Risk factors for cytomegalovirus reactivation after liver transplantation: Can pre‐transplant cytomegalovirus antibody titers predict outcome?

<jats:p>Despite preexisting cytomegalovirus (CMV) immunity, CMV‐seropositive liver transplantation (LT) patients remain at risk of CMV infection. We hypothesized that the pre‐transplant CMV antibody titer correlates with the risk of CMV reactivation. We conducted a retrospective study of CMV‐seropositive LT recipients who did not receive anti‐CMV prophylaxis from 2007 to 2013. The pre‐transplant CMV immunoglobulin G (IgG) titer, which was measured with an enzyme‐linked fluorescent immunoassay, was assessed as a risk factor for CMV reactivation with multivariate Cox proportional hazards models. The population consisted of 225 CMV‐seropositive LT patients with a median age of 57 years (interquartile range, 47‐62 years). The CMV titer distributions were as follows: <60 (40%) and ≥60 AU/mL (60%). The Kaplan‐Meier estimates for CMV infection were 17% at 3 months, 18% at 6 months, and 19% at 12 months after transplantation. In a univariate analysis, a marginally significant increased risk of CMV infection was seen in LT recipients with a pre‐transplant CMV IgG titer < 60 AU/mL versus ≥ 60 AU/mL [hazard ratio (HR), 1.79; 95% confidence interval (CI), 0.98‐3.28 (<jats:italic toggle="yes">P =</jats:italic> 0.06)]. This risk was statistically significant in the subgroup of recipients who received allografts from CMV‐seropositive donors [HR, 2.21; 95% CI, 1.15‐4.26 (<jats:italic toggle="yes">P =</jats:italic> 0.02)]. In a multivariate analysis, a pre‐transplant CMV IgG titer < 60 AU/mL was significantly associated with CMV infection [HR, 3.11; 95% CI, 1.60‐6.03 (<jats:italic toggle="yes">P</jats:italic> < 0.001)]. The other risk factors were high body mass index, donor CMV seropositivity, prolonged cold ischemic time, use of an interleukin‐2 receptor antagonist for induction therapy, and high numbers of post‐transplant infections. A lower pre‐transplant CMV antibody titer is significantly associated with CMV infection after LT. Quantitative measurement of CMV‐specific humoral immunity may have a potential role in improving the CMV prevention strategy in CMV‐seropositive LT recipients. <jats:italic toggle="yes">Liver Transpl 21:539–546, 2015</jats:italic>. © 2015 AASLD.</jats:p>