CRP-34

CRP-34

Clinical History

The patient is a 23 year old male with history of end-stage renal disease secondary to IgA nephropathy. Status post living related donor transplant. Creatinine has increased from 1.8 to 3.0. Hematuria, but no proteinuria.

Gross Description

Received in transport media are two cores measuring 16 mm and 15 mm in length and 0.5 mm in diameter. Two 1-mm pieces are taken for EM, a 15-mm piece is submitted for immunofluorescence, and the remainder is submitted for light microscopy.

Pathology

Case CRP-034 Silver

Microscopic Description, Immunofluorescence, and Electron Microscopy

Microscopic Description

Light Microscopy

The specimen consists of two fragments of renal cortex, one of which has a small piece of capsule on one end. The other fragment has a very tiny portion of medulla on one end. There are sixteen glomeruli in the three levels. None of these are obsolete, and none show segmental sclerosis. There is focal mild increase in mesangial matrix, but there is no hypercellularity. The capillary basement membranes are unremarkable with the silver and PASH stains. There is mild focal fibrosis with corresponding focal tubular atrophy. There is also interstitial edema, and a number of mononuclear inflammatory cells are present throughout the cortex. These are primarily lymphocytes with occasional eosinophils. Tubulitis is easily identified, although the most severely involved tubules contain less than ten lymphocytes per cross-section. Arterioles show mild thickening, but there is no arteritis

Immunofluorescence

There are four glomeruli in the sections. There is 1+ granular mesangial staining for IgM, but there is no glomerular staining for IgG, IgA, Clq, C3 or light chains. Blood vessels show 1+ staining for C3, and there is also focal staining for C3 in tubular epithelial cells. There is no staining of the tubular basement membranes.

Electron Microscopy

Two thick section are available, and each contains one glomerulus. These are similar to those described above and show essentially normal morphology. Ultrastructural examination reveals mild thickening of the capillary basement membranes, and there is focal fusion of the epithelial foot processes. No electron dense deposits are identified in the glomeruli.

Diagnosis and Comments

Kidney, transplant, needle. biopsy - Mild acute interstitial rejection, Banff Grade I.

Protein in the urine is indicative of glomerular dysfunction.