1/25 Renal Disorders in Children - Carlson Flashcards
normal nephrogenesis
tissue and timeline
____nephros x3
renal pelvis, collecting tubules/nephrons/glomeruli
nephrogenesis complete
urogenital system derived predominantly from intermediate mesoderm
- kidneys start low and then ASCEND and ROTATE to get to final position
- develop blood vessels from around locations they settle at
pronephros: 22d-4wk
mesonephros: 24d-8wk
metanephros: 28-32d
renal pelvis: 33d
collecting tubules and nephrons: 44d
glomeruli: 8-9wk
nephrogenesis complete (1M nephrons/kidney): 35wk
development of kidney
- mesonephric duct
- ureteric bud
renal developmental anomalies
- most are unilateral or asymmetric
- M > F
- over 400 candidate genes/proteins identified
- majority of anomalies are result of complex hereditary traits and environmental factors
most common cause of chronic kidney disease and renal transplantation among children
renal devpt anomalies
(list)
cross fused ectopy
fused
nonfused
bilateral
renal dysplasia
types
M:F
steps
unilateral or bilateral
M:F ratio
- unilateral: 1.9x males
- bilateral: 1.3x males
steps
- voiding cystourethrography to be considered in all
- look for other urogenital abnormalities
- DMSA/DTPA radionuclide scan for differential fx of each kidney
vesico-ureteral reflux
retrograde passage of urine from bladder into upper urinary tract
- most common urologic anomaly in children (approx 1% of newborns, up to 30-45% in young children with UTI)
- can present:
- prenatally with uni or bilat hydronephrosis
- postnatally with frequent UTIs
- VCUG for dx and grading
genetic disorders of the kidney
- auto rec polycystic kidney disease (ARPKD)
- auto dom polycystic kidney disease (ADPKD)
- Alport’s Syndrome
- congenital nephrotic syndrome
- nephronopthisis (NPH)
- genetic forms of focal segmental glomerulosclerosis (FSGS)
ARPKD
rare
multiple microscopic corticomedullary cysts
- principally involve distal collecting ducts
cause: mutations in PKHD1 gene → fibrocystin (protein)
clinical manifestions: oligohydramnios, pulmo hypoplasia, HTN, congestic cardiac failure, liver disease, renal failure
perinatal prognosis depends on pulmo status
ADPKD
common
bilateral renal enlargement secondary to multiple cysts
cause: mutations in either PKD1 (85%) → polycystin1 or PDK2 (15%) → polycystin2
- proteins are localized to primary cilia of renal epithelial cells
clinical manifestation: variability - most pts have significant clinical findings only in adulthood
- subset of kids have early onset of disease
- sx: gross or microscopic hematuria, HTN, peoteinuria, cyst infection, renal insufficiency
- kidneys are HUGE with big cysts
- big association: cerebral aneurysm
- be wary of “worst headache of life”
Alport’s Syndrome
hereditary nephritis
primary basement membrane disorder arising form mutations in genes encoding several members of type IV collagen protein family
- X linked, auto rec, or auto dom transmission
-
associated sx/hx
- ocular abnormalities (ant. lenticonus)
- sensorineural hearing loss
- family hx of hematuria assoc with renal failure and deafness
- renal manifestations: microscopic hematuria, progressive proteinuria
- prognosis is unfavorable - endstage disease by mid30s
thickening, fraying of basement membrane
collagen staining: will be absent!
thin basement membrane disease
acquired disorders of kidney in children
- pre-renal acute renal failure
- acute tubular necrosis
- HUS
- interstitial nephritis
- idiopathic nephrotic syndrome
- post-infectious glomerulonephritis
- renal injury associated with systemic disease (SLE, HTN, DM)
- post-renal acute renal failure
hemolytic uremic syndrome
most common cause of acute renal failure
constellation of:
- microangiopathic hemolytic anemia (schistocytes on smear)
- acute renal failure
- thrombocytopenia
cause: verotoxin → endothelial damage
two types:
- diarrhea (D+): mainly secondary to E Coli O157-H7
- no diarrhea (D-): possibly secondary to Strep pneumo
- worse prognosis w recurrent disease, eventual endstage renal disease
acute? high mortality, but 65-85% recover completely
post infectious glomerulonephritis
most commonly secondary to nephritogenic strains of group A, beta hemolytic streptococci (ex. type 12, type 49)
- younger children below 7 at highest risk
- during an epidemic:
- 5-10% kids with pharyngitis
- 25% kids with skin infections
clinical presenation:
- asymptomatic, microscopic hematuria to full blown acute nephritic syndrome
- red to brown urine
- proteinuria (which can reach the nephrotic range)
- edema, HTN, acute renal failure
excellent prognosis with 95% full recovery
look at complement levels
- low C3 level, nl C4 level → normal C3 and C4
starry sky on neoflourescence
humps/dumps on electron microscopy
idiopathic nephrotic syndrome
constellation of
- proteinuria (more than 2gm/d)
- edema
- hypoalbuminemia (serum albumin < 2.5g) (→ edema!!!)
- hyperlipidemia (serum chol >240mg)
two major types:
- minimal change disease (MCD)
- focal segmental glomerulosclerosis (FSGS)
2-6yo, puffy all over, swelling getting worse
give steroids
