Case 93
With discussion
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CASE 93 (November 2013)

Clinical information

A 63-year-old woman was admitted due to rapid deterioration of her renal function, anuria and general malaise. The patient related upper respiratory symptoms during the last 15-20 days. She had no medical history of renal disease, her serum creatinine was 1.0 mg/dL a year before when was evaluated for hypertension. She had also dyslipidemia. She had smoked for more than forty years and denied the use of any drug.

On physical examination: patient alert and afebrile with edema in the lower extremities. Blood pressure: 160/95 mm Hg, pulse rate: 84 beats/min, respiratory rate: 16 breaths/min. No skin lesions. X-ray demonstrated mild opacities in central portion of both lungs. Renal ultrasound revealed that the size of both kidneys and the renal cortex echogenicity were slightly elevated.

Laboratory: Hb: 10.4 g/dL; platelet count: 172,000 /μL; SCr: 8.9 mg/dL, CrCl: 8 mL/min, BUN: 98 mg/dL. Serum proteins: 6.7 g/dL, albumin: 3.1 g/dL. Urinalysis: proteins: 2+, erythrocytes 50-60 /HPF, leukocytes: 10-12 /HPF. Urinary volume: 250 mL/24h. Test for hepatitis viruses: negative; HIV: negative. ANA: negative, C3: 124 mg/dL (90-180), C4: 27 mg/dL (10-40). ANCA: negative. Cryoglobulins: negative. Hemodialysis was started.

A renal biopsy was undertaken.

Figure 1. H&E, X100.

Figure 2. H&E, X400.

Figure 3. H&E, X400.

Figure 4. Masson's trichrome stain, X400.

Figure 5. PAS stain, X400.

Figure 6. Methenamine-silver stain, X400.

Figure 7. Methenamine-silver stain, X400.

Figure 8. Masson's trichrome stain, X400.

Figure 9. Direct immunofluorescence for IgG, X400.

Figure 10. Another image of direct immunofluorescence for IgG, X400.

Figure 11. Direct immunofluorescence for C3, X400.

Figure 12. Direct immunofluorescence for fibrinogen, X400.

Direct immunofluorescence for IgA, IgM, C1q: negative. Kappa and lambda: similar immunostaining as for IgG.

What is your diagnosis?

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