Case 37
With discussion
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CASE 37 (March 2009)

Clinical information

The patient is a 12-year-old girl. She presented with a 3-weeks history of subjective fever, legs and face edema, and dyspnea. She has presented dark urine and skin lesions in her left leg. On physical examination she presents increased blood pressure (140/100 mm Hg) and scar lesions in her left leg that could correspond to healed pyodermitis.

On questioning, the patient reported having had treated malaria one year ago; she does not know the Plasmodium species.

Laboratory tests: Mild normochromic anemia; the white-cell count was 6,900 per cubic millimeter (40.8% neutrophils, 34.7% lymphocytes); platelets 297,000. Urinalysis: proteinuria: 2,183 mg/24h, leucocytes: 12 hpf; erythrocytes: 40 hpf; granular casts: 3 hpf. Serum creatinine: 1.1 mg/dL; BUN 27 mg/dL; creatinine clearance: 68 mL/min.

ASLO: 392; ANAs 1/160 speckled pattern; anti-DNA: 1/20 (two tests); ENAs: Negative. C3: 15 (90-180); C4 39 (10-40).

A renal biopsy is carried out. See the images.

Figure 1. H&E, X100.

Figure 2. H&E, X400.

Figure 3. H&E, X400.

Figure 4. Methenamine-silver stain, X400.

Figure 5. Masson's trichrome stain, X400.

Figure 6. Masson's trichrome stain, X1,000.

Figure 7. Direct immunofluorescence using antiserum to IgG, X400.

Figure 8. Direct immunofluorescence using antiserum to C3, X400.

Figure 9. Immunohistochemical stain for C4d in paraffin-embedded tissue (policlonal antibody, Biomedica Gruppe, Austria), X400.

Direct immunofluorescence for IgM: parietal, segmental positivity; IgA and C1q: negative.

What is your diagnosis?

See diagnosis and discussion