CASE 201 (November 2022)

Clinical information

A 26-year-old man presents with edema of about a year's duration, with no other specific symptoms. He reports occasional headaches and intermittent weakness. He does not report skin, joint or mucous membrane alterations. No pathological personal history. He had not consulted previously due to economic and geographical difficulties; the patient is a peasant farmer; now he goes to the emergency room because the edema and weakness have increased and make it difficult for him to work.

On physical examination: BP 140/90, anasarca, mucous membranes and skin without alterations. There are no other abnormal findings.

Paraclinical: Hct: 45%, Hb: 14.5%; normal platelets and leukogram. Serum creatinine: 1.0 mg/dL, BUN: 12 mg/dL; proteinuria: 8.4 g/24 h, urinary sediment without hematuria, leukocyturia or casts; total serum protein: 4.7 g/dL; albumin: 2.1 g/dL. There is dyslipidemia. ANAs, anti-DNA and complement: normal. Studies for viruses: negative.

A kidney biopsy was taken. Look at the images:

Figure 1. H&E, X100. Areas with chronic changes.

Figure 2. H&E, X400. Mild thickening of capillary walls. Hyalinosis in arteriole or vascular pole.

Figure 3. H&E, X400. Interstitial inflammation.

Figure 4. Masson's trichrome stain, X400. Mild segmental increase in mesangial cellularity.

Figure 5. Masson's trichrome stain, X400. Segmental sclerosing lesion, indicating chronicity.

Figure 6. Methenamine-silver stain, X400. Some thickened capillary walls, without clear spikes.

Figure 7. Direct immunofluorescence for IgG, X400. Trace, nonspecific.

Figure 8. EM, original magnification, X1,500. Marked podocyte damage and thickening of capillary walls.

Figure 9. EM, original magnification, X3,000. In addition to podocyte damage and basal thickening, note what is within the GBM.

Figure 10. EM, original magnification, X2.100. MBG projections (spikes)? Or invaginations of the pedicels within the GBM (infolding)?

Figure 11. EM, original magnification, X2,100.

Figure 12. EM, original magnification, X3,000. Note material within the GBM, like granules or microspherules.

Direct immunofluorescence for IgA, IgM, C3, and C1q: Negative. Kappa and lambda: similar to IgG.

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