CRP-42

CRP-42

Clinical History

Thirteen-year-old black female with sickle cell disease, systemic lupus erythematosus and proteinuria. Percutaneous needle biopsy of the right kidney was performed.

Gross Description

The specimen is labeled “Renal bx”. It consists of two portions of light tan tissue measuring 0 8 x 0.1 x 0.1 cm and 0.3 x 0.1 x 0.1 cm. (Jar 0)

Pathology

Case CRP-042 PASH

Microscopic Description, Immunofluorescence, and Electron Microscopy

Microscopic Description

Light Microscopy

The sections show portions of sub capsular cortex. Up to twelve glomeruli are available for examination on multiple sections. The glomeruli are enlarged and show mild segmental expansion of the mesangial matrix and segmental thickening of the peripheral capillary walls, which have a beaded appearance on trichrome and Jones silver stains. Numerous capillary loops are ectatic and contain sickled erythrocytes. No globally or segmentally sclerosed glomeruli are found. The interstitium, tubules and blood vessels are essentially unremarkable. One tubulointerstitial calcific deposit is noted. There are no detectable glomerular or tubular hemosiderin deposits. ABPASH, trichrome and Jones silver stains have appropriately reactive controls.

Immunofluorescence

One glomerulus is available for examination by immunofluorescence on sections stained with IgG, IgM, IgA, C1q and C3. There is finely granular basement membrane staining with IgM (1+) and linearly granular staining with IgA (trace). No glomerular staining is noted with IgG, C1q and C3. No glomeruli are available for examination on sections stained with C4, fibrinogen, albumin or kappa and lambda light chains.

Electron Microscopy

Three glomeruli are present on multiple plastic-embedded BFMB-stained sections. The glomeruli are enlarged and show segmental mesangial matrix expansion and segmental thickening of the capillary walls. The capillary lumina contain sickled erythrocytes. Ultrastructural examination shows segmental thinning and segmental wrinkling of the glomerular basement membranes. There is extensive mesangial interposition and segmental accumulation of subendothelial flocculent material. The capillary lumina are ectatic and contain sickled erythrocytes. The mesangium is expanded by basement membrane-like material. There is segmental foot process obliteration of the visceral epithelial cells. Some of the visceral epithelial cells contain irregular electron dense iron deposits and ingested effete erythrocytes. No electron-dense deposits are recognized.

Diagnosis and Comments

Kidney, right, biopsy: Sickle Cell Nephropathy

The biopsy shows light microscopy, immunofluorescence and ultrastructural features of the nephropathy of sickle cell disease. Features of systemic lupus erythematosus are not recognized.

Protein in the urine is indicative of glomerular dysfunction.