
What dietary restriction helps manage APSGN?
Sodium restriction
What antibiotic is given for 10 days to treat residual streptococcal infection in APSGN?
Penicillin
How long should microscopic hematuria be monitored in APSGN?
12-24 months
How soon should C3 normalize after APSGN onset?
Within 6 weeks
What is the histologic hallmark of Membranoproliferative Glomerulonephritis (MPGN) Type I?
Lobular pattern and capillary wall thickening
What is the characteristic finding in Type II MPGN (Dense Deposit Disease)?
C3 immunofluorescence without Ig
What autoantibody is found in Type II MPGN?
C3 nephritic factor
How is MPGN diagnosed?
Renal biopsy and persistently low C3
What is the prognosis of MPGN 10 years after onset?
50% progress to ESRD
What is the prognosis of MPGN 20 years after onset?
90% progress to ESRD
What is another name for Rapidly Progressive Glomerulonephritis (RPGN)?
Crescentic glomerulonephritis
What is the defining feature of RPGN?
Rapid progression to ESRD
What is the biopsy hallmark of RPGN?
Crescents overlying the glomerulus
What is the classification of Primary RPGN Type I?
Anti-GBM antibody disease (e.g.
What is the classification of Primary RPGN Type II?
Immune complex mediated
What is the classification of Primary RPGN Type III?
Pauci-immune (ANCA-positive)
What systemic diseases can cause Secondary RPGN?
SLE
What are the main diagnostic tools for RPGN?
Clinical evaluation
What is the main treatment for RPGN?
High-dose steroids and cyclophosphamide
What adjunct treatment can be used in severe RPGN cases?
Plasmapheresis
