Case 6
Helmut Hopfer, University Hospital Basel, Switzerland
morphological features
•
•
•
•
increased number of endocapillary leukocytes
endothelial swelling
dilatation of capillary loops
occlusion or near occlusion of capillary lumina with cells
usually a focal and segmental lesion!
EM differential diagnosis
 transplant glomerulitis
 endocapillary glomerulonephritis
 (intravascular lymphoma)
transplant glomerulitis: definition
• recognizing a pattern:
1.
2.
3.
4.
increased number of endocapillary leukocytes
endothelial swelling
dilatation of capillary loops
occlusion or near occlusion of capillary lumina with cells
• counting mononuclear cells (arbitrary cut-off)
→ no clear distinction between cell types by light microscopy!
→ immunohistochemistry, definition of cut-off by ROC
CD5
Example: endocapillary immune-complex GN
CD20
CD68
ERG
counting cells will not tell you
anything about the pathogenesis
glomerular rejection: pathogenesis
antibodies & complement
↓
endothelial cell damage
lytic
necrotic
sublytic
procoagulant
proinflammatory
proliferative /
reparative
1.
1.
2.
3.
discussion & conclusions
antibodies & complement
↓
endothelial cell damage
lytic
sublytic
proliferative / reparative
proinflammatory
procoagulant
necrotic
• Why are the leukocytes
there?
• What are the monocytes /
macrophages doing there?
• What are the lymphocytes
doing there?
→ monocytes exert an early
endocapillary reparative
function on the endothelial
cells
case presentation
Clinical history:
39 year old male. Renal transplantation (TR) in 2005 due to hypertension.
Malcompliance with immunosuppresion → two episodes of interstitial cellular
rejection.
Diagnostic biopsy (BX) 40 months after TR, rise in creatinine and newly diagnosed
proteinuria.
Diagnosis:
Transplant glomerulitis (by EM), severe diffuse interstitial cellular rejection, C4d
negative. Focal IFTA (10-20%).
Follow up:
Dialysis dependence 7 months later. BX with mixed T cell- and antibody-mediated
rejection, C4d positive.