Renal Flashcards
GFR approximates adult values at what age in children
3 yr old
Definition of Hematuria
presence of more than 5 RBCs/HPF in uncentrifuged urine
rbc result suggestive of underlying pathology in urinalysis
10-50 RBCs/uL
significant hematuria
> 50 RBCs/HPF
Scenario wherein hematuria becomes false-negative
use of formalin
high concentration of ascorbic acid
Scenario wherein hematuria becomes false-positive
Alkaline urine (pH >8)
Urine is contaminated with oxidizing agents such as H2O2 used for cleaning perineum
most common cause of GROSS hematuria
bacterial/viral UTI
this is considered when a child presents with unexplained perineal bruising and hematuria
child abuse
if a patient presents to you with asymptomatic isolated hematuria and normal evaluation, how often do you monitor?
every 3 months until hematuria resolves with BP monitoring
most common cause of chronic glomerular disease in children
Immunoglobulin A nephropathy/ Berger nephropathy
True or false: IgA nephropathy is commonly seen in female than in male?
False
IgA nephropathy is seen more often in male
how long does gross hematuria in IgA nephropathy presents after an upper respiratory or GI infection?
within 1-2 days
- this differentiates the latency period observed in post infectious glomerulonephritis which presents after 4-6 weeks
test to distinguish IgA nephropathy from postinfectious glomerulonephritis
Normal serum C3
poor prognostic indicators at presentation or follow up in IgA nephropathy
Persistent hypertension
Diminished renal function
Significant/increasing/prolonged proteinuria
how to diagnose IgA nephropathy
thru Renal biopsy
primary treatment of IgA nephropathy
appropriate blood pressure control - using ACEi or ARB
management of significant proteinuria - use of immunosuppresive therapy with corticosteroids
other term for hereditary nephritis
Alport Syndrome
type of protein mutated in Alport Syndrome
Type IV collagen
- major component of basement membrane
Presentation of all patients with Alport syndrome
Asymptomatic microscopic hematuria
An abnormality seen in Alport syndrome which is never congenital
Bilateral sensorineural hearing loss
- 90% of hemizygous males with X-linked AS
- 10% of heterozygous females with X-linked AS
- 67% with autosomal recessive AS
pathognomonic ophthalmic finding in Alport Syndrome
Anterior lenticonus
Features supportive of Alport syndrome (at least 2)
Macular flecks
Recurrent corneal erosions
GBM thickening and thinning
Sensorineural deafness
How frequent are Ocular abnormalities seen in X-linked Alport Syndrome?
30-40%
Ocular abnormalities include anterior lenticonus, macular flecks and corneal erosions
Presentation of Thin Basement Membrane Disease
Persistent Microscopic Hematuria
Isolated thinning of the GBM
This type of infection leads to postinfectious glomerulonephritis
Group A beta-hemolytic streptococcal infection
presentation of acute nephritic syndrome
gross hematuria
edema
hypertension
renal dysfunction
characteristic of immunofluorescence microscopy seen in Acute poststreptococcal glomerulonephritis
pattern of “lumpy-bumpy” deposits of immunoglobulin and complement on the GBM and in mesangium
This type of protein has nephritogenic strains that cause APSGN
M proteins
Poststreptococcal GN is most common in what age group, and uncommon to which age group
common in children 5-12 years old
uncommon <3 yr old
onset of PSGN
after pharyngitis: _____
after pyoderma: _____
1-2 weeks after pharyngitis
3-6 weeks after pyoderma
What is the serum C3 level in APSGN?
Significantly reduced in >90% in the acute phase
- returns to normal 6-8 weeks after the onset
recommended antibiotic treatment for ASPGN
10 days of Penicillin
- limits the spread of nephritogenic organisms
- although this does not affect the natural history of APSGN
Best characterized and recognized causes of Membranous nephropathy in children
Chronic Hepatitis B infection
Congenital Syphilis
Membranoproliferative glomerulonephritis (MPGN) or mesangiocapillary glomerulonephritis (secondary forms) is most commonly associated with what type of infections
Hepatitis B and C
Syphilis
Subacute bacterial endocarditis
Infected shunts
Known as the dense deposit disease
Type II MPGN
type of MPGN in which the C3 nephritic factor is present and appears not to be mediated by immune complexes
Type II
Most common in the second decade of life
Membranoproliferative glomerulonephritis
natural history of most forms of CGN
rapid loss of the renal function
this has histopathologic finding of epithelial crescents involving 50% or more glomeruli
Crescentic Glomerulonephritis//Rapidly progressive Glomerulonephritis
presentation of nephrotic syndrome
proteinuria
edema
hypoalbuminemia
classic histopathologic lesion of HIV-associated nephropathy
focal segmental glomerulosclerosis
most important cause of morbidity and mortality in SLE
Lupus nephritis
diagnostic/characteristic of Lupus Nephritis
granular deposition of all Ig isotypes (IgG, IgM, IgA) and complements (C3, C4, C1q) in the glomerular mesangium and capillary walls
SLE is common in what age group
adolescent age group, usually females (5:1 ratio)
remains the cornerstone of therapy in children with SLE
Immunosuppression
Initial therapy of patients with SLE
Prednisone at 1-2 mg/kg/day, followed by slow steroid taper over 4-6 months beginning 4-6 weeks after achieving serologic remission
what is meant by clinical remission in lupus nephritis-SLE?
normalization of renal function and proteinuria
alternative of cyclophosphamide in treatment of lupus nephritis
Mycophenolate mofetil or Azathioprine at 1.5-2 mg/kg single dose OD
major side effects of mycophenolate mofetil
Diarrhea
Leukopenia
Teratogenicity
risk factors for progression to end-stage renal disease in lupus nephritis
Diffuse Class IV lupus nephritis
Poor renal function at presentation or
persistent nephrotic-range proteinuria
known as IgA vasculitis
Henoch-Schönlein Purpura Nephritis
most common small-vessel vasculitis in children
HSP
Enumerate the s/sx of HSP/classic tetrad of HSP
Palpable purpuric rash
Arthritis/arthralgia
Abdominal pain
Evidence of renal disease
indications for a kidney biopsy in HSP nephritis
Significant proteinuria (urine protein >1g/day or urine protein/creatinine ratio >1.0)
Significant Hypertension
Elevated serum creatinine
does mild HSP nephritis need treatment?
no because it resolves spontaneously
S/Sx of Goodpasture Disease
Pulmonary Hemorrhage
Rapidly progressive glomerulonephritis
Elevated Anti GBM antibody titers
In goodpasture disease, what is the pathognomonic findings in immunofluorescence microscopy?
continuous linear deposition of IgG along the GBM
Most common form of thrombotic microangiopathy (TMA) in children
Hemolytic-Uremic Syndrome
This causes the most common form of HUS
Shiga toxin-producing Escherichia coli (STEC)
STEC-HUS is commonly transmitted via?
undercooked meat or unpasteurized (raw) milk and apple cider
A major feature characteristic of genetic forms of HUS
absence of a preceding diarrheal prodrome
Diagnosis of HUS
Combination of microangiopathic hemolytic anemia with schistocytes
Thrombocytopenia
Kidney involvement
++ with the presence of a diarrheal prodrome or pneumococcal infection
Why are platelets not be administered in HUS?
because they are rapidly consumed by the active coagulation and theoretically can worsen the clinical course
FDA approved for the treatment of atypical HUS
Eculizumab
most common cause of intrinstic acute kidney injury (AKI)
Acute Tubular Necrosis
Nephrotic range proteinuria
> 40 mg/m2/hr
ratio of urine-protein creatinine which is suggestive of nephrotic-range proteinuria
greater than 2
most common cause of persistent proteinuria in school-age children and adolescents
Orthostatic (Postural) proteinuria
This confirms the diagnosis of orthostatic proteinuria
absence of proteinuria (dipstick negative/trace, normal UPCR) on the first morning urine sample for 3 consecutive days
possible causes of Orthostatic proteinuria
- altered renal hemodynamics
- partial left renal vein obstruction in the upright lordotic position
- increased BMI
this is the predominant cell of injury in most glomerular diseases characterized by heavy proteinuria
podocyte
triad of clinical findings associated with nephrotic syndrome
Hypoalbuminemia (<2.5 g/dL)
Edema
Hyperlipidemia (cholesterol >200 mg/dL)
standard therapy for nephrotic syndrome
glucocorticoid therapy
why are children with nephrotic syndrome susceptible to infections?
because of hypoglobulinemia, defects in the complement cascade — resulting from urinary losses of IgG, complement factors (C3, C5) leading to impaired opsonization of microorganisms
what particular type of infection in children with NS is susceptible with?
infection with encapsulated bacteria/ pneumococcal disease
90% of children with NS have this type of NS
Idiopathic nephrotic syndrome
85% of total cases of nephrotic syndrome in children
Minimal change nephrotic syndrome
most common cause of end-stage renal disease in adolescents
Focal segmental glomerulosclerosis
MCNS most commonly appears in what age group
2 - 6 yr
mainstay therapy for MCNS
Corticosteroids
definition of response in the treatment of MCNS
attaintment of remission (UPCR <0.2 or <1+ protein on urine dipstick testing for 3 consecutive days) within the initial 4 weeks of corticosteroid therapy
Dyslipidemia in children with NS should be managed with
low-fat diet
Definition of relapse in nephrotic syndrome
UPCR of >2 or >=3+ protein on urine dipstick testing for 3 consecutive days
how many percentage is the risk for ESRD for children with steroid resistant nephrotic syndrome
50% risk within 5 years of diagnosis
recommended initial therapy for children with steroid-resistant nephrotic syndrome
Calcineurin inhibitors such as cyclosporine or tacrolimus
Vaccines to be given in Nephrotic syndrome
- Pneumococcal vaccine (13 valent conjugant, 23 valent polysaccharide)
- Influenza
> defer live vaccination until prednisone dose <1 mg/kg daily or 2 mg/kg on alternate days
treatment period for Nephrotic syndrome
at least 12 week of steroid treatment
- single daily dose of 60 mg/m2/day or 2 mkday, max of 60 mg OD for 4-6 weeks followed by alternate day prednisone (40 mg/m2/day QOD or 1.5 mg/kg QOD) for 8 weeks to 5 months
This is caused by mutations in the WT1 gene, resulting in abnormal podocyte function
Denys-Drash Syndrome
— early-onset failure with renal mesangial sclerosis and male pseudohermaphrodism
Mainstream therapy for congenital nephrotic syndrome
- Albumin and diuretic infusion
- High amount of protein (3-4 g/kg), lipids
- High caloric intake
- Vitamin and thyroid hormone replacement
Definitive treatment of congenital nephrotic syndrome
Renal transplantation
Enumerate the 4 main types of RTA
Type I: Classic Distal
Type II: Proximal RTA
Type III: Combined
Type IV: Hyperkalemic RTA
rare X linked disorder characterized by congenital cataracts, mental retardation and Fanconi syndrome
Lowe Syndrome
presentation of Fanconi Syndrome
- low molecular weight proteinuria
- glycosuria
- phosphaturia
- aminoaciduria
- PROXIMAL RTA
Electrolyte imbalance seen in distal Type I RTA
Hypokalemia
Hypercalciuria
distinguishing features of distal RTA
Nephrocalcinosis
Hypercalciuria
differentiate urine pH of proximal and distal RTA
pH <5.5 in proximal RTA and pH >6.0 in distal RTA
Formula of serum anion gap and urine anion gap
Serum: [Na] - [Cl + HCO3]
Urine: [Na + K ] - Cl
Mainstay of therapy in all forms of RTA
bicarbonate replacement
defined as an abrupt loss of kidney function leading to a rapid decline in the glomerular filitrate rate (GFR), accumulation of waste products such as BUN and creatinine, dysregulation of extracellular volume and electrolyte homeostasis
Acute Kidney Injury
UO of 0.5 cc/kg/hr for 6-12 hour: What stage in the KDIGO staging of AKI
Stage I
anuria for >12 hour: what stage in the KDIGO staging of AKI
Stage III
Definition of AKI
Increase in serum crea by >0.3 mg/dL from baseline within 48 hour or
increase in serum crea to >1.5x baseline within the prior 7 days or
Urine volume <0.5 cc/kg/hr for 6 hr
Indications for dialysis in AKI
-Anuria/oliguria
-Vol overload with evidence of hypertension and/or pulmonary edema refractory to diuretic therapy
-Persistent hyperkalemia
-Severe metabolic acidosis unresponsive to medical management
-Uremia (encephalopathy, pericarditis, neuropathy)
-Calcium:phosphorus imbalance
Leading causes of death in childhood onset ESRD
Infectious diseases
Cardiovascular cause
Criteria for definition of CKD
Either of the ff:
1. Kidney damage >/= 3 months, defined as structural or functional abnormalities of the kidney, with or without decreased eGFR
— abnormalities in the composition of the blood or urine
— abnormalities in imaging tests
— abnormalities on kidney biopsy
- GFR <60 for >/= 3 months, with/without other signs of kidney damage
primary determinant of CKD progression
Progression of tubulointerstitial fibrosis
gold standard of BP evaluation
Ambulatory Blood Pressure monitoring over 24 hours
cause of hypertension in patients with CKD
Volume overload or excessive production of renin
most common cause of neonatal AKI (seen in 70% of cases)
Sepsis
classic triad of PSGN
Hematuria
Edema
Hypertension
++ renal dysfunction
In acute poststrep GN, when does the acute phase resolves, as well as the urinary protein excretion, hypertension and persistent microscopic hematuria
Acute phase: 6-8 weeks
Urinary protein excretion and hypertension: 4-6 weeks
Persistent microscopic hematuria: 1-2 years
