Sample questions / Renal & Urinary

Organ system

Renal & Urinary questions for Step 1

Work through renal & urinary vignettes that mix physiology, pathology and pharmacology, the way the exam does. Every explanation covers all five options.

MicrobiologyEasy

Staphylococcus saprophyticus

A 25-year-old woman has 2 days of dysuria and frequency without fever or flank pain. Urine grows catalase-positive, coagulase-negative gram-positive cocci that are novobiocin resistant.

What is the most likely organism?

1. Streptococcus pyogenes
2. Staphylococcus epidermidis
3. Enterococcus faecalis
4. Staphylococcus aureus
5. Staphylococcus saprophyticus

PharmacologyMedium

Anti-GBM disease treatment

A 40-year-old man has 3 weeks of hemoptysis and dyspnea, plus dark urine and oliguria. BUN 65, creatinine 5.2, RBC casts. Chest film shows bilateral alveolar infiltrates. Anti-GBM antibody is high, and biopsy shows crescents with linear IgG along the GBM. Plasmapheresis is started.

Which part of treatment prevents antibody rebound?

1. Rituximab
2. Cyclophosphamide
3. Mycophenolate
4. Azathioprine
5. Prednisone

PhysiologyMedium

Distal RTA

A 40-year-old woman has had bilateral calcium phosphate stones for 5 years, with weakness and bone pain. K+ is 2.9 mEq/L, Cl- 112 mEq/L, HCO3- 16 mEq/L, with a normal anion gap acidosis. Urine pH is always above 7.0, urine calcium is high and citrate low. After ammonium chloride loading, urine pH does not fall below 5.5.

Which diagnosis best explains these findings?

1. Distal renal tubular acidosis with impaired hydrogen ion secretion
2. Chronic carbonic anhydrase inhibitor use causing proximal bicarbonate wasting
3. Milk-alkali syndrome with compensatory renal acid retention
4. Urease-producing bacterial infection causing alkaline urine
5. Primary hyperparathyroidism with increased renal calcium excretion

ImmunologyMedium

BK virus after transplant

On day 45 after an allogeneic marrow transplant for AML, a 55-year-old man has visible blood in his urine, painful urination and suprapubic pain. Urine culture is negative and urine PCR shows a high BK polyomavirus load.

Loss of which immune component mainly allows this virus to reactivate?

1. Loss of complement-mediated virolysis through the classical pathway activated by anti-viral IgM antibodies
2. Loss of virus-specific CD8+ cytotoxic T lymphocytes that recognize viral peptides presented on MHC class I molecules
3. Loss of neutrophil-mediated oxidative burst that generates reactive oxygen species to kill intracellular pathogens
4. Loss of interferon-gamma-producing CD4+ Th1 helper T cells that activate macrophage-mediated viral clearance
5. Loss of natural killer (NK) cell surveillance that normally recognizes and destroys virus-infected cells lacking MHC class I

PathologyEasy

Wilms BWS

A 6-month-old infant has an abdominal mass and high blood pressure. CT shows a large kidney mass with a claw sign. Histology shows blastemal, epithelial and stromal parts.

Which genetic syndrome has the strongest link among the choices?

1. Tuberous sclerosis
2. Beckwith-Wiedemann syndrome
3. Neurofibromatosis type 1
4. Von Hippel-Lindau syndrome
5. Li-Fraumeni syndrome

Other systems

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