LATEST NEPHROLOGY CERTIFICATION EXAM
FOR THE AMERICAN BOARD OF INTERNAL
MEDICINE (ABIM) | COMPLETE EXAM Q&A
WITH RATIONALES
1. A 55-year-old male with hypertension presents with
fatigue and edema. Labs: creatinine 2.5 mg/dL
(baseline 1.0), BUN 40, potassium 5.2, bicarbonate
18. Urinalysis shows 2+ protein, no RBCs. Renal
ultrasound shows normal-sized kidneys. What is the
most appropriate next step?
A) Renal biopsy
B) ACE inhibitor
C) Stop all antihypertensives
D) IV fluids
Correct answer: A
Rationale: Acute kidney injury with proteinuria,
normal-sized kidneys, no obstruction: biopsy to
diagnose glomerulonephritis or acute interstitial
nephritis.
2. A 68-year-old male with diabetes and hypertension
presents with progressive leg edema. Labs:
creatinine 1.5, albumin 2.8, cholesterol 300. Urine
,protein/creatinine ratio is 8 g/g. What is the most
likely diagnosis?
A) Diabetic nephropathy
B) Minimal change disease
C) Membranous nephropathy
D) FSGS
Correct answer: A
Rationale: Nephrotic-range proteinuria in long-
standing diabetes is most likely diabetic nephropathy
(nodular glomerulosclerosis). Biopsy if atypical.
3. A 45-year-old female presents with acute onset of
gross hematuria, edema, and hypertension 1 week
after a sore throat. Labs: creatinine 2.0, C3 low, C4
normal. What is the most likely diagnosis?
A) Post-streptococcal glomerulonephritis
B) IgA nephropathy
C) Membranoproliferative glomerulonephritis (MPGN)
D) Lupus nephritis
Correct answer: A
Rationale: Post-streptococcal GN: acute nephritic
syndrome 1-2 weeks after pharyngitis, low C3,
normal C4. Usually self-limited.
,4. A 62-year-old female with SLE presents with
nephrotic syndrome. Renal biopsy shows diffuse
global glomerulosclerosis in 80% of glomeruli. What
is the most appropriate next step?
A) Immunosuppression (mycophenolate mofetil)
B) ACE inhibitor and supportive care
C) Cyclophosphamide
D) Rituximab
Correct answer: B
Rationale: Chronic sclerosing lupus nephritis
(advanced chronicity) does not respond to
immunosuppression. Treat with ACE inhibitor and
manage CKD.
5. A 70-year-old male with a history of NSAID use
presents with acute kidney injury (creatinine 3.0).
Urinalysis shows sterile pyuria, WBC casts, and mild
proteinuria. What is the most likely diagnosis?
A) Acute interstitial nephritis (AIN)
B) Acute tubular necrosis (ATN)
C) Prerenal azotemia
D) Glomerulonephritis
, Correct answer: A
Rationale: AIN: fever, rash, eosinophilia, sterile
pyuria, WBC casts. NSAIDs are a common cause.
6. A 55-year-old male with cirrhosis and ascites
develops acute kidney injury (creatinine 2.0 from
1.0). He has no response to 1.5 L albumin after
diuretic withdrawal. Urine sodium is <10 mEq/L. What
is the most likely diagnosis?
A) Hepatorenal syndrome (HRS-AKI)
B) Acute tubular necrosis
C) Prerenal azotemia
D) Postrenal obstruction
Correct answer: A
Rationale: HRS-AKI: cirrhosis, ascites, AKI, no
improvement after volume expansion, urine sodium
<10. Treat with terlipressin/norepinephrine +
albumin.
7. A 45-year-old male presents with acute flank pain
and anuria. Renal ultrasound shows bilateral
hydronephrosis. What is the most appropriate next
step?
FOR THE AMERICAN BOARD OF INTERNAL
MEDICINE (ABIM) | COMPLETE EXAM Q&A
WITH RATIONALES
1. A 55-year-old male with hypertension presents with
fatigue and edema. Labs: creatinine 2.5 mg/dL
(baseline 1.0), BUN 40, potassium 5.2, bicarbonate
18. Urinalysis shows 2+ protein, no RBCs. Renal
ultrasound shows normal-sized kidneys. What is the
most appropriate next step?
A) Renal biopsy
B) ACE inhibitor
C) Stop all antihypertensives
D) IV fluids
Correct answer: A
Rationale: Acute kidney injury with proteinuria,
normal-sized kidneys, no obstruction: biopsy to
diagnose glomerulonephritis or acute interstitial
nephritis.
2. A 68-year-old male with diabetes and hypertension
presents with progressive leg edema. Labs:
creatinine 1.5, albumin 2.8, cholesterol 300. Urine
,protein/creatinine ratio is 8 g/g. What is the most
likely diagnosis?
A) Diabetic nephropathy
B) Minimal change disease
C) Membranous nephropathy
D) FSGS
Correct answer: A
Rationale: Nephrotic-range proteinuria in long-
standing diabetes is most likely diabetic nephropathy
(nodular glomerulosclerosis). Biopsy if atypical.
3. A 45-year-old female presents with acute onset of
gross hematuria, edema, and hypertension 1 week
after a sore throat. Labs: creatinine 2.0, C3 low, C4
normal. What is the most likely diagnosis?
A) Post-streptococcal glomerulonephritis
B) IgA nephropathy
C) Membranoproliferative glomerulonephritis (MPGN)
D) Lupus nephritis
Correct answer: A
Rationale: Post-streptococcal GN: acute nephritic
syndrome 1-2 weeks after pharyngitis, low C3,
normal C4. Usually self-limited.
,4. A 62-year-old female with SLE presents with
nephrotic syndrome. Renal biopsy shows diffuse
global glomerulosclerosis in 80% of glomeruli. What
is the most appropriate next step?
A) Immunosuppression (mycophenolate mofetil)
B) ACE inhibitor and supportive care
C) Cyclophosphamide
D) Rituximab
Correct answer: B
Rationale: Chronic sclerosing lupus nephritis
(advanced chronicity) does not respond to
immunosuppression. Treat with ACE inhibitor and
manage CKD.
5. A 70-year-old male with a history of NSAID use
presents with acute kidney injury (creatinine 3.0).
Urinalysis shows sterile pyuria, WBC casts, and mild
proteinuria. What is the most likely diagnosis?
A) Acute interstitial nephritis (AIN)
B) Acute tubular necrosis (ATN)
C) Prerenal azotemia
D) Glomerulonephritis
, Correct answer: A
Rationale: AIN: fever, rash, eosinophilia, sterile
pyuria, WBC casts. NSAIDs are a common cause.
6. A 55-year-old male with cirrhosis and ascites
develops acute kidney injury (creatinine 2.0 from
1.0). He has no response to 1.5 L albumin after
diuretic withdrawal. Urine sodium is <10 mEq/L. What
is the most likely diagnosis?
A) Hepatorenal syndrome (HRS-AKI)
B) Acute tubular necrosis
C) Prerenal azotemia
D) Postrenal obstruction
Correct answer: A
Rationale: HRS-AKI: cirrhosis, ascites, AKI, no
improvement after volume expansion, urine sodium
<10. Treat with terlipressin/norepinephrine +
albumin.
7. A 45-year-old male presents with acute flank pain
and anuria. Renal ultrasound shows bilateral
hydronephrosis. What is the most appropriate next
step?
