NEET-PG 2013 Practice Questions

Q: Cystatin C levels are used for

Estimating GFR. ***Estimating GFR*** - **Cystatin C** is a **proteinase inhibitor** produced by all nucleated cells at a constant rate, and its level in the blood is inversely related to the **glomerular filtration rate (GFR)**. - Unlike **creatinine**, Cystatin C levels are less affected by **muscle mass, diet, or inflammation**, making it a more reliable marker for early and subtle changes in GFR, especially in certain populations. *Detecting UTI* - **Urinary tract infections (UTIs)** are primarily detected through **urinalysis** (presence of **leukocytes, nitrites**, and **bacteria**) and **urine culture**. - **Cystatin C** is a serum marker for renal function and has no direct role in detecting the presence of bacterial infection in the urinary tract. *Estimating difference between CRF and ARF* - Differentiating between **chronic renal failure (CRF)** and **acute renal failure (ARF)** typically involves assessing the **chronicity of symptoms**, trend in **creatinine levels**, and **kidney size** and **echogenicity** on ultrasound. - While Cystatin C can reflect current GFR, it doesn't inherently provide discriminatory power between acute and chronic processes without serial measurements or additional clinical context. *Screening for Renal Ca* - **Renal cell carcinoma (RCC)** screening is primarily done using **imaging techniques** like **ultrasonography, CT, or MRI**, especially in individuals with risk factors or symptoms like **hematuria**. - **Cystatin C** is a marker of kidney function and does not serve as a tumor marker for renal cancer.

Q: What is the expected Transtubular Potassium Gradient (TTKG) in a patient with hypokalemia due to extrarenal losses?

< 3-4. ***< 3-4*** - A **Transtubular Potassium Gradient (TTKG)** of less than 3-4 indicates appropriate renal potassium conservation in response to hypokalemia. - This suggests that the hypokalemia is likely due to **extrarenal losses**, such as gastrointestinal losses (diarrhea, vomiting) or inadequate dietary intake, as the kidneys are working to retain potassium. *3-4* - A TTKG value in this range is typically considered indeterminate but could still point towards appropriate renal conservation if other clinical signs of extrarenal losses are present. - However, it does not as strongly confirm appropriate renal conservation as a value clearly below 3. *> 4-5* - A TTKG greater than 4-5 suggests **inappropriate renal potassium excretion** for a patient with hypokalemia. - This would indicate that the kidneys are complicit in the potassium loss, pointing towards renal causes of hypokalemia, such as **mineralocorticoid excess** or **diuretic use**. *> 5-6* - A TTKG greater than 5-6 strongly indicates significant **renal potassium wasting**. - This would be seen in conditions where the kidneys are actively secreting potassium despite hypokalemia, thereby contributing to the low potassium levels rather than conserving it.

Q: Which of the following is commonly seen in Polycythemia Vera?

Thrombosis. ***Spontaneous severe infection*** - In Polycythemia Vera, there is usually an **increased red blood cell mass** leading to complications like thrombosis, rather than a predisposition to severe infections. - Severe infections are not a typical feature, as the condition usually maintains **functional immunity** despite hyperviscosity. *Thrombosis* - Individuals with Polycythemia Vera have increased blood viscosity that results in a higher risk of **thrombosis**, which is a common complication [1]. - Events like **deep vein thrombosis (DVT)** or **cerebral venous sinus thrombosis** are often observed due to altered hemodynamics. *Hyperuricemia* - Hyperuricemia occurs due to increased cell turnover and breakdown of red cells in Polycythemia Vera, leading to elevated **uric acid levels** [1]. - Patients may experience **gout attacks** as a consequence of this elevated uric acid [1]. *Prone for acute leukemia* - While there is an increased risk of transformation to myeloid neoplasms, the risk for **acute leukemia** is not directly attributed to Polycythemia Vera in most cases. - It is more related to myelofibrosis or secondary conditions developing over time rather than a direct association.

Q: Which of the following is not a treatment option for hypercalcemia?

Strontium. ***Strontium*** - **Strontium ranelate** is primarily used in the treatment of **osteoporosis** to promote bone formation and inhibit bone resorption. - It does not have a recognized role in the acute or long-term management of **hypercalcemia** and could potentially worsen it due to its bone-targeting effects if not carefully managed. *Steroids* - **Glucocorticoids** are effective in treating hypercalcemia associated with **granulomatous diseases** (e.g., sarcoidosis) and certain malignancies (e.g., multiple myeloma) by reducing calcitriol production or tumor burden. - They decrease intestinal calcium absorption and increase renal calcium excretion in conditions where 1,25-dihydroxyvitamin D is elevated. *Bisphosphonates* - **Bisphosphonates** (e.g., zoledronic acid, pamidronate) are potent inhibitors of **osteoclast-mediated bone resorption** and are a cornerstone in the treatment of moderate to severe hypercalcemia, especially due to malignancy. [1] - They are administered intravenously and act by inducing osteoclast apoptosis, thereby reducing the release of calcium from bone. [1] *Phosphate* - **Intravenous phosphate** can be used in severe, resistant hypercalcemia, as it promotes calcium deposition into bone and soft tissues, and forms insoluble calcium-phosphate complexes, thus lowering serum calcium. - Its use is limited due to risks of **ectopic calcification**, renal failure, and hypotension, and it is usually reserved for life-threatening situations where other treatments have failed.

Q: Which of the following is a characteristic finding in distal RTA?

Hypercalciuria. ***Hypercalciuria*** - **Hypercalciuria** is a characteristic finding in distal RTA (Type 1), leading to increased calcium in the urine. - This occurs due to reduced **distal tubular reabsorption of calcium** and increased bone resorption from chronic acidosis. *Urine pH 5.5** [1]. - A urine pH < 5.5 would suggest a normal kidney response to systemic acidosis, ruling out distal RTA. *Hypokalemia* - While hypokalemia can occur in distal RTA, it is not always present and is not the most definitive characteristic finding. - **Hypokalemia** is more characteristic of Type 1 RTA due to increased potassium excretion in an attempt to excrete H+ ions. *Nephrolithiasis* - **Nephrolithiasis** (kidney stones) is a common complication of distal RTA due to hypercalciuria and alkaline urine [2]. - However, hypercalciuria is the *reason* for the increased risk of nephrolithiasis, making it a more fundamental characteristic finding.

Q: Pea soup diarrhea is seen in -

Typhoid. ***Typhoid*** - **Pea soup diarrhea** is a classic symptom of **typhoid fever**, caused by *Salmonella Typhi* [1]. - This characteristic stool is a greenish-yellow watery diarrhea due to inflammation and ulceration of the Peyer's patches in the small intestine [1]. *Cholera* - Characterized by **rice-water stools**, which are profuse, watery, and often contain flecks of mucus, resembling water in which rice has been rinsed [2]. - This type of diarrhea is due to the potent **cholera toxin** causing massive fluid and electrolyte secretion [2]. *Yersinosis* - Causes diarrhea that can range from watery to bloody, often associated with severe **abdominal pain** mimicking appendicitis. - While it can cause enterocolitis, the stool consistency is not typically described as "pea soup" like in typhoid. *Hepatitis* - Hepatitis primarily affects the **liver** and typically does **not cause diarrhea** as a prominent symptom. - Common symptoms include jaundice, dark urine, and pale stools due to impaired bilirubin metabolism.

Q: A 68-year-old patient presents with sudden onset of right-sided weakness and slurred speech. The symptoms completely resolve within 30 minutes with no residual neurological deficits. This clinical presentation is most consistent with:

Transient Ischemic Attack (TIA). ***Transient Ischemic Attack (TIA)*** - A TIA is characterized by **transient neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia**, without acute infarction [1]. - The key diagnostic feature here is the **complete resolution of symptoms within a short period** (30 minutes) with no residual deficits, fitting the definition of TIA [1]. *Subarachnoid hemorrhage* - This typically presents with a **sudden, severe headache** (often described as "thunderclap"), stiff neck, and altered mental status. - While it can cause sudden neurological deficits, these symptoms usually **do not resolve completely within minutes**, and often lead to persistent deficits or life-threatening complications. *Intracerebral hemorrhage* - An intracerebral hemorrhage involves **bleeding directly into the brain tissue**, leading to sudden onset of neurological deficits that **progress over time** [2]. - The symptoms are generally **severe and persistent**, and would not resolve completely within 30 minutes. *Ischemic stroke* - An ischemic stroke is caused by a **blockage of blood flow to the brain**, resulting in brain tissue damage (infarction) and persistent neurological deficits [2]. - While initial symptoms can be similar to a TIA [3], an ischemic stroke by definition involves **permanent damage and lasting deficits**, unlike what is described in the patient's presentation.

Q: Which of the following is not a feature of distal renal tubular acidosis

Hyperkalemia. ***Hyperkalemia*** - **Distal renal tubular acidosis (dRTA)** is characterized by impaired acid excretion, leading to metabolic acidosis. The impaired excretion of acid is often accompanied by impaired potassium secretion, resulting in **hypokalemia**, not hyperkalemia. - While hyperkalemia is a feature of **type 4 RTA**, which is characterized by hypoaldosteronism or renal tubular unresponsiveness to aldosterone, it is not a feature of **distal RTA (type 1)**. [1] *Normal anion gap* - **Distal RTA** is a form of **normal anion gap metabolic acidosis**, also known as **hyperchloremic metabolic acidosis**. [1] - The anion gap is calculated as [Na+] - ([Cl-] + [HCO3-]), and in dRTA, the bicarbonate loss is compensated by an increase in chloride, maintaining a normal anion gap. *Renal hypercalciuria* - **Distal RTA** is associated with **impaired acid excretion**, which leads to chronic metabolic acidosis. - This **acidosis** promotes the dissolution of bone, releasing calcium, and decreases tubular reabsorption of calcium, resulting in **hypercalciuria**. *Alkaline urine* - In **distal RTA**, the distal tubule is unable to acidify the urine due to a defect in hydrogen ion secretion. - This leads to a persistent **urine pH > 5.5** (typically alkaline or inappropriately normal) despite systemic acidosis, making it a key diagnostic feature. [1]

Q: Hyperkalemia aciduria is seen in

Type IV Renal Tubular Acidosis. Type IV Renal Tubular Acidosis - This condition is characterized by **hyperkalemia** and **aciduria**, often due to a deficiency in aldosterone or a renal tubular insensitivity to aldosterone [1]. - The impaired aldosterone action leads to reduced potassium excretion and decreased ammonium production, both contributing to **hyperkalemia** and metabolic acidosis [1]. *Type I Renal Tubular Acidosis* - Type I RTA (distal RTA) is characterized by a defect in acid secretion in the distal tubule, leading to **hypokalemia** and metabolic acidosis with persistently high urine pH [2]. - Patients typically excrete an alkaline urine despite systemic acidosis, contrasting with the aciduria seen with hyperkalemia [2]. *Sigmoidocolostomy procedure* - A sigmoidocolostomy can lead to **hyperchloremic metabolic acidosis** due to the reabsorption of chloride and excretion of bicarbonate by the colonic mucosa. - However, it typically causes **hypokalemia** as potassium is secreted into the colonic lumen from the blood. *Type II Renal Tubular Acidosis* - Type II RTA (proximal RTA) involves a defect in bicarbonate reabsorption in the proximal tubule, resulting in **hypokalemia** and metabolic acidosis. - The kidney's ability to acidify urine is still largely intact in the distal nephron once the bicarbonate buffer system is overwhelmed.

Q: A diabetic patient presents with hyperkalemia and urinary pH < 5.5. What is the MOST likely underlying cause?

Type IV RTA. ***Type IV RTA*** - Patients with **diabetes mellitus** frequently develop **hyporeninemic hypoaldosteronism**, leading to Type IV RTA [1]. - This condition is characterized by **hyperkalemia** and **acidosis** with a paradoxically low urinary pH (typically < 5.5). *Uremia* - **Uremia** can cause hyperkalemia and acidosis, but it is a broader term for severe kidney failure and not the most specific underlying cause for the given urinary findings. - While patients with uremia can have aciduria, the combination of **diabetic hyperkalemia** and acid urine points more directly to a specific tubular defect. *Primary hyperaldosteronism* - **Primary hyperaldosteronism** is characterized by **hypertension**, **hypokalemia**, and metabolic alkalosis, which is the opposite of the patient's presentation [1]. - This condition involves excessive aldosterone production, leading to increased potassium excretion [1]. *Type I Renal tubular acidosis* - **Type I RTA** (distal RTA) is characterized by the inability to acidify urine, resulting in a **urinary pH > 5.5** despite systemic acidosis [1]. - While it can cause hypokalemia (due to increased distal K+ secretion) and acidosis, the elevated urinary pH is a key differentiating factor from this patient's presentation [1].

Question 1

Cystatin C levels are used for

Accepted Answer

Estimating GFR

Answer

Detecting UTI

Answer

Screening for Renal Ca

Answer

Estimating difference between CRF and ARF

Question 2

What is the expected Transtubular Potassium Gradient (TTKG) in a patient with hypokalemia due to extrarenal losses?

Accepted Answer

< 3-4

Answer

3-4

Answer

> 4-5

Answer

> 5-6

Question 3

Which of the following is commonly seen in Polycythemia Vera?

Accepted Answer

Thrombosis

Answer

Hyperuricemia

Answer

Prone for acute leukemia

Answer

Spontaneous severe infection

Question 4

Which of the following is not a treatment option for hypercalcemia?

Accepted Answer

Strontium

Answer

Bisphosphonates

Answer

Steroids

Answer

Phosphate

Question 5

Which of the following is a characteristic finding in distal RTA?

Accepted Answer

Hypercalciuria

Answer

Urine pH < 5.5

Answer

Hypokalemia

Answer

Nephrolithiasis

Question 6

Pea soup diarrhea is seen in -

Accepted Answer

Typhoid

Answer

Cholera

Answer

Yersinosis

Answer

Hepatitis

Question 7

A 68-year-old patient presents with sudden onset of right-sided weakness and slurred speech. The symptoms completely resolve within 30 minutes with no residual neurological deficits. This clinical presentation is most consistent with:

Accepted Answer

Transient Ischemic Attack (TIA)

Answer

Subarachnoid hemorrhage

Answer

Intracerebral hemorrhage

Answer

Ischemic stroke

Question 8

Which of the following is not a feature of distal renal tubular acidosis

Accepted Answer

Hyperkalemia

Answer

Renal hypercalciuria

Answer

Normal anion gap

Answer

Alkaline urine

Question 9

Hyperkalemia aciduria is seen in

Accepted Answer

Type IV Renal Tubular Acidosis

Answer

Type I Renal Tubular Acidosis

Answer

Sigmoidocolostomy procedure

Answer

Type II Renal Tubular Acidosis

Question 10

A diabetic patient presents with hyperkalemia and urinary pH < 5.5. What is the MOST likely underlying cause?

Accepted Answer

Type IV RTA

Answer

Uremia

Answer

Primary hyperaldosteronism

Answer

Type I Renal tubular acidosis

NEET-PG 2013

Biochemistry

Internal Medicine