Nephrology Practice Questions

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: What is the recommended rate of correction for sodium deficit in patients with chronic hyponatremia?

0.5 mmol/hour. ***0.5 mmol/hour*** [1] - This rate of correction is recommended to avoid **osmotic demyelination syndrome (ODS)**, also known as central pontine myelinolysis [1]. - The aim is to correct the sodium deficit gradually, with a maximum increase not exceeding **8-10 mmol/L in any 24-hour period** [1]. *1 mmol/hour* - This rate is generally considered too rapid for chronic hyponatremia and increases the risk of **osmotic demyelination syndrome**. - While acceptable in some acute severe cases, it is typically avoided in chronic settings where the brain has adapted to lower osmolality. *1.5 mmol/hour* - This rate would lead to an even faster correction of sodium, significantly elevating the risk of **osmotic demyelination syndrome**. - It would result in a correction of 36 mmol/L over 24 hours, far exceeding the recommended daily limit of 8-10 mmol/L. *2.0 mmol/hour* - Such a rapid correction rate is highly dangerous and almost guarantees the development of **osmotic demyelination syndrome**. - This aggressive correction would lead to severe brain injury due to rapid osmotic shifts.

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: Calciphylaxis is a severe life-threatening condition. Which of the following is most commonly associated with it?

End stage Renal disease. ***End stage Renal disease*** - Calciphylaxis frequently occurs in patients with **end-stage renal disease**, primarily associated with **secondary hyperparathyroidism** [1] and **calcium-phosphate imbalance**. - It leads to **cutaneous ischemia** and necrosis, often requiring aggressive management due to its high **mortality rate**. *Parathyroidectomy* - While parathyroidectomy may affect calcium levels, it is not directly linked to calciphylaxis. - Calciphylaxis more commonly develops due to underlying **chronic renal failure** [1] rather than surgical interventions. *Hyperthyroidism* - Hyperthyroidism primarily causes symptoms related to metabolism, **thyroid hormone excess**, and does not lead to calciphylaxis. - There is no direct correlation between hyperthyroid states and the pathophysiology of calciphylaxis. *Medullary carcinoma thyroid* - This condition involves **medullary thyroid carcinoma**, associated with calcitonin production and does not cause calciphylaxis. - Patients typically experience **thyroid-related symptoms** rather than the vascular complications seen in calciphylaxis.

Q: Interstitial nephritis is common with

Nonsteroidal anti-inflammatory drugs (NSAIDs). ***Nonsteroidal anti-inflammatory drugs (NSAIDs)*** - **NSAIDs** are a known cause of **acute interstitial nephritis** (AIN), an inflammatory condition affecting the tubules and interstitium of the kidney [1]. - This adverse reaction often manifests as **fever**, **rash**, **eosinophilia**, and **acute kidney injury**, typically 7-10 days after drug exposure. *Black water fever* - **Blackwater fever** is a severe complication of **malaria**, characterized by massive hemolysis leading to **hemoglobinuria**, which darkens the urine. - It primarily causes **acute kidney injury** through **acute tubular necrosis** due to hemoglobin precipitation in the renal tubules, not interstitial nephritis. *Rhabdomyolysis* - **Rhabdomyolysis** involves the breakdown of muscle tissue, releasing myoglobin into the bloodstream, which is toxic to the kidneys. [1] - This condition leads to **acute kidney injury** predominantly through **acute tubular necrosis** due to myoglobin casts obstructing tubules and direct toxicity, not interstitial inflammation. *Tumor lysis syndrome* - **Tumor lysis syndrome** occurs when large numbers of cancer cells are rapidly destroyed, releasing intracellular contents like potassium, phosphate, and nucleic acids. - The high concentration of **uric acid** and **phosphate** in the renal tubules leads to crystal formation, causing **acute kidney injury** primarily through **acute uric acid nephropathy** and **phosphate nephropathy**, rather than interstitial nephritis [1].

Q: Which of the following statements about HIV associated nephropathy (HIVAN) is incorrect?

HIVAN is associated with shrunken kidneys.. ***Shrunken kidneys*** - In HIV-associated nephropathy, kidneys typically appear **enlarged** due to hyperplasia of podocytes and other glomerular changes. - **Shrunken kidneys** are not a characteristic feature, making this statement incorrect. *Develops when CD4<200* - HIV-associated nephropathy often arises when CD4 counts drop **below 200 cells/mm³**, indicating severe immunosuppression. - This is a common threshold for the occurrence of opportunistic infections and kidney issues in HIV patients. *15% cases show mesengial proliferation* - **Mesangial proliferation** can occur in about **15% to 30%** of cases of HIV-associated nephropathy, which aligns with the typical histological findings. - Incorrect assumptions might stem from misunderstanding the varying morphologies associated with HIV nephropathy. *Proteinuria* - **Proteinuria** is a common clinical feature of HIV-associated nephropathy, with the condition often presenting with significant protein loss in the urine. - The nephropathy especially results in **nephrotic syndrome**, characterized by high levels of proteinuria.

Q: Which of the following statements about Alport's syndrome is incorrect?

Autosomal dominant. ***Autosomal dominant*** - While there are rare autosomal dominant forms, the most common and classic presentation of **Alport's syndrome is X-linked recessive**, affecting males more severely. - This statement is incorrect because it implies that autosomal dominant inheritance is the primary or typical mode, which is not true for the majority of cases. *Nerve deafness* - **Sensorineural hearing loss**, particularly for high frequencies, is a common and characteristic extra-renal manifestation of Alport's syndrome. - This symptom typically progresses with age and is a key diagnostic feature. *Glomerulonephritis* - **Progressive glomerulonephritis** is the hallmark renal feature of Alport's syndrome, leading to hematuria, proteinuria, and eventually end-stage renal disease. - It is caused by mutations in collagen type IV genes, which disrupt the integrity of the glomerular basement membrane. *X-linked* - The majority of Alport's syndrome cases (about 85%) are **X-linked recessive**, caused by mutations in the *COL4A5* gene located on the X chromosome. - This explains why males are more severely affected and typically present with earlier onset and more rapid progression of renal disease.

Q: In which of the following conditions is hypomagnesemia not typically observed?

Diabetes mellitus. Diabetes mellitus - While hypomagnesemia can occur in poorly controlled diabetes due to osmotic diuresis, it is not a typical or defining feature of the condition itself in the same way as other options. - Many individuals with controlled diabetes may have normal magnesium levels, and it's often associated with complications rather than the primary disease process. Diarrhea - Chronic or severe diarrhea leads to significant gastrointestinal losses of electrolytes, including magnesium. - This is a common cause of hypomagnesemia, as the body loses fluids and minerals before they can be absorbed. Gitelman syndrome - This is a renal tubular disorder characterized by a defect in the thiazide-sensitive Na-Cl cotransporter in the distal convoluted tubule. - It leads to hypomagnesemia (due to increased renal excretion) and hypokalemia, along with metabolic alkalosis. Bartter syndrome - This syndrome involves a defect in the Na-K-2Cl cotransporter in the thick ascending limb of the loop of Henle. - It results in significant renal wasting of magnesium [1], leading to hypomagnesemia, along with hypokalemia and metabolic alkalosis.

Q: What is the most common presentation for IgA nephropathy?

Repeated gross hematuria. ***Repeated gross hematuria*** - The hallmark of **IgA nephropathy** is recurrent episodes of **gross hematuria**, particularly following **respiratory infections** [1]. - It is often associated with **renal impairment** but can present initially with **visible blood** in the urine [1]. *Nephritic syndrome* - While IgA nephropathy can lead to nephritic features, it does not commonly present primarily as **nephritic syndrome**, which includes hypertension and edema. - Nephritic syndrome is characterized by significant **proteinuria** and acute renal failure, rather than the classic presentation of hematuria [2]. *Microscopic hematuria* - Although **microscopic hematuria** can occur in IgA nephropathy, it is not the most common and noticeable presentation; **gross hematuria** is more characteristic [1]. - Microscopic hematuria lacks the acute visual symptoms seen in cases proving the diagnosis. *Nephritic syndrome* - This option is a repetition of and does not provide any additional unique characteristics specific to **IgA nephropathy**. - It shares the same clinical features discussed previously and is thus not representative of the most common presentation.

Q: What is the initial treatment of choice for managing secondary hyperparathyroidism in patients with renal osteodystrophy?

Phosphate binders. ***Phosphate binders*** - **Phosphate binders** are the initial treatment because **hyperphosphatemia** is the primary driver of secondary hyperparathyroidism in renal disease, triggering parathyroid hormone (PTH) release [1]. - They work by binding dietary phosphate in the gastrointestinal tract, preventing its absorption and thus lowering serum phosphate levels [1]. *Cinacalcet* - **Cinacalcet** is a calcimimetic that increases the sensitivity of calcium-sensing receptors on the parathyroid gland, reducing **PTH secretion** [1]. - It is often used if **phosphate binders** and **vitamin D analogs** are insufficient in controlling PTH, making it a second-line treatment [1]. *Bisphosphonates* - **Bisphosphonates** are used to treat osteoporosis by inhibiting osteoclast activity and reducing bone resorption. - They are generally contraindicated in advanced renal osteodystrophy due to concerns about adynamic bone disease and are not an initial treatment for **secondary hyperparathyroidism**. *Calcium restriction* - While restricting dietary calcium might seem intuitive, **hypocalcemia** is often a problem in renal disease due to impaired vitamin D activation [1]. - Overly restricting calcium can worsen hypocalcemia, which would further stimulate PTH release, thus it is not an initial treatment for **secondary hyperparathyroidism**.

Question 1

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 2

What is the recommended rate of correction for sodium deficit in patients with chronic hyponatremia?

Accepted Answer

0.5 mmol/hour

Answer

1 mmol/hour

Answer

1.5 mmol/hour

Answer

2.0 mmol/hour

Question 3

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

Accepted Answer

Hypercalciuria

Answer

Urine pH < 5.5

Answer

Hypokalemia

Answer

Nephrolithiasis

Question 4

Calciphylaxis is a severe life-threatening condition. Which of the following is most commonly associated with it?

Accepted Answer

End stage Renal disease

Answer

Parathyroidectomy

Answer

Medullary carcinoma thyroid

Answer

Hyperthyroidism

Question 5

Interstitial nephritis is common with

Accepted Answer

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Answer

Black water fever

Answer

Rhabdomyolysis

Answer

Tumor lysis syndrome

Question 6

Which of the following statements about HIV associated nephropathy (HIVAN) is incorrect?

Accepted Answer

HIVAN is associated with shrunken kidneys.

Answer

HIVAN is characterized by proteinuria.

Answer

HIVAN typically develops when CD4 count is less than 200.

Answer

About 15% of cases show mesangial proliferation.

Question 7

Which of the following statements about Alport's syndrome is incorrect?

Accepted Answer

Autosomal dominant

Answer

Nerve deafness

Answer

Glomerulonephritis

Answer

X-linked

Question 8

In which of the following conditions is hypomagnesemia not typically observed?

Accepted Answer

Diabetes mellitus

Answer

Diarrhea

Answer

Gitelman syndrome

Answer

Bartter syndrome

Question 9

What is the most common presentation for IgA nephropathy?

Accepted Answer

Repeated gross hematuria

Answer

Nephritic syndrome

Answer

Nephrotic syndrome

Answer

Microscopic hematuria

Question 10

What is the initial treatment of choice for managing secondary hyperparathyroidism in patients with renal osteodystrophy?

Accepted Answer

Phosphate binders

Answer

Cinacalcet

Answer

Bisphosphonates

Answer

Calcium restriction

Nephrology — MCQs

Nephrology — MCQs

On this page

Practice by Chapter

Want unlimited practice?