Nephrology Practice Questions

Q: A 7-year-old child presents with generalized edema, frothy urine, and fatigue for 2 weeks. Laboratory findings show serum albumin 1.8 g/dL, total cholesterol 350 mg/dL, and 24-hour urine protein 5 g/day. Renal function is normal. Kidney biopsy shows normal glomeruli on light microscopy but effacement of podocyte foot processes on electron microscopy. What is the most appropriate initial treatment?

Oral prednisone. ***Oral prednisone*** - The presentation (nephrotic syndrome in a 7-year-old child with normal light microscopy, biopsy showing only **podocyte foot process effacement**) is diagnostic of **Minimal Change Disease (MCD)**. - High-dose **oral prednisone** (or prednisolone) is the standard, first-line initial treatment for MCD in children, achieving remission in over 90% of cases (**steroid-sensitive nephrotic syndrome**). - Standard regimen: Daily prednisone 60 mg/m²/day (or 2 mg/kg/day, max 60 mg) for 4-6 weeks, followed by alternate-day therapy. *Intravenous methylprednisolone pulse therapy* - IV methylprednisolone pulse therapy (20-30 mg/kg/dose for 3 consecutive days) is reserved for **steroid-resistant**, **severe**, or **life-threatening** cases of nephrotic syndrome. - It is not the initial treatment approach for uncomplicated MCD; oral steroids are preferred as first-line therapy. *ACE inhibitors only* - ACE inhibitors are primarily used to treat **hypertension** and reduce **proteinuria** by decreasing glomerular filtration pressure. - They are adjunctive therapies and do not constitute the specific, initial disease-modifying treatment for MCD. *Cyclophosphamide* - This is an immunosuppressive agent reserved for children with MCD who are **steroid-dependent** or experience **frequent relapses**. - It is utilized as a steroid-sparing agent, typically after the initial steroid course has proven insufficient or resulted in dependence.

Q: A 12-year-old child is diagnosed with systemic lupus erythematosus (SLE) and presents with nephrotic-range proteinuria. Renal biopsy reveals "wire loop lesions." Which of the following is the drug of choice in this case?

IV Steroids + cyclophosphamide. ***IV Steroids + cyclophosphamide*** - The presence of "wire loop lesions" on renal biopsy signifies **Diffuse Proliferative Lupus Nephritis (Class IV)**, which is the most common and severe form of Lupus Nephritis. - Induction therapy for Class IV LN requires a combination of high-dose corticosteroids (IV methylprednisolone) and a potent cytotoxic agent, making **cyclophosphamide** the standard aggressive regimen [1]. *IV Steroids only* - Although high-dose steroids (pulses) are essential for controlling acute inflammation, they are **insufficient as monotherapy** for the severe, widespread immune complex deposition seen in **Class IV LN** [1]. - Steroid monotherapy is typically used for less aggressive forms, such as Class I or II (minimal or mesangial) LN. *Mycophenolate mofetil* - **Mycophenolate mofetil (MMF)**, combined with steroids, is an alternative induction therapy, particularly favored for maintenance but is less reliably potent than cyclophosphamide in severe, life-threatening flares of **Class IV** in some regimens. - MMF alone is never used for induction; it must be administered with high-dose **corticosteroids** to manage acute disease activity. *Cyclophosphamide only* - **Cyclophosphamide** is a powerful induction agent, but it must always be combined with high-dose **corticosteroids** during the induction phase to maximize anti-inflammatory effects and achieve remission effectively [1]. - Administration of a cytotoxic agent without simultaneous acute inflammation control is substandard care.

Q: A 1 month old child with recurrent episodes of fever. On examination a suprapubic swelling was noticed and mother reports poor urinary stream. MCUG was performed. All are true about the condition shown except:

Urgent intravenous pyelography. ***Urgent intravenous pyelography*** - **Intravenous pyelography (IVP)** uses intravenous contrast and is generally *not* the primary or urgent imaging modality for diagnosing lower urinary tract obstruction in infants. - While it can show renal function and hydronephrosis, a **voiding cystourethrogram (VCUG)** (which was performed in the scenario) and **renal ultrasound** are typically preferred for initial evaluation of suspected posterior urethral valves (PUV). *Trabeculated bladder* - The image shows a bladder with an irregular, thickened wall, consistent with **trabeculation**, which develops due to chronic obstruction and increased intravesical pressure (e.g., from posterior urethral valves). - This finding on VCUG is indicative of significant bladder outflow obstruction. *Dilated posterior urethra* - The VCUG image displays a **dilated posterior urethra**, a hallmark finding of **posterior urethral valves (PUV)**, as the valves obstruct urine flow, leading to proximal dilation. - This is a key diagnostic feature for PUV. *Fulguration of posterior urethral valves is required* - **Fulguration (ablation)** of the posterior urethral valves is the definitive surgical treatment for this condition, aimed at relieving the obstruction and preventing further renal damage. - Given the classic clinical presentation (recurrent fever, suprapubic swelling, poor stream) and MCUG findings, surgical correction is indicated.

Q: A 5-year-old boy from upper socioeconomic background presents with bowing of legs. On work up serum calcium was $9 \mathrm{mg} \%$ with serum phosphate of $1 \mathrm{mg} \%$ with normal serum alkaline phosphatase (ALP) and normal serum PTH. X-ray wrist joint is given. Comment on the diagnosis:

Hypophosphatemic rickets. ***Hypophosphatemic rickets*** - The classic presentation of **bowing of the legs** (rickets) in a child with **isolated low serum phosphate** (1 mg%), normal calcium and PTH, points directly to hypophosphatemic rickets. - The **X-ray of the wrist joint** would likely show characteristic findings of rickets such as **widening and fraying of growth plates**, confirming the diagnosis. *Bartter syndrome* - This is a rare genetic disorder affecting the kidneys, leading to **salt wasting**, **hypokalemic metabolic alkalosis**, and normal to low blood pressure. - It does not primarily cause rickets or the specific electrolyte imbalance seen here (isolated hypophosphatemia). *Chronic renal failure* - While chronic renal failure can lead to renal osteodystrophy (a form of rickets), it would typically involve **elevated PTH**, **hyperphosphatemia (initially)** or varied calcium levels, and often metabolic acidosis. - In this case, PTH is normal and phosphate is low, making chronic renal failure less likely. *Polycystic kidneys* - This is a genetic disorder characterized by the growth of numerous cysts in the kidneys, which can cause kidney dysfunction over time. - However, it does not directly present with isolated **hypophosphatemia** and bone bowing in a 5-year-old without other clear signs of significant renal failure.

Q: A child during evaluation of recurrent hematuria has the following eye finding. He has sensorineural deafness and history of similar illness in family members. What is the diagnosis?

Alport syndrome. ***Alport syndrome*** - The combination of **recurrent hematuria**, **sensorineural deafness**, and a **family history of similar illness** is classic for Alport syndrome. - The image shows **anterior lenticonus**, a pathognomonic eye finding in Alport syndrome, which is a protrusion of the anterior lens capsule and cortex. *IgA nephropathy* - While associated with **recurrent hematuria**, it typically does not present with sensorineural deafness or specific ocular findings like **anterior lenticonus**. - Renal biopsy showing **IgA deposits** in the mesangium is characteristic. *Thin glomerular basement membrane disease* - This condition presents with **benign familial hematuria** and usually has a good prognosis, but it is not typically associated with **sensorineural deafness** or specific ocular abnormalities. - The glomerular basement membrane is uniformly thin on electron microscopy. *Post Streptococcal glomerulonephritis* - This is an **acute** condition following a streptococcal infection, characterized by **hematuria**, **edema**, and **hypertension**. - It is not a recurrent condition and does not involve **sensorineural deafness** or **anterior lenticonus**.

Q: A child with history of diarrhea 1 week back presents with sudden onset pallor and oliguria. Peripheral smear findings are shown below. Which of the following is unlikely finding in this disorder?

Elevated PT. ***Elevated PT*** - **Hemolytic-uremic syndrome (HUS)** is a microangiopathic hemolytic anemia with **normal coagulation parameters**. - **PT** or **aPTT** are not typically elevated in HUS, making this an unlikely finding. *Coomb's test negative* - HUS is a **non-immune hemolytic anemia**, meaning the red cell destruction is not antibody-mediated. - A **negative Coombs test** is an expected finding in HUS, differentiating it from autoimmune hemolytic anemia. *Increased urinary sodium excretion* - HUS causes **acute kidney injury (AKI)**, often leading to tubular damage and impaired sodium reabsorption. - This can result in **increased fractional excretion of sodium** and high urinary sodium concentrations. *Thrombocytopenia* - **Thrombocytopenia** is a hallmark feature of HUS, caused by platelet consumption in the microthrombi formed in the damaged microvasculature. - The severity of thrombocytopenia can vary but is almost always present.

Q: Identify this condition?

Prune belly syndrome. ***Prune belly syndrome*** - The image shows the characteristic **wrinkled, prune-like appearance** of the abdominal wall due to **absent or deficient abdominal wall musculature**. - This condition is part of a triad including **urinary tract abnormalities** and **undescended testes** in males, with the distinctive loose, redundant abdominal skin. *Omphalocele* - An **omphalocele** presents with **abdominal contents herniating through the umbilical ring**, covered by a peritoneal membrane. - The image does not show any **herniated organs** or a sac-like protrusion at the umbilical area. *Gastroschisis* - **Gastroschisis** involves an **abdominal wall defect** typically to the right of the umbilical cord with **exposed bowel loops**. - No evidence of **herniated intestinal contents** or abdominal wall dehiscence is visible in this image. *Peritonitis* - **Peritonitis** is an **inflammatory condition** of the peritoneum presenting with abdominal rigidity and systemic signs. - This is not a structural abnormality visible externally but rather an **internal inflammatory process** requiring clinical assessment.

Q: A 3-year-old boy presents with occasional episodes of passing urine after very long durations, going up to as long as 12 hours. Since the child cries due to discomfort and then passes urine with straining, a VCUG is ordered. The VCUG image is shown below. What is the diagnosis?

Posterior urethral valves. ***Posterior urethral valves*** - The image shows a **dilated posterior urethra** and a thickened, trabeculated bladder, which are classic VCUG findings in posterior urethral valves. - The clinical presentation of a young boy with **straining to void**, prolonged intervals between urination, and discomfort points to a **lower urinary tract obstruction**, consistent with this diagnosis. *Neurogenic bladder* - While neurogenic bladder can cause voiding dysfunction, its VCUG appearance is typically characterized by a **smooth, funnel-shaped bladder neck** and not necessarily posterior urethral dilation. - The history does not provide evidence of neurological deficits that would suggest a neurogenic cause for bladder dysfunction. *Detrusor instability* - Detrusor instability (or overactivity) typically presents with **frequent urination**, urgency, and sometimes incontinence, which is contrary to the long voiding intervals described. - VCUG findings for detrusor instability primarily show an **unstable bladder contraction** during filling, without the characteristic urethral abnormalities seen in the image. *Vesical fistula* - A vesical fistula involves an **abnormal connection** between the bladder and another organ or the skin, leading to continuous leakage of urine. - This condition would not explain the **obstructive symptoms** like straining to void or the VCUG findings of posterior urethral dilation.

Q: A 12-year-old child with renal tubular acidosis type I is having muscle cramps and weakness. ECG shows all except:

Absent P waves. ***Absent P waves*** - **Hypokalemia (low potassium)**, common in renal tubular acidosis type I, does not typically cause absent P waves. Absent P waves are characteristic of certain **atrial arrhythmias** or severe **hyperkalemia** with sine wave formation. - The image provided clearly shows visible P waves before each QRS complex, indicating **sinus rhythm** and normal atrial depolarization. *T wave inversion with U waves* - **Hypokalemia** can cause characteristic ECG changes including **T wave flattening**, **T wave inversion**, and prominent **U waves**, especially in leads V2-V4. - The provided ECG shows evidence of T wave flattening or inversion and visible U waves, which are consistent with hypokalemia. *ST depression* - **ST depression** can occur in cases of significant **hypokalemia**, particularly when potassium levels are very low. - The ECG shows some subtle **ST segment depression**, especially in leads like V3, which is a recognized finding in hypokalemia. *Heart rate of 75 beats per minute* - To calculate the heart rate, count the number of large squares between two R waves (e.g., in V5, there are approximately 4 large squares). The heart rate is 300 / number of large squares = 300 / 4 = **75 bpm**. - A heart rate of 75 bpm is a **normal sinus rhythm** and is not inconsistent with hypokalemia.

Question 1

A 7-year-old child presents with generalized edema, frothy urine, and fatigue for 2 weeks. Laboratory findings show serum albumin 1.8 g/dL, total cholesterol 350 mg/dL, and 24-hour urine protein 5 g/day. Renal function is normal. Kidney biopsy shows normal glomeruli on light microscopy but effacement of podocyte foot processes on electron microscopy. What is the most appropriate initial treatment?

Accepted Answer

Oral prednisone

Answer

Intravenous methylprednisolone pulse therapy

Answer

ACE inhibitors only

Answer

Cyclophosphamide

Question 2

A 5-year-old child with chronic kidney disease (CKD) presents with bow legs. Laboratory investigations reveal: Serum Calcium: 9.1 mg/dL (normal) Serum Phosphate: 6.9 mg/dL (elevated) Alkaline Phosphatase: Elevated 25(OH) Vitamin D: Low What is the most appropriate next step in management?

Accepted Answer

Oral calcium + Vitamin D

Answer

Growth hormone therapy

Answer

Phosphate binder

Answer

Calcium supplementation

Question 3

A 12-year-old child is diagnosed with systemic lupus erythematosus (SLE) and presents with nephrotic-range proteinuria. Renal biopsy reveals "wire loop lesions." Which of the following is the drug of choice in this case?

Accepted Answer

IV Steroids + cyclophosphamide

Answer

Mycophenolate mofetil

Answer

Cyclophosphamide only

Answer

IV Steroids only

Question 4

A 1 month old child with recurrent episodes of fever. On examination a suprapubic swelling was noticed and mother reports poor urinary stream. MCUG was performed. All are true about the condition shown except:

Accepted Answer

Urgent intravenous pyelography

Answer

Trabeculated bladder

Answer

Dilated posterior urethra

Answer

Fulguration of posterior urethral valves is required

Question 5

A 5-year-old boy from upper socioeconomic background presents with bowing of legs. On work up serum calcium was $9 \mathrm{mg} \%$ with serum phosphate of $1 \mathrm{mg} \%$ with normal serum alkaline phosphatase (ALP) and normal serum PTH. X-ray wrist joint is given. Comment on the diagnosis:

Accepted Answer

Hypophosphatemic rickets

Answer

Bartter syndrome

Answer

Chronic renal failure

Answer

Polycystic kidneys

Question 6

A child during evaluation of recurrent hematuria has the following eye finding. He has sensorineural deafness and history of similar illness in family members. What is the diagnosis?

Accepted Answer

Alport syndrome

Answer

IgA nephropathy

Answer

Thin glomerular basement membrane disease

Answer

Post Streptococcal glomerulonephritis

Question 7

A child with history of diarrhea 1 week back presents with sudden onset pallor and oliguria. Peripheral smear findings are shown below. Which of the following is unlikely finding in this disorder?

Accepted Answer

Elevated PT

Answer

Coomb's test negative

Answer

Increased urinary sodium excretion

Answer

Thrombocytopenia

Question 8

Identify this condition?

Accepted Answer

Prune belly syndrome

Answer

Omphalocele

Answer

Gastroschisis

Answer

Peritonitis

Question 9

A 3-year-old boy presents with occasional episodes of passing urine after very long durations, going up to as long as 12 hours. Since the child cries due to discomfort and then passes urine with straining, a VCUG is ordered. The VCUG image is shown below. What is the diagnosis?

Accepted Answer

Posterior urethral valves

Answer

Neurogenic bladder

Answer

Detrusor instability

Answer

Vesical fistula

Question 10

A 12-year-old child with renal tubular acidosis type I is having muscle cramps and weakness. ECG shows all except:

Accepted Answer

Absent P waves

Answer

T wave inversion with U waves

Answer

ST depression

Answer

Heart rate of 75 beats per minute

Nephrology — MCQs

Nephrology — MCQs

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