C4d Recomendations

1
C4d Recomendations

• C4d staining should be done on all diagnostic
  renal transplant biopsies.

2
Criteria for C4d Positivity

• 1. Cryostat section, Monoclonal Ab,
  immunofluorescence.
• Widespread, strong, linear, circumferential,
• peritubular capillary staining in either
  cortex or medulla
• Excluding scarred or necrotic areas
• Concurrent positive control (essential, if neg
  being
• reported)
•   
• Reports should include the of area of positive
  PTC and intensity.

3
Criteria for C4d Positivity

• 2. Paraffin, Polyclonal Ab, immunohistochemistry
• Same as frozen tissue, but
• strong staining not required
• The type of pretreatment influences the
  intensity. GBM/mesangial staining in the sample
  cannot be used as a positive control, but
  membranous GN is satisfactory.