Complement C4d immunohistochemistry in the assessment of liver allograft biopsy samples: Applications and pitfalls

✍ Scribed by Christopher O. C. Bellamy

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 77 KB
• Volume: 17
• Category: Article
• ISSN: 1527-6465
• DOI: 10.1002/lt.22323

✦ Synopsis

This report by Aguilera et al. is the first to link complement component 4d (C4d) immunopositivity in liver allograft biopsies to donor-specific alloreactivity that is not related to ABO incompatibility or donorspecific human leukocyte antigen antibodies (DSAs). The intensively studied patients had an unusual form of donor-specific posttransplant hepatitis that was associated with the development after transplantation of an immune response to glutathione-S-transferase (GSTT1), which had not been expressed in each patient's native liver. Lymphoplasmacytic hepatitis then manifested in a subset of those developing high titers of circulating anti-GSTT1 antibodies. In all 9 positive biopsy samples (from 7 of 8 patients), C4d was restricted to portal tract vessels, although the staining illustrated was rather weak; interestingly however, C4d also stained small nerves when they were present (3 cases), and these were also shown to express GSTT1. This kind of hepatic nerve staining may be specific to this diagnosis. The comparison groups did not show the portal C4d pattern, with no staining for the patients with recurrent hepatitis C; however, 4 of 6 patients with chronic rejection showed sinusoidal C4d positivity, but the staining illustrated was again weak.

This interesting study arrives on the heels of 2 other studies by Kozlowski et al. 2 and Musat et al., 3 who