Nephrology Practice Questions

Q: A patient develops gross hematuria 3 days after an upper respiratory infection. Which of the following is responsible?

IgA nephropathy. ### Explanation **Correct Option: C. IgA nephropathy** The hallmark of **IgA nephropathy (Berger’s disease)** is **synpharyngitic hematuria**—gross hematuria occurring concurrently or within 1–3 days of an upper respiratory tract infection (URTI) [1]. The underlying mechanism involves the overproduction of galactose-deficient IgA1 in response to mucosal triggers, which forms immune complexes that deposit in the glomerular mesangium, leading to inflammation and hematuria [3]. **Why other options are incorrect:** * **A. Acute Glomerulonephritis (PSGN):** Post-Streptococcal Glomerulonephritis typically has a **latent period** of 1–3 weeks after a sore throat (pharyngitis) or 3–6 weeks after a skin infection (impetigo). It does not occur within 3 days of the trigger. * **B. Minimal Change Disease:** This typically presents as **Nephrotic Syndrome** (massive proteinuria, edema, hypoalbuminemia) rather than gross hematuria [2]. It is not classically triggered by an infection within a 3-day window. * **D. Drug abuse:** While certain drugs (like NSAIDs or heroin) can cause interstitial nephritis or secondary FSGS, they do not present with the classic "infection-to-hematuria" temporal relationship seen in this case. **High-Yield Clinical Pearls for NEET-PG:** * **IgA Nephropathy** is the most common cause of primary glomerulonephritis worldwide. * **Complement levels (C3, C4):** Are **normal** in IgA nephropathy but **decreased** in PSGN. * **Prognosis:** The most important prognostic factor is the degree of proteinuria and hypertension. * **Henoch-Schönlein Purpura (HSP):** Is considered the systemic vasculitic form of IgA nephropathy, presenting with a tetrad of palpable purpura, arthralgia, abdominal pain, and renal involvement.

Q: All of the following are indicated in the management of acute hyperkalemia except?

Sodium polystyrene sulfonate. **Explanation:** The management of **acute hyperkalemia** (typically defined as $K^+ > 6.5$ mEq/L or presence of ECG changes) focuses on three immediate goals: stabilizing the cardiac membrane, shifting potassium into cells, and removing potassium from the body [1]. **Why Option D is the correct answer:** **Sodium polystyrene sulfonate (Kayexalate)** is a cation-exchange resin. While it does remove potassium from the body via the GI tract, its onset of action is very slow (several hours to days). Therefore, it has **no role in the emergency/acute management** of life-threatening hyperkalemia. Furthermore, recent guidelines discourage its use due to the risk of intestinal necrosis. **Analysis of Incorrect Options (Indicated Treatments):** * **A. IV Calcium Gluconate:** This is the first-line treatment if ECG changes are present [1]. It **stabilizes the cardiac myocyte membrane** (antagonizes the membrane effect of hyperkalemia) without lowering serum potassium levels [1]. * **B. IV Glucose and Insulin:** This is the most reliable method to **shift potassium intracellularly**. Insulin stimulates the Na-K ATPase pump; glucose is co-administered to prevent hypoglycemia [2]. * **C. Beta-2 Agonist Inhalation:** Salbutamol (Albuterol) nebulization also promotes the **intracellular shift** of potassium [2]. It acts synergistically with insulin. **NEET-PG High-Yield Pearls:** 1. **Fastest acting:** IV Calcium Gluconate (onset 1-3 mins) – but it does *not* lower $K^+$. 2. **Most effective for shifting $K^+$:** Insulin + Glucose. 3. **Definitive management:** Hemodialysis is the fastest way to *remove* potassium in patients with renal failure. 4. **ECG Sequence:** Tall peaked T-waves $→$ PR prolongation $→$ Loss of P-wave $→$ Widening of QRS $→$ Sine wave pattern $→$ Asystole.

Q: Clinical features of chronic renal failure (CRF) appear when renal function is reduced to what percentage of normal?

20%. **Explanation:** The kidneys possess a remarkable functional reserve, meaning they can maintain homeostasis even when a significant portion of nephrons is lost. Clinical features of Chronic Renal Failure (CRF) typically do not manifest until the **Glomerular Filtration Rate (GFR) falls below 20-25% of its normal value.** [1] 1. **Why 20% is correct:** This threshold marks the transition from "Renal Insufficiency" to "Renal Failure." At this stage, the remaining nephrons can no longer compensate for the loss. Patients begin to develop overt symptoms such as azotemia (elevation of BUN/Creatinine), anemia (due to decreased erythropoietin), and impaired concentrating ability (isosthenuria) [1]. 2. **Why other options are incorrect:** * **70% & 50%:** At these levels, the kidney is in the stage of **Decreased Renal Reserve.** Patients are asymptomatic, and routine blood tests (BUN/Creatinine) are often within normal limits because the surviving nephrons undergo compensatory hypertrophy. * **30%:** This represents moderate renal insufficiency. While biochemical abnormalities may be detectable, many patients remain relatively asymptomatic or have very mild, non-specific symptoms [1]. **High-Yield NEET-PG Pearls:** * **Stages of CKD:** Defined by GFR. Stage 1 (>90), Stage 2 (60-89), Stage 3 (30-59), Stage 4 (15-29), and Stage 5 (<15 ml/min) [1]. * **Earliest Clinical Sign:** Polyuria and nocturia (due to loss of urinary concentrating ability). * **Earliest Biochemical Sign:** Increase in serum Creatinine (though it only rises significantly after 50% nephron loss). * **Uremic Syndrome:** Usually occurs when GFR drops below 5-10% (End-Stage Renal Disease) [1].

Q: Nephrocalcinosis is seen in which of the following conditions?

All the above. Explanation: Nephrocalcinosis refers to the generalized deposition of calcium salts (calcium phosphate or calcium oxalate) within the renal parenchyma, most commonly in the renal medulla. It is primarily driven by states of hypercalcemia, hypercalciuria, or hyperoxaluria. Breakdown of Options: * **Sarcoidosis (Option A):** This is a granulomatous disease where macrophages within the granulomas produce 1-alpha-hydroxylase. This enzyme converts Vitamin D into its active form (1,25-dihydroxyvitamin D), leading to increased intestinal calcium absorption, hypercalcemia, and subsequent hypercalciuria, which causes calcium deposition in the kidneys [2]. * **Medullary Cystic Disease (Option B):** While often confused with Medullary Sponge Kidney (MSK), both can be associated with nephrocalcinosis [1]. In MSK, urinary stasis in dilated collecting ducts promotes stone formation; in certain cystic diseases, metabolic derangements and structural changes facilitate calcification. * **Milk-Alkali Syndrome (Option C):** This results from excessive ingestion of calcium and absorbable alkali [2]. It leads to the triad of hypercalcemia, metabolic alkalosis, and renal insufficiency. The high serum calcium levels directly lead to metastatic calcification within the renal tissue [2]. Clinical Pearls for NEET-PG: 1. **Most Common Cause:** Primary Hyperparathyroidism is the most frequent cause of nephrocalcinosis [2]. 2. **Distal Renal Tubular Acidosis (Type 1 RTA):** A high-yield association. It causes nephrocalcinosis due to alkaline urine, hypercalciuria, and hypocitraturia. 3. **Imaging:** Ultrasonography is the most sensitive initial screening tool, showing "hyperechoic pyramids" [1]. 4. **Differential:** Do not confuse nephrocalcinosis (parenchymal calcification) with nephrolithiasis (stones within the pelvicalyceal system).

Q: Which of the following conditions does NOT cause contracted kidney?

Diabetic nephropathy. In chronic kidney disease (CKD), the hallmark finding is typically **contracted kidneys** (small, shrunken, and scarred) due to progressive fibrosis and loss of nephrons [1]. However, certain conditions are notable exceptions where the kidneys remain normal-sized or even enlarged despite renal failure. ### **Why Diabetic Nephropathy is the Correct Answer** In **Diabetic Nephropathy**, the kidneys are characteristically **enlarged or normal-sized**, even in advanced stages of chronic renal failure. This occurs due to: * **Hyperfiltration and hypertrophy:** Early stages involve glomerular hyperfiltration. * **Matrix expansion:** Accumulation of basement membrane material and mesangial matrix (Kimmelstiel-Wilson nodules) [2]. * **Glycation products:** Deposition of advanced glycation end-products (AGEs) leads to structural bulk. ### **Why the Other Options are Incorrect** * **Chronic Glomerulonephritis (B):** This is the classic cause of bilateral, symmetrically contracted kidneys with a granular surface due to global glomerular scarring. * **Chronic Pyelonephritis (C):** Leads to asymmetrical contraction with characteristic **U-shaped cortical scars** overlying blunted calyces [1]. * **Benign Nephrosclerosis (D):** Long-standing hypertension causes hyaline arteriolosclerosis, leading to ischemic atrophy and finely granular, shrunken kidneys. ### **High-Yield Clinical Pearls for NEET-PG** To excel in questions regarding "Large Kidneys in CKD," remember the mnemonic **"DAPAM"**: 1. **D**iabetic Nephropathy (Most common cause) 2. **A**myloidosis (Due to extracellular protein deposition) 3. **P**olycystic Kidney Disease (ADPKD - due to multiple expanding cysts) 4. **A**IV (HIV-associated nephropathy) 5. **M**yeloma Kidney (Light chain deposition) *Note: In Diabetic Nephropathy, kidneys only begin to shrink in the very terminal stages if there is significant superimposed atherosclerotic renovascular disease.*

Q: What is the most common renal condition observed in HIV patients?

Focal segmental glomerulosclerosis. **Explanation:** The most common renal manifestation of HIV infection is **HIV-Associated Nephropathy (HIVAN)**, which characteristically presents as a **collapsing variant of Focal Segmental Glomerulosclerosis (FSGS)** [1]. 1. **Why FSGS is correct:** HIVAN is caused by the direct infection of renal tubular and glomerular cells by the HIV virus, leading to podocyte dysregulation [1]. It typically presents with heavy proteinuria (nephrotic range), rapidly progressive renal failure, and normal-sized or enlarged kidneys on ultrasound. It is most frequently seen in patients of African descent due to the presence of **APOL1 gene** risk variants. 2. **Why other options are incorrect:** * **Mesangial proliferation:** While seen in some viral infections (like Hepatitis B), it is not the primary or most common lesion associated with HIV [1]. * **Membranous glomerulonephritis:** This is more commonly associated with **Hepatitis B**, syphilis, or gold therapy, rather than HIV. * **Minimal change disease:** This is the most common cause of nephrotic syndrome in children and is associated with NSAIDs or Hodgkin’s lymphoma, but not specifically with HIV [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Pathology Hallmark:** "Collapsing" FSGS (wrinkling and collapse of the glomerular basement membrane). * **Ultrasound Finding:** Unlike most chronic kidney diseases where kidneys shrink, in HIVAN, kidneys are often **large and echogenic**. * **Treatment:** Initiation of **HAART (Highly Active Antiretroviral Therapy)** is the most effective way to slow the progression of HIVAN. * **Immune Complex Disease:** HIV patients can also develop "HIVICK" (HIV-associated immune complex kidney disease), but FSGS remains the most common classic association.

Question 1

Metabolic complications in chronic renal failure (CRF) include all of the following EXCEPT?

Accepted Answer

Hypophosphatemia

Answer

Hyperkalemia

Answer

Hypocalcemia

Answer

Hypokalemia

Question 2

A patient develops gross hematuria 3 days after an upper respiratory infection. Which of the following is responsible?

Accepted Answer

IgA nephropathy

Answer

Acute glomerulonephritis

Answer

Minimal change disease

Answer

Drug abuse

Question 3

All of the following are indicated in the management of acute hyperkalemia except?

Accepted Answer

Sodium polystyrene sulfonate

Answer

Intravenous Calcium gluconate

Answer

Intravenous Glucose and Insulin

Answer

Beta2 agonist inhalation

Question 4

Clinical features of chronic renal failure (CRF) appear when renal function is reduced to what percentage of normal?

Accepted Answer

20%

Answer

70%

Answer

50%

Answer

30%

Question 5

Nephrocalcinosis is seen in which of the following conditions?

Accepted Answer

All the above

Answer

Sarcoidosis

Answer

Medullary cystic disease

Answer

Milk alkali syndrome

Question 6

Which of the following conditions does NOT cause contracted kidney?

Accepted Answer

Diabetic nephropathy

Answer

Chronic glomerulonephritis

Answer

Chronic pyelonephritis

Answer

Benign nephrosclerosis

Question 7

Which of the following conditions causes euvolemic hyponatremia?

Accepted Answer

Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH)

Answer

Nephrotic syndrome

Answer

Diarrhea

Answer

Vomiting

Question 8

What is the most common renal condition observed in HIV patients?

Accepted Answer

Focal segmental glomerulosclerosis

Answer

Mesangial proliferation

Answer

Membranous glomerulonephritis

Answer

Minimal change disease

Question 9

A diabetic male presents with hypertension and 24-hour urine showing 200 mg of albumin. In a diabetic patient with microalbuminuria, what is the appropriate drug for the treatment of hypertension to prevent the progression of renal failure?

Accepted Answer

Angiotensin converting enzyme inhibitor

Answer

Beta blocker

Answer

Thiazide diuretic

Answer

Short-acting dihydropyridine calcium channel blocker for precise control (nifedipine)

Question 10

What is the drug of choice for stage I hypertension with diabetic nephropathy associated with frank proteinuria?

Accepted Answer

ACE inhibitor

Answer

Alpha blocker

Answer

Beta blocker

Answer

Calcium channel blocker

Nephrology — MCQs

Nephrology — MCQs

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