Pediatrics - Nephrology Flashcards
PED - 8.1
Which of the factors shown below is at the origin of proteinuria in pediatric minimal change nephrotic syndrome?
A) immune-complex deposition in the glomeruli
B) functional damage of the podocyte-basement immune-complex functional unit
C) hypercholesterinaemia
D) none of the above
ANSWER
B) functional damage of the podocyte-basement immune-complex functional unit
EXPLANATION
The cause of proteinuria in idiopathic nephrotic syndrome is the functional damage of the podocyte-basement membrane unit
PED - 8.2
Characteristic for minimal change nephrotic syndrome are the following (with one exception). Which one is the exception?
A) hypoproteinaemia
B) hypercholesterinaemia
C) low serum calcium level
D) predisposition to hypocalcemic spasms
ANSWER
D) predisposition to hypocalcemic spasms
EXPLANATION
Nephrotic syndrome is characterized by heavy proteinuria and hypoproteinemia, together with low total calcium level. However, the ionized calcium level is normal, thus hypocalcemic spasm (tetany) does not occur
PED - 8.3
Characteristics for minimal change nephrotic syndrome are the following with one exception. Which one is the exception?
A) its onset is usually between 1–6 years
B) podocyte foot process effacement is seen on electron microscopy
C) it frequently leads to renal insufficiency
D) hypertension is not part of the clinical signs
E) patients have hyperlipidemia
ANSWER
C) it frequently leads to renal insufficiency
EXPLANATION
Idiopathic nephrotic syndrome in childhood is usually a benign condition, responding to steroid treatment. Histology usually shows minimal change, it does not lead to renal impairment.
PED - 8.5
What is the definition of steroid resistance in idiopathic nephrotic syndrome in childhood?
A) if hematuria is present from the beginning of observation
B) if the patient needs high doses of steroid to stay in remission
C) in case of extreme cushingoid appearance
D) if after 4 weeks of high dose prednisolone treatment (60 mg/m2) the patient is still proteinuric
E) if hypertension develops during therapy
ANSWER
D) if after 4 weeks of high dose prednisolone treatment (60 mg/m2) the patient is still proteinuric
EXPLANATION
In the case of steroid sensitive minimal change nephrotic syndrome remission is usually achieved after 1-2 weeks of treatment; 95% of patients are in remission after 4 weeks. If after 4 weeks treatment the patient is still proteinuric the patients is regarded steroid resistant.
PED - 8.6
The following are signs of acute post-streptococcal glomerulonephritis, with one exception. Which one is the exception?
A) Hematuria
B) Proteinuria
C) Bacteriuria
D) Hypertension
E) Elevated ASO titer
ANSWER
C) Bacteriuria
EXPLANATION
Acute post-streptococcal glomerulonephritis is an immune-mediated inflammation of the glomeruli. Thus, there are no pathogenic bacteria in the urine.
PED - 8.7
Acute poststreptococcal glomerulonephritis is characterized by the following with one exception. Which is the exception?
A) early antibiotic treatment of the primary infection may prevent the development of the disease
B) it may be the consequence of scarlet fever
C) the prognosis in childhood is usually good
D) hypertensive encephalopathy may be the first presenting sign
E) Streptococci are always present in the urine
ANSWER
E) Streptococci are always present in the urine
EXPLANATION
In the case of post-streptococcal glomerulonephritis, the pathogenic bacteria are causing a primary infection at the upper respiratory tract or less frequently on the skin. About two weeks later the immune response to this infection leads to glomerular injury. At that time, the pathogenic bacteria may already be cleared from the primary site of infection. The urine is free of streptococci during the whole process. (See also question PED-8.6.).
PED - 8.8
All but one of the following may be complications of acute glomerulonephritis. Which one is the exception?
A) heart failure
B) urosepsis
C) hyperkalaemia
D) uraemia
E) encephalopathy
ANSWER
B) urosepsis
EXPLANATION
A sterile, immune-mediated inflammation is at the origin of the acute glomerulonephritis, thus urosepsis cannot develop.
PED - 8.9
The following pediatric diseases may cause hematuria with one exception. Which one is the exception?
A) Wilms-tumor
B) minimal change nephrotic syndrome
C) polycystic kidney disease
D) subacute bacterial endocarditis
E) renal artery thrombosis
F) renal vein thrombosis
ANSWER
B) minimal change nephrotic syndrome
EXPLANATION
Microscopic hematuria is not characteristic for minimal change nephrotic syndrome.
PED - 8.11
Bacteriuria is termed significant if the mid-stream urine culture shows one of the results below. Which one?
A) some uniform colonies of bacteria
B) 100 000/ml mixed bacterial colonies
C) 100 000/ml uniform colonies of a single bacterium strain
D) 1000/ml E. Coli + Proteus
E) 1 000 000/ml mixed bacterial colonies
ANSWER
C) 100 000/ml uniform colonies of a single bacterium strain
EXPLANATION
100000/ml uniform colonies of a single bacterium strain from a correctly collected midstream urine are regarded as significant bacteriuria.
PED - 8.13
One of the statements below does not apply to pediatric lower urinary tract infections. Which one?
A) leucocyturia and bacteriuria are present
B) high fluid intake is part of the therapy
C) preemptive treatment with penicillin as the first choice is indicated until the results of urine culture allow targeted treatment
D) targeted treatment should be continued at least for 5-7 days
E) after ending treatment penicillin urine control is indicated
ANSWER
C) preemptive treatment with penicillin as the first choice is indicated until the results of urine culture allow targeted treatment
EXPLANATION
penicillin enteric bacteria, predominantly E Coli are usually at the origin of urinary tract infections in childhood the penicillin treatment is inefficient
PED - 8.17
All but one of the following are used to treat acute renal failure. Which one is the exception?
A) fluid rescue in the case of hypovolemia
B) furosemide should be used as diuretic
C) an osmotic diuretic (20% Mannisol) may be tried
D) if oligo-anuria persists further fluid intake should be restricted
E) an oral fluid load is used to break through oliguria
ANSWER
E) an oral fluid load is used to break through oliguria
EXPLANATION
Although the answers A and E resemble at a first glance the major difference is as follows: if renal insufficiency is caused by volume depletion (prerenal azotemia), fluid rescue may lead to the restitution of urine production that can be increased by further diuretic treatment (answers A-D). An uncontrolled oral fluid load in a patient with impaired glomerular filtration may lead to volume retention and in a severe case to hyponatremia caused by dilution and water intoxication.
PED - 8.18
All but one among the causes below may cause chronic renal insufficiency. Which is the exception?
A) chronic pyelonephritis
B) about half of the cases of acute post-streptococcal glomerulonephritis
C) nephrocalcinosis
D) membranoproliferative glomerulonephritis
E) focal segmental glomerulosclerosis
ANSWER
B) about half of the cases of acute post-streptococcal glomerulonephritis
EXPLANATION
Acute post-streptococcal glomerulonephritis is usually self-limited, with a tendency to spontaneous resolution.
PED - 8.19
Intravenous urography is indicated in childhood, in one of the following cases:
A) in acute upper urinary tract infection
B) in every case following acute urinary tract infection
C) in nephrotic or nephritic syndrome, if macroscopic hematuria is also present
D) in the case of obstructive uropathy associated with pyelon and ureter duplex, if surgical intervention is planned
ANSWER
D) in the case of obstructive uropathy associated with pyelon and ureter duplex, if surgical intervention is planned
EXPLANATION
The indication of intravenous pyelography is very limited in the last years, due to its high radiation exposure and the use of iodinated contrast material. It is very rarely performed in specific cases – ex. as preoperative clear up of the anatomy of double ureters at the ureterovesical junction. It is indicated neither in the acute phase of urinary tract infection nor following the eradication of the infection, as other imaging techniques (sonography, dynamic and static radionuclide imaging, retrograde cystourethrography) are convenient and suitable to elucidate the presence of eventual malformations and functional damage.
PED - 8.20
Steroids are effective in the treatment of most cases of pediatric idiopathic nephrotic syndrome since there is an inflammation mediated by immuncomplexes in the glomeruli.
A) both are true and there is a cause-effect relation between them
B) both are true but there is no cause-effect relation between them
C) the first is true, the second is false
D) the first is false, the second is true
E) both are false
ANSWER
C) the first is true, the second is false
EXPLANATION
Idiopathic nephrotic syndrome usually reacts to steroids thus the first part of the answer is correct. The cause of proteinuria is the functional alteration of the podocyte-basement membrane unit; there are no immune-complexes at the basement membrane. Thus, the second answer is false.
PED - 8.21
The most probable diagnosis is:
A 6-year-old boy complains for abdominal pain, nausea, his left knee and right ankle are painful and swollen. He is transferred to the hospital because of epigastrial pain and bloody stools. At admission his feet is swollen and painful. Erythematous, maculo-papular eruptions are seen at the lower extremities, the ankles and the buttocks. The differential shows moderate leucocytosis and anemia. In the urine microscopic hematuria is present. Blood pressure is normal for his age. Antistreptolysin titer is high (1200 U).
A) rheumatoid arthritis
B) colitis ulcerosa
C) Schönlein–Henoch-purpura
D) SLE
E) febris rheumatica
F) haemolytic uraemic syndrome
G) acute glomerulonephritis
ANSWER
C) Schönlein–Henoch-purpura
EXPLANATION
Based on the acute onset, the joint pain, gastrointestinal symptoms, skin rash and urinary involvement the most probable diagnosis is Schönlein-Henoch – IgA vasculitis. It is in some cases caused by streptococcal infection – in this case, the high ASO titer is indicative for that etiology. Remark: rarely other types of vasculitis (as SLE, or paraneoplastic syndromes, etc.) may mimic the symptoms of Sch-H purpura. This is rather the case in adult patients. Here the most probable diagnosis should be given. Thrombocyte count may help to differentiate from hemolytic uremic syndrome where thrombocytopenia is present. As the ASO titer was elevated we have to consider the streptococcal origin of the disease, thus penicillin treatment may be indicated to eradicate the bacteria eventually still present and to eliminate the ongoing antigenic trigger. Sch-H purpura is often associated with hematuria. This may be caused by the presence of vasculitis in the urinary tract that may cause local hematuria, with occasionally macroscopic hematuria and (very rarely) severe bleeding from the urinary tract causing even ureteric obstruction. On the other hand, the immune-mediated glomerular injury (nephritis) usually appears after a delay of some days-weeks. Thus, both parts of the relation analysis are false. The nephritis associated to Sch-H purpura is usually benign, however in some cases a more severe course and even renal insufficiency may occur. The disease may be caused by streptococci. There is no relation between the two answers
