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Flashcards in Renal Deck (85)
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Define hematuria

at least 5 rbc per microliter of urine


significant hematuria

>50 rbc per microliter of urine


When does the GFR of a child approach adult values?

at 3 yrs old


Between GFR and BUN, which value is affected by state of hydration and nitrogen balance? Which value is primarily influenced by the level of glomerular function?

GFR: affected by glomerular function
BUN: hydration and nitrogen balance


The most common cause of gross hematuria

bacterial urinary tract infection


Presentation with gross hematuria is usually within 1-2 days after the onset of an apparent viral upper respiratory tract infection and typically resolves within 5 days

immunoglobulin A (IgA) nephropathy

- contrasts to a latency period of 7-21 days occurring between the onset of a streptococcal pharyngitis or impetiginous skin infection and the development of poststreptococcal acute glomerulonephritis
- the most common chronic glomerular disease


Chronic infection that is the most common cause of membranous nephropathy worldwide



Nephropathy presenting in the 2nd decade of life, commonly as nephrotic syndrome. Microscopic hematuria present, some have hypertension, sometimes associated with renal vein thrombosis. Normal C3.

Membranous nephropathy

- dx by renal bx
- common indications for bx: nephrotic syndrome in a child >10 yr or unexplained persistent hematuria with significant proteinuria


Most common etiology of secondary membranous nephropathy

SLE or chronic infections (chronic hepB, congenital syphilis, malaria)


PSGN and MPGN both have similar clinical presentations. MPGN can present as acute nephritic syndrome (hematuria, hypertension, renal insufficiency) or nephrotic syndrome. C3 is low in both diseases. How can the two be differentiated?

PSGN usually +ASO, with hx of strep infection, C3 level low but resolves in 6-8 wks

MPGN C3 persists beyond 2 mos. In this case, renal bx is warranted for a histopathologic diagnosis


the most common small vessel vasculitis in childhood. It is characterized by a purpuric rash and commonly accompanied by arthritis and abdominal pain

Henoch-Schonlein purpura (HSP)

- 50% of patients with HSP develop renal manifestations, which vary from asymptomatic microscopic hematuria to severe, progressive glomerulonephritis
- nephritis usually follows onset of the rash, often weeks or even months after the initial presentation of the disease


What is the histopathologic hallmark of crescentic GN?

crescents in glomeruli

- CGN presents as acute nephritis (hematuria, some degree of renal insufficiency, and hypertension) and usually have concomitant proteinuria, often with nephrotic syndrome.
- If the patient has no extrarenal manifestations and a negative serologic evaluation, and if the biopsy has no immune or EM deposits, the diagnosis is idiopathic, rapidly progressive CGN.


Characterized by pulmonary hemorrhage and glomerulonephritis

usually presents as hemoptysis and acute nephritic syndrome with hematuria, proteinuria, and hypertension

Goodpasture disease

- crescentic GN on biopsy
- rare in children
- rapidly progressive course
- Other diseases that can cause a pulmonary-renal syndrome: SLE, HSP, Wegener granulomatosis, microscopic polyangiitis
- Goodpasture has serum antibodies directed against GBM (anti–type IV collagen in GBM), and characteristic renal biopsy findings


One of the most common causes of community-acquired acute kidney failure in young children, characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency, usually occuring after an acute gastrointestinal illness (~3wks after onset of GI illness; acute or bloody diarrhea)

Hemolytic-Uremic syndrome

- thrombotic thrombocytopenic purpura (TTP) is also characterized by microangiopathic hemolytic anemia, renal injury and low platelet, but TTP usually has CNS involvement, fever and a more gradual onset
- diagnosis is mainly clinical


What is the most common form of HUS?

HUS caused by toxin-producing Escherichia coli (shiga toxin of Shigella or verotoxin of E. coli ) that cause prodromal acute enteritis

- Disease is usually transmitted by undercooked meat or unpasteurized milk or apple cider


Bilateral flank mass in a patient with oligohydramnios, pulmonary hypoplasia, and hypertension and absence of renal cysts by sonography of parents

Autosomal recessive polycystic kidney disease

- this is different from autosomal dominant polycystic kidney disease, which is the most common hereditary human kidney disease


What is the most common cause of persistent proteinuria in school-aged children and adolescents?

orthostatic proteinuria

- asymptomatic
- dx: collection of first morning urine for 3 consecutive days, do complete urinalysis and spot UPr:UCr; absence of proteinuria confirms diagnosis


Triad of clinical findings characteristic of nephrotic syndrome

- nephrotic range proteinuria: >2-3 UPr:UCr
- protein excretion of >40 mg/m2/24hr


What is the hallmark of idiopathic nephrotic syndrome?

Extensive effacement of podocyte foot processes


Among the idiopathic nephrotic syndromes which one usually does not present with hypertension and gross hematuria

Minimal change nephrotic syndrome

- common in 2-6 yo
- urinalysis: 3+ to 4+ protein
- microscopic hematuria in 20%
- spot UPr:UCr >2
- serum crea normal
- serum albumin <2.5 g/dL
- serum TG and TC elevated
- C3 normal
- renal bx not routinely performed
- 95% steroid responsive (4-6 wks)


Subset of patients that relapse while on alternate day steroid therapy or within 28 days of completing a successful course of prednisone therapy

steroid dependent


Patients who respond well to steroid therapy but relapse >=4 times in 12 mos

frequent relapsed


Patients who fail to respond to steroid therapy within 8 wks of therapy

steroid resistant

- steroid-resistant nephrotic syndrome are usually caused by FSGS (80%), MCNS or MPGN


What are the most common organisms causing spontaneous bacterial peritonitis in children with nephrotic syndrome?

S. pneumoniae and E. coli


What particula vaccines should children with nephrotic syndrome receive?


- usually when child is on remission and off prednisone therapy
- for children on steroids, since they are immunocompromised, avoid giving live vaccines (MMRV, OPV, RV) - may be given one month after discontinuation of prednisone


low molecular weight proteinuria, glycosuria, phosphaturia, aminoaciduria, and proximal RTA

Fanconi Syndrome


Rare X-linked disorder characterized by congenital cataracts, mental retardation, and Fanconi syndrome

Oculocerebrorenal syndrome of Lowe

- present in infancy with cataracts, progressive growth failure, hypotonia, and Fanconi syndrome
- Significant proteinuria is common.
- Blindness and renal insufficiency often develop
- Characteristic behavioral abnormalities are also seen, including tantrums, stubbornness, stereotypy (repetitive behaviors), and obsessions.


characterized by a normal anion gap (hyperchloremic) metabolic acidosis in the setting of normal or near-normal glomerular filtration rate

Renal Tubular Acidosis


Pathophysiology of RTAI and RTAII

Proximal RTA (RTA II) results from impaired bicarbonate reabsorption and distal RTA (RTA I) from failure to secrete acid.


global proximal tubular dysfunction characterized by low molecular weight proteinuria, glycosuria, phosphaturia, aminoaciduria, and proximal RTA

Fanconi syndrome