Nephrology — MCQs

Nephrology Indian Medical PG Practice Questions and MCQs

Question 351: Which of the following clinical findings is more likely to be associated with acute rather than chronic glomerulonephritis?

A. Osteomalacia
B. Increased anion gap metabolic acidosis
C. Oliguria
D. Preservation of concentrating ability (Correct Answer)

Explanation: The distinction between acute and chronic glomerulonephritis (GN) lies in the extent of structural damage to the nephron. **Why "Preservation of concentrating ability" is correct:** In **Acute Glomerulonephritis (AGN)**, the primary pathology is glomerular inflammation and hypercellularity, which reduces the Glomerular Filtration Rate (GFR) [1]. However, the **renal tubules** often remain functionally intact during the early stages. Since the concentrating mechanism (counter-current multiplier system) is a tubular function, it is preserved in AGN. In contrast, **Chronic Glomerulonephritis (CGN)** involves progressive interstitial fibrosis and tubular atrophy, leading to "isosthenuria" (loss of concentrating ability) [3]. **Analysis of Incorrect Options:** * **A. Osteomalacia:** This is a feature of **Chronic Kidney Disease (CKD)**. It results from the failure of 1-alpha-hydroxylase to convert Vitamin D to its active form (Calcitriol) and secondary hyperparathyroidism, which takes months to years to develop. * **B. Increased anion gap metabolic acidosis:** While seen in acute kidney injury, it is a hallmark of **advanced CGN/CKD** where the kidney can no longer excrete fixed acids (phosphates, sulfates). * **C. Oliguria:** This can occur in both acute (e.g., RPGN) and end-stage chronic GN [2]. It is not a specific differentiator, though it is a classic component of the "Nephritic Syndrome" in acute presentations [1]. **NEET-PG High-Yield Pearls:** * **Isosthenuria:** Fixed specific gravity of urine (~1.010); it is one of the earliest signs of chronic renal failure [3]. * **Small, shrunken kidneys** on ultrasound are the most reliable indicator of CGN (except in Diabetes, Amyloidosis, and Polycystic Kidney Disease where kidneys may be enlarged). * **Broad Waxy Casts** in urine sediment are highly suggestive of chronic end-stage renal disease.

Question 352: Which of the following is a manifestation of nephritic syndrome?

A. Syphilis
B. Hypotension
C. Hematuria (Correct Answer)
D. Polyuria

Explanation: Nephritic syndrome is characterized by an **inflammatory process** within the glomeruli, leading to a breakdown of the glomerular filtration barrier [2]. This allows red blood cells to leak into the urine, making **Hematuria** (often presenting as "cola-colored" or "smoky" urine) the hallmark clinical manifestation [3]. **Why the other options are incorrect:** * **Syphilis (Option A):** While secondary syphilis is associated with glomerular disease, it typically manifests as **Nephrotic syndrome** (specifically Membranous Nephropathy) due to immune complex deposition, rather than a primary nephritic picture [2]. * **Hypotension (Option B):** Nephritic syndrome is associated with **Hypertension**, not hypotension [4]. The decrease in Glomerular Filtration Rate (GFR) leads to fluid retention and activation of the Renin-Angiotensin-Aldosterone System (RAAS) [3]. * **Polyuria (Option C):** Patients with nephritic syndrome typically experience **Oliguria** (reduced urine output) due to the inflammatory reduction in GFR and subsequent salt and water retention [4]. **NEET-PG High-Yield Pearls:** * **The Nephritic Triad:** Hematuria (with RBC casts), Hypertension, and Oliguria/Azotemia [4]. * **Proteinuria:** In nephritic syndrome, proteinuria is present but usually in the **sub-nephrotic range** (<3.5 g/day). * **Common Causes:** Post-Streptococcal Glomerulonephritis (PSGN), IgA Nephropathy (Berger’s disease), and Rapidly Progressive Glomerulonephritis (RPGN) [3]. * **Differentiating Feature:** The presence of **RBC casts** in the urine sediment is pathognomonic for glomerular bleeding (nephritic origin) [1].

Question 353: What is the cause of renal failure in rhabdomyolysis?

A. Increased potassium
B. Increased phosphate
C. Increased uric acid
D. Myoglobin (Correct Answer)

Explanation: **Explanation:** Rhabdomyolysis involves the rapid breakdown of skeletal muscle, leading to the release of intracellular contents into the systemic circulation. The primary driver of Acute Kidney Injury (AKI) in this condition is **Myoglobin**. **Why Myoglobin is the correct answer:** Myoglobin causes renal failure through three distinct mechanisms: 1. **Intratubular Obstruction:** Myoglobin filters into the glomerulus and precipitates with Tamm-Horsfall protein in the distal tubules, forming obstructing casts (exacerbated by acidic urine). 2. **Direct Cytotoxicity:** The iron-containing heme moiety of myoglobin generates reactive oxygen species, causing oxidative stress and lipid peroxidation of tubular cell membranes (Acute Tubular Necrosis). 3. **Renal Vasoconstriction:** Myoglobin scavenges Nitric Oxide (NO), leading to intrarenal vasoconstriction and medullary ischemia. **Why other options are incorrect:** * **A & B (Potassium and Phosphate):** These are intracellular electrolytes released during muscle lysis [1]. While they cause life-threatening complications (hyperkalemia causes arrhythmias; hyperphosphatemia causes hypocalcemia), they are **consequences** of the cell breakdown rather than the primary cause of the renal failure itself. * **C (Uric Acid):** While hyperuricemia occurs due to the breakdown of muscle purines and can contribute to tubular obstruction, it is a secondary factor compared to the massive pigment load of myoglobin [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Classic Triad:** Muscle pain, weakness, and dark (tea-colored) urine. * **Diagnosis:** Serum **Creatine Kinase (CK)** levels >5 times the upper limit (most sensitive marker). * **Urinalysis Clue:** Urine dipstick is positive for "blood," but microscopy shows **no RBCs** (due to myoglobinuria). * **Management:** Aggressive IV fluid resuscitation (Normal Saline) is the most important step to prevent AKI [1]. Urine alkalinization is sometimes used to prevent myoglobin precipitation.

Question 354: Hepatorenal syndrome is characterized by all of the following except?

A. Serum creatinine more than 1.5 mg/dL
B. An intrinsically normal kidney
C. Low or absent proteinuria
D. Presence of a precipitating cause (Correct Answer)

Explanation: **Explanation:** Hepatorenal Syndrome (HRS) is a functional renal failure that occurs in patients with advanced chronic liver disease or acute liver failure [1]. It is primarily caused by extreme splanchnic vasodilation leading to severe renal vasoconstriction. **Why Option D is the correct answer:** While HRS can be triggered by precipitating factors (such as spontaneous bacterial peritonitis, GI bleeding, or over-diuresis), a **precipitating cause is NOT a requirement** for the diagnosis. HRS can occur spontaneously due to the progressive nature of portal hypertension. According to the International Club of Ascites (ICA) criteria, the diagnosis is based on the exclusion of other causes of kidney injury, not the presence of a trigger [1]. **Analysis of Incorrect Options:** * **Option A (Serum Creatinine >1.5 mg/dL):** Historically, this was a hallmark diagnostic threshold. While the newer ICA-AKI criteria focus on a rise in creatinine from baseline (≥0.3 mg/dL or 50% increase), a creatinine level >1.5 mg/dL remains a classic clinical indicator of significant renal impairment in HRS [1]. * **Option B (Intrinsically normal kidney):** HRS is a **functional** disorder. The kidneys are structurally intact and would function normally if transplanted into a patient with a healthy liver. * **Option C (Low or absent proteinuria):** Since the pathology is pre-renal (vasoconstrictive) rather than glomerular, there is typically no significant proteinuria (<500 mg/day) or hematuria [1]. **Clinical Pearls for NEET-PG:** * **Type 1 HRS:** Rapidly progressive; doubling of creatinine in <2 weeks [1]. * **Type 2 HRS:** Slowly progressive; associated with refractory ascites [1]. * **Urine Sodium:** Typically **<10 mEq/L** (due to intense sodium retention) [1]. * **Treatment of Choice:** Vasoconstrictors (**Terlipressin** is preferred) + **Albumin** [1]. * **Definitive Treatment:** Liver Transplantation [1].

Question 355: High urinary chloride is seen in all of the following conditions except?

A. Baer syndrome
B. Gitelman syndrome
C. Vomiting (Correct Answer)
D. Thiazide diuretics

Explanation: This question tests the ability to differentiate causes of metabolic alkalosis based on **urinary chloride (UCl⁻)** levels, a high-yield concept for NEET-PG. [1] ### **Explanation of the Correct Answer** **Vomiting (Option C)** is characterized by **low urinary chloride (<10-20 mEq/L)**. When a patient vomits, they lose hydrochloric acid (HCl), leading to metabolic alkalosis and volume depletion [1]. The kidneys respond to volume depletion by activating the Renin-Angiotensin-Aldosterone System (RAAS), which increases proximal tubule reabsorption of sodium and water. To maintain electrical neutrality, chloride is avidly reabsorbed alongside sodium. Consequently, the urine is "chloride-depleted." This is termed **Chloride-Responsive** metabolic alkalosis because it corrects with saline infusion. ### **Analysis of Incorrect Options** All other options are causes of **Chloride-Resistant** metabolic alkalosis, where **urinary chloride is high (>20 mEq/L)**: * **Bartter Syndrome (Option A):** A genetic defect in the thick ascending limb (NKCC2 transporter), mimicking the effect of loop diuretics. It presents with salt wasting and high UCl⁻. * **Gitelman Syndrome (Option B):** A genetic defect in the distal convoluted tubule (NCCT transporter), mimicking thiazide diuretics. It presents with hypocalciuria and high UCl⁻. * **Thiazide Diuretics (Option D):** These drugs inhibit the Na-Cl symporter in the distal tubule, directly increasing the excretion of chloride into the urine. ### **NEET-PG High-Yield Pearls** * **UCl⁻ < 10 mEq/L (Saline Responsive):** Vomiting, Nasogastric suction, Remote diuretic use, Laxative abuse. * **UCl⁻ > 20 mEq/L (Saline Resistant):** Bartter’s, Gitelman’s, Mineralocorticoid excess (Conn’s, Cushing’s), Current diuretic use. * **Differential Tip:** If the question mentions **hypocalciuria**, think **Gitelman’s**; if **hypercalciuria**, think **Bartter’s**.

Question 356: What is the treatment of choice for Hepatorenal syndrome?

A. ACE inhibitors
B. Calcium channel blockers
C. Peritoneal dialysis
D. Liver transplant (Correct Answer)

Explanation: **Explanation:** **Hepatorenal Syndrome (HRS)** is a functional renal failure occurring in patients with advanced cirrhosis or portal hypertension, characterized by intense renal vasoconstriction [1]. **1. Why Liver Transplant is the Correct Answer:** Liver transplantation is the **definitive treatment of choice** for HRS [1]. Since the underlying pathology is a systemic circulatory dysfunction triggered by liver failure, replacing the diseased liver reverses the portal hypertension and the neurohumoral triggers causing renal vasoconstriction. While medical therapies act as a "bridge," only a transplant offers a permanent cure and restores normal renal function [1]. **2. Why Other Options are Incorrect:** * **ACE Inhibitors (A):** These are strictly contraindicated. They cause systemic vasodilation and inhibit the renin-angiotensin-aldosterone system (RAAS), which is already compensatory. This can lead to profound hypotension and worsen renal perfusion. * **Calcium Channel Blockers (B):** These have no role in HRS and can exacerbate systemic hypotension, further reducing the glomerular filtration rate (GFR). * **Peritoneal Dialysis (C):** Dialysis (usually Hemodialysis or CRRT) is used only as a temporary measure for electrolyte imbalances or fluid overload [1]. It does not treat the underlying cause and is associated with high complication rates in cirrhotic patients (e.g., peritonitis, bleeding). **3. NEET-PG High-Yield Pearls:** * **Medical Bridge Therapy:** The most effective medical management is a combination of **Terlipressin** (a systemic vasoconstrictor) and **Albumin** (to expand effective circulatory volume) [1]. * **Pathophysiology:** Splanchnic vasodilation → Decreased effective arterial blood volume → Activation of RAAS/SNS → Intense **Renal Vasoconstriction** [1]. * **Diagnostic Criteria:** Absence of shock, no recent nephrotoxic drugs, and failure of serum creatinine to improve after 2 days of diuretic withdrawal and volume expansion with albumin [1].

Question 357: What is the investigation of choice to establish the diagnosis in adult nephrotic syndrome?

A. Renal biopsy (Correct Answer)
B. DMSA scan
C. CT Scan
D. MRI

Explanation: **Explanation:** In adults, nephrotic syndrome is most commonly caused by primary glomerulopathies (like Membranous Nephropathy or FSGS) or systemic diseases (like Diabetes or Amyloidosis) [1]. Unlike in children, where Minimal Change Disease is so prevalent that steroids are started empirically, the etiology in adults is highly variable [3]. Therefore, a **Renal Biopsy** is the investigation of choice (Gold Standard) to establish a definitive histological diagnosis, determine prognosis, and guide specific immunosuppressive therapy [2]. **Analysis of Options:** * **Renal Biopsy (Correct):** It allows for light microscopy, immunofluorescence, and electron microscopy, which are essential to differentiate between various types of glomerulonephritis [4]. * **DMSA Scan (Incorrect):** This is a nuclear medicine scan used primarily to detect cortical scarring (common in chronic pyelonephritis) or to evaluate functional renal mass. It has no role in diagnosing the cause of nephrotic syndrome. * **CT Scan & MRI (Incorrect):** These are structural imaging modalities. While they can identify tumors, stones, or renal vein thrombosis (a complication of nephrotic syndrome), they cannot visualize the microscopic glomerular changes required for a nephrotic diagnosis. **High-Yield Clinical Pearls for NEET-PG:** * **Indications for Biopsy in Children:** Unlike adults, children are biopsied only if they are "Steroid Resistant," have atypical features (age <1 or >12 years), or show low C3 levels. * **Most common cause of Nephrotic Syndrome:** * **Children:** Minimal Change Disease (MCD). * **Adults (Worldwide):** Focal Segmental Glomerulosclerosis (FSGS) [1]. * **Adults (Historically/Older texts):** Membranous Nephropathy. * **Contraindications for Renal Biopsy:** Solitary kidney (relative), uncontrolled hypertension, bleeding diathesis, and small echogenic kidneys (suggesting ESRD).

Question 358: Which of the following is the most important factor in determining the development of diabetic nephropathy?

A. Duration of the disease (Correct Answer)
B. Hypertension
C. Pre-existing renal disease
D. Control with treatment

Explanation: **Explanation:** The development of diabetic nephropathy (DN) is a progressive process primarily driven by the **duration of the disease** [1]. While multiple factors contribute to its pathogenesis, the cumulative exposure to hyperglycemia over time is the most critical determinant. * **Duration of the Disease (Correct):** DN rarely occurs within the first 5 years of Type 1 Diabetes (T1DM) [1]. Its prevalence peaks after 15–20 years of disease duration. In Type 2 Diabetes (T2DM), many patients already have microalbuminuria at the time of diagnosis because the actual onset of hyperglycemia often precedes clinical diagnosis by years. * **Hypertension (Incorrect):** Hypertension is a major risk factor for the *progression* of existing renal damage and is often a consequence of DN [3]. While controlling BP is vital to slow the decline of GFR, it is not the primary factor determining whether DN will develop initially. * **Pre-existing renal disease (Incorrect):** While it complicates the clinical picture, DN is a specific microvascular complication of diabetes itself [3], occurring in previously healthy kidneys due to metabolic and hemodynamic changes (e.g., hyperfiltration). * **Control with treatment (Incorrect):** Strict glycemic control (as shown in the DCCT and UKPDS trials) significantly *reduces the risk* and delays the onset [2], but it does not eliminate it entirely. Even with good control, the "metabolic memory" and duration of exposure remain the dominant predictors. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest Clinical Sign:** Microalbuminuria (30–300 mg/day) [1]. * **Earliest Pathological Change:** Thickening of the Glomerular Basement Membrane (GBM) [1]. * **Most Specific Pathological Finding:** Kimmelstiel-Wilson (KW) nodules (nodular glomerulosclerosis) [1]. * **Natural History:** Characterized by initial glomerular hyperfiltration (increased GFR), followed by microalbuminuria, overt proteinuria, and finally a decline in GFR [1].

Question 359: All of the following may be associated with massive proteinuria except?

A. Amyloidosis
B. Renal vein thrombosis
C. Polycystic kidneys (Correct Answer)
D. All

Explanation: **Explanation:** **1. Why Polycystic Kidney Disease (PKD) is the correct answer:** Massive proteinuria (defined as >3.5g/day, or nephrotic-range proteinuria) is a hallmark of glomerular diseases. **Autosomal Dominant Polycystic Kidney Disease (ADPKD)** is primarily a **tubulointerstitial/cystic disorder**, not a primary glomerulopathy [1]. While patients with ADPKD may develop mild to moderate proteinuria due to secondary focal segmental glomerulosclerosis (FSGS) or cyst-induced architectural distortion, it is rarely "massive." The clinical presentation is typically dominated by hypertension, hematuria, and progressive renal failure rather than nephrotic syndrome [1]. **2. Analysis of Incorrect Options:** * **Amyloidosis:** This is a classic cause of massive proteinuria. Deposition of amyloid fibrils (AL or AA) in the glomerular basement membrane disrupts the filtration barrier, frequently leading to nephrotic syndrome and some of the highest levels of protein loss seen in clinical practice [2]. * **Renal Vein Thrombosis (RVT):** There is a bidirectional relationship here. While RVT is often a *consequence* of nephrotic syndrome (due to loss of Antithrombin III), it can also be a *cause* of massive proteinuria. Acute increase in renal venous pressure leads to glomerular congestion and increased permeability, resulting in significant protein leakage. **3. NEET-PG High-Yield Pearls:** * **Definition:** Massive proteinuria = >3.5 g/24 hours (Nephrotic range). * **Most common cause of Nephrotic Syndrome in adults:** Membranous Nephropathy (often associated with RVT). * **Most common cause in children:** Minimal Change Disease [2]. * **Amyloidosis Fact:** Suspect Amyloidosis in a patient with chronic inflammatory disease (like RA or TB) who develops sudden massive proteinuria and enlarged kidneys on ultrasound. * **ADPKD Fact:** The most common extra-renal manifestation is **Liver Cysts**, but the most life-threatening is **Berry Aneurysm** (Subarachnoid Hemorrhage).

Question 360: All of the following are true about hepatorenal syndrome except:

A. Seen in advanced stage of cirrhosis
B. Type II has a more serious prognosis than Type I (Correct Answer)
C. Caused by intense hypoperfusion of the kidney
D. A functional renal failure without intrinsic renal pathology

Explanation: **Explanation:** Hepatorenal Syndrome (HRS) is a form of functional renal failure occurring in patients with advanced liver disease, characterized by intense renal vasoconstriction despite histologically normal kidneys [1]. **1. Why Option B is the correct answer (The Exception):** In HRS, **Type I is significantly more severe than Type II.** * **Type I HRS** is characterized by rapid, progressive renal failure (doubling of serum creatinine to >2.5 mg/dL in less than 2 weeks). It is often triggered by a precipitating event like SBP and has a very poor median survival (approx. 2 weeks) without treatment [1]. * **Type II HRS** is a more chronic, slowly progressive form, typically presenting as refractory ascites [1]. While it has a poor long-term prognosis, it is less acutely life-threatening than Type I. **2. Analysis of Incorrect Options:** * **Option A:** HRS is almost exclusively seen in patients with **advanced cirrhosis** and portal hypertension [1]. * **Option C:** The pathophysiology involves splanchnic vasodilation leading to decreased effective arterial blood volume. This triggers the RAAS and sympathetic nervous systems, causing **intense renal vasoconstriction and hypoperfusion.** * **Option D:** It is a **functional failure.** If the liver is transplanted or the patient recovers, renal function often returns to normal because there is no structural damage to the nephrons [1]. **Clinical Pearls for NEET-PG:** * **Diagnosis:** Requires exclusion of shock, nephrotoxic drugs, and intrinsic kidney disease (proteinuria <500mg/day, normal ultrasound) [1]. * **Treatment of Choice:** **Terlipressin** (vasoconstrictor) plus **Albumin** (volume expansion) [1]. * **Definitive Treatment:** Liver Transplantation [1]. * **Key Trigger:** Spontaneous Bacterial Peritonitis (SBP) is the most common precipitant for Type I HRS.

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Acute Kidney Injury

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Chronic Kidney Disease

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Glomerular Diseases

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Tubulointerstitial Diseases

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Nephrotic and Nephritic Syndromes

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Urinary Tract Infections

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Renal Replacement Therapy

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Fluid and Electrolyte Disorders

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Acid-Base Disorders

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Kidney in Systemic Diseases

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Kidney Stones and Obstructive Uropathy

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Hypertension in Kidney Disease

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Nephrology — MCQs

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