Purpose
Age-related macular degeneration (AMD) is the most common cause of irreversible blindness in the developed world. The complement system is implicated in its pathogenesis. Complement C3 protein is central to both the classic and alternate complement pathway. We investigated whether AMD in a previously recruited liver transplant cohort was associated with recipient rs2230199 sequence variation in the C3 gene. We also investigated whether there was an association between the C3 rs2230199 sequence variation and recipient plasma C3, the activation product C3a, and terminal complement complex (TCC) levels.
Methods
rs2230199 C3 genotyping and plasma C3 levels were determined in 223 Western European patients at least 55 years old, who had undergone LT at least 5 years previously. AMD status was determined using a standard grading system. C3 rs2230199 was determined from DNA extracted from whole blood, and genotyped by KBiosciences Ltd (Cambridge, UK). Plasma C3, C3a and TCC were measured using enzyme-linked immunosorbent assays. Statistics was carried out using SPSS version 19 (IBM).
Results
Using logistic regression, AMD status was not associated with recipient C3 genotype (p=0.779) after controlling for age, gender, smoking status, and body mass index (table 1). Using the Mann-Whitney test, there was no association between the presence of the C3 rs2230199 sequence variation, and plasma C3, C3a and TCC levels (p=0.684, 0.804 and 0.840 respectively - table 2).
Conclusions
AMD was not associated with recipient C3 genotype in a liver transplant cohort. Presence of the C3 rs2230199 sequence variation did not seem to impact upon plasma levels of C3, its activation product C3a, and TCC. The C3 rs2230199 sequence variation may not have a direct functional consequence on activation of the complement pathway.
Keywords: 412 age-related macular degeneration •
539 genetics •
557 inflammation