Nephrology Practice Questions

Q: An adolescent male presents with hypokalemia, metabolic alkalosis, hypercalciuria, and nephrocalcinosis. His blood pressure is normal. What is the likely diagnosis?

Bartter syndrome. **Explanation:** The clinical presentation of **hypokalemia**, **metabolic alkalosis**, and **normal blood pressure** narrows the differential diagnosis to salt-wasting tubulopathies. The presence of **hypercalciuria** and **nephrocalcinosis** is the pathognomonic feature that confirms **Bartter syndrome**. 1. **Bartter Syndrome (Correct):** This condition results from a defect in the thick ascending limb of the Loop of Henle (mimicking chronic loop diuretic use). The failure of the Na-K-2Cl cotransporter leads to salt wasting, secondary hyperaldosteronism (causing hypokalemia and alkalosis), and a failure to reabsorb calcium. This excess urinary calcium (hypercalciuria) leads to nephrocalcinosis. 2. **Gitelman Syndrome:** Often confused with Bartter, it mimics thiazide diuretic use (defect in the distal convoluted tubule). Crucially, Gitelman presents with **hypocalciuria** (low urine calcium) and hypomagnesemia. It typically presents later in childhood and does not cause nephrocalcinosis. 3. **Liddle Syndrome:** While it causes hypokalemia and alkalosis, it presents with **hypertension** (due to ENaC overactivity) and low renin/aldosterone levels. 4. **Renal Tubular Acidosis (RTA):** Distal RTA (Type 1) can cause hypokalemia and nephrocalcinosis, but it results in **metabolic acidosis**, not alkalosis. **High-Yield Clinical Pearls for NEET-PG:** * **Bartter vs. Gitelman:** Look at urine calcium. Bartter = High Calcium (Loop diuretic-like); Gitelman = Low Calcium (Thiazide-like). * **Bartter Syndrome:** Often associated with polyhydramnios in utero and failure to thrive in infancy. * **Liddle Syndrome:** "Pseudo-hyperaldosteronism"—presents like Conn’s syndrome but with low aldosterone. Treatment is Amiloride, not Spironolactone.

Q: Hypercoagulation in Nephrotic syndrome is caused by:

Loss of Antithrombin III. **Explanation:** Nephrotic syndrome is characterized by a "hypercoagulable state," leading to an increased risk of venous and arterial thrombosis (most notably **Renal Vein Thrombosis**). **Why Option A is correct:** The primary mechanism for hypercoagulability is the **urinary loss of low-molecular-weight proteins** due to increased glomerular permeability. **Antithrombin III (AT-III)**, a natural anticoagulant that inhibits thrombin and factor Xa, has a relatively small molecular weight (approx. 58 kDa) and is easily lost in the urine. Low levels of AT-III shift the balance toward clot formation. **Why the other options are incorrect:** * **Option B:** In Nephrotic syndrome, there is actually an **increase in Fibrinogen** levels. The liver increases the synthesis of fibrinogen and other clotting factors (V, VII, VIII, X) as a reactive response to low oncotic pressure. * **Option C:** Vitamin K metabolism is not significantly altered in Nephrotic syndrome; the pathology is related to protein loss and hepatic overproduction, not vitamin deficiencies. * **Option D:** **Protein C and Protein S** levels are typically **decreased** (due to urinary loss), not increased. An increase in these proteins would provide an anticoagulant effect, which contradicts the clinical presentation. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of thrombosis:** Renal Vein (especially in Membranous Nephropathy). * **Other factors:** Increased platelet aggregation and hemoconcentration (due to diuretics) further contribute to the prothrombotic state. * **Triad of Nephrotic Syndrome:** Massive proteinuria (>3.5g/day), Hypoalbuminemia (<3g/dL), and Generalized Edema. Hyperlipidemia is also a hallmark.

Q: All of the following are causes of hematuria in a child except?

Porphyria. **Explanation:** The core concept in this question is distinguishing between **true hematuria** (presence of intact RBCs in urine) and **discoloration of urine** (pseudohematuria). **Why Porphyria is the correct answer:** In **Porphyria**, the urine turns a characteristic "port-wine" or dark red color upon standing. This is due to the oxidation of porphobilinogen (PBG) into porphobilin or the presence of uroporphyrins. Crucially, there are **no red blood cells** present in the urine. Therefore, it causes red-colored urine but not hematuria. **Analysis of incorrect options:** * **Polycystic Kidney Disease (PCKD):** Both Autosomal Dominant (ADPKD) and Autosomal Recessive (ARPKD) forms can cause hematuria. In ADPKD, it often results from cyst rupture or associated nephrolithiasis. * **Renal Vein Thrombosis (RVT):** This is a classic cause of hematuria in neonates (often presenting with a flank mass and thrombocytopenia). The venous congestion leads to capillary rupture and bleeding into the collecting system. * **Idiopathic Hypercalciuria:** This is one of the most common causes of isolated asymptomatic microscopic hematuria in children. High urinary calcium levels cause micro-calculi that irritate the urothelium, leading to bleeding even in the absence of a visible stone. **High-Yield Clinical Pearls for NEET-PG:** * **Dipstick vs. Microscopy:** If a urine dipstick is positive for blood but microscopy shows **no RBCs**, consider **Hemoglobinuria** (intravascular hemolysis), **Myoglobinuria** (rhabdomyolysis), or **Porphyria** (though Porphyria may not always trigger the heme-reagent strip). * **Dysmorphic RBCs:** Presence of acanthocytes or dysmorphic RBCs suggests a **glomerular** source of hematuria (e.g., Post-streptococcal glomerulonephritis). * **Commonest cause:** The most common cause of gross hematuria in children is **UTI**, while the most common glomerular cause is **IgA Nephropathy** (Berger’s disease).

Q: Low C3 levels are seen in which of the following conditions?

Mesangial capillary glomerulonephritis. **Explanation:** The measurement of serum complement (C3) levels is a crucial diagnostic step in pediatric nephrology to differentiate between various glomerular diseases. **1. Why Mesangial Capillary Glomerulonephritis (MCGN) is correct:** MCGN, also known as **Membranoproliferative Glomerulonephritis (MPGN)**, is characterized by the persistent activation of the complement pathway. * **Type I MPGN:** Activation of the classical pathway (low C3 and C4). * **Type II MPGN (Dense Deposit Disease):** Activation of the alternative pathway due to **C3 nephritic factor** (an autoantibody that stabilizes C3 convertase), leading to profound and persistent **low C3** with normal C4 levels. **2. Why the other options are incorrect:** * **IgA Nephropathy:** This is a "normocomplementemic" nephropathy. While the alternative pathway is involved locally in the kidney, systemic serum C3 levels remain **normal**. * **Minimal Change Disease (MCD):** This is a non-inflammatory podocytopathy. There is no complement activation; hence, C3 levels are **normal**. * **Focal Segmental Glomerulosclerosis (FSGS):** Similar to MCD, FSGS is generally a non-immune complex-mediated disease (except in rare secondary forms), and serum C3 levels are typically **normal**. **High-Yield Clinical Pearls for NEET-PG:** * **Low C3 + Low C4:** Systemic Lupus Erythematosus (SLE), Cryoglobulinemia, MPGN Type I. * **Low C3 + Normal C4:** Post-Streptococcal Glomerulonephritis (PSGN), MPGN Type II. * **Transient Low C3:** In PSGN, C3 levels typically return to normal within **6–8 weeks**. If C3 remains low beyond 8 weeks, suspect MPGN. * **Normal C3 Glomerular Diseases:** IgA Nephropathy, HSP (Henoch-Schönlein Purpura), MCD, FSGS, and Alport Syndrome.

Question 1

Which of the following statements is true regarding specific nephrological conditions?

Accepted Answer

Inulin clearance is the best measure of Glomerular Filtration Rate (GFR).

Answer

Henoch-Schönlein purpura (HSP) is associated with IgG deposition.

Answer

Hemolytic Uremic Syndrome (HUS) causes thrombocytopenia.

Answer

Post-Streptococcal Glomerulonephritis (PSGN) is associated with increased complement levels.

Question 2

An adolescent male presents with hypokalemia, metabolic alkalosis, hypercalciuria, and nephrocalcinosis. His blood pressure is normal. What is the likely diagnosis?

Accepted Answer

Bartter syndrome

Answer

Gitelman syndrome

Answer

Liddle syndrome

Answer

Renal tubular acidosis

Question 3

What is the definition of hypertension in children?

Accepted Answer

Average systolic blood pressure (SBP) and/or diastolic BP that is >=95th percentile for age, sex, and height on >=3 occasions

Answer

Average systolic blood pressure (SBP) and/or diastolic BP that is >=95th percentile for age, sex, and height on >=2 occasions

Answer

Average systolic blood pressure (SBP) and/or diastolic BP that is >=90th percentile for age, sex, and height on >=2 occasions

Answer

Average systolic blood pressure (SBP) and/or diastolic BP that is >=90th percentile for age, sex, and height on >=3 occasions

Question 4

What is true about Post-Streptococcal Glomerulonephritis?

Accepted Answer

Glomerulonephritis secondary to skin infection is more common in summer

Answer

50% of cases occur after pharyngitis

Answer

Early treatment of pharyngitis eliminates the risk of PSGN

Answer

Recurrence is seen

Question 5

Hypercoagulation in Nephrotic syndrome is caused by:

Accepted Answer

Loss of Antithrombin III

Answer

Decreased Fibrinogen

Answer

Decreased Metabolism of Vitamin K

Answer

Increase in Protein C

Question 6

Frequent relapse in Nephrotic syndrome implies which of the following definitions?

Accepted Answer

Two or more relapses in a 6-month period following initial response

Answer

Three or more relapses in a 1-year period

Answer

Relapse every month

Answer

Relapse every 3 months

Question 7

An 8-year-old child presents with a blood pressure of 180/100 mmHg, urea of 90 mg/dL, creatinine of 5.3 mg/dL, and urinalysis showing 15-20 pus cells, 12 RBCs, and protein 1+. The child has no significant past history of similar complaints. What is the most likely diagnosis?

Accepted Answer

Chronic interstitial nephritis with vesicoureteral reflux

Answer

Post-infective glomerulonephritis

Answer

Accelerated hypertension with acute renal failure

Answer

Idiopathic rapidly progressive glomerulonephritis

Question 8

All of the following are causes of hematuria in a child except?

Accepted Answer

Porphyria

Answer

Polycystic kidney disease (PCKD)

Answer

Renal vein thrombosis

Answer

Idiopathic hypercalciuria

Question 9

Low C3 levels are seen in which of the following conditions?

Accepted Answer

Mesangial capillary glomerulonephritis

Answer

IgA nephropathy

Answer

Minimal change disease

Answer

Focal segmental glomerulosclerosis

Question 10

A 5-year-old male child presents with complaints of fever and abdominal distension. On examination, there are 6-8 pus cells/hpf in urine. WBC count shows 78% neutrophils. What is the best line of management?

Accepted Answer

Send urine for culture and sensitivity and start antibiotics immediately.

Answer

Send urine for culture and sensitivity and wait for results.

Answer

Send urine for culture and perform an USG.

Answer

Radionuclide scan.

Nephrology — MCQs

Nephrology — MCQs

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