Nephrology Practice Questions

Q: A 30-year-old man presents with hematuria. Examination reveals an elevated blood pressure of 164/94 mm Hg. An ultrasound of the kidneys shows multiple renal cysts in both kidneys. His father had a similar condition. Which of the following is NOT associated with this syndrome?

Rheumatoid arthritis (RA). The clinical presentation of a young male with hypertension, hematuria, bilateral multiple renal cysts, and a positive family history (father) is diagnostic of **Autosomal Dominant Polycystic Kidney Disease (ADPKD)** [1]. **Why Option D is the Correct Answer:** **Rheumatoid Arthritis (RA)** is an autoimmune inflammatory joint disease and has **no known association** with ADPKD. ADPKD is a systemic genetic disorder involving connective tissue and epithelial cell abnormalities, but it does not predispose patients to RA. **Analysis of Incorrect Options:** * **Option A (Liver cysts):** Polycystic liver disease is the **most common extra-renal manifestation** of ADPKD. While usually asymptomatic, they increase in frequency with age [1]. * **Option B (Intracranial aneurysms):** Approximately 5-10% of ADPKD patients develop "Berry aneurysms" in the Circle of Willis. Rupture leads to subarachnoid hemorrhage, a major cause of mortality. * **Option C (Autosomal dominant inheritance):** ADPKD follows an autosomal dominant pattern, typically caused by mutations in the **PKD1** (Chromosome 16 - 85% cases) or **PKD2** (Chromosome 4 - 15% cases) genes [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of death:** Cardiovascular disease (due to hypertension and LVH). * **Other Extra-renal manifestations:** Pancreatic cysts, Mitral Valve Prolapse (MVP), diverticulosis, and seminal vesicle cysts. * **Diagnosis:** Ultrasound is the primary screening tool. Criteria are based on the number of cysts relative to age (e.g., ≥3 cysts bilaterally in ages 15–39). * **Treatment:** Tolvaptan (V2-receptor antagonist) is used to slow disease progression in rapidly progressing cases.

Q: Which of the following leads to hyponatremia and low osmolality?

CHF. **Explanation:** The correct answer is **CHF (Congestive Heart Failure)**. **1. Why CHF is correct:** Hyponatremia is classified based on serum osmolality. CHF causes **hypoosmolar hypervolemic hyponatremia** [1]. In CHF, decreased effective arterial blood volume (EABV) triggers the baroreceptors, leading to a non-osmotic release of **Antidiuretic Hormone (ADH)**. ADH acts on the V2 receptors in the collecting ducts, causing water retention that exceeds sodium retention [1]. This results in a "dilutional" hyponatremia where both serum sodium and serum osmolality are low. **2. Why the other options are incorrect:** * **Hyperlipidemia (A) and Hyperproteinemia (B):** These cause **Pseudohyponatremia**. In these conditions, the lipid or protein fraction of the plasma is increased, leading to a falsely low sodium measurement when using older flame photometry. Crucially, the **serum osmolality remains normal** (Isotonic hyponatremia). * **IVIG therapy (C):** High-dose IVIG can lead to **Translocational Hyponatremia**. The infusion of sucrose (often used as a stabilizer in IVIG) increases plasma osmolality, drawing water from the intracellular to the extracellular space. This results in hyponatremia with **high serum osmolality** (Hypertonic hyponatremia). **3. High-Yield NEET-PG Pearls:** * **True Hyponatremia** is always associated with **low serum osmolality** (<280 mOsm/kg). * **Hypertonic Hyponatremia:** Think Hyperglycemia or Mannitol [2]. * **Isotonic Hyponatremia (Pseudohyponatremia):** Think Hypertriglyceridemia or Paraproteinemia (Multiple Myeloma). * **Urine Sodium in CHF:** Typically **<20 mEq/L** (due to RAAS activation), helping differentiate it from renal causes of volume overload [1].

Q: All of the following are true about Rhabdomyolysis, except:

Hypercalcemia. Explanation: Rhabdomyolysis involves the rapid breakdown of skeletal muscle, leading to the release of intracellular contents into the systemic circulation. **Why Hypercalcemia is the Correct Answer (The Exception):** In the **acute phase** of rhabdomyolysis, **hypocalcemia** (low calcium) is typically observed rather than hypercalcemia. This occurs because calcium deposits into the damaged muscle tissues (dystrophic calcification) and binds with the excess phosphate released from cells. While hypercalcemia can occur later during the recovery phase (due to the mobilization of these deposits), it is not a characteristic feature of the initial presentation. **Analysis of Other Options:** * **Hyperuricemia (A):** Muscle breakdown releases purines, which are metabolized by the liver into uric acid. This can lead to secondary gout or contribute to acute kidney injury (AKI). * **Hyperphosphatemia (B):** Phosphorus is a major intracellular anion. Massive cell lysis releases large amounts of phosphate into the blood. * **Elevated Creatine Kinase (D):** CK is the most sensitive marker for muscle damage. Levels typically exceed five times the upper limit of normal (often >10,000 U/L) and are diagnostic of the condition. **NEET-PG High-Yield Pearls:** * **Classic Triad:** Muscle pain, weakness, and dark (tea-colored) urine. * **Urinalysis Paradox:** The dipstick is positive for "blood" (due to myoglobinuria), but microscopy shows **no RBCs**. * **Most Common Electrolyte Abnormality:** Hyperkalemia (the most life-threatening complication). * **Treatment:** Aggressive fluid resuscitation (Normal Saline) to maintain urine output and prevent Myoglobin-induced AKI.

Q: A 22-year-old male presents with fever, hematuria, and hypertension. Intravenous pyelography (IVP) shows a "spider leg" deformity. What is the most likely diagnosis?

Autosomal dominant polycystic kidney disease (ADPKD). ### Explanation **Correct Option: A. Autosomal dominant polycystic kidney disease (ADPKD)** The "spider leg" appearance on Intravenous Pyelography (IVP) is a classic radiological sign of ADPKD. This occurs because multiple large, fluid-filled cysts in the renal parenchyma compress and stretch the renal calyces and pelvis, making them appear elongated, thin, and spindly—resembling the legs of a spider. Clinically, ADPKD often presents in young adults (20–40 years) [1] with a triad of hypertension, hematuria, and palpable abdominal masses (flank pain). **Analysis of Incorrect Options:** * **B. ARPKD:** Typically presents in infancy or childhood with bilateral flank masses and renal failure. On IVP, it shows a characteristic **"sunray" or "paintbrush" appearance** due to dilated collecting ducts, rather than calyceal stretching. * **C. Medullary sponge kidney:** Characterized by cystic dilatation of the collecting ducts. The classic IVP finding is a **"bouquet of flowers" or "paintbrush" appearance** [2] due to the accumulation of contrast in the dilated ducts. * **D. Hydronephrosis:** Results in the dilatation of the renal pelvis and calyces. On IVP, this appears as **"clubbing" of the calyces**, not the thin, elongated deformity seen in ADPKD. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Most common cause is a mutation in the **PKD1 gene** (Chromosome 16), followed by PKD2 (Chromosome 4) [1]. * **Extra-renal manifestations:** The most common is **Liver cysts**. The most serious is **Berry aneurysms** (leading to Subarachnoid Hemorrhage). Others include mitral valve prolapse and diverticulosis. * **Diagnosis:** Ultrasound is the initial investigation of choice (Revised Ravine’s criteria). * **Treatment:** Tolvaptan (Vasopressin V2 receptor antagonist) is used to slow disease progression.

Q: How is glomerular proteinuria differentiated from non-glomerular proteinuria?

Proteinuria > 3.0 - 3.5 g/day. The differentiation between glomerular and non-glomerular (tubular or overflow) proteinuria is based on the **quantity** and **composition** of the proteins excreted. **1. Why Option A is Correct:** The glomerular filtration barrier (basement membrane and podocytes) normally restricts large proteins like albumin [2]. When this barrier is significantly damaged (e.g., Nephrotic Syndrome), massive amounts of protein leak into the urine [1]. **Proteinuria > 3.0 - 3.5 g/day** is almost exclusively a hallmark of **glomerular disease** [1]. In contrast, tubular or overflow proteinuria rarely exceeds 2 g/day because the filtered load of small proteins is limited. **2. Analysis of Incorrect Options:** * **Option B:** In glomerular proteinuria, **Albumin > Globulin** (selective or non-selective). Globulins predominate in "Overflow Proteinuria" (e.g., Multiple Myeloma) [1]. * **Option C:** The **Albumin to $eta_2$-microglobulin ratio** is a classic differentiator. In glomerular disease, the ratio is high (**>1000:1**) because albumin is the primary protein. A ratio of **<10:1** suggests tubular disease, where low-molecular-weight proteins like $eta_2$-microglobulin are not reabsorbed. * **Option D:** **Tamm-Horsfall protein** (Uromodulin) is a physiological protein secreted by the thick ascending limb of Henle. It is the matrix for all urinary casts but does not help differentiate the etiology of pathological proteinuria. **Clinical Pearls for NEET-PG:** * **Gold Standard for quantification:** 24-hour urine protein collection (though Spot Protein-Creatinine Ratio is preferred in practice) [1]. * **Dipstick Sensitivity:** Primarily detects **Albumin** [1]. It may miss Bence-Jones proteins (globulins) seen in Multiple Myeloma (Sulfosalicylic acid test is used instead) [1]. * **Microalbuminuria:** 30–300 mg/day; the earliest sign of Diabetic Nephropathy [1].

Q: A 60-year-old woman presents with symptoms of muscle weakness and fatigue. Her examination reveals blood pressure of 110/80 mm Hg, pulse of 100/min, JVP of 1 cm, normal heart sounds, and clear lungs. Laboratory findings include serum potassium of 2.5 mEq/L, bicarbonate of 15 mEq/L, and a normal anion gap. Urine potassium is 10 mEq/L. For this patient with hypokalemia, what is the most likely diagnosis?

Lower gastrointestinal losses. This clinical scenario tests the systematic approach to **hypokalemia** by evaluating urinary potassium excretion and acid-base status. ### **Explanation of the Correct Answer** The patient presents with hypokalemia (2.5 mEq/L) and metabolic acidosis (Bicarbonate 15 mEq/L). The key to the diagnosis lies in the **Urine Potassium level (10 mEq/L)** [1]. * In hypokalemia, the normal renal response is to conserve potassium. A **Urine K+ < 15–20 mEq/L** indicates **extra-renal losses** (the kidneys are functioning correctly by holding onto potassium) [1]. * Lower GI losses (e.g., chronic diarrhea, laxative abuse) result in the loss of potassium and bicarbonate. This leads to hypokalemia and a **Normal Anion Gap Metabolic Acidosis (NAGMA)** [1]. ### **Why Other Options are Incorrect** * **B & D (Diuretics):** Both current and prior diuretic use typically cause **increased** urinary potassium excretion (Urine K+ > 20 mEq/L) and are usually associated with metabolic **alkalosis**, not acidosis. * **C (Renal Tubular Acidosis):** While RTA (Types 1 and 2) causes NAGMA and hypokalemia, it is a **renal** cause of potassium loss. Therefore, the Urine K+ would be inappropriately **high** (> 20 mEq/L) despite the low serum potassium. ### **NEET-PG High-Yield Pearls** 1. **Urinary K+ Threshold:** Use **20 mEq/L** as the cutoff. 20 mEq/L = Renal loss (Diuretics, RTA, Hyperaldosteronism) [1]. 2. **Acid-Base Clues:** * Hypokalemia + Acidosis = Diarrhea or RTA [1]. * Hypokalemia + Alkalosis = Vomiting, Diuretics, or Conn’s Syndrome. 3. **Transtubular Potassium Gradient (TTPG):** A TTPG > 7 in a hypokalemic patient suggests renal potassium wasting.

Q: Which of the following is not a common manifestation of nephrotic syndrome?

Hematuria. **Explanation:** The hallmark of **Nephrotic Syndrome** is the disruption of the glomerular filtration barrier (specifically the podocytes), leading to massive protein loss [1]. To diagnose Nephrotic Syndrome, a triad of clinical findings must be present: **Heavy proteinuria (>3.5 g/day), Hypoalbuminemia (<3 g/dL), and Generalized Edema (Anasarca).** **Why Hematuria is the correct answer:** Hematuria is the classic feature of **Nephritic Syndrome**, which involves inflammatory damage to the glomerular capillaries (e.g., PSGN, IgA Nephropathy) [1]. While "microscopic" hematuria can occasionally occur in certain nephrotic conditions (like Membranous Nephropathy), it is **not** a defining or common manifestation. Nephrotic syndrome is primarily a "non-inflammatory" protein-losing state. **Analysis of Incorrect Options:** * **Hypoalbuminemia:** Direct result of massive urinary protein loss (proteinuria) [1]. As the liver cannot synthesize albumin fast enough to compensate for the loss, serum levels drop. * **Anasarca:** Low serum albumin decreases **plasma oncotic pressure**, leading to fluid extravasation into the interstitium, causing generalized edema (anasarca) [1]. * **Hyperlipidemia:** In response to low oncotic pressure, the liver increases the synthesis of lipoproteins (LDL, VLDL) [1]. Additionally, there is decreased catabolism of lipids due to the loss of lipoprotein lipase in the urine. **High-Yield Clinical Pearls for NEET-PG:** * **Hypercoagulability:** Nephrotic patients are at high risk for venous thromboembolism (especially **Renal Vein Thrombosis**) due to the urinary loss of **Antithrombin III**, Protein C, and S [1]. * **Infection Risk:** Increased susceptibility to encapsulated organisms (e.g., *S. pneumoniae*) due to the loss of **Immunoglobulins** and Complement factors in urine [1]. * **Maltese Cross Appearance:** Seen under polarized microscopy in the urine sediment due to lipiduria (fatty casts).

Q: Chronic laxative abuse can result in the formation of which type of renal stone?

Ammonium urate. **Explanation:** The correct answer is **Ammonium urate**. **Pathophysiology:** Chronic laxative abuse leads to chronic diarrhea, resulting in significant loss of water, bicarbonate, and potassium from the gastrointestinal tract. This triggers a specific metabolic environment conducive to ammonium urate stone formation: 1. **Dehydration:** Leads to low urine volume and concentrated urine. 2. **Metabolic Acidosis:** Loss of bicarbonate causes the kidneys to increase **ammoniagenesis** (production of $NH_4^+$) to buffer the acid. 3. **Hypokalemia:** Intracellular potassium depletion further stimulates renal ammonia production. 4. **Hyperuricosuria:** The resulting acidic, concentrated urine with high ammonium concentrations promotes the precipitation of ammonium acid urate. **Analysis of Incorrect Options:** * **A. Xanthine:** These are rare stones typically associated with hereditary xanthine oxidase deficiency or the use of Allopurinol. * **B. Cysteine:** These occur due to an autosomal recessive defect in the transport of dibasic amino acids (COLA: Cysteine, Ornithine, Lysine, Arginine) in the proximal tubule. * **D. Struvite (Triple Phosphate):** These are "infection stones" (Magnesium Ammonium Phosphate) associated with urease-producing bacteria like *Proteus* or *Klebsiella*, which make the urine alkaline [1]. **Clinical Pearls for NEET-PG:** * **Ammonium urate stones** are radiolucent (like pure uric acid stones) but may appear faintly radiopaque if they co-precipitate with calcium [2]. * They are also commonly seen in patients with **inflammatory bowel disease (IBD)** due to similar chronic malabsorption/diarrhea mechanisms. * **Key Triad for Laxative Abuse:** Hypokalemia, metabolic alkalosis (if vomiting) or acidosis (if diarrhea), and ammonium urate stones.

Question 1

Hemodialysis can be performed for long periods from the same site due to which of the following?

Accepted Answer

Arteriovenous fistula results in aerialization of vein

Answer

Arteriovenous fistula reduces bacterial contamination of site

Answer

Arteriovenous fistula reduces chances of graft failure

Answer

Arteriovenous fistula facilitates small bore needles for high flow rates

Question 2

A 30-year-old man presents with hematuria. Examination reveals an elevated blood pressure of 164/94 mm Hg. An ultrasound of the kidneys shows multiple renal cysts in both kidneys. His father had a similar condition. Which of the following is NOT associated with this syndrome?

Accepted Answer

Rheumatoid arthritis (RA)

Answer

Liver cysts

Answer

Intracranial aneurysms

Answer

Autosomal dominant inheritance

Question 3

Which of the following leads to hyponatremia and low osmolality?

Accepted Answer

CHF

Answer

Hyperlipidemia

Answer

Hyperproteinemia

Answer

IVIG therapy

Question 4

All of the following are true about Rhabdomyolysis, except:

Accepted Answer

Hypercalcemia

Answer

Hyperuricemia

Answer

Hyperphosphatemia

Answer

Elevated Creatine kinase

Question 5

A 30-year-old female patient is undergoing hemodialysis with an internal arteriovenous fistula in place. What measures should be taken to prevent complications associated with this device?

Accepted Answer

Avoid taking blood pressures in the arm with the fistula.

Answer

Insert intravenous lines above the fistula.

Answer

Palpate pulses above the fistula.

Answer

Report any bruit or thrill over the fistula to the physician.

Question 6

A 22-year-old male presents with fever, hematuria, and hypertension. Intravenous pyelography (IVP) shows a "spider leg" deformity. What is the most likely diagnosis?

Accepted Answer

Autosomal dominant polycystic kidney disease (ADPKD)

Answer

Autosomal recessive polycystic kidney disease (ARPKD)

Answer

Medullary sponge kidney

Answer

Hydronephrosis

Question 7

How is glomerular proteinuria differentiated from non-glomerular proteinuria?

Accepted Answer

Proteinuria > 3.0 - 3.5 g/day

Answer

Globulin > albumin

Answer

Albumin to B2 microglobulin ratio 100:1

Answer

Tamm-Horsfall protein

Question 8

A 60-year-old woman presents with symptoms of muscle weakness and fatigue. Her examination reveals blood pressure of 110/80 mm Hg, pulse of 100/min, JVP of 1 cm, normal heart sounds, and clear lungs. Laboratory findings include serum potassium of 2.5 mEq/L, bicarbonate of 15 mEq/L, and a normal anion gap. Urine potassium is 10 mEq/L. For this patient with hypokalemia, what is the most likely diagnosis?

Accepted Answer

Lower gastrointestinal losses

Answer

Prior use of diuretics

Answer

Renal tubular acidosis

Answer

Current use of diuretics

Question 9

Which of the following is not a common manifestation of nephrotic syndrome?

Accepted Answer

Hematuria

Answer

Hyperlipidemia

Answer

Anasarca

Answer

Hypoalbuminemia

Question 10

Chronic laxative abuse can result in the formation of which type of renal stone?

Accepted Answer

Ammonium urate

Answer

Xanthine

Answer

Cysteine

Answer

Struvite

Nephrology — MCQs

Nephrology — MCQs

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