Nephrology Practice Questions

Q: A 5-year-old boy presents with a history of nocturnal enuresis and recurrent urinary tract infections. What is the most appropriate initial investigation?

Renal ultrasound. ***Renal ultrasound*** - A **renal ultrasound** is the most appropriate initial investigation as it is non-invasive and can assess for structural abnormalities of the **kidneys** and **bladder**, such as hydronephrosis, renal scarring, or bladder wall thickening, which may contribute to **nocturnal enuresis** and **recurrent UTIs**. - It helps rule out conditions like **vesicoureteral reflux (VUR)** indirectly by showing **dilated ureters** or **renal pelvis**, guiding further, more invasive tests if needed. *Voiding cystourethrogram* - A **voiding cystourethrogram (VCUG)** is primarily used to diagnose and grade **vesicoureteral reflux (VUR)**, which is often associated with recurrent UTIs. - While important, it is typically performed *after* an ultrasound has identified potential abnormalities or if the clinical suspicion for VUR is high due to persistent UTIs despite antibiotic prophylaxis. *Intravenous pyelogram* - An **intravenous pyelogram (IVP)** uses contrast dye and X-rays to visualize the urinary tract, providing detailed anatomical and functional information. - However, it is an **invasive procedure** involving radiation and contrast exposure, and is generally reserved for more complex cases or when other less invasive imaging (like ultrasound) has not provided sufficient diagnostic information. *Urodynamic studies* - **Urodynamic studies** assess bladder function, including storage, emptying, and sphincteric control. - These are usually reserved for cases where **neuropathic bladder dysfunction** or complex functional voiding issues are suspected, especially after initial anatomical assessments have been completed.

Q: A 7-year-old child presents with hematuria, hypertension, and periorbital edema. Laboratory tests show elevated antistreptolysin O (ASO) titers. What is the most likely diagnosis?

Post-Streptococcal Glomerulonephritis. ***Post-Streptococcal Glomerulonephritis*** - This diagnosis is strongly supported by the triad of **hematuria**, **hypertension**, and **periorbital edema** in a child, coupled with **elevated ASO titers**, indicating a recent streptococcal infection. - The disease typically presents 1-3 weeks after a **pharyngeal** or **skin infection** with nephritogenic strains of Group A Streptococcus. *IgA Nephropathy* - While it can cause **hematuria**, it is often **macroscopic** and occurs **concurrently with or shortly after an upper respiratory infection**, unlike the delayed presentation associated with PSGN. - It would not typically present with significantly **elevated ASO titers** as a primary diagnostic feature. *Henoch-Schönlein Purpura* - Characterized by **palpable purpura**, **arthralgia**, and **abdominal pain**, in addition to potential renal involvement, which are not mentioned in this presentation. - Renal involvement in HSP is also an **IgA vasculitis**, and while it can cause hematuria, the classic systemic symptoms are missing. *Nephrotic Syndrome* - Characterized by **massive proteinuria**, **hypoalbuminemia**, and **severe edema**, often without significant hematuria or hypertension initially. - Elevated ASO titers are not a typical feature of nephrotic syndrome.

Q: An 8-year-old child presents with hematuria 5 days after a throat infection. What is the most likely diagnosis?

Post streptococcal nephropathy. ***Post streptococcal glomerulonephritis*** - **Post-streptococcal glomerulonephritis (PSGN)** is the most common cause of acute glomerulonephritis in children aged 5-12 years. - Typically presents with **hematuria 1-2 weeks (7-21 days, average 10 days)** after a streptococcal pharyngitis or 3-6 weeks after skin infection. - **5 days post-throat infection** falls within the early range of the latent period for PSGN. - Clinical features include **gross hematuria ("cola-colored" urine)**, **edema**, **hypertension**, and **low C3 complement levels**. - The time interval and clinical presentation in this 8-year-old child are classic for PSGN. *IgA nephropathy* - IgA nephropathy presents with **synpharyngitic hematuria** - occurring **within 1-2 days** (24-48 hours) of an upper respiratory infection. - The **5-day interval** in this case is too long for typical IgA nephropathy presentation. - More common in older children and young adults, and shows normal C3 complement levels. *Nephrotic syndrome* - **Nephrotic syndrome** is characterized by **massive proteinuria (>40 mg/m²/hr)**, **hypoalbuminemia (<2.5 g/dL)**, **edema**, and **hyperlipidemia**. - The primary presentation is **edema and frothy urine**, not acute gross hematuria following infection. - Hematuria, if present, is typically microscopic rather than macroscopic. *Alport syndrome* - **Alport syndrome** is a hereditary nephritis caused by **collagen type IV defects**. - Presents with **persistent microscopic hematuria** from early childhood, often with **sensorineural hearing loss** and **ocular abnormalities**. - Does not have the acute temporal relationship with throat infection seen in this case.

Q: In HSP gross hematuria is seen in what % of children?

10 - 20%. ***10 - 20%*** - **Gross (macroscopic) hematuria** in **Henoch-Schönlein purpura (HSP)** occurs in approximately **10-20%** of children with the condition. - While **microscopic hematuria** is present in the majority (80-100%) of children with renal involvement, **visible blood in urine** is less common. - This represents a **significant but minority proportion** of HSP cases with renal manifestations. *5 - 10%* - This range represents the **lower estimates** for gross hematuria in HSP, which may be seen in some cohorts. - While some studies report rates in this range, the **consensus estimate** is slightly higher at 10-20%. *20 - 30%* - This percentage is **higher than typically reported** for gross hematuria in children with HSP. - This range may represent **overall renal involvement** (which can be 30-50%) rather than specifically **gross hematuria**. - **Microscopic hematuria** occurs at much higher rates than gross hematuria in HSP. *30 - 40%* - This percentage significantly **overestimates** the incidence of **gross hematuria** in HSP. - Such high rates might reflect **any urinary abnormality** or **microscopic hematuria**, not specifically visible blood in urine. - Gross hematuria remains a **minority finding** even among children with renal involvement in HSP.

Q: A 6-year-old boy came with a history of recurrent urinary tract infections. Imaging was done and showed retrograde flow of urine from the bladder into the ureters. What is the most likely diagnosis based on the imaging findings?

Vesicoureteric reflux (VUR). ***Vesicoureteric reflux (VUR)*** - VUR is defined by the **retrograde flow of urine from the bladder into the ureters**, which directly matches the imaging finding described - This is the **most common cause of recurrent UTIs in children**, as reflux allows bacteria to ascend from the bladder to the kidneys - Diagnosed by **voiding cystourethrogram (VCUG)**, which shows contrast refluxing into ureters during micturition - Graded from I to V based on severity; can lead to **reflux nephropathy** and renal scarring if untreated *Urinary bladder diverticulum* - An **outpouching of the bladder wall** through weakened muscle layers - May predispose to UTIs due to urinary stasis within the diverticulum, but does **not cause retrograde flow into ureters** - Imaging would show a **saccular projection** from the bladder, not ureteral filling *Vesicocolic fistula* - An **abnormal communication between bladder and colon**, typically from inflammatory bowel disease, malignancy, or trauma in adults (rare in children) - Presents with **pneumaturia (air in urine)**, fecaluria, and recurrent UTIs - Would not demonstrate **retrograde ureteral flow** on imaging *Urinary bladder hernia* - Protrusion of bladder through a **hernial defect** (inguinal, femoral, or abdominal wall) - Presents as a **reducible mass** that may increase with Valsalva - Does not cause **ureteral reflux** and has a distinct clinical and radiological presentation

Q: Which of the following is NOT typically associated with posterior urethral valves?

Painful stress incontinence. ***Painful stress incontinence*** - **Posterior urethral valves (PUV)** primarily affect male infants and lead to chronic, not acute, obstruction. **Stress incontinence** is rare and not a typical presenting symptom. It usually occurs in older women due to **pelvic floor weakness**. - While urinary symptoms are present, they are usually related to **poor bladder emptying** and **overflow incontinence**, not painful stress incontinence. *Palpable bladder* - **Posterior urethral valves (PUV)** cause outflow obstruction, leading to a chronically distended and often **palpable bladder** due to the accumulation of urine. - This is a common finding in male infants with PUV, indicating the severity of the obstruction and **incomplete bladder emptying**. *Hydronephrosis* - The obstruction caused by **posterior urethral valves** leads to backflow of urine, resulting in **dilation of the ureters** and **renal pelvis**, which is known as hydronephrosis. - **Bilateral hydronephrosis** is a common and serious consequence, often detected prenatally and indicating obstructive uropathy. *Recurrent UTI* - The chronic residual urine in the bladder due to **posterior urethral valves** provides a fertile ground for bacterial growth, leading to an increased risk of **recurrent urinary tract infections**. - **Incomplete bladder emptying** and **urinary stasis** are primary factors contributing to this susceptibility.

Q: Which of the following statements about chronic pyelonephritis in children is true?

Associated with renal scarring. ***Associated with renal scarring*** - **Chronic pyelonephritis** in children is definitively associated with **renal scarring**, which is a major cause of chronic kidney disease and hypertension in later life - Repeated inflammatory episodes from recurrent infections damage the renal parenchyma, resulting in **permanent fibrotic changes and cortical scarring** - This is the correct statement about chronic pyelonephritis *Not associated with Intrarenal reflux - INCORRECT* - This statement is FALSE - **Intrarenal reflux** (reflux of urine into the collecting ducts within the kidney) is a **significant factor** in the development of renal scarring in children with vesicoureteral reflux (VUR) - Intrarenal reflux allows infected urine to reach the renal parenchyma directly, initiating the inflammatory cascade that leads to pyelonephritis and scarring *Not more common in females than males - INCORRECT* - This statement is FALSE - **Urinary tract infections (UTIs)** and chronic pyelonephritis are **significantly more common in females** than males, particularly after infancy - This is due to anatomical differences including a **shorter urethra** in females, which facilitates bacterial ascent from the perineum to the bladder *Not associated with Ureteric reflux - INCORRECT* - This statement is FALSE - **Vesicoureteral reflux (VUR)** is the **primary predisposing factor** for chronic pyelonephritis and renal scarring in children - VUR allows the abnormal backward flow of urine from the bladder into the ureters and kidneys, facilitating bacterial ascent and recurrent pyelonephritis

Q: What is the frequency of renal involvement in Henoch-Schönlein purpura (HSP)?

40-60%. ***40-60%*** - Renal involvement in Henoch-Schönlein purpura (HSP) is common, affecting approximately **40-60% of patients**. - Renal complications can range from microscopic hematuria to proteinuria, and in some cases, **progressive glomerulonephritis** leading to renal failure. *25-35%* - This percentage underestimates the actual frequency of **renal complications** in HSP. - While mild symptoms might fall within this range, a broader spectrum of renal manifestations is observed. *60-80%* - This percentage overestimates the reported frequency of **renal involvement** in HSP. - Although it is common, a majority of patients do not develop renal symptoms. *5-10%* - This range is too low for the frequency of **renal involvement** in HSP. - Even though it's benign in many cases, some form of renal pathology like hematuria is quite frequent.

Q: Which of the following is the MOST COMMON cause of acute hypocomplementemia in children following an infection?

PSGN. ***PSGN*** - **Post-streptococcal glomerulonephritis (PSGN)** is the **most common cause of acute hypocomplementemia** in children following a streptococcal infection [1]. - Characterized by **immune complex deposition** in the glomeruli with activation of the complement system [2]. - Results in **transient hypocomplementemia** (both C3 and C4 decreased) that typically normalizes within 6-8 weeks. - Classic presentation: acute nephritic syndrome 1-3 weeks after pharyngitis or 3-6 weeks after skin infection [1]. *Membranous GN* - **Membranous glomerulonephritis** presents with **nephrotic syndrome** and immune complex deposition [2]. - Associated with **normal complement levels** in most cases. - Complement activation is not severe enough to cause significant consumption. *Focal Segmental Glomerulosclerosis (FSGS)* - **FSGS** causes nephrotic syndrome with **scarring of selected glomeruli** [3]. - **Not an immune complex-mediated disease**, hence no complement consumption [3]. - Complement levels remain **normal**. *Membranoproliferative GN (MPGN)* - **MPGN** can also cause hypocomplementemia, particularly Type II (dense deposit disease) with persistent C3 consumption due to C3 nephritic factor. - However, **MPGN is much less common** than PSGN in the pediatric population. - Type I MPGN may show low C3 with normal or low C4. - PSGN remains the **classic and most frequent** acute post-infectious cause [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 914-915. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, p. 915. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 927-928.

Q: An infant presenting with failure to thrive, hypertension, metabolic acidosis, and hyperkalemia is most likely suffering from which condition?

Gordon syndrome. ***Gordon syndrome*** - **Gordon syndrome** (Pseudohypoaldosteronism Type II) is characterized by **hypertension**, **hyperkalemia**, and **metabolic acidosis**, which perfectly matches the clinical presentation in this infant. - The underlying defect involves abnormal regulation of the **WNK kinase pathway**, leading to increased activity of the thiazide-sensitive Na-Cl cotransporter (NCC) in the distal convoluted tubule, resulting in increased sodium reabsorption and impaired potassium excretion. - This causes **volume expansion** (leading to hypertension), **hyperkalemia** (due to reduced potassium secretion), and **metabolic acidosis** (due to impaired hydrogen ion secretion). *Liddle's syndrome* - This syndrome presents with **hypertension**, **hypokalemia**, and **metabolic alkalosis**, due to increased activity of the epithelial sodium channel (ENaC) in the collecting duct. - The presence of **hyperkalemia** and **metabolic acidosis** rules out Liddle's syndrome. *Bartter's syndrome* - Characterized by **hypokalemia**, **metabolic alkalosis**, and **normal or low blood pressure**, due to impaired reabsorption in the thick ascending limb of the loop of Henle. - The combination of **hypertension**, **hyperkalemia**, and **metabolic acidosis** is completely inconsistent with Bartter's syndrome. *Gitelman's syndrome* - This syndrome typically causes **hypokalemia**, **metabolic alkalosis**, **hypomagnesemia**, and **hypocalciuria**, due to a defect in the thiazide-sensitive NaCl cotransporter in the distal convoluted tubule. - The infant's **hyperkalemia**, **hypertension**, and **metabolic acidosis** are completely inconsistent with Gitelman's syndrome.

Question 1

A 5-year-old boy presents with a history of nocturnal enuresis and recurrent urinary tract infections. What is the most appropriate initial investigation?

Accepted Answer

Renal ultrasound

Answer

Voiding cystourethrogram

Answer

Intravenous pyelogram

Answer

Urodynamic studies

Question 2

A 7-year-old child presents with hematuria, hypertension, and periorbital edema. Laboratory tests show elevated antistreptolysin O (ASO) titers. What is the most likely diagnosis?

Accepted Answer

Post-Streptococcal Glomerulonephritis

Answer

IgA Nephropathy

Answer

Henoch-Schönlein Purpura

Answer

Nephrotic Syndrome

Question 3

An 8-year-old child presents with hematuria 5 days after a throat infection. What is the most likely diagnosis?

Accepted Answer

Post streptococcal nephropathy

Answer

Nephrotic syndrome

Answer

IgA nephropathy

Answer

Alport syndrome

Question 4

In HSP gross hematuria is seen in what % of children?

Accepted Answer

10 - 20%

Answer

5 - 10%

Answer

20 - 30%

Answer

30 - 40%

Question 5

A 6-year-old boy came with a history of recurrent urinary tract infections. Imaging was done and showed retrograde flow of urine from the bladder into the ureters. What is the most likely diagnosis based on the imaging findings?

Accepted Answer

Vesicoureteric reflux (VUR)

Answer

Urinary bladder diverticulum (UBD)

Answer

Vesicocolic fistula (VCF)

Answer

Urinary bladder hernia (UBH)

Question 6

Which of the following is NOT typically associated with posterior urethral valves?

Accepted Answer

Painful stress incontinence

Answer

Palpable bladder

Answer

Hydronephrosis

Answer

Recurrent UTI

Question 7

Which of the following statements about chronic pyelonephritis in children is true?

Accepted Answer

Associated with renal scarring

Answer

Not associated with Intrarenal reflux

Answer

Not more common in females than males

Answer

Not associated with Ureteric reflux

Question 8

What is the frequency of renal involvement in Henoch-Schönlein purpura (HSP)?

Accepted Answer

40-60%

Answer

25-35%

Answer

60-80%

Answer

5-10%

Question 9

Which of the following is the MOST COMMON cause of acute hypocomplementemia in children following an infection?

Accepted Answer

PSGN

Answer

Membranous GN

Answer

Focal Segmental Glomerulosclerosis (FSGS)

Answer

Membranoproliferative GN (MPGN)

Question 10

An infant presenting with failure to thrive, hypertension, metabolic acidosis, and hyperkalemia is most likely suffering from which condition?

Accepted Answer

Gordon syndrome

Answer

Liddle's syndrome

Answer

Bartter's syndrome

Answer

Gittelman's syndrome

Nephrology — MCQs

Nephrology — MCQs

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