USMLE Step 2 Quiz
Practice Glomerular And Tubulointerstitial Disease in USMLE Step 2 with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.
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A 24-year-old man presents to the emergency department with severe shortness of breath and hemoptysis. He has also noted swelling in his legs and decreased urine output for the past week. His creatinine is 5.0 mg/dL. Urinalysis reveals dysmorphic red blood cells and RBC casts. A chest X-ray shows diffuse bilateral alveolar infiltrates.
Which of the following serologic tests would be most specific for diagnosing this patient's condition?
This quiz focuses on Glomerular And Tubulointerstitial Disease, giving you a quick way to practice the rules, question types, and explanations that matter most for USMLE Step 2.
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A 24-year-old man presents to the emergency department with severe shortness of breath and hemoptysis. He has also noted swelling in his legs and decreased urine output for the past week. His creatinine is 5.0 mg/dL. Urinalysis reveals dysmorphic red blood cells and RBC casts. A chest X-ray shows diffuse bilateral alveolar infiltrates.
Which of the following serologic tests would be most specific for diagnosing this patient's condition?
Explanation: The combination of rapidly progressive glomerulonephritis (hematuria, RBC casts, acute renal failure) and pulmonary hemorrhage (hemoptysis, alveolar infiltrates) constitutes a pulmonary-renal syndrome. In a young man, the most likely diagnosis is Goodpasture syndrome, which is caused by autoantibodies directed against the alpha-3 chain of type IV collagen in the glomerular and alveolar basement membranes. The most specific diagnostic test is an assay for anti-GBM antibodies.
A 10-year-old boy is brought to the clinic with a 3-day history of dark, 'cola-colored' urine and puffiness around his eyes. His mother reports he was treated for impetigo on his legs three weeks ago. Physical examination reveals a blood pressure of 145/95 mmHg and periorbital edema. Urinalysis shows 2+ protein, large blood, and red blood cell casts. A serum C3 level is low.
Which of the following is the most likely diagnosis?
Explanation: This patient presents with a classic acute nephritic syndrome (hypertension, hematuria with RBC casts, edema) following a streptococcal skin infection (impetigo). The latency period of 2-4 weeks and the finding of low serum C3 are highly characteristic of poststreptococcal glomerulonephritis (PSGN).
A 68-year-old man with a history of hypertension and gastroesophageal reflux disease is hospitalized for community-acquired pneumonia. Ten days after starting treatment with amoxicillin and omeprazole, he develops a diffuse maculopapular rash, a fever of 38.5°C (101.3°F), and a rise in his serum creatinine from a baseline of 1.1 mg/dL to 3.2 mg/dL. Urinalysis reveals numerous white blood cells and white blood cell casts. Peripheral blood smear shows eosinophilia.
What is the most likely diagnosis?
Explanation: The classic triad of fever, rash, and eosinophilia combined with acute kidney injury after exposure to a new medication (penicillins, PPIs, NSAIDs) is highly suggestive of drug-induced acute interstitial nephritis (AIN). The urinalysis finding of sterile pyuria with white blood cell casts is a key feature that distinguishes AIN from other causes of AKI like acute tubular necrosis (which would show muddy brown casts).
A 29-year-old woman with a history of systemic lupus erythematosus, characterized by arthritis and a malar rash, presents with new-onset bilateral leg swelling and frothy urine. Her blood pressure is 150/92 mmHg. Laboratory studies reveal a serum creatinine of 1.9 mg/dL, serum albumin of 2.5 g/dL, and a urine protein-to-creatinine ratio of 5.5 g/g. Serologic tests show low C3 and C4 levels and high titers of anti-dsDNA antibodies.
The renal pathology in this patient is most likely caused by which of the following mechanisms?
Explanation: Lupus nephritis is a major cause of morbidity in patients with SLE and is caused by the deposition of circulating anti-dsDNA-containing immune complexes within the glomeruli. This deposition triggers inflammation and complement activation (evidenced by low C3/C4), leading to glomerular damage, which can manifest as either a nephritic or nephrotic syndrome, as seen in this patient.
A 23-year-old man presents to his primary care physician with an episode of dark brown urine that began two days ago. He also reports having a sore throat, cough, and low-grade fever that started three days ago. This is the third such episode in the past two years, with each occurring concurrently with an upper respiratory infection. His blood pressure is normal, and he has no edema. Urinalysis shows numerous dysmorphic red blood cells and 1+ protein.
What is the most likely diagnosis?
Explanation: Recurrent episodes of gross hematuria that occur concurrently with or within a few days of an upper respiratory tract infection (synpharyngitic hematuria) in a young adult is the classic presentation of IgA nephropathy (Berger disease). This contrasts with poststreptococcal glomerulonephritis, which has a latent period of 1-3 weeks after the infection.
A 65-year-old man with a history of chronic hepatitis B infection presents with a 4-month history of progressive bilateral lower extremity edema and a 15-lb weight gain. He denies any chest pain or shortness of breath. Laboratory results show a serum albumin of 2.1 g/dL and a 24-hour urine collection reveals 10 g of protein. A renal biopsy is performed.
Which of the following is the most likely finding on electron microscopy?
Explanation: This patient presents with nephrotic syndrome. In an adult, primary (idiopathic) membranous nephropathy is a common cause, but it can also be secondary to conditions like hepatitis B, malignancy, or SLE. The pathognomonic finding on electron microscopy for membranous nephropathy is the presence of dense immune complex deposits in the subepithelial space, which correspond to the 'spike and dome' appearance seen on silver stain.
A 72-year-old woman is hospitalized for a hip fracture and undergoes surgery. Her postoperative course is complicated by hypotension requiring vasopressors. On postoperative day 4, her serum creatinine rises from 1.0 mg/dL to 3.8 mg/dL, and her urine output decreases to 20 mL/hour. She was also started on piperacillin-tazobactam for a suspected infection.
Which urinalysis finding would most strongly suggest acute tubular necrosis (ATN) rather than acute interstitial nephritis (AIN) as the cause of her kidney injury?
Explanation: This patient has multiple risk factors for acute tubular necrosis (ATN), including hypotension (ischemia) and potential exposure to nephrotoxins. The hallmark urinalysis finding in ATN is muddy brown granular casts, which are formed from sloughed, dead tubular epithelial cells. White blood cell casts and eosinophils would suggest acute interstitial nephritis (AIN), while red blood cell casts would indicate glomerulonephritis.
A 60-year-old man with a 25-year history of poorly controlled type 2 diabetes mellitus presents for evaluation. His blood pressure is 155/95 mmHg. A urine dipstick is positive for 3+ protein. Serum creatinine is 2.0 mg/dL. He has evidence of diabetic retinopathy on funduscopic exam.
The development of this patient's renal disease is primarily initiated by which of the following pathophysiologic changes?
Explanation: The earliest pathophysiologic change in diabetic nephropathy is glomerular hyperfiltration, driven by increased glomerular capillary hydrostatic pressure. This initial insult leads to a cascade of events over years, including thickening of the glomerular basement membrane, mesangial expansion, and ultimately glomerulosclerosis, culminating in the proteinuria and decline in GFR seen in this patient.
A 40-year-old woman presents with hematuria, periorbital edema, and new-onset hypertension. Laboratory studies show a serum creatinine of 2.2 mg/dL and a 24-hour urine protein of 5 grams. Urinalysis confirms the presence of dysmorphic red blood cells and red blood cell casts.
Which of the following best describes this patient's clinical syndrome?
Explanation: This patient exhibits features of both nephritic and nephrotic syndromes. The presence of hematuria with red blood cell casts, hypertension, and azotemia are characteristic of a nephritic process. However, the proteinuria is in the nephrotic range (>3.5 g/day). This combination is termed a nephritic-nephrotic syndrome (or mixed nephritic-nephrotic picture) and is often seen in conditions like membranoproliferative glomerulonephritis and diffuse proliferative lupus nephritis.
A 67-year-old man presents with a 2-week history of fatigue, shortness of breath, and coughing up small amounts of blood. His serum creatinine has risen from 1.2 to 4.5 mg/dL over this period. Urinalysis shows 3+ blood and red blood cell casts. A chest x-ray shows patchy bilateral opacities. Serologic testing is positive for anti-proteinase 3 antibodies (c-ANCA).
A kidney biopsy is performed. Immunofluorescence microscopy is most likely to show which of the following patterns?
Explanation: This patient's presentation of rapidly progressive glomerulonephritis, pulmonary symptoms (hemoptysis), and a positive c-ANCA (anti-PR3) is classic for granulomatosis with polyangiitis, an ANCA-associated vasculitis. The characteristic finding on renal biopsy for ANCA-associated vasculitides is a pauci-immune glomerulonephritis, meaning there is little to no deposition of immunoglobulin or complement on immunofluorescence microscopy.
A 50-year-old man is evaluated for worsening renal function discovered on routine labs. He has a history of hypertension but feels well otherwise. His blood pressure is 150/90 mmHg, and he has no peripheral edema. His serum creatinine is 1.9 mg/dL. A microscopic urinalysis is ordered.
Which of the following findings on urinalysis is the most specific indicator of glomerular disease?
Explanation: Red blood cell (RBC) casts are pathognomonic for glomerulonephritis. They are formed when RBCs that have leaked from damaged glomeruli become trapped within the tubular lumen in a protein matrix. While proteinuria and microscopic hematuria are common in glomerular disease, they are not specific and can be seen in many other renal and urologic conditions. Leukocyte esterase indicates pyuria, typically from infection or inflammation (like AIN).
A 38-year-old man with HIV, who is not compliant with antiretroviral therapy, presents with rapidly progressive renal failure, severe edema, and frothy urine. His CD4 count is 90 cells/μL. His blood pressure is 165/105 mmHg. A 24-hour urine collection shows 15 grams of protein.
What is the most likely diagnosis for his kidney disease?
Explanation: HIV-associated nephropathy (HIVAN) is a classic complication of advanced HIV infection, particularly in patients of African descent. The characteristic pathology is a collapsing variant of focal segmental glomerulosclerosis (FSGS). Clinically, it presents with a rapid decline in renal function and heavy nephrotic-range proteinuria, as seen in this patient.
A 55-year-old Caucasian man presents with new-onset peripheral edema. He has no other medical conditions and takes no regular medications. Workup reveals a serum albumin of 2.4 g/dL and 24-hour urine protein of 8 grams. Serologic evaluation for hepatitis B, hepatitis C, and systemic lupus erythematosus is negative.
Which of the following is the most common cause of primary nephrotic syndrome in this patient's demographic?
Explanation: Membranous nephropathy is the most common cause of primary (idiopathic) nephrotic syndrome in non-diabetic Caucasian adults. While FSGS is also a major cause of nephrotic syndrome in adults, it is more common in individuals of African descent. Minimal change disease is the most common cause in children, and IgA nephropathy typically presents with hematuria (nephritic syndrome).
A 42-year-old African American woman presents with a dry cough, fatigue, and joint pain. A chest x-ray reveals bilateral hilar adenopathy. Laboratory studies are significant for a serum calcium of 11.5 mg/dL and a serum creatinine of 2.1 mg/dL. Urinalysis shows 1+ protein and sterile pyuria.
A renal biopsy in this patient would most likely reveal which of the following findings?
Explanation: This patient's presentation with bilateral hilar adenopathy, hypercalcemia, and renal dysfunction is highly suggestive of sarcoidosis. The most common renal manifestation of sarcoidosis is granulomatous interstitial nephritis, which is characterized by noncaseating granulomas in the renal interstitium on biopsy. Hypercalcemia can also contribute to the renal dysfunction.
An 8-year-old boy with generalized edema is diagnosed with nephrotic syndrome based on a urine protein-to-creatinine ratio of 10 g/g. He is started on a course of oral prednisone. After 8 weeks of therapy, he continues to have significant proteinuria and edema.
A renal biopsy is performed. In light of his resistance to steroid therapy, which of the following is the most likely diagnosis?
Explanation: While minimal change disease is the most common cause of nephrotic syndrome in children and is typically steroid-responsive, a lack of response to an adequate course of corticosteroids should raise suspicion for focal segmental glomerulosclerosis (FSGS). FSGS is the most common cause of steroid-resistant nephrotic syndrome in children and often progresses to end-stage renal disease.
A 17-year-old female presents with fatigue and swelling in her legs. She has a history of a rash that worsens with sun exposure. Laboratory results show a serum creatinine of 1.5 mg/dL, proteinuria of 4 g/day, and hematuria. Serum complement C3 and C4 levels are persistently low. She is diagnosed with a primary glomerular disease.
A renal biopsy in this patient would most likely show which finding on light microscopy?
Explanation: This patient's photosensitive rash, mixed nephritic-nephrotic presentation, and persistently low complement levels are highly suggestive of systemic lupus erythematosus with lupus nephritis. Lupus nephritis commonly presents as membranoproliferative glomerulonephritis (MPGN) pattern, either as a primary MPGN pattern or as part of diffuse proliferative lupus nephritis. The characteristic finding of MPGN on light microscopy is thickening of the glomerular basement membrane and mesangial hypercellularity, which creates a 'tram-track' or double-contour appearance on silver or PAS stains.
A 17-year-old boy is evaluated for persistent microscopic hematuria discovered on a pre-participation sports physical. His family history is notable for an uncle and a maternal cousin who developed end-stage renal disease before age 30. On further questioning, the patient admits to some difficulty hearing his teachers in class. An audiogram confirms bilateral sensorineural hearing loss. Ophthalmic examination is normal.
This patient's condition results from a genetic defect affecting the synthesis of which of the following proteins?
Explanation: The triad of renal disease (hematuria progressing to renal failure), sensorineural hearing loss, and ocular abnormalities (though not present here) is characteristic of Alport syndrome. This is an inherited disorder caused by mutations in the genes encoding for the alpha chains of type IV collagen, a crucial structural component of the glomerular basement membrane, cochlea, and lens of the eye.
A 5-year-old boy is brought to the pediatrician by his mother due to swelling around his eyes and in his feet for the past week. She also notes that his urine appears 'bubbly.' He has had no recent illnesses, fever, or rash. On examination, he has significant periorbital and 2+ pitting pedal edema. Blood pressure is 100/60 mmHg. Urinalysis shows 4+ protein but is negative for blood, leukocytes, and nitrites. Microscopic examination reveals oval fat bodies.
What is the most likely diagnosis?
Explanation: This patient's presentation of sudden-onset edema, massive proteinuria, and bland urinary sediment in a young child is classic for minimal change disease (MCD). MCD is the most common cause of nephrotic syndrome in children. The diagnosis is often made clinically, and treatment with corticosteroids is typically initiated without a biopsy.
A 68-year-old woman with a long-standing history of rheumatoid arthritis presents with progressive edema, fatigue, and an 11-kg (25-lb) weight gain over six months. Her blood pressure is 110/70 mmHg. Laboratory studies reveal a serum albumin of 2.0 g/dL and a 24-hour urine protein of 12 grams. The kidneys are enlarged on ultrasound.
A renal biopsy is performed. Staining the tissue with Congo red and viewing it under polarized light would most likely reveal which finding?
Explanation: This patient's history of a chronic inflammatory disease (rheumatoid arthritis) and presentation with severe nephrotic syndrome and enlarged kidneys is highly suspicious for secondary (AA) amyloidosis. The diagnosis of amyloidosis is confirmed by a tissue biopsy (often of abdominal fat pad or kidney) that demonstrates amorphous eosinophilic deposits which exhibit apple-green birefringence when stained with Congo red and viewed under polarized light.
A 34-year-old African American man with poorly controlled hypertension presents with progressive lower extremity edema. His blood pressure is 160/100 mmHg. Laboratory studies show a serum albumin of 2.8 g/dL and a 24-hour urine protein of 7 grams. Urinalysis reveals microscopic hematuria. He has no history of diabetes, autoimmune disease, or recent infections.
A renal biopsy in this patient is most likely to show which of the following on light microscopy?
Explanation: This patient's demographics (African American), clinical presentation of nephrotic syndrome, hypertension, and microscopic hematuria are most consistent with focal segmental glomerulosclerosis (FSGS). Light microscopy in FSGS characteristically shows sclerosis (scarring) and hyalinosis (deposition of glassy material) in only a portion (segmental) of some (focal) glomeruli.