17-year old female comes to
your office complaining of an episode of gross hematuria. For the past 5 days
she has had pharyngitis, nasal discharge, and flu-like symptoms. Over the past
two days has taken 8 Bactrim tablets left over from a previous episode of
bronchitis. She reports no change in her urine output.
On examination her key findings: her weight is 55
kg, Pulse-76 bpm, BP 130/80 mmHg. Heart, lungs, abdomen are normal. There is no rash or edema.
Laboratory Studies
Hb-14 g/dL, WBC-5400 (normal diff), BUN-25, creat-1.7, C388 (100-233),
C4-28 (14-48), ASLO-200 (normal is less
than 200), ANA, GBM, ANCA negative. Urine protein2.4g/24h, UA-2+ protein, 20-30
RBCs, 4-6 WBC, occasional rbc casts
During close outpatient monitoring, blood pressure and creat
remain unchanged. On follow-up 12 weeks later, laboratory studies reveal;
Bun-24, creat-1.9, C3-70, C4-20, UA- 2+protein, 3-8 RBCs, 0-4 wbcs, no casts
A renal biopsy is performed:
Which of the following
is the most likely diagnosis?
A. Allergic interstitial nephritis
B. Post-strep glomerulonephritis
C. Membranoproliferative glomerulonephritis
D. IgA Nephropathy
(Source: Dr. Brad Denker, Renal Division, Beth Israel Deaconess Medical Center/Harvard Medical School)
