Mannose-binding lectin and Ficolin-2 gene polymorphisms predispose to cytomegalovirus (re)infection after orthotopic liver transplantation

Background & Aims: The lectin pathway of complement activation is a crucial effector cascade of the innate immune response to pathogens. Cytomegalovirus (CMV) infection occurs frequently in immunocompromised patients after orthotopic liver transplantation (OLT). Single-nucleotide polymorphisms (SNPs) in the lectin pathway genes determine their liver-derived protein level and functional activity. We examined the association between these SNPs and the risk for CMV infection in OLT. Methods: OLT patients (n = 295) were genotyped for recipient and donor SNPs in mannose-binding lectin (MBL2), Ficolin-2 (FCN2) and MBL-associated serine protease (MASP2) genes. Results: Combined analysis of independently associated variant MBL2 [HR 1.65, p <0.02 and wild-type FCN2 [1.85; p <0.02 SNPs in the donor liver showed an increased risk of CMV infection for either and both risk genotypes [HR 2.02 and HR 3.26, respectively, p = 0.004, especially in CMV Donor-/Recipient+ (D-/R+) patients [HR 4.7 and HR 10.0, respectively, p = 0.01. A genetic donor-recipient mismatch for MBL2 and FCN2 increased the CMV risk independently, also combined [HR 5.35; p <0.001, particularly in CMV D-/R+ patients [HR 16.6; p = 0.009. Multivariate Cox analysis showed a consistent stepwise increase in CMV infection risk with the gene profile of the donor [up to HR 2.77; p <0.005 and the combined MBL2 and FCN2 donor-recipient mismatch profile [up to HR 4.57; p <0.001, independent from donor-recipient CMV serostatus, also at higher CMV (re)infection cut-off values. Conclusions: MBL2 and FCN2 risk alleles of donor liver and recipient constitute independent risk factors for CMV infection after OLT. Patients with these risk genes probably need intensified CMV monitoring and anti-viral therapy.