BRCU 2024: Test Your Knowledge
An 81-year-old woman with history of hypertension, congestive heart failure, osteoarthritis, and gastroesophageal reflux disease presents with a three-month history of fatigue, malaise, a 6.8-kg (15-lb) weight loss, and a one-week history of cough. Six weeks ago, she was treated with amoxicillin for a urinary tract infection. She takes losartan, hydralazine, carvedilol, furosemide, aspirin, omeprazole, and naproxen as needed.
On examination, her BP is 162/90 mm Hg, rhonchi are present in her lungs bilaterally, and she has no edema and no rash. Laboratory values are as follows: serum creatinine 2.1 mg/dL (six weeks ago, it was 0.8); Hb 7.3 g/dL (six weeks ago, it was 9.8), and ferritin 11 ng/mL (reference range: 12–260). UA 2+ protein, large blood, 30 RBC/HPF and RBC casts; urine protein-to-creatinine ratio of 1.2 g/g. The patient's ANA titer ratio is +1:160 with a homogeneous pattern; C3 and C4 concentrations are 68 mg/dL and 8 mg/dL, respectively; double-stranded DNA concentration is 12 IU/mL; myeloperoxidase (MPO) antibodies:1232 units (reference range <0.9); proteinase 3 (PR3) antibodies, 742 units (reference range <0.9).
You recognize that this patient has a rapidly progressive glomerulonephritis (RPGN) and you begin IV methylprednisolone. A photomicrograph of a percutaneous renal biopsy is shown below:
There is 10% interstitial fibrosis and tubular atrophy. IF microscopy shows 2+ mesangial deposits of IgG, IgA, IgM, C3, and C1q, coequal for κ and λ; and electron microscopy is pending.
On the basis of the clinicopathologic presentation, which of the following do you diagnose?
- Lupus nephritis, class IV
- Granulomatous polyangiitis (PR3 vasculitis)
- Microscopic polyangiitis (MPO vasculitis)
- Drug-induced vasculitis
- Anti-GBM syndrome
Reference:
- Santoriello, D., A.S. Bomback, S. Kudose, et al. "Anti-neutrophil Cytoplasmic Antibody Associated Glomerulonephritis Complicating Treatment with Hydralazine." Kidney International 100, no. 2 (2021): 440–46. doi: 10.1016/j.kint.2021.03.029
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ASN's Board Review Course & Update (BRCU) is the gold standard to maximize your readiness for the ABIM Nephrology Board certification and recertification exams. This course also provides a comprehensive and essential update for practicing nephrologists and healthcare professionals.