01/30 Disorders of the Kidney and Urologic Systems in Childhood Flashcards
1. Identify how kidney disease in children may differ from that in adults 2. Become familiar with childhood glomerular diseases 3. Review some inherited and metabolic conditions that may lead to tubulointerstitial dysfunction in children 4. Correlate genitourinary embryology with cystic dysplastic kidney disease and congenital anomalies of the urinary tract
DDx of Hematuria in kids
When you see blood in the urine, first branch-point question is: is this glomerular or non-glom.
Glomerular causes—e.g. Glomerulonephritis
—E.g. Post-Infectious GN by far most common (not just strep; common post-GI bugs, too!)
—Also: IgA Nephropathy, HSP, SLE, Membranoproliferative GN (Idiopathic type), HUS, Alport Syndrome
Non-Glomerular Conditions (TTICCCHSS) —Trauma —Tumor —Infection —Cystic disease —Congenital obstruction —hyperCalcuria —Stones —Sickle Cell
Work-Up for GN in kids
Assess Severity
—Lytes, BUN, Cr
—Quantitate protein (nephritis still has prot)
Assess Etiology CBC —Systemic/chronic illness (e.g. Lupus)? Consider —Strep titers, C3, C4, ANA, others
define anasarca
severe, generalized edema
labs needed to dx nephrotic syndrome
- nephrotic range proteinuria or high protein : Cr ratio
- edema
- hypoalbuminemia
- high cholesterol
I say swollen eyes, you think
nephrotic syndrome
DDx of Nephrotic Syndrome in Kids
**Just know these big categories
-
Primary Nephropathy
—Minimal Change Disease (etc. FSGN, membranous in teens) - Secondary Nephropathy
—(e.g. SLE) - Glomerulonephritis (Mixed nephritis/nephrosis)
—(e.g. post-infx GN with nephrotic syndrome) - Hereditary causes
Working up Nephrotic syndrome
If everything consistent (young age, no GN s/sx (no RBC casts, nl BP, nl Cr)…
—…can make presumptive diagnosis based on treatment response to prednisone
_If anything atypical, or fails to respond to treatment, then further evaluation, likely including biopsy necessary
Treating Minimal Change Dz
—Expected outcomes
—Re-occurence?
Presumptive treatment = Prednisone
—Usual response in 2-4 wks, small # take longer
—Tx intercurrent infections/triggers
Majority recur, but eventually “outgrow”
—Significant minority one and done
—Frequent relapse
—Steroid dependent
**Steroid resistant—think other etiology
Pedi Tubulointerstitial Dzs: walk through the nephron and rattle off dzs
PT: Fanconi’s Syndrome
LoH: Bartter’s Syndrome
DCT: Gitelman’s, Gordon’s Syndrome
CD: Type IV RTA, Nephrogenic DI, Liddle’s Syndrome
Fanconi's Syndrome —Where? —What happens —Presentation —Tx?
Global PT Dysfunction
—Water, sodium, bicarbonate, calcium, phosphate, uric acid, glucose, amino acids
Clinically most significant findings include
—Poor growth, metabolic acidosis, rickets
Tx
—Targeted to underlying etiology
—Supportive biochemical correction
Bartter’s Syndrome
—Presentation
—Where?
—What happens
Como Esos Niños Presentan
—Polyuria, Polydipsia
—Salt craving!!
Occurs in LoH - akin to chronic lasix use
Lo Que Pasa
—Dehydration from water and H2O wasting → RAAS activation ↑ K+ excretion → Hypokalemia AND ↑ (H+) excretion → Metab Alk
—Hypercalciuria (loss of paracellular reabs)
Gitelman’s Syndrome
—Presentation
—Where?
—What happens
PRESENTACÍON
—crave vinegar! (pickle juice, V8)
Occurs in DCT: TSC (thiazide-sensitive NaCl cotransporter)
—Autosomal recessive
PATHOPHY —Hypokalemia —Metabolic acidosis —Hypomagnesemia —Hypocalciuria (Thiazide is Ca-Sparing)
Gordon’s Syndrome
—Presentation
—Where?
—What happens
Super rare - mirror image of Gitelman’s
Present w/ Salt and H2O retention = ↓ renin HTN
Occurs in DCT: NaCl co-transporter (NCCT) constitutively activated (vs. inactive in Gitelman’s)
—Hyperkalemia, Metabolic Acidosis
Tx w/ thiazides
Liddle’s Syndrome
“Pseudo-aldosteronism”
PRESENTATION
—Early presenting severe HTN
Occurs in Collecting Duct:
—Autosomal Dominant: Gain-of-function mutations of ENaC channel (Channels not recycled off membrane)
Sodium retention → = ↓ renin HTN
—Hypokalemia and Metabolic Alkalosis
—No response to Spironolactone
—Treat with Amiloride, a direct ENaC antagonist
Only 30 cases ever reported!
Multi-Cystic Dysplastic Kidney (MCDK) Disease —Presentation —Etiology —Diagnostic —Complications
PRESENTATION
By strict definition a non-reniform collection of cysts
—Appears as a collection of grapes
—No identifiable “renal” tissue
ETIOLOGY
—Abnormal interaction between ureteric bud and metanephric mesenchyme
DIAGNOSTIC
Most cases are now identified on prenatal ultrasonography
—Formerly commonly detected as a neonatal abdominal mass
—Incidence is between 0.3 to 1 in 1000; most often unilateral
COMPLICATIONS
—Risk for contralateral kidney or lower urinary tract abnormalities
—If other side normal, usually asymptomatic
—If on left and presses stomach → GERD
