Nephrology Practice Questions

Q: Lowest recurrence in nocturnal enuresis is seen with-

Bed alarms. ***Bed alarms*** - **Bed alarms** are the most effective long-term treatment for nocturnal enuresis due to their ability to condition the child to wake up to the sensation of a full bladder, leading to the **lowest recurrence rates**. - This method provides a **behavioral solution** by teaching the brain to recognize and respond to bladder signals, thus addressing the underlying issue rather than just managing symptoms. *Oxybutynin* - **Oxybutynin** is an anticholinergic medication that primarily works by reducing **detrusor muscle overactivity**, which can contribute to enuresis. - While effective for some, its action is primarily symptomatic, and recurrence rates are higher once the medication is stopped compared to behavioral approaches. *Desmopressin* - **Desmopressin** is an analog of **vasopressin** that reduces urine production overnight, addressing a potential deficiency in ADH secretion. - While it can significantly reduce enuretic episodes during treatment, its effect is mostly symptomatic, and the **relapse rate** upon discontinuation is considerable. *Imipramine* - **Imipramine**, a tricyclic antidepressant, works through multiple mechanisms, including anticholinergic effects, central nervous system stimulation, and deep sleep reduction. - It has a higher risk of **side effects** and, similar to desmopressin and oxybutynin, its benefits often cease once the medication is stopped, resulting in higher recurrence.

Q: In SCHWARTZ formula for calculation of creatinine clearance in a child, the constant depends on the following except –

Severity of renal failure. ***Severity of renal failure*** - The constant in the **Schwartz formula** primarily accounts for factors like muscle mass and maturation, not the severity of renal failure itself. - The formula is designed to estimate glomerular filtration rate (GFR) over a range of renal function, with the creatinine value reflecting the severity, not the constant. *Age* - The original Schwartz formula uses an age-dependent constant, with different values for infants, children, and adolescents, reflecting changes in **muscle mass** and **creatinine generation** with age. - Specifically, constants like 0.33, 0.45, 0.55, and 0.65 are used depending on the patient's age group. *Mass* - The constant implicitly accounts for differences in **muscle mass** and body composition, which are related to age and sex, influencing creatinine production. - The formula itself includes **height** in cm as a direct variable, which is a proxy for lean body mass. *Method of estimation of creatinine* - The constant is adjusted based on the method used to measure **serum creatinine**, specifically whether it's an **enzymatic** method or a **Jaffe reaction-based** method. - Different constants are necessary because Jaffe assays can overestimate true creatinine levels due to interference from non-creatinine chromogens.

Q: A 10-year-old boy presents with hypertension. There is no history of urinary tract infections, abdominal pain, or family history of renal disease. Urine analysis reveals microscopic hematuria, proteinuria, and red blood cell casts. What is the most likely diagnosis?

Chronic glomerulonephritis. ***Chronic glomerulonephritis*** - The combination of **microscopic hematuria, proteinuria, and RBC casts** is pathognomonic for **glomerular disease**. - **RBC casts** specifically indicate glomerular bleeding and are highly specific for **glomerulonephritis**. - **Hypertension** in chronic glomerulonephritis results from sodium retention, fluid overload, and activation of the renin-angiotensin-aldosterone system. - The absence of acute features suggests a **chronic** process rather than acute post-streptococcal glomerulonephritis. *Reflux nephropathy* - While reflux nephropathy can cause hypertension and proteinuria, it typically presents with a history of **recurrent urinary tract infections**, which is explicitly absent in this case. - **RBC casts are NOT a feature** of reflux nephropathy; urinalysis may show proteinuria and occasionally WBCs/bacteria if infection is present. - Diagnosis requires imaging (VCUG, DMSA scan) showing vesicoureteral reflux and renal scarring. *Polycystic kidney disease* - **Autosomal dominant PKD** rarely presents with symptoms in childhood; it typically manifests in the 3rd-4th decade. - **Autosomal recessive PKD** presents in infancy/early childhood with enlarged kidneys and renal failure. - While PKD can cause hematuria (from cyst rupture), **RBC casts are not characteristic** as the pathology is cystic, not glomerular. - Diagnosis is made by ultrasound showing multiple bilateral renal cysts. *All of the options* - This is incorrect because the **specific urinalysis findings** (particularly **RBC casts**) point definitively to **glomerular pathology**. - RBC casts are the hallmark of glomerulonephritis and are not seen in reflux nephropathy or polycystic kidney disease. - The clinical presentation with specific laboratory findings allows differentiation between these conditions.

Q: 2 year old child with length 85cm and weight of 11kg was found to have serum urea of 49mg/dl, serum creatinine 2mg/dl What is the estimated GFR of this child, as per Schwartz formula?

19. ***19*** - The **Schwartz formula** for estimating GFR in children is: **GFR = k × (length in cm / serum creatinine in mg/dL)**. - For a 2-year-old child, the constant **k is typically 0.45**. Therefore, GFR = 0.45 × (85 cm / 2 mg/dL) = 0.45 × 42.5 = 19.125, which rounds to **19 mL/min/1.73m²**. - This GFR value indicates **moderate to severe chronic kidney disease** in a child. *48* - This value is likely obtained if an incorrect **k constant** was used (such as k = 0.55 for older children) or if there was a calculation error. - A GFR of 48 mL/min/1.73m² would indicate **moderate chronic kidney disease (Stage 3)**, but the calculation using the appropriate k value does not support this. *9* - This value would result from using an incorrect k value (possibly dividing 0.45 by 2) or making an **arithmetic error** in the calculation. - A GFR of 9 mL/min/1.73m² would suggest **severe kidney failure (Stage 5 CKD)**, which is inconsistent with the provided parameters when calculated correctly. *90* - A GFR of 90 mL/min/1.73m² or higher generally indicates **normal kidney function**. - This value is significantly higher than what would be calculated using the Schwartz formula with the given creatinine level of 2 mg/dL, which indicates significant kidney impairment in a child.

Q: Most common cause of nephrotic syndrome in paediatric age group is

Minimal change disease. ***Minimal change disease*** - **Minimal change disease (MCD)** is the most frequent cause of **nephrotic syndrome** in children, accounting for 70-90% of cases in the paediatric age group. - It is characterized by normal kidney appearance on light microscopy, with **effacement of foot processes** visible only on electron microscopy. *Mesangioproliferative glomerulonephritis* - While various forms of mesangioproliferative glomerulonephritis can cause nephrotic syndrome, they are **not the most common cause** in paediatric patients. - This diagnosis often involves **cellular proliferation within the mesangium**, which is distinct from the characteristic findings of MCD. *Malarial infection* - **Malarial infection**, particularly *Plasmodium malariae*, can cause **malaria-associated nephropathy**, which may present as nephrotic syndrome. - However, this is typically seen in **endemic malarial regions** and is not the most common global cause of paediatric nephrotic syndrome. *Membranous glomerulonephritis* - **Membranous glomerulonephritis** is a common cause of nephrotic syndrome in **adults**, especially in those over 40 years of age. - It is **rare in children** and is characterized by subepithelial immune deposits and thickening of the glomerular basement membrane.

Q: A characteristic feature of nephritic syndrome in children is:

RBC casts in urine. ***RBC casts in urine*** - The presence of **red blood cell (RBC) casts** in urine is a **pathognomonic sign** of **glomerulonephritis**, which is the underlying pathology in nephritic syndrome. - This indicates **glomerular inflammation** and bleeding, where RBCs leak through damaged glomeruli and are molded into casts within the renal tubules. *WBC casts in urine* - **White blood cell (WBC) casts** are characteristic of **pyelonephritis** (kidney infection) or other severe interstitial nephritis, indicating inflammation within the renal tubules. - While infection can sometimes accompany nephritic syndrome, WBC casts are not a primary diagnostic feature of the syndrome itself. *Lipid casts in urine* - **Lipid casts** and **fatty oval bodies** are typically associated with **nephrotic syndrome**, resulting from significant proteinuria and hyperlipidemia. - They signify severe disruption of glomerular filtration leading to lipid excretion, which is not the defining feature of nephritic syndrome. *Albumin in urine* - While **proteinuria (albumin in urine)** is present in nephritic syndrome, it is a non-specific finding and is also a hallmark of **nephrotic syndrome**, where it is much more severe. - The *quality* of the proteinuria (e.g., whether it contains RBCs) is more indicative for differentiating nephritic from nephrotic syndrome.

Q: Which of the following is NOT commonly associated with pediatric nephrotic syndrome?

Thrombocytopenia. ***Thrombocytopenia*** - **Thrombocytopenia**, or low platelet count, is generally **not associated** with pediatric nephrotic syndrome and is even less common than thrombocytosis. - While thrombotic and thromboembolic events can occur due to **hypercoagulability**, these are typically related to **increased clotting factors** and rarely involve low platelet counts. *Proteinuria* - **Proteinuria** (specifically **nephrotic range proteinuria** >40 mg/m2/hr or urine protein-to-creatinine ratio >2 mg/mg) is a **hallmark** feature of nephrotic syndrome. - It results from increased **glomerular permeability** leading to excessive leakage of protein into the urine. *Hyperlipidemia* - **Hyperlipidemia** is a common compensatory mechanism in nephrotic syndrome, as the liver increases lipoprotein synthesis to counteract the decreased **oncotic pressure** from albumin loss. - This often leads to elevated levels of **cholesterol** and **triglycerides**. *Hypoalbuminemia* - **Hypoalbuminemia** (<2.5 g/dL) is a **defining characteristic** of nephrotic syndrome, resulting from the significant urinary loss of albumin. - This low serum albumin contributes to **generalized edema** due to decreased plasma oncotic pressure.

Q: A 5 year child is brought with brown coloured urine and oliguria since 3 days with mild facial puffiness and pedal edema with 3+ proteinuria, BP 126/90. Urine examination shows RBCs 100/hpf and granular casts. Which of the following doesn't present with this finding?

Minimal change disease. ***Minimal change disease*** - This condition is the most common cause of **nephrotic syndrome** in children, characterized by **marked proteinuria**, **edema**, and **normal renal function**. - It typically does **NOT** present with **hematuria**, **hypertension**, or **red blood cell casts** in the urine, which are prominent features in this case. - MCD presents with **pure nephrotic syndrome** without nephritic features, making it the condition that doesn't match this clinical presentation. *FSGS* - **Focal segmental glomerulosclerosis (FSGS)** can present with a **mixed nephrotic-nephritic picture**, including significant **proteinuria**, **hematuria**, and **hypertension**. - The presence of **RBC casts** and **hypertension** is consistent with FSGS, which can show inflammatory glomerular changes. *Membranous glomerulonephritis* - **Membranous glomerulonephritis (MGN)** primarily causes **nephrotic syndrome** in adults but can occur in children. - While MGN predominantly presents with **proteinuria** and **edema**, it can occasionally have **microscopic hematuria** and mild **hypertension**. - The prominent **nephritic features** (marked hematuria, RBC casts, oliguria) make MGN less likely but not impossible in this case. *IgA nephropathy* - **IgA nephropathy** is the **best match** for this presentation with **brown-colored urine** (gross hematuria), **proteinuria**, **hypertension**, and **edema**. - Classically presents with **episodic gross hematuria** following upper respiratory tract infections. - The presence of **RBCs**, **granular casts**, and **acute nephritic features** (oliguria, facial puffiness, hypertension) are highly consistent with IgA nephropathy.

Q: A 5-year-old child presented with edema for the last few months. It started on the face but now it is generalized with pedal edema as well as ascites. He showed good response to steroids. His blood pressure was normal. On urine examination the findings were unremarkable. On electron microscopy of kidney biopsy, effacement of podocytes was seen. Identify the given condition.

A. Minimal change disease. ***Minimal change disease*** - This condition is characterized by **edema**, especially periorbital, in a young child with **normal blood pressure** and a good response to **steroids**. - **Electron microscopy showing effacement of podocytes** is the characteristic histological finding despite a normal light microscopy (hence "minimal change"). *Poststreptococcal glomerulonephritis* - Typically presents with **hematuria**, hypertension, and oliguria, often 1-3 weeks after a **streptococcal infection**. - It does not usually show a dramatic response to steroids, and electron microscopy would reveal **subepithelial humps**, not just podocyte effacement. *Focal segmental glomerulosclerosis* - Although it can present with **nephrotic syndrome** and podocyte effacement, it is often **steroid-resistant** and progresses to chronic kidney disease. - The "focal" and "segmental" scarring would be visible on light microscopy, which is not described as unremarkable here. *Membranous glomerulonephritis* - More common in **adults** and is characterized by **thickened glomerular basement membranes** on light microscopy. - Electron microscopy would show **subepithelial immune deposits** and spike formation, which is different from isolated podocyte effacement.

Question 1

What is the best method to estimate the amount of proteinuria in a 2-year-old child with nephrotic syndrome?

Accepted Answer

Single morning spot urine sample for protein/creatinine ratio

Answer

24 hr urine protein

Answer

Dipstick testing

Answer

Microalbuminuria

Question 2

Lowest recurrence in nocturnal enuresis is seen with-

Accepted Answer

Bed alarms

Answer

Oxybutynin

Answer

Desmopressin

Answer

Imipramine

Question 3

In SCHWARTZ formula for calculation of creatinine clearance in a child, the constant depends on the following except –

Accepted Answer

Severity of renal failure

Answer

Age

Answer

Mass

Answer

Method of estimation of creatinine

Question 4

A 10-year-old boy presents with hypertension. There is no history of urinary tract infections, abdominal pain, or family history of renal disease. Urine analysis reveals microscopic hematuria, proteinuria, and red blood cell casts. What is the most likely diagnosis?

Accepted Answer

Chronic glomerulonephritis

Answer

Reflux nephropathy

Answer

Polycystic kidney disease

Answer

All of the options

Question 5

2 year old child with length 85cm and weight of 11kg was found to have serum urea of 49mg/dl, serum creatinine 2mg/dl What is the estimated GFR of this child, as per Schwartz formula?

Accepted Answer

19

Answer

48

Answer

9

Answer

90

Question 6

Most common cause of nephrotic syndrome in paediatric age group is

Accepted Answer

Minimal change disease

Answer

Mesangioproliferative glomerulonephritis

Answer

Malarial infection

Answer

Membranous glomerulonephritis

Question 7

A characteristic feature of nephritic syndrome in children is:

Accepted Answer

RBC casts in urine

Answer

WBC casts in urine

Answer

Albumin in urine

Answer

Lipid casts in urine

Question 8

Which of the following is NOT commonly associated with pediatric nephrotic syndrome?

Accepted Answer

Thrombocytopenia

Answer

Proteinuria

Answer

Hyperlipidemia

Answer

Hypoalbuminemia

Question 9

A 5 year child is brought with brown coloured urine and oliguria since 3 days with mild facial puffiness and pedal edema with 3+ proteinuria, BP 126/90. Urine examination shows RBCs 100/hpf and granular casts. Which of the following doesn't present with this finding?

Accepted Answer

Minimal change disease

Answer

FSGS

Answer

Membranous glomerulonephritis

Answer

IgA nephropathy

Question 10

A 5-year-old child presented with edema for the last few months. It started on the face but now it is generalized with pedal edema as well as ascites. He showed good response to steroids. His blood pressure was normal. On urine examination the findings were unremarkable. On electron microscopy of kidney biopsy, effacement of podocytes was seen. Identify the given condition.

Accepted Answer

A. Minimal change disease

Answer

B. Poststreptococcal glomerulonephritis

Answer

C. Focal segmental glomerulosclerosis

Answer

D. Membranous glomerulonephritis

Nephrology — MCQs

Nephrology — MCQs

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