Nephrology Practice Questions

Q: A 60-year-old man presents with hematuria and flank pain. Laboratory results show elevated serum creatinine and red blood cell casts in the urine. What is the most likely diagnosis?

Glomerulonephritis. ***Glomerulonephritis*** - The presence of **hematuria**, **elevated serum creatinine**, and **red blood cell casts** in the urine is the classic triad indicating **glomerulonephritis**. - **Red blood cell casts** are pathognomonic for glomerular bleeding and inflammation. *Kidney stones* - Kidney stones typically present with **severe, colicky flank pain** and **hematuria**, but usually without elevated serum creatinine unless there's an obstruction. - While red blood cells may be present in the urine, **red blood cell casts** are not typically seen with kidney stones. *Pyelonephritis* - Characterized by **fever**, **flank pain**, and symptoms of a **urinary tract infection**, often with **white blood cell casts** in the urine analysis. - While leukocyturia is common, **red blood cell casts** are not a typical finding, and elevated creatinine is usually seen only in severe, complicated cases. *Interstitial nephritis* - Often presents with **fever**, **rash**, and **eosinophilia**, often due to an **allergic reaction** to drugs. - While it can cause elevated creatinine and sometimes hematuria, **white blood cell casts** (especially eosinophil casts) are more characteristic than red blood cell casts.

Q: A 28-year-old man presents with a history of recurrent hemoptysis and hematuria. Laboratory tests show elevated creatinine, and urinalysis reveals red blood cell casts. What is the most likely diagnosis?

Goodpasture's syndrome. ***Goodpasture's syndrome*** - The combination of **recurrent hemoptysis (pulmonary hemorrhage)** and **hematuria (renal pathology)**, along with elevated creatinine and RBC casts, is highly suggestive of **Goodpasture's syndrome**, which involves both lung and kidney damage. - This condition is characterized by the presence of **anti-glomerular basement membrane (anti-GBM) antibodies**, which attack collagen in both the renal glomeruli and pulmonary alveoli. *IgA nephropathy* - While IgA nephropathy can cause **hematuria** and elevated creatinine, it typically does not present with significant recurrent **hemoptysis** as a primary symptom. [1] - It is characterized by **IgA deposition** in the mesangium of the glomeruli, often following an upper respiratory or gastrointestinal infection. [1] *Wegener's granulomatosis* - Wegener's granulomatosis (now known as **Granulomatosis with Polyangiitis**) can affect both the kidneys and lungs, but it typically presents with **granulomatous inflammation** of the upper and lower respiratory tracts, often *without* recurrent prominent hemoptysis as the initial major lung symptom. - It is associated with **ANCA (antineutrophil cytoplasmic antibodies)**, particularly c-ANCA, which are not mentioned here. *Henoch-Schönlein purpura* - Henoch-Schönlein purpura (HSP) can cause **renal involvement** (hematuria, proteinuria) and skin manifestations (**palpable purpura**), and occasionally GI symptoms, but recurrent severe **hemoptysis** is not a characteristic feature. - It is an **IgA-mediated vasculitis** primarily affecting small vessels, often in children.

Q: A patient who received a kidney transplant 2 years ago presents with progressive renal dysfunction and proteinuria. A biopsy shows interstitial fibrosis and tubular atrophy. What is the most likely cause of these findings?

Chronic rejection; adjust immunosuppressive therapy. ***Chronic rejection; adjust immunosuppressive therapy*** - Chronic rejection typically manifests with **progressive renal dysfunction** and **interstitial fibrosis** and is a common complication in kidney transplant recipients [1]. - This condition often requires **adjustment of immunosuppressive therapy** to control the ongoing immune response against the graft [1]. *Acute cellular rejection; increase corticosteroids* - Acute cellular rejection usually presents acutely within days to weeks post-transplant, unlike the chronic presentation described here. - While corticosteroids are used to manage acute rejection, they are not appropriate for chronic rejection management. *Recurrent glomerulonephritis; start plasmapheresis* - Recurrent glomerulonephritis would typically cause different histological findings and not the **interstitial fibrosis** seen in chronic rejection. - Plasmapheresis is indicated for specific conditions like **antibody-mediated rejection**, not typically for chronic rejection [2]. *Drug toxicity; discontinue nephrotoxic medications* - Drug toxicity may cause renal impairment, but the biopsy findings suggest **chronic rejection** rather than acute damage from medication [1]. - Discontinuing nephrotoxic medications may help, but it does not address the underlying issue of chronic rejection.

Q: A 65-year-old male with a history of diabetes mellitus and chronic kidney disease presents with fatigue and reduced exercise tolerance. His lab results show a hemoglobin level of 9 g/dL, normal iron stores, and elevated serum creatinine. What is the most likely cause of his anemia?

Erythropoietin deficiency. ***Erythropoietin deficiency*** - **Chronic kidney disease** is the primary cause, leading to impaired synthesis of **erythropoietin** by the kidneys [1], [2]. - Erythropoietin is crucial for stimulating **red blood cell production** in the bone marrow [1]. *Iron deficiency* - The patient has **normal iron stores**, which rules out iron deficiency as the cause of anemia. - Iron deficiency typically presents with **microcytic, hypochromic anemia**. *Vitamin B12 deficiency* - This typically causes **macrocytic anemia** with neurological symptoms, which are not described. - Diagnosis requires evaluation of serum **vitamin B12** and **methylmalonic acid** levels. *Hemolysis* - Hemolysis involves the **premature destruction of red blood cells**, leading to elevated indirect bilirubin and LDH, and decreased haptoglobin. - No evidence of hemolysis is presented in the patient's symptoms or lab results.

Q: A 60-year-old male with a history of diabetes presents with fever, dysuria, and flank pain. His urine culture grows E. coli. What is the most likely diagnosis?

Pyelonephritis. ***Pyelonephritis*** - The combination of **fever**, **flank pain**, and **dysuria** in a diabetic patient, along with *E. coli* in urine, strongly indicates **pyelonephritis**, an upper urinary tract infection [1]. - **Diabetes** is a risk factor for more severe and complicated UTIs, predisposing patients to upward spread of infection to the kidneys. *Cystitis* - **Cystitis** is a lower urinary tract infection primarily affecting the bladder, characterized by **dysuria**, frequency, and urgency, generally without **fever** or **flank pain** [1]. - While *E. coli* is a common cause of cystitis, the presence of systemic symptoms like fever and flank pain points to kidney involvement [1]. *Prostatitis* - **Prostatitis** in men involves inflammation of the prostate gland, presenting with **perineal or ejaculatory pain**, **dysuria**, and sometimes fever [1]. - However, **flank pain** is not a typical symptom of prostatitis, making it less likely given the patient's presentation [1]. *Urethritis* - **Urethritis** is an inflammation of the urethra, often caused by sexually transmitted infections, presenting primarily with **dysuria** and **urethral discharge**, but rarely with fever or flank pain [1]. - The patient's symptoms, especially the **fever** and **flank pain**, are more consistent with an upper urinary tract infection [1].

Q: Which of the following is the most reliable indicator of diabetic nephropathy in a patient with insulin-dependent diabetes mellitus diagnosed at the age of 15 years?

Urinary albumin excretion > 300 mg/day. ***Urinary albumin excretion > 300 mg/day*** - This indicates **macroalbuminuria**, which is a **definitive sign of established diabetic nephropathy**, reflecting significant glomerular damage [2]. - It is a more sensitive and specific marker than other options for diagnosing and staging diabetic kidney disease [1]. *Presence of ketonuria* - Ketonuria indicates the body is breaking down fat for energy, often seen in **poorly controlled diabetes** or **diabetic ketoacidosis**. - While concerning, it is not a direct or reliable indicator of **renal structural damage** associated with diabetic nephropathy. *Elevated serum creatinine* - An elevated serum creatinine signifies a **decrease in glomerular filtration rate (GFR)**, indicating more advanced kidney disease [3]. - However, **significant renal damage** needs to occur before creatinine rises, making it a less sensitive early indicator compared to albuminuria [1]. *Persistent glycosuria* - Glycosuria indicates **elevated blood glucose levels** exceeding the renal threshold, meaning glucose is spilling into the urine. - While characteristic of uncontrolled diabetes, it does not directly reflect **kidney damage** or **nephropathy development**.

Q: A 30-year-old woman with chronic renal failure presents with laboratory findings of high BUN, high creatinine, low calcium, high phosphate, and elevated PTH. Renal ultrasound shows small, shrunken kidneys. What is the diagnosis?

Chronic renal failure. ***Chronic renal failure*** - The combination of **high BUN**, **high creatinine**, **low calcium**, and **high phosphate** alongside elevated **PTH** supports chronic renal failure, indicating long-standing kidney dysfunction [1]. - The **shrunken kidneys** observed on ultrasound are indicative of irreversible changes in chronic kidney disease [1]. *Acute renal failure* - Acute renal failure typically presents with a **sudden increase** in creatinine and BUN, which is absent in this long-standing scenario. - Kidney size is often normal or enlarged in acute conditions rather than the **shrunken appearance** seen here. *Nephrotic syndrome* - Nephrotic syndrome is characterized by **massive proteinuria**, **edema**, and **hypoalbuminemia**, which are not reflected in the patient's findings. - The lab findings here show **elevated phosphate** and altered calcium levels, not typical in nephrotic syndrome. *Nephritic syndrome* - Nephritic syndrome is associated with **hematuria**, **hypertension**, and **proteinuria**, leading to acute kidney injury, contradictory to chronic findings. - The presence of **elevated PTH** is more consistent with chronic illness rather than the acute processes of nephritic syndrome [1].

Q: A patient with chronic kidney disease is found to have hypertension and hyperkalemia. Which hormone's decreased levels could account for these findings?

Aldosterone. ***Aldosterone*** - **Aldosterone** normally promotes sodium reabsorption and potassium excretion in the kidneys [1]. Decreased aldosterone leads to **sodium wasting** and **potassium retention**, causing hyperkalemia [1]. - Reduced aldosterone also impairs the kidney's ability to excrete water, contributing to **fluid overload** and **hypertension** [4]. *Antidiuretic hormone* - **Antidiuretic hormone (ADH)** primarily regulates water balance by promoting water reabsorption in the collecting ducts, without directly impacting potassium levels. - Decreased ADH would lead to **diabetes insipidus**, characterized by polyuria and polydipsia, not hyperkalemia or hypertension in this context. *Cortisol* - **Cortisol** is a glucocorticoid involved in stress response, metabolism, and inflammation, and plays a minor role in electrolyte balance. - Decreased cortisol is associated with **adrenal insufficiency** (Addison's disease), which can cause hypotension and hyponatremia, not primarily hypertension and hyperkalemia [3]. *Insulin* - **Insulin** primarily regulates glucose metabolism and helps shift potassium into cells [2]. - Reduced insulin would lead to **hyperglycemia** and, when severe, can exacerbate hyperkalemia by preventing potassium uptake into cells. However, it's not the primary cause of hypertension and chronic hyperkalemia in CKD.

Q: A 55-year-old man with a history of chronic kidney disease presents with generalized weakness and hyperkalemia. Which medication is most appropriate for the immediate management of hyperkalemia?

Calcium gluconate. ***Calcium gluconate*** - This medication is the most appropriate for **immediate management** as it stabilizes the **cardiac membrane**, protecting the heart from the arrhythmogenic effects of hyperkalemia [1]. - While it does not lower potassium levels, it is crucial in preventing life-threatening **cardiac arrhythmias**, which are common in severe hyperkalemia [1]. *Sodium polystyrene sulfonate (Kayexalate)* - **Kayexalate** works by exchanging sodium for potassium in the gastrointestinal tract, leading to a reduction in serum potassium levels. - However, its onset of action is relatively slow (hours), making it unsuitable for **immediate stabilization** of life-threatening hyperkalemia. *Furosemide (Loop diuretic)* - Furosemide promotes renal excretion of potassium, thereby *lowering serum potassium levels*. - However, its effectiveness is limited in patients with **chronic kidney disease** (CKD) due to impaired renal function, and it doesn't provide immediate cardiac protection. *Beta-blocker* - Beta-blockers can actually worsen hyperkalemia by inhibiting the **cellular uptake of potassium**, especially in patients with impaired renal function [1]. - They are not indicated for the management of hyperkalemia and can even be detrimental in this context.

Q: A 58-year-old male with CKD stage 4, diabetes mellitus, and hypertension presents with persistent hyperkalemia despite dietary modifications. The ECG shows peaked T waves. Laboratory results indicate potassium levels of 6.5 mEq/L and creatinine levels of 4.0 mg/dL. What is the most appropriate initial management for this patient?

Administer calcium gluconate for cardiac protection.. ***Administer calcium gluconate for cardiac protection.*** - **Calcium gluconate** provides immediate **cardiac stabilization** by lowering the threshold potential and reducing myocardial excitability, counteracting the effects of hyperkalemia on the heart [1]. - The presence of **peaked T waves** on ECG indicates significant cardiac effects of hyperkalemia, making cardiac protection the most urgent initial step [1]. *Administer insulin and glucose to shift potassium intracellularly.* - **Insulin and glucose** therapy shifts potassium from the extracellular to the intracellular space, which helps **lower serum potassium levels**. - While important for reducing potassium, this treatment does not provide immediate cardiac protection and should be administered after cardiac stabilization. *Initiate dialysis immediately.* - **Dialysis** is a highly effective method for removing potassium from the body and is indicated for severe, refractory hyperkalemia, especially in patients with **CKD stage 4**. - However, it takes time to set up and initiate, making it a less immediate option for patients with ECG changes requiring urgent cardiac protection. *Administer oral potassium binders.* - **Oral potassium binders** (such as sodium polystyrene sulfonate or patiromer) increase fecal potassium excretion and are useful for chronic management of hyperkalemia or less severe cases. - They have a **delayed onset of action** and are not suitable for acute, symptomatic hyperkalemia with cardiac manifestations.

Question 1

A 60-year-old man presents with hematuria and flank pain. Laboratory results show elevated serum creatinine and red blood cell casts in the urine. What is the most likely diagnosis?

Accepted Answer

Glomerulonephritis

Answer

Kidney stones

Answer

Pyelonephritis

Answer

Interstitial nephritis

Question 2

A 28-year-old man presents with a history of recurrent hemoptysis and hematuria. Laboratory tests show elevated creatinine, and urinalysis reveals red blood cell casts. What is the most likely diagnosis?

Accepted Answer

Goodpasture's syndrome

Answer

Wegener's granulomatosis

Answer

IgA nephropathy

Answer

Henoch-Schönlein purpura

Question 3

A patient who received a kidney transplant 2 years ago presents with progressive renal dysfunction and proteinuria. A biopsy shows interstitial fibrosis and tubular atrophy. What is the most likely cause of these findings?

Accepted Answer

Chronic rejection; adjust immunosuppressive therapy

Answer

Acute cellular rejection; increase corticosteroids

Answer

Drug toxicity; discontinue nephrotoxic medications

Answer

Recurrent glomerulonephritis; start plasmapheresis

Question 4

A 65-year-old male with a history of diabetes mellitus and chronic kidney disease presents with fatigue and reduced exercise tolerance. His lab results show a hemoglobin level of 9 g/dL, normal iron stores, and elevated serum creatinine. What is the most likely cause of his anemia?

Accepted Answer

Erythropoietin deficiency

Answer

Iron deficiency

Answer

Vitamin B12 deficiency

Answer

Hemolysis

Question 5

A 60-year-old male with a history of diabetes presents with fever, dysuria, and flank pain. His urine culture grows E. coli. What is the most likely diagnosis?

Accepted Answer

Pyelonephritis

Answer

Cystitis

Answer

Prostatitis

Answer

Urethritis

Question 6

Which of the following is the most reliable indicator of diabetic nephropathy in a patient with insulin-dependent diabetes mellitus diagnosed at the age of 15 years?

Accepted Answer

Urinary albumin excretion > 300 mg/day

Answer

Presence of ketonuria

Answer

Elevated serum creatinine

Answer

Persistent glycosuria

Question 7

A 30-year-old woman with chronic renal failure presents with laboratory findings of high BUN, high creatinine, low calcium, high phosphate, and elevated PTH. Renal ultrasound shows small, shrunken kidneys. What is the diagnosis?

Accepted Answer

Chronic renal failure

Answer

Acute renal failure

Answer

Nephrotic syndrome

Answer

Nephritic syndrome

Question 8

A patient with chronic kidney disease is found to have hypertension and hyperkalemia. Which hormone's decreased levels could account for these findings?

Accepted Answer

Aldosterone

Answer

Antidiuretic hormone

Answer

Cortisol

Answer

Insulin

Question 9

A 55-year-old man with a history of chronic kidney disease presents with generalized weakness and hyperkalemia. Which medication is most appropriate for the immediate management of hyperkalemia?

Accepted Answer

Calcium gluconate

Answer

Beta-blocker

Answer

Sodium polystyrene sulfonate (Kayexalate)

Answer

Furosemide (Loop diuretic)

Question 10

A 58-year-old male with CKD stage 4, diabetes mellitus, and hypertension presents with persistent hyperkalemia despite dietary modifications. The ECG shows peaked T waves. Laboratory results indicate potassium levels of 6.5 mEq/L and creatinine levels of 4.0 mg/dL. What is the most appropriate initial management for this patient?

Accepted Answer

Administer calcium gluconate for cardiac protection.

Answer

Administer insulin and glucose to shift potassium intracellularly.

Answer

Initiate dialysis immediately.

Answer

Administer oral potassium binders.

Nephrology — MCQs

Nephrology — MCQs

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