C6: synthesis by the liver in vivo

Area of Science:

• Immunogenetics
• Complement System Biology

Background:

• The sixth component of complement (C6) is a crucial part of the complement system.
• Understanding the site of C6 synthesis is important for complement biology.

Observation:

• C6 allotype was assessed in a liver transplant recipient before and after the procedure.
• The patient's C6 phenotype changed from the recipient's original type (A) to the donor's type (B) within 10 days post-transplant.

Findings:

• The C6 phenotype fully adopted the donor's (B) phenotype by 17 weeks after transplantation.
• This rapid and complete shift indicates a significant change in C6 production.

Implications:

• The liver is identified as the primary or sole organ responsible for C6 synthesis in humans.
• This finding has implications for understanding complement deficiencies and developing targeted therapies.